WO2017162612A1 - A scanner and method for measuring a dose of ionizing radiation - Google Patents

Abstract

A scanner and method for measuring a dose of ionizing radiation5 A scanner (100) for measuring dose of ionizing radiation, comprising a photodetector (128), and an add-on part (130) on the photodetector (128) for coupling an optical fiber (140) thereto such that the optical fiber (140) and the photodetector (128) are functionally coupled such that radiation traveling through the optical fiber (140) can be read out by the photodetector (128).

Description

A scanner and method for measuring a dose of ionizing radiation

Technical field

The invention relates to the field of radiation dosimetry.

More specifically it relates to scanners and methods for measuring dose of ionizing radiation based on optically stimulated luminescence dosimetry.

It also relates to an associated luminescent patch and an associated docking station.

Background art

Cancer remains a major public health problem in Europe and the rest of the world. An important modality in any therapeutic cancer strategy is irradiation of the tumor with high energy photons or particles, i.e. radiotherapy. Developments in radiotherapy treatments have brought solutions that allow a more precise delivery of a higher dose of irradiation to the tumor with fewer side effects to healthy tissues. Among the new techniques, hadron therapy plays an increasingly important role, due to their intrinsic high ballistic precision. Hadron therapy allows applying a very high dose to the target volume, while keeping the dose to the surrounding healthy tissues limited.

The advancement of these treatments is thoroughly related to advances in dosimetry, to fully exploit their high tumor conformity. There are several reported cases of accidents in conventional radiotherapy treatments due to malfunctioning of the equipment, or due to human errors. Similarly, it has been demonstrated that a significant percentage of radiotherapy centers has errors beyond the tolerance limit, when delivering a predetermined treatment, for different tumors.

In-vivo dosimetry allows a fundamental independent check to make sure that the predetermined dose (the planned treatment) is correctly delivered to the patient.

Today, only a few on-line in-vivo dosimetry systems are in use in the clinical routine.

Among the different dosimetric technologies available for in-vivo dosimetry, whereby a received dose (an intermediate dose) is determined for a portion of the skin of a patient during a predetermined irradiation therapy, optically stimulated luminescence (OSL) represents a very interesting solution. Whenever specific ceramic materials (called OSL materials; such as for instance AI2O3, A C^C or BeO) are exposed to ionizing radiation, they are capable of storing dosimetric information within impurities of their crystalline structure. This information can at any moment be extracted from the material, by stimulating it using light with a specific wavelength/color (for instance blue, green...) and detecting the light emitted by the material, using a photodetector. The amount of emitted light is a function of the absorbed dose, i.e. it has been shown to be proportional thereto, and a calibration procedure, of which examples are known to the skilled person, can define a relation between light recorded by the photodetector and absorbed dose.

OSL dosimeters are readily available as commercial products. They are mostly available in the form of square or round chips, with different sizes and can be used to perform point measurements (i.e. measurements at a single location).

Similarly, solutions were proposed at a research level, where the OSL material is fixed on the tip of an optical fiber, which is used to conduct stimulating light to the dosimetric material and, after excitation, guide the light emitted by the material, back to the detector.

A 2-dimensional (2D) detector configuration was proposed in scientific literature, such as in Jahn et al. Progress in 2D-OSL-dosimetry with beryllium oxide, Radiation Measurement 46(12), pages 1909-1911 or in Ahmed M.F. et al., Development of a 2D dosimetry system based on the optically stimulated luminescence of AI203, Radiation Measurements Vol. 71, December 2014, pages 187-198.

Importantly, where 2D systems are presented, it is necessary to remove the dosimeters from the patient in order to perform the readout. This is a significant drawback when repeated dose measurements have to be performed over time. In fact, when removing the 2D set of detectors (or film) and placing it back on the patients after readout, it is very challenging to put it at exactly the same anatomical location, jeopardizing the comparison of measurements over time.

This is particularly crucial when the irradiation modality is such that sharp dose gradients are involved, such as for instance in stereotactic body radiation therapy or in brachytherapy. In these clinical situations, a small error (e.g. smaller than three, or smaller than two, or smaller than one mm) in re-positioning of the patch, may result in a dramatic difference in the dose measured on a same point of the patch, therefore potentially leading to erroneous clinical decisions.

Readers used to perform OSL dosimetry mainly consist of: a stimulating light source, a light detector, filters.

In the prior art, some systems including an optical fiber, allow a true in-vivo readout (i.e. with the detectors placed on, and thus with a fixed relative position with respect to, the patient). As an example, the system discussed in C.E. Andersen et al. Characterization of a fiber-coupled AI203.C luminescence dosimetry system for online in vivo dose verification during lr-192 brachytherapy, Med. Phys. 36, 708 (2009), allows measurement using OSL material deposited on the tip of an optical fiber (i.e. at one single point). In this particular example A C^C was used as material. An important weakness of these systems is that they allow only measurements at one point or, in the best case, in a very limited number of points along a single line (as for example in WO2012159201 A1 ). This can prove to be a serious limitation when monitoring dose in a region characterized by sharp gradients, since the positioning of the optical fiber becomes crucial. User intervention is required, to relocate the tip of the fiber, whenever measurements at different locations may be needed. This can for instance lead to unacceptable prolongation of the overall treatment time.

Most of the OSL readers found in the prior art do not make use of an optical fiber. In these cases, the irradiation dosimeter has first to be removed from the place of exposure (for instance the patient) so that it can be inserted in the reader. None of the prior art systems allows direct readout of dosimeter on the patient.

In WO2012037224 A3 a mobile reader is presented. Also in this system, the dosimeter needs necessarily to be placed in the reader in order to acquire dosimetric information. As such, an in-vivo use is not possible. As discussed previously this is a significant drawback when repeated dose measurements over time, at the same locations, are needed. WO2010/1 18478 describes an apparatus and method for detecting radiation exposure levels. The apparatus comprises a portable dosimeter device adapted to receive, and multiple phosphor elements to allow population screening in event of mass exposure. The phosphor elements are subject to radiation, and a detection unit directs light via an optical fiber to the phosphor, which becomes photoexcited and emits light. This emitted light travels back to the detector unit, where the emission spectrum is detected and analyzed to determine the radiation dosage received at the probe location. WO2006/130486 discloses a method of determining the radiation type and energy distribution of a radiation source that outputs radiation. The method includes providing a plurality of detector materials and exposing the plurality of detector materials to radiation. Each of the plurality of detector materials stores a signal in response to being exposed to the radiation. The signals are representative of the radiation. The plurality of detector materials is stimulated to output the signals as measured signals. These measured signals are used to determine the radiation type and energy distribution of the radiation.

Although the methods and systems disclosed in the prior art provide useful solutions for performing dosimetry under certain conditions, there still exists a need for an improved system and method for efficiently measuring a radiation dose on a point (a single location), along a line or on a surface, in-vivo.

