KR20050084202A - Device and method for producing radioisotopes - Google Patents

Abstract

The present invention is related to a device and a method for producing a radioisotope of interest from a target fluid irradiated with a beam of accelerated charged particles, said device comprising in a circulation circuit (17):- an irradiation cell (1) comprising a metallic insert (2) able to form a cavity (8) designed to house the target fluid and closed by an irradiation window (7), said cavity (8) comprising at least one inlet (4) and at least one outlet (5);- a pump (16) for circulating the target fluid inside the circulation circuit (17);- an external heat exchanger (15);said pump (16) and said external heat exchanger (15) forming external cooling means of said target fluid;said device being characterized in that it further comprises pressurizing means (14) of said circulation circuit (17) and the external cooling means of said target fluid are arranged in such a way that the target fluid remains inside the cavity (8) essentially in the liquid state during the irradiation.

Description

Device and method for producing radioactive isotopes {DEVICE AND METHOD FOR PRODUCING RADIOISOTOPES}

The present invention is directed to producing a radioactive isotope, such as ¹⁸ F, by irradiating a target material containing the precursor of the radioisotope using a beam of charged particles. An apparatus and method are provided.

One of the applications of the present invention relates to nuclear medicine, and more particularly to positron emission tomography.

Positron emission tomography (PET) is a precise, noninvasive medical imaging technique. In practice, radiopharmaceuticals differentiated by positron emitting radioisotopes are injected into the patient's body, resulting in disruption resulting in the release of in situ gamma-rays. These gamma-rays are analyzed and detected with an imaging device to reconstruct the biodistribution of the injected radioisotopes in three dimensions and obtain their tissue concentration.

Fluorine 18 (T _1/2 = 109.6 min) has four photopositive emission radioisotopes of interest ( ¹³ N, ¹¹ C, ¹⁵ O, ¹⁸ F) with half-lives long enough to allow use outside of their production site. ) Is one of.

Among the many radiation drug synthesis from the relevant radioisotope, namely fluorine ^18, 2- [18 F] fluoro-2-deoxy-glucose -D- ^{(2- [18 F] fluoro-} 2-deoxy-D-glucose: FDG) is the radio-tracer most frequently used in positron emission tomography. This makes it possible to analyze the metabolism of glucose in cancer, heart and various brain diseases.

^{The 18} F radioisotope is produced by impacting the target material, in this case composed of a beam of charged particles, in particular protons and ¹⁸ O-concentrated water (H ₂ ¹⁸ O). To produce the radioisotope, it is common to use a device having a "hollowed out" cavity in the metal portion and to accept the target material used as the precursor.

The cavity in which the target material is located is sealed by a window called an "irradiation window" through which charged particles of the irradiation beam pass through specific radiation. Through the interaction of the target material with the charged particles, a nuclear reaction occurs to produce the radioisotope of interest.

The beam of charged particles is preferably accelerated by an accelerator such as cyclotron.

Today, because of the ever-increasing demand for radioisotopes, especially ¹⁸ F, there is always a demand for increased yield of nuclear reactions to produce more radioisotopes. This increase in production alters the beam energy of the charged particles (protons), depending on the thick target yield on the particle energy, or by altering the intensity of the beam, which strikes the target material. It seems to change the accelerated particles of.

However, the power scattered by the target materials irradiated to the accelerated particle beam limits the energy and / or intensity of the particle beam used.

This is because the force scattered by the target material is determined by the intensity and energy of the particle beam through the following equation (1):

P (watts) = E (MeV) × I (μA) (1)

here:

P = force in watts;

E = energy of the beam in units of MeV; And

I = beam intensity in units of μA.

In other words, therefore, the force scattered by the target material is much higher than the energy and / or intensity of the particle beam.

Therefore, the intensity and / or energy of the beam of accelerated charged particles cannot be increased without rapidly occurring in the cavity of the production device, especially in the irradiation window, the excess pressure or temperature will not damage the window. It will be understood that there is.