Summary of the disclosure

It is an object of embodiments of the present invention to provide efficient devices, systems and methods for performing in-vivo dosimetry at a single point, along a line or along a surface, in real-time. In a first aspect, the present invention provides a scanner for measuring dose of ionizing radiation. The scanner comprises a photodetector, and an add-on part on the photodetector for coupling an optical fiber thereto such that the optical fiber and the photodetector are functionally coupled such that radiation traveling through the optical fiber can be read out by the photodetector. It is an advantage that the scanner allows in-vivo dosimetry, whereby a received dose is determined in real-time for a portion of the skin of a patient during a predetermined irradiation therapy. A scanner according to embodiments of the present invention may further comprise an optical fiber coupled to the add-on part. The optical fiber may comprise a radiation detector. The radiation detector on the optical fiber may comprise radioluminescent material. In a specific embodiment, an add-on part may be used, mounted on a filter holder, that allows the coupling of an optical fiber to the portable scanner. The filter holder is mounted directly on the photodetector. In particular embodiments, the scanner furthermore comprises an optical fiber (dosimetric optical fiber) connected to the addon part. The fiber also comprises a radiation detector. In this embodiment the portable scanner measures in real-time the amount of luminescence produced by the detector on the fiber, during exposure to radiation.

In one embodiment, the dosimetric optical fiber is obtained by gluing light radio- luminescent or scintillating materials, to a common passive fiber (i.e. fiber without any dosimetric material). The radio-luminescent or scintillating material can be in a bulk or powder form.

In another embodiment, the radio-luminescent or scintillating material is brought onto the common passive fiber by using coating technology. In this case, the material may be in a powder form and may be first dispersed in an optical glue.

The assembled dosimetric fiber, i.e. the optical fiber provided with light radio- lumineschent or scintillating materials, can further comprise a reflective cap on its tip. This cap has several functions: 1 ) reflect light produced by the radio-luminescent or scintillating material, back into the fiber; 2) prevent ambient light to penetrate in the fiber and bias the measurement; 3) enhance visibility of the fiber tip on images such as CT images. The cap can also be designed in a way that it improves the energy response of the dosimetric fiber.

The use of optical fiber based systems for dosimetry is hampered by the so-called stem effect. This refers to the fact that the passive fiber also emits light, when exposed to ionizing radiation. This is due to the Cherenkov effect and to intrinsic fluorescence in the passive fiber.

In all embodiments, the dosimetric optical fiber according to embodiments of the present invention may preferably be characterized by a high signal to noise ratio (SNR), so that it can be used in very different measurement conditions. In fact, a high SNR also guarantees an effective suppression of the stem effect.

In embodiments of the present invention, the scanner may further comprise

a. a stimulating light source, adapted for emitting light in a first wavelength range, to a substrate, for instance to a luminescent substrate, e.g. a patch applied on skin portion of a patient; b. a light detector, adapted for receiving light in a second wavelength range, emitted from the substrate such as the luminescent substrate, e.g. luminescent patch. Preferably, the second wavelength range is different from the first wavelength range. The first and second wavelength ranges can for instance comprise an overlap of less than 50%, or less than 40%, or less than 30% or less than 20%, or less than 10%, or less than 5% or less than 1 % or less than 0.1 % or less than 0.01 % in emitted energy spectrum. This is certainly the case for embodiments of the continuous wave mode type as described in more detail below. In embodiments of the pulsed mode type, as described below, the first and second wavelength ranges may overlap to a larger extent or may correspond.

The scanner is preferably a portable scanner. In particular embodiments, the scanner further comprises a substrate (e.g. body) applicator adapted for providing a light-tight coupling between a/the luminescent substrate/patch applied on a skin portion of the patient and both the stimulating light source and the light detector. The light-tight coupling hereby preferably results in the definition of a light channel, the light channel having an inner end (e.g. within the housing) and an outer end opposite to the inner end (e.g. away from the rest of the housing; arranged for being brought in contact with the substrate/patch/patient's skin). Preferably, the housing is defined by light impermeable walls/surfaces. Preferably, the light channel is defined by light impermeable walls/surfaces, except for a readout opening.

It is an advantage that the scanner allows in-vivo dosimetry, whereby a received dose (an intermediate dose) is determined for a portion of the skin of a patient during a predetermined irradiation therapy, for instance at predetermined time intervals, such as for instance regular time intervals (as opposed to only at the end, after the irradiation has taken place). Hereby a measurement is made whereby the dosimetric material is sticking to a portion of the body/skin of the patient when the portion is being exposed to ionizing radiation.

According to particular embodiments, the substrate applicator is adapted for providing a light-tight coupling with a luminescent patch applied on a curved skin portion of the patient.

According to particular embodiments, the substrate applicator is adapted for providing a light-tight coupling with a luminescent patch applied on a skin portion of the patient, which can be maintained when moving the scanner along the luminescent patch. According to particular embodiments, the substrate applicator comprises a readout opening through which the simulation light and emitted light from the substrate, e.g. the patch are passing respectively out and into said scanner. The readout opening may preferably have a circular cross-section, but can have other shapes. The readout opening may preferably have a cross-sectional surface within the range of 0.75mm² to 400mm², more preferably within the range of 0.75mm² to 225mm².

For instance, in case the readout opening is circular, it may preferably have a diameter between 0.5mm and 20mm, more preferably between 1 mm and 15mm.

According to particular embodiments, the substrate applicator comprises a compressible (elastically deformable) light sealing means or structure surrounding the readout opening. For instance, the compressible light sealing means or structure can be embodied as a compressible ring (e.g. made of rubber or similar material) or similar structure, which is light impermeable. According to particular embodiments, the substrate applicator further comprises a rigid (uncompressible) light sealing structure surrounding the readout opening. The compressible (elastically deformable) light sealing structure preferably surrounds the rigid light sealing structure, if present. According to particular embodiments, the compressible light sealing structure or ring extends further away from the surface defined by the readout opening than the rigid light sealing ring.

For instance, the rigid light sealing means or structure can be embodied as a ring (e.g. made of plastic or metal) or similar structure. The rigid light sealing structure preferably defines the readout opening.

The rigid light sealing ring and compressible light sealing ring can be arranged concentrically. The readout opening, the rigid light sealing ring and compressible light sealing ring can be arranged concentrically.

It is an advantage of a compressible light sealing means that it allows deformation of the substrate applicator in order to adapt to the shape of the portion of the body of the patient under consideration, thereby maintaining light-tightness. It is an advantage of a rigid light sealing means that it allows to keep a fixed distance between the readout opening and the light detector and stimulating light source, improving the measurement precision.

In case both the rigid light sealing means as well as the deformable light sealing means are provided, the measurement precision and light tightness are both optimally combined.

According to particular embodiments, the scanner comprises a housing and the light channel is at least partially, or completely, defined by the housing.

According to particular embodiments, wherein said light channel has an outer end to be positioned on the substrate, e.g. the patch, and an inner end away from said outer end opposite to said inner end, the scanner further comprises - a shutter (or shutter device) arranged in said channel and adapted for optically opening, in a first state, or interrupting, in a second state, the light channel;

- a photodetector means (e.g. a semiconductor photodetector device) arranged in the light channel, arranged and adapted for determining the light intensity in the channel in the portion between the shutter and the outer end;

- a controller adapted for controlling the shutter as a function of the light intensity. According to particular embodiments, the scanner further comprises one or more micro mirrors arranged and adapted for deflecting the light from the light source to a plurality of different points on the luminescent substrate, e.g. the patch without moving the portable scanner. Particularly, the one or more micro mirrors may be arranged and adapted for deflecting the light from the light source to a plurality of different points on the luminescent substrate, e.g. the patch such that a 2D illumination (and thus a 2D interrogation) of the luminescent substrate, e.g. the patch can be obtained. In particular, the micro mirror may be arranged in the light channel.

According to particular embodiments, of the pulsed mode type, the scanner is adapted for providing pulsed light signals by means of the stimulating light source.

According to particular embodiments, of the continuous wave mode type, the scanner is adapted for providing a continuous light signal by means of the stimulating light source, and further comprises at least one filter arranged in front of the light detector for filtering out the first wavelength range.

Indeed, according to particular embodiments, the scanner further comprises one or more filters. These filters can be used to avoid that the stimulation light reaches the photodetector, along with the light emitted by the substrate, e.g. the patch. As an example, one can consider a patch wherein AI203:C is dispersed. After irradiation the patch is stimulated using blue light. AI203:C will then emit light in the blue and UV range. UV passband only filters (centered around 340nm) are then used in front of the photodetector to capture only light coming from AI203:C, thus filtering out the contribution in the blue range (part of which is emitted by AI203:C and part by the stimulation source). Preferably, the filters are suitably arranged within the light channel. For instance, the filter can be arranged in front of the photodetector device.

According to particular embodiments, the scanner further comprises an optical light guide, comprising for example an optical fiber and a focusing lens.

According to particular embodiments, the scanner further comprises a photographic camera arranged and adapted for imaging the skin of the patient. The photographic camera is preferably arranged in a separate cavity of the housing, and is arranged such that it can image the skin portion of the patient from a window which is independent of, or is placed outside, the light channel.

According to particular embodiments, the scanner further comprises a communication means for transmitting dose and/or imaging information obtained by the scanner with an external processing means. The communication means can comprises for instance a wireless communication module, comprising a wireless transmitter and receiver.

In a second aspect of the present invention, a docking station is disclosed adapted for receiving a scanner according to embodiments of the first aspect, adapted for receiving a luminescent substrate, e.g. a luminescent patch or catheter or glove (all comprising some luminescent material) or a biological sample holder comprising a biological material comprising a luminescent component/marker material, and adapted for driving a scanning movement of the scanner over the luminescent substrate. In particular embodiments, it may be adapted for providing a light-tight coupling between the scanner and the substrate during the scanning movement, within a dark room. According to particular embodiments, the docking station comprises a housing, the dark room is provided in the housing, and the housing comprises one or more openings for inserting the luminescent substrate into the housing.

According to particular embodiments, at least some of the openings are adapted for receiving a hand, or fingers, wearing a luminescent glove, in a light-tight manner.

According to particular embodiments, at least some of the openings are adapted for receiving luminescent catheters, in a light-tight manner. According to particular embodiments, the docking station is provided with a controller which is adapted for controlling the scanning movement of the scanner over the luminescent substrate. The pattern described by the scanning movement may for instance depend on the size of the luminescent substrate. The scanning movements may be predetermined, for instance based on the type and size of the luminescent substrate.

In a third aspect of the present invention, an optical fiber comprising a radiation detector with scintillating or radio-luminescent material is provided. According to embodiments of the present invention, the scintillating or radio-luminescent material is provided at the outer surface of the optical detector.

In embodiments of the present invention, a luminescent patch for measuring dose of ionizing radiation is disclosed, comprising

- an adhesive layer adapted for sticking to human skin;

a detection layer on top of and in contact with the adhesive layer, the detection layer comprising luminescent material being dispersed in a transparent matrix material;

a protection layer on top of and in contact with the detection layer, the protection layer for instance being opaque to environment light (e.g. day light).

The protection layer can protect the detection layer for instance from any of, or any combination of, environment light, liquids (e.g. water), dirt or dust, or mechanical impact.

The protection layer may be opaque to environment light when the luminescent material of the detection layer comprises AI2O3 (doped or undoped) or BeO. When the material of the detection layer comprises radiophotoluminescent glass, the protection layer may not be opaque to environment light (e.g. daylight).

According to particular embodiments, the protection layer can be stripped off from the detection layer. According to particular embodiments, the protection layer comprises markers that can be used to position the patient, before treatment, e.g. before submitting the patient/patch to ionizing radiation, and/or for localizing the patch on the anatomy of the patient. Particularly, the protection layer can be selectively removed from the detection layer, e.g. without leaving any residue of one of the layers on the other layer. For instance, the protection layer and detection layer may be attached to each other by means of electrostatic force or by means of a glue layer. According to particular embodiments, the protection layer is pre-cut so as to define, for instance regularly spaced, flaps of the detection layer. The flaps can be such that they can individually be semi-detached from the protection layer and put back to their original position afterwards. According to particular embodiments, the protection layer is radiochromatic.

According to particular embodiments, each layer can be stripped off from the rest of the patch individually. For instance, the respective layers can comprise side flaps which are non-overlapping and which are adapted for easy manipulation when removing the respective layer from the rest of the stack of layers.

According to particular embodiments, the detection layer comprises a geometrical pattern and/or a plurality of tags. In yet another embodiment the top layer of the patch (protection layer) can be water proof, and preferably makes the entire patch water proof so that the patient wearing it can also keep the patch on when coming in contact with water (for example when taking a shower). In a particular embodiment, the protection layer comprises markers that can be used to correctly position the patient before treatment, in external radiotherapy and/or for localization of the patch on the patient's anatomy.

In a particular embodiment, the luminescent material used in the patch, e.g. in the detection layer, comprises AI2O3 (doped or undoped) or BeO or radiophotoluminescent glass powder. In particular embodiments, the luminescent powder is dispersed in a material that can be selected among (but not limited thereto): polyvinyl alcohol, polyethylene, polypropylene, polyester, polyvinyl chloride, forming the detection layer. In a fourth aspect of the present invention, a method is disclosed for measuring a dose of ionizing irradiation received in a pre-determined part of the body during radiotherapy, comprising:

a) bringing an optical fiber comprising a radiation detector with scintillating or radio- luminescent material at the pre-determined part of a patient's body to be irradiated, before irradiating said predetermined part of said body;

b) coupling into the optical fiber light generated by the scintillating or radio- luminescent material upon irradiation of the pre-determined part of the patient's body with ionizing irradiation;

c) reading out the light coupled into the optical fiber so as to determine a dose of ionizing radiation received.

A method according to embodiments of the present invention may furthermore comprise

d) sticking a luminescent patch according to embodiments of the third aspect on a pre-determined part of a patient's body by means of the adhesive layer, before irradiating the predetermined part of the body with ionizing radiation (i.e. before providing ionizing radiation to the predetermined part);

e) irradiating the predetermined part of the body with ionizing radiation;

f) using a portable scanner according to any of the embodiments of the first aspect to stimulate the irradiated patch at at least one location by means of the stimulating light source, and to detect the light emitted from that at least one location by means of the light detector;

g) deriving an exposed dose value for the at least one location for the patient, based on parameters of the irradiation light of the stimulating light source and of the detected light emitted from the patch at the at least one location.