In addition, in the case of ¹⁸ F radioisotope production, especially given the expensive ¹⁸ O-enriched water, only a small amount of these target materials, up to several milliliters, is in the cavity. Thus, the problem of dissipating heat generated by irradiation of such small amounts of target material creates an important problem to be overcome. Typically, for an amount of 0.2 to 5 ml of ¹⁸ O-enriched water, for 18 MeV proton beams having an intensity of 50 to 100 μA, during irradiation time varying from several minutes to several hours, the power to be dissipated Between 900 and 1800 watts.

More generally, the irradiation intensity for producing radioisotopes, given the problem of heat dissipation by the target material, is currently limited to 40 μA for 2 ml of irradiated target material. However, current cyclotrons used in nuclear medicine today are theoretically capable of accelerating proton beams with intensity ranges from 80 to 100 μA, or even higher. Therefore, the possibilities offered by current cyclotrons are obviously insufficiently used.

A solution has been proposed in the prior art to overcome the problem of heat dissipation by the target material of the cavity in the radioisotope production device. In particular, it is proposed to provide a means for cooling the target material.

Thus, document BE-1011263 describes a cavity sealed by a window, the cavity having a target material, the cavity allowing a double-walled jacket to allow circulation of coolant to cool the target material. An irradiation cell comprising a cavity surrounded by is disclosed. Moreover, cooling of the irradiation window by means of helium may also be considered.

However, as long as the device dissipates heat in this configuration, the target material is static in that most defects are formed in this way and are physically limited due to the heat exchange coefficient of the container and the liquid. In addition, due to the high temperature reached in the sealed cavity, the entire apparatus must be kept at a constant pressure. Indeed, it is practically impossible to "monitor" the amount of ¹⁸ F produced with such a device, and therefore the results with regard to activity and gain are only inductively known.

It also allows the device to be used in the form of a circuit comprising a cavity and an irradiation cell comprising a target material and an external heat exchanger, where the H ₂ ¹⁸ O target material is recycled to be cooled (International Symposium “Target Tree and Target”). Published by Jongen and Morelle in "Proceedings of the third workshop on targetry and target chemistry", http://www.triumf.ca/wttc/proceedings.html , Vancouver , June 1989). Therefore, this device compared with that of the above-mentioned prior art has the advantage of using a target material which can be called "dynamic" because it is recycled. Nevertheless, the apparatus and method did not use a means to maintain a constant pressure so that control of pressure is a practical problem in such apparatus. In addition, the apparatus and method are not described in detail and in practice tend to be difficult for the main technical implementation.

1 is a schematic illustration of an apparatus for producing a radioisotope of interest in accordance with the apparatus and method of the present invention.

2 is a rear view of the irradiation cell used in the apparatus and method according to the invention, according to the first embodiment.

3 and 4 are respective longitudinal cross-sectional views along the A-A and B-B planes of the irradiation cell, as disclosed in FIG. 2.

5 is a rear view of the irradiation cell used in the apparatus and method according to the invention, in accordance with a second embodiment.

6 and 7 are respective longitudinal cross-sectional views along the A-A and B-B planes of the irradiation cell, as disclosed in FIG. 5.

8A, 8B, 8C show respective runs for charging the irradiation cell, operating the cell during irradiation, and exiting the cell after irradiation.

It is an object of the present invention to provide an apparatus and method for producing a radioisotope of interest that does not have the drawbacks of prior art devices and methods, such as ¹⁸ F, from a beam of accelerated particles and irradiated target material.

In particular, it is an object of the present invention is a high current strength, preferably with from irradiation of the target material in case consisting of a proton beam and a more concentrated 18O- the water (H ₂ ¹⁸ O) with a high current intensity than 40 μA, ¹⁸ F Likewise, there is provided an apparatus and method for producing a radioisotope of interest.

It is another object of the present invention to provide an apparatus and method which ensures maximum heat exchange during operating conditions, ie irradiation and production of such radioisotopes of interest.