In a fifth aspect of the present invention, a method is disclosed for measuring a dose of ionizing irradiation received in a pre-determined part of the body during radiotherapy, comprising:

d) using a portable scanner according to any of the embodiments of the first aspect to stimulate an irradiated luminescent glove or catheter at least at one location by means of the stimulating light source, and to detect the light emitted from that at least one location by means of the light detector; e) deriving an exposed dose value for the at least one location, based on parameters of the irradiation light of the stimulating light source and of the detected light emitted from the glove or catheter at the at least one location. Features and advantages disclosed for one of the above aspects of the present invention are hereby also implicitly disclosed for the other aspects, mutatis mutandis, as the skilled person will recognize.

Certain objects and advantages of various inventive aspects have been described herein above. It is understood that this summary is merely an example and is not intended to limit the scope of the disclosure. The disclosure, both as to organization and method of operation, together with features and advantages thereof, may best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings.

Brief description of the drawings

The disclosure will be further elucidated by means of the following description and the appended figures.

Figs. 1 (a) and (b) illustrate a frontal and side view of a scanner according to embodiments of the present invention.

Fig. 2 and Fig. 3 illustrate the scanning process of a luminescent substrate, wherein the scanner and substrate are positioned in a docking station.

Fig. 4 illustrates a top view of a patch according to embodiments of the present invention.

Fig. 5 illustrates a docking station adapted for scanning fingers, which are carrying luminescent gloves.

Fig. 6 illustrates a docking station adapted for scanning luminescent catheters.

Figs. 7 (a) and (b) illustrate a scanner according to particular embodiments of the present invention, respectively adapted for functioning in pulsed mode and continuous wave mode.

Figs. 8 (a), (b) and (c) illustrate particular embodiments of the rigid and compressible light sealing means comprised in the substrate applicator of the scanner according to embodiments of the present invention. Figs. 9 (a) and (b) illustrate a patch according to embodiments of the present invention.

Fig. 10 illustrates the configuration wherein an add-on part is used to connect an optical fiber to the scanner, according to a specific embodiment of the present invention.

Detailed description of illustrative embodiments

The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. The terms are interchangeable under appropriate circumstances and the embodiments of the invention can operate in other sequences than described or illustrated herein.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. The terms so used are interchangeable under appropriate circumstances and the embodiments of the invention described herein can operate in other orientations than described or illustrated herein.

Furthermore, the various embodiments, although sometimes referred to as "preferred", are to be construed as example manners in which the invention may be implemented rather than as limiting the scope of the invention.

In a first aspect, the present invention provides a portable scanner 100 (illustrated in Fig. 10) for measuring a dose of ionizing radiation dose received by a body part. The scanner 100 for measuring the dose of ionizing radiation, comprises a photodetector 128, and an add-on part 130 on the photodetector 128 for coupling an optical fiber 140 thereto such that the optical fiber 140 and the photodetector 128 are functionally coupled such that radiation traveling through the optical fiber 140 can be read out by the photodetector 128. In embodiments of the present invention, the scanner 100 may further comprise an optical fiber 140 coupled to the add-on part 130. The optical fiber 140 may comprise a radiation detector 141 , for instance a radiation detector 141 on the optical fiber 140 comprising radio-luminescent or scintillating material. Radio- luminescent or scintillating material 141 is material that exhibits scintillation, i.e. the property of luminescence, when excited by ionizing radiation. In the specific embodiment, illustrated in Fig. 10, the portable scanner 100 is used in combination with an optical fiber 140, in which a radiation detector 141 is integrated. Such optical fiber 140 with integrated radiation detector 141 may be considered a dosimetric optical fiber, as it allows to perform dosimetry. To use the portable scanner 100 in combination with such dosimetric optical fiber 140, an add-on part 130 is mounted onto the photodetector 128, possibly onto a filter holder 129, so that coupling of the optical fiber 140 to the portable scanner 100 can happen in a light tight way. A filter holder 129 may be mounted directly on the photodetector 128. In this embodiment the portable scanner 100 measures in real-time the amount of luminescence generated, by means of the detector integrated in the optical fiber 140.

In one embodiment, the dosimetric optical fiber 140 is obtained by gluing light radio- luminescent or scintillating materials 141 , to a common passive fiber (i.e. fiber without any dosimetric material). The radio-luminescent or scintillating material 141 can be in a bulk or powder form.

In another embodiment, the radio-luminescent or scintillating material 141 is brought onto the common passive fiber by using coating technology. In this case, the material may be in a powder form and may be first dispersed in an optical glue. The assembled dosimetric fiber 140, i.e. the optical fiber provided with light radio- lumineschent or scintillating materials, can further comprise a reflective cap 142 on its tip remote from the add-on part 130. This cap 142 has several functions: 1 ) reflect light produced by the radio-luminescent or scintillating material 141 , back into the fiber 140; 2) prevent ambient light to penetrate in the fiber 140 and bias the measurement; 3) enhance visibility of the fiber tip on images such as CT images. The cap can also be designed in a way that it improves the energy response of the dosimetric fiber 140.

In use, the dosimetric fiber 140 is brought at the location of the body part to be irradiated by ionizing radiation. This may be an internal or an external body part. For instance: the dosimetric fiber 140 may be introduced into the body, via natural or artificial body openings, e.g. it may be introduced in the stomac, in the bladder, etc. Alternatively, the dosimetric fiber 140 may be attached externally to the body, for instance it may be fixed to the body by means of fixing material such as for instance tape.

Due to the fact that the optical fiber is at least partly covered with scintillating or radio- luminescent material, and that this scintillating or radio-luminescent material is brought in position at the location to be irradiated by ionizing radiation, light is automatically generated upon irradiation of this scintillating or radio-luminescent material. The generation of the light is omni-directional, and part of the thus generated light falls in onto the optical fiber under an angle which allows incoupling of the light. The reflective cap 142 may improve incoupling of the light into the optical fiber. Hereto the reflective cap 142 may not only cover the end surface of the optical fiber 140, but also a part of the sidewall thereof.

The incoupled radio-luminescent or scintillation light is transported via the optical fiber 140 to the photodetector 128. The detection of this light allows determining the dose of ionizing irradiation received at the level of the part of the optical fiber 140 covered with the radio-luminescent or scintillating material 141 , and thus at the surrounding body parts. This thus allows to determine an amount of ionizing radiation received exactly at the location of a tumor, for instance. Moreover, this system allows to get a realtime indication of the dose of ionizing radiation received. The scintillating or radio-luminescent material may be provided with tags which can be visualized through an imaging technology such as for instance CT or MR. This allows projecting the dose measured onto the patient's anatomy, using a specific algorithm.

Optionally, in embodiments thereof, the present invention furthermore provides a portable scanner 100 (illustrated in Fig. 1 , and Fig. 7) which, on top of the dosimetric optical fiber 140 for realtime measurements, provides means for measuring a radiation dose received by an OSL detector/luminescent patch. It comprises at least: a stimulating light source 102, a light detector 103, possibly also optical filters 1 12, and a substrate applicator 104. Optical filters 1 12 may be needed to separate light emitted from the stimulating light source (having wavelength λι) from light emitted by the OSL detector (having wavelength λ2), upon stimulation. In particular embodiments, it comprises also a light shutter 1 10. The light detector 103 can for instance comprise or consist of a photomultiplier tube, which counts the number of light photons. Alternatively, the photodetector can comprise photodiodes.

In the latter case, it preferably comprises at least an amplification module. The amplification module may be needed to amplify the light produced at the output of the photodiode 103.

In embodiments of the present invention, the photodetector 128 with add-on part 130 may be provided in a first housing, and the means for measuring a radiation dose received by an OSL detector / luminescent patch 106 may be provided in a second housing, whereby the first and the second housing are functionally coupled. Alternatively, means for implementing both types of measurements may be provided in one and the same housing. The photodetector 128 may be physically the same element as photodetector 103. Alternatively, both may be distinguished photodetectors.

The portable scanner 100 may be powered by a battery, such that it can be used in a wireless manner. The portable scanner 100 is preferably battery powered, but could be powered alternatively via a power cable.

The scanner 100 uses a photodetector 103 to capture the luminescent signal emitted by a luminescent substrate as for instance a luminescent patch (being itself a detector for ionizing radiation), upon light stimulation by means of a stimulating light source 102, of the dosimetric sample (luminescent material) in the patch. In embodiments of the present invention, both photodetector 103 and stimulating light source 102 may for instance be provided in the housing of the scanner 100, for instance in a light channel defined within the housing. In alternative embodiments of the present invention, the photodetector 103 may be provided in the housing of the scanner 100, while the light source 102 is provided in a separate module, which also forms part of the scanner 100. Both an electrical link (e.g. via an electrical cable) and an optical link (e.g. via an optical fiber) are provided between the housing of the scanner 100 and the separate module, to provide the light source 102 in the separate module with electrical energy, and to provide the light emitted by the light source 102 to the location where it is needed for stimulating the luminescent substrate.

The dosimetric material in the luminescent substrate is stimulated for instance by using a blue light source incorporated in the scanner 100. The portable scanner can for instance be operated in continuous wave mode or in pulsed mode.

In continuous wave mode, illustrated in Fig. 7 (b), the stimulating light source 102 is switched on and, meanwhile, the photodetector 103 records light emitted by the substrate e.g. patch. In this particular setting, the light (having wavelength λι) coming from the light source 102 must be separated from light (having wavelength λ2) emitted by the substrate, e.g. patch. As an example, when using AI2O3 stimulated with blue light, 340nm bandpass filters 1 12 can be used to prevent blue light of reaching the photodetector 103, since these two types of light are present at the same time.

In pulsed mode, illustrated in Fig. 7(a), the photodetector 103 is only activated when the stimulation light source 102 is switched off (after a stimulation light pulse). Typical pulse lengths have a duration within the range of \ [\sec to 1 msec. This latter configuration is preferred since special filters are believed not to be needed to separate stimulation light (having wavelength λι) from the light (having wavelength λ2) emitted from the substrate, e.g. patch. In fact, as opposed to continuous wave stimulation, separation of stimulating light from light emitted by the substrate, e.g. patch, can be obtained by temporal gating, wherein the photodetector 103 only starts measuring when the preceding stimulating light pulse is terminated.

In a particular embodiment, the portable scanner has a light shutter 1 10 (Fig. 1 ). The 1 10 shutter is opened when the measurement sequence is started, for instance by pushing on a button 101 (Fig. 1 ).

In particular embodiments, a safety photodiode/light sensor 1 1 1 may be used along with the light shutter 1 10. Only when the portable scanner 100 is correctly positioned on the dosimetric sample, sticking on the body or being present in the docking station, and allowing a light tight coupling, the safety photodiode 1 1 1 provides a signal allowing opening of the shutter 1 10 and therefore starting of the dosimetric measurement. The opening of the shutter 1 10 can thus be further controlled by the signal of a light sensor 1 1 1 arranged in the light channel in the portion 1003 in between the shutter 1 10 and the outer end of the light channel. The scanner 100 can be configured such that an actuation of the button 101 will only cause the opening of the shutter 1 10 when the light level measured by the sensor 1 1 1 is below a predetermined level (e.g. background level).

In particular embodiments, the photodetector 103 can be selected among: photomultiplier tubes, photodiodes, silicon photomultiplier and avalanche photodiodes. In particular embodiments, the stimulating light source 102 in the portable scanner can be selected among a red, green, infrared, ultra violet (UV) power led, or a combination thereof.

In a particular embodiment, optical lenses or light guides are used to focus light of the stimulating light source 102 onto the dosimetric sample. Lenses or light guides are also used to collimate light emitted from the dosimetric sample, back to the light detector 103. Light is emitted isotropically and, considering the finite diameter of the active window of the photodetector 103 (for instance 8mm), only part of this light will be captured (depending on the distance between patch and photodetector). This can be improved by means of a lens or a light guide, focusing all the light emitted to the photodetector 103.

In a particular embodiment, the scanner 100 has a substrate applicator 104 (Fig. 2) that allows coupling the scanner 100 to a substrate, e.g. a patch stuck on/attached to the body. The applicator 104 is such that it guarantees a light tight coupling between the scanner 100 and the substrate, e.g. patch sticking on the body. It can for instance be a compressible ring or similar structure.

In a particular embodiment, the portable scanner 100 is used manually by holding it against the substrate, e.g. dosimetric patch stuck onto the skin of the patient, and for instance moving it along the patch (along one or more directions), so that readout at different spots/locations is made possible. Hereby, light tightness can or cannot be maintained when transferring the portable scanner to a next spot/location from a previous spot/location.

In a particular embodiment, the portable scanner 100 also comprises a data communication module (not illustrated in the drawings) in order to wirelessly transmit data to a control unit that will process the data and optionally display the measured doses (or dose map), matching this with anatomy of the patient.

In a particular embodiment, the portable scanner 100 also comprises a small photographic camera. This is used to take a picture of the patient with the dosimetric patch in place. The picture will be sent to a control unit, along with the dosimetric data, so that the doses can be matched spatially with patient's anatomy. This is preferably done in the control unit.

Fig. 8 (a) (side cross-sectional view), Fig. 8 (b) (frontal view) and Fig. 8 (c) (side cross-sectional view when the scanner is applied on a patch on a patient's skin) illustrate particular embodiments of the substrate applicator 104.

The substrate applicator 104 comprises a readout opening 1 13 through which the stimulation light (wavelength λι) and emitted light (wavelength λ2) from the patch are passing respectively out and into the scanner 100. In use, the scanner 100 is placed against the patch 106 which is provided on the patient's skin 3 and which is typically flexible. In principle, the scanner 100 can be put against the patch 106, without exerting pressure or while exerting only small pressure.