The present invention relates to an apparatus for producing a radioisotope of interest from a beam of accelerated charged particles and irradiated target fluid, which apparatus is included in a circulation circuit:

An irradiation cell comprising a metallic insert designed to receive a target fluid and closed by an irradiation window, the metallic insert being able to form a cavity comprising at least one inlet and at least one outlet;

A pump for circulating the target fluid inside the circulation circuit;

External heat exchanger;

The pump and the external heat exchanger forming an external cooling means of the target fluid;

The apparatus is further characterized in that it further comprises pressure holding means of the circulation circuit and external cooling means of the target fluid prepared in such a way that the target fluid inevitably remains inside the cavity during the irradiation.

Preferably, the pump generates a flow rate sufficient to maintain the target fluid at an average temperature of less than 130 ° C.

Preferably, the pump produces a flow rate faster than 200 ml / min.

Advantageously, the pump produces a flow rate faster than 500 ml / min, preferably faster than 1000 ml / min, and more preferably faster than 1500 ml / min.

Preferably, in the device of the present invention, the cavity may comprise an amount of target fluid between 0.2 and 5.0 ml.

Preferably, the device is configured such that the total amount of target fluid in the circulation circuit comprises less than 20 ml.

Advantageously, the inlet and outlet are arranged in such a way that the flow of the target fluid creates a vortex inside the cavity.

Preferably, one of the inlet or outlet is inevitably positioned in contact with the cavity.

According to a first embodiment of the invention, the inlet and outlet are located on the inner surface of the cavity above the same meridian.

According to another embodiment of the invention, the accelerated charged particle beam strikes the cavity window at the impact point and the target fluid inflow is at the impact point in such a way that the inflow hits the window in frontal collision with the beam. Hit directly.

In particular, according to the embodiment detailed below as the "second embodiment", the cavity represents the central axis of the circumference in which the lateral surface is shown, the outlet is connected to the inner surface and the inlet is along the central axis.

Moreover, in the device of the present invention, the irradiation cell may comprise internal cooling means.

Preferably, the internal cooling means is in the form of a double wall jacket surrounding the cavity.

The internal cooling means can also be a common indirect cooling means.

Preferably, the apparatus comprises helium-based cooling means for cooling the irradiation window of the irradiation cell.

Another object of the invention is a method for producing a radioactive isotope of interest from a target fluid used as a precursor of the radioactive isotope of interest irradiated inside a irradiation cell with a beam of accelerated charged particles, said metal comprising an insert. The irradiation cell may be closed by the irradiation window and form a cavity designed to receive the target fluid, the cavity being provided with at least one inlet and at least one outlet;

The method is characterized in that the target fluid circulates inside the circulation circuit, including in addition to the irradiation cell, at least one pump for circulation of material and an external heat exchanger;

The method ensures that the pressure of the circuit is controlled by means of constant pressure maintaining means of the circulation circuit, and that the pump and the external heat exchanger are arranged in such a way that the liquid inevitably remains inside the cavity while the target fluid is irradiated. It is an additional feature.

Preferably, in the method, vortex in the flow of target fluid is caused inside the cavity.

Preferably, the pump generates a flow rate sufficient to maintain the target fluid at an average temperature of less than 130 ° C.

Preferably, the pump produces a flow rate faster than 200 ml / min, more preferably faster than 500 ml / min. Advantageously, the pump produces a flow rate faster than 1000 ml / min and more advantageously faster than 1500 ml / min.

The invention also relates to an irradiation cell comprising a metallic insert comprising at least one inlet and at least one outlet and capable of forming a cavity designed to receive a target fluid, the cavity having a circumferentially developed circumferential surface. A cavity defined by a central axis, the cavity closed by a radiation window and closed by a second surface opposite to the radiation window and inevitably perpendicular to the central axis, the radiation cell having a second entrance whose entrance is necessarily perpendicular to the central axis; The outlet is connected to the surface while the outlet is connected to the surface.

Another object of the present invention is the use of the device, method or irradiation cell of the invention as mentioned above for the preparation of a compound of a radiopharmaceutical, particularly for medical applications such as positron emission tomography.

1 generally discloses the principle of operation of the apparatus