In order to achieve a good light-tight coupling, the substrate applicator 104 comprises a compressible (elastically deformable) light sealing means 1 15 or structure surrounding the readout opening 1 13. For instance, the compressible light sealing means 1 15 or structure can be embodied as a compressible ring (e.g. made of rubber or similar material) or similar structure. To achieve a good light-tight coupling, exerting some pressure may be required. The exerted pressure may then impact a distance d between the patch 106 and the stimulating light source 102 and light detector 103, which may vary over different measurements on different or the same locations, jeopardizing the measurement precision.

According to particular embodiments, the substrate applicator 104 thus further comprises a rigid (uncompressible) light sealing structure 1 14 surrounding the opening 1 13. The compressible (elastically deformable) light sealing means 1 15 ir structure preferably surrounds the rigid light sealing structure 1 14, if present. According to particular embodiments, the compressible light sealing means or structure, for example a ring, extends further away from the surface defined by the opening 1 13 than the rigid light sealing ring 1 14 (see Fig. 8(a)). This allows for elastic deformation of the compressible light sealing means 1 15 in first instance, until light- tight coupling is obtained. Then, the rigid light sealing structure 1 14 functions as a stop or distance keeper as soon as it gets into contact with the patch 106, with as a result a general improvement of the measurement precision (See Fig. 8(c)).

For instance, the rigid light sealing means or structure 1 14 can be embodied as a ring (e.g. made of plastic or metal) or similar structure. The rigid light sealing structure 1 14 may define the readout opening. In other words, the edge of the readout opening 1 13 can be formed by the rigid light sealing means 1 14.

The rigid light sealing ring 1 14 and compressible light sealing ring 1 15 can be arranged concentrically, whereby the compressible light sealing ring 1 15 surrounds the uncompressible light sealing ring 1 14. The readout opening 1 13, the rigid light sealing ring 1 14 and compressible light sealing ring 1 15 can be arranged concentrically. In case both the rigid light sealing means 1 14 as well as the compressible light sealing means 1 15 are present, the measurement precision and light tightness are both optimally combined.

Further, when the readout opening 1 13 is defined by the rigid light sealing means 1 14 or structure, the readout opening 1 13 may for instance have a cross-sectional surface within the range of 0.75mm² to 400mm², such as within the range of 0.75mm² to 225mm². For instance, in case the readout opening 1 13 is circular, it may have a diameter between 1 mm and 15mm. It is believed that a deformation of the skin 3 / patch 106 in the area of the readout opening 1 13, when the scanner 100 (and thus the rigid light sealing means 1 14 or structure) is exerting pressure on the patch 106 / skin 3, may impact the measurement, if the cross-sectional area of the readout opening 103 would be too large (see the unwanted curving of the skin/patch as depicted in Fig. 8(c)). In a second aspect, the present invention provides a docking station 105 (Fig. 2) where the portable scanner 100 can be plugged in, in order to perform, if desired, an automatic readout of the dosimetric material.

In particular embodiments, the portable scanner 100 is operated after having been plugged in the docking station 105. The docking station 105 can comprise an X-Y (2 dimensional) programmable slider, as illustrated in Fig. 3. The portable scanner 100 is preferably plugged onto the docking station 105 in a light tight way. The scanner 100 will stimulate the dosimetric sample 106 placed in the docking station 105 and will record the light emitted from it. The trajectory followed by the portable scanner 100 can be entirely programmed on the docking station 105, for instance via a user interface. The docking station 105 should be light tight, so as the coupling between docking station 105 and portable scanner 100. Otherwise ambient light reaching the photodetector 103 might possibly saturate it, preventing the system from a correct dose readout.

In a specific embodiment, the docking station 105 has holes suitable for receiving both hands 108 (Fig. 5). This may for instance be used to monitor dose to hands for interventional radiologists. In this particular embodiment the luminescent patch dosimeter (dosimetric sample) can be integrated in surgical disposable gloves. The holes are such that, after insertion of the hands (or only fingers) light tightness of the systems in assured.

In another specific embodiment, the docking station 105 has a number of holes 109 (Fig. 6) through which catheters can be inserted so that the dose they have been exposed to in the body can be monitored. The holes are such that, after insertion of the catheters, light tightness of the system is preserved.

In yet another embodiment, the different above described configurations of the docking station can be combined.

In a third aspect, the present invention provides a dosimetric fiber 140, being an optical fiber provided with a radiation detector 141 of light radio-luminescent or scintillating material provided at least at part of the optical fiber 140. The radio- luminescent or scintillating material can be in bulk or powder form glued to an optical fiber, or can be in powder form dispersed in an optical glue and this way applied to the optical fiber, or can be printed to the optical fiber. The radio-luminescent or scintillating material can be applied to the outer surface of the optical fiber. By providing a coating of radio-luminescent or scintillating material on the outer surface of the optical fiber 140 in any suitable way, a very reproducible result may be obtained. This allows a calibration in batch, rather than having to calibrate every optical fiber separately.

In further embodiments, the present invention furthermore provides a luminescent dosimetric sample embodied as a patch 106 (illustrated in Fig. 4 and Fig. 9(a) (side view) and Fig. 9(b) (top view)). The patch 106 comprises at least three layers: a top layer III protecting the patch, for instance from one or more of environment light, water, dirt or dust, or mechanical impact (the latter avoiding/reducing deformation of the second layer); a second layer II (detection layer) where luminescent powder is dispersed in a transparent matrix; and an adhesive layer I. On the detection layer II geometrical patterns such as regular spaced dots or lines (horizontal and/or vertical) can be present so that the user can have an easy visual reference for performing a manual scan, with the patch 106 sticking on the patient. Similarly, the docking station 105 can use computer vision algorithms in order to recognize the spatial patterns and decide how to scan the patch 106, with minimal user intervention. Besides the geometrical pattern, also a number of tags 120 may be present in this second layer II (Fig. 4), and in the first layer I. These tags 120 are useful for matching the position of the patch 106 on the body with the recorded dose information, at one particular location on the patch 106. Part of these tags 120 can be such that they can be visualized on CT or MRI (or other) imaging scanners. The third layer I is an adhesive layer adapted for sticking on the human body. Each layer can be removed individually from the patch 106.

In preferred embodiments, the top layer III of the patch (protective layer) is provided with small removable components 107 (Fig. 4). These components 107 can for instance be semi-attached or partly attached to the rest of the protective layer III. The components 107 can for instance be falling-water-drop-shaped. For instance, the upper point of the drop shape can be left uncut such that the semi-detachability of the component is achieved. Alternatively, for instance, the lower rounded end of the drop shape can be uncut, such that the semi-detachability of the component is achieved. In the latter case the upper point of the drop shape provides the advantage that it can easily be detached for instance by means of a finger-nail or similar object. Removing these components 107, allows the clinicians to perform a manual dose check, where the protective component was removed, while keeping the rest of the patch protected from environment light. Tags 120 corresponding to each location on the patch 106 (Fig. 4) allow the correct association of the measured dose to a particular location on the patch 106 and eventually to patient's anatomy, via a picture of the patch or via patient's scans (MRI, CT) where these tags 120 are visible as well.

In particular embodiments the top layer III of the patch (protection layer) can be water proof, and preferably makes the entire patch water proof so that the patient wearing it can also keep the patch on when coming in contact with water (for example when taking a shower).

In a particular embodiment, the luminescent material used in the patch, e.g. in the second layer II, comprises or consists of AI2O3 (doped or undoped) or BeO or radiophotoluminescent glass powder.

In particular embodiments, the material in which the luminescent powder is dispersed, e.g. in the second layer II, can be selected among (but not limited to): polyvinyl alcohol, polyethylene, polypropylene, polyester, polyvinyl chloride.

According to particular embodiments, each layer can be stripped off from the rest of the patch 106 individually. For instance, the respective layers can comprise side flaps which are non-overlapping and which are adapted for easy manipulation when removing the respective layer from the rest of the stack of layers (See e.g. Fig 9(b)). In a fourth aspect of the present invention, a method is disclosed for measuring a dose of ionizing irradiation received in a predetermined part of the body during radiotherapy, the method comprising:

a) bringing an optical fiber 140 comprising a radiation detector 141 with scintillating or radio-luminescent material at the pre-determined part of a patient's body to be irradiated, before irradiating said predetermined part of said body;

b) coupling into the optical fiber 140 light generated by the scintillating or radio- luminescent material upon irradiation of the pre-determined part of the patient's body with ionizing irradiation;

c) reading out the light coupled into the optical fiber 140 so as to determine a dose of ionizing radiation received.

This method allows real-time determination of dose or ionizing radiation received, for instance, but not limited thereto, ionizing radiation received inside the body such as at the location of a tumor.

The present invention may furthermore comprise steps for determining dose of ionizing radiation simultaneously received at a second location during the same irradiation step, e.g. at the skin of the patient. The method then furthermore comprises:d) sticking a luminescent patch 106 according to embodiments of the third aspect on a pre-determined part of a patient's body by means of the adhesive layer I; e) using a portable scanner 100 according to embodiments of the first aspect to stimulate the irradiated patch 106 at at least one location by means of the stimulating light source 102, and to detect the light emitted from those locations by means of the light /photo detector 103;

f) deriving an exposure dose value for the location for the patient, based on parameters of the irradiation light of the stimulating light source 102 and of the detected light emitted from the patch 106 at the at least one location. This can for instance be achieved by making use of a calibration curve, relating (at a fixed stimulated power light level) the dose to the light emitted by the patch 106 and captured by the photodetector 103.

In a fifth aspect of the present invention, a method is disclosed for measuring a dose of ionizing irradiation received in a pre-determined part of the body during radiotherapy, the method comprising: d) using a portable scanner 100 according to embodiments of the first aspect to stimulate an irradiated luminescent glove or catheter at at least one location by means of the stimulating light source 102, and to detect the light emitted from that at least one location by means of the light detector 103;

e) deriving an exposed dose value for the at least one location, based on parameters of the irradiation light of the stimulating light source 102 and of the detected light emitted from the glove or catheter at the at least one location.

In a further aspect, a control unit is disclosed which is adapted for calculating a dose of ionizing radiation received by the dosimetric material 141 , II and recorded under the form of light by the portable scanner 100 and relating this dose information to a patient's anatomy. The dose may be derived using a calibration algorithm, stored in the control unit, which relates the amount of light measured by photodetector 128, 103, to the absorbed dose. The control unit may also be capable of projecting the dose measured onto the patient's anatomy, using a specific algorithm. The projection may be made possible by means of tags 120, present on the dosimetric material (patch 106 or catheter or other), which can be visualized optically or through a different imaging technology (CT, MR). Below, a number of examples of applications are provided in which aspects of the present invention can advantageously be applied/used.

Example 1 : External radiotherapy

As a first example, one can consider a female patient undergoing external radiation therapy for breast cancer. Skin dose monitoring at and around the breast is a very important factor, since skin is an organ at risk and, as such, limits the maximal dose given to the tumor.

Before starting the treatment, a dosimetric optical fibre with a radiation detector comprising radioluminescent material, according to embodiments of the present invention, is introduced in the chest of the patient, such that the radioluminescent material covering the optical fiber is located close to the tumor. Furthermore, an adhesive patch including AI2O3, according to embodiments of the present invention, may be stuck on the chest of the patient.

The treatment is started by taking images of the patient, using the onboard imaging equipment, to verify the correct placement of the patient on the table. The optical fibre will monitor in real-time the dose of ionizing radiation received at the level of the tumor, while the patch will monitor skin dose at the breast and also skin entrance dose at the level of the heart. The heart is in fact another important organ at risk for this group of patients. It should be noted that the amount of dose due to imaging is negligible with respect to the dose related to the treatment.

During irradiation, the detector on the optical fiber monitors the ionizing radiation in real-time. After irradiation the clinician removes the patch from the patient and, after having removed the first layer (light protecting layer), inserts it in the docking station (which also receives the portable scanner). An entire 2D dose map can then be produced by the docking station, which provides a scanning movement of the scanner over the substrate / patch, in a light-tight manner within a dark room. Thanks to the markers present on the (e.g. second layer of the) patch the 2D map is easily relatable to the patient's anatomy. Example 2: brachytherapy

In this second example, one considers a patient undergoing breast cancer brachytherapy. One of the main potential issues here is skin exposure. As for external radiotherapy, skin is an organ at risk and therefore limits the overall dose that can be given to the tumor.

Before starting the treatment, a dosimetric optical fibre with a radiation detector comprising radioluminescent material, according to embodiments of the present invention, is introduced in the chest of the patient, such that the radioluminescent material covering the optical fiber is located close to the tumor.

The treatment is performed by first introducing a number of polymer catheters into the breast, across the tumor. The catheters are then connected to an after-loader machine which temporarily introduces lr-192 sources in them, following a predetermined trajectory, intended as position in the catheter as a function of time. The trajectory of the sources, along with their activity at the day of treatment, completely determines the delivered dose. For instance, 8 catheters can typically be introduced. A luminescent patch according to embodiments of the present invention may furthermore be applied on the skin of the patient, so that also skin exposure can be monitored.

During treatment, the dose received at the tumor is measured in real-time. After having completed dose delivery through the first catheter, the clinician takes the portable scanner according to embodiments of the present invention and checks the dose on the breast, by pointing the scanner to some predefined spots/locations. If an error is spotted, the trajectory of the following sources can be corrected in almost real time. It is important that the patch stays on the patient during the entire course of the treatment so that repeated dose checks, at exactly the same locations can be performed.

Example 3: interventional radiology, eye lens dose

In this third example, one considers a physician performing an interventional cardiology procedure. For instance, one considers insertion of multiple stents.

In these kind of procedures, ionizing radiation is used in the form of fluoroscopic imaging, in order to guide the entire procedure.

Typically, the procedure starts with inserting a catheter which is adapted for providing an X-ray contrast agent, so that the locations where the stents have to be inserted can be precisely identified and visualized. After this first part (generally taking few minutes), a new catheter (guiding catheter) is introduced and this is kept in place for the entire duration of the procedure.

The interventional cardiologist performing the procedure is exposed, every time that the imaging beam is activated, to a variable amount of scattered radiation. Nowadays, it is well established that radiation induced cataract is an important issue for interventional cardiologists and radiologists. As a first consequence, the maximal equivalent dose to the eye lens was recently lowered from 150mSv to 20mSv in a year, averaged over 5 years, with no year exceeding the limit of 50mSv.

Before starting the complex procedure, the clinician conveniently sticks two small dosimetric optical fibres with a radiation detector comprising radioluminescent material, according to embodiments of the present invention next to the eyes, with the radioluminescent material close to the eyes, in a way that they are also shielded by the lead glasses that the clinician is typically wearing.

During the whole procedure, in real-time, the clinicians can use the portable scanner to check what the dose per eye has been, in order to make sure that the limits are not exceeded.

Example 4: scanning of biologic samples which comprise a luminescent component. A more general use of a scanner according to embodiments of the present invention is related to the use of scanning biological samples which comprise a luminescent component or material, and/or comprise luminescent markers. Hereto, the biological material is provided in a sample holder. The scanner can be applied onto the sample holder (substrate) in a light-tight manner in order to readout luminescent properties of the biologic sample. Based on the measured luminescence properties, other properties of the biologic material can be derived, such as concentration, distribution etc.

The foregoing description details certain embodiments of the invention. It will be appreciated, however, that no matter how detailed the foregoing appears in text, the disclosure may be practiced in many ways.

While the above detailed description has shown, described, and pointed out novel features of the invention as applied to various embodiments, it will be understood that various omissions, substitutions, and changes in the form and details of the device or process illustrated may be made by those skilled in the technology without departing from the invention.

Claims

CLAIMS \ - A scanner (100) for measuring dose of ionizing radiation, comprising a photodetector (128), and an add-on part (130) on the photodetector (128) for coupling an optical fiber (140) thereto such that the optical fiber (140) and the photodetector (128) are functionally coupled such that radiation traveling through the optical fiber (140) can be read out by the photodetector (128).

2. - A scanner (100) according to claim 1 , further comprising an optical fibre (140) coupled to the add-on part (130).

3. - A scanner (100) according to claim 2, wherein the optical fiber (140) comprises a radiation detector (141 ).

4.- A scanner (100) according to claim 3, wherein the radiation detector (141 ) on the optical fiber (140) comprises radioluminescent material.

5. - A scanner (100) according to any of the previous claims, further comprising

a. a stimulating light source (102), adapted for emitting light in a first wavelength range (λι) to a luminescent substrate (106); b. a light detector (103), adapted for receiving light in a second wavelength range (λ2) emitted by said luminescent substrate (106); wherein said scanner (100) further comprises a substrate applicator (104) adapted for providing a light-tight coupling between said luminescent substrate (106) and both said stimulating light source (102) and said light detector (103), said light-tight coupling resulting in the definition of a light channel.

6. - A scanner (100) according to claim 5, wherein said luminescent substrate (106) is a luminescent patch applied to a skin portion (3) of a patient.

7. - A scanner (100) according to claim 6, wherein said substrate applicator (104) is adapted for providing a light-tight coupling with said luminescent patch (106) applied on a curved skin portion (3) of said patient. A scanner (100) according to any of claims 5 to 7, wherein said sub applicator (104) comprises a compressible light sealing structure surrounding a readout opening (1 13).

A scanner (100) according to any of claims 5 to 8, wherein said substrate applicator (104) comprises a rigid light sealing structure (1 14) surrounding a readout opening (1 13).

A scanner (100) according to claim 9 in as far as dependent on claim 8, wherein said compressible light sealing structure (1 15) surrounds said rigid light sealing structure (1 14).

A scanner (100) according to any of claims 5 to 10, wherein said light channel has an outer end to be positioned on the luminescent substrate (106) and an inner end away from said outer end opposite to said inner end, further comprising

o - a shutter (1 10) arranged in said channel and adapted for optically opening, in a first state, or interrupting, in a second state, the light channel; o - a photodetector (1 1 1 ) arranged in said light channel, arranged and adapted for determining the light intensity in the channel in the portion between said shutter (1 10) and said outer end;

o - a controller adapted for controlling said shutter (1 10) as a function of said determined light intensity.

A scanner (100) according to any of claims 5 to 1 1 , adapted for providing pulsed light signals with said stimulating light source (102).

A scanner (100) according to any of claims 5 to 1 1 , adapted for providing a continuous light signal with said stimulating light source (102), and further comprising at least one optical filter (1 12) arranged in front of said light detector (103) for filtering out said first wavelength range (λ1 ).

A scanner (100) according to any of the previous claims, further comprising a photographic camera arranged and adapted for imaging the skin (3) of the patient. A docking station adapted for receiving a scanner (100) according to any of the claims 5 to 14, adapted for receiving a luminescent substrate (106), adapted for driving a scanning movement of said scanner (100) over said luminescent substrate (106), and adapted for providing a light-tight coupling between said scanner (100) and said substrate (106) during said scanning movement, within a dark room.

A docking station according to claim 15, comprising a housing, wherein said dark room is provided in said housing, and wherein said housing comprises one or more openings for inserting said luminescent substrates into said housing.

17. - An optical fiber (140) comprising a radiation detector (141 ) with scintillating or radio-luminescent material.

18. - An optical fiber (140) according to claim 17, wherein the scintillating or radio- luminescent material is provided at the outer surface of the optical detector.

A luminescent patch (106) for measuring dose of ionizing radiation, comprising o an adhesive layer (I) adapted for sticking to human skin;

o a detection layer (II) on top of and in contact with said adhesive layer (I), said detection layer (II) comprising luminescent material being dispersed in a transparent matrix material;

o a protection layer (III) on top of and in contact with said detection layer (II).

A luminescent patch (106) according to claim 19, wherein said protection layer (III) can be stripped off from said detection layer (II).

A luminescent patch (106) according to any of claims 19 or 20, wherein said protection layer (III) is pre-cut so as to define flaps which can individually be semi-detached from said protection layer (III) and put back to their original position afterwards.

22.- A method of measuring a dose of ionizing irradiation

predetermined part of the body during radiotherapy, comprising a) bringing an optical fiber (140) comprising a radiation detector (141 ) with scintillating or radio-luminescent material at the pre-determined part of a patient's body to be irradiated, before irradiating said predetermined part of said body;

b) coupling into the optical fiber (140) light generated by the scintillating or radio- luminescent material upon irradiation of the pre-determined part of the patient's body with ionizing irradiation;

c) reading out the light coupled into the optical fiber (140) so as to determine a dose of ionizing radiation received.

A method according to claim 19, furthermore comprising

d) sticking a luminescent patch (106) according to any of claims 19 to 21 on a pre-determined part of a patient's body by means of said adhesive layer (I), before irradiating said predetermined part of said body;

e) irradiating said predetermined part of said body;

f) using a portable scanner (100) according to any of claims 5 to 14 to stimulate the irradiated patch (106) at at least one location by means of said stimulating light source (102), and detecting the light emitted from said at least one location by means of said light detector (103);

g) deriving an exposed dose value for said at least one location for said patient, based on parameters of said irradiation light of said stimulating light source (102) and of said detected light emitted from said patch (106) at said at least one location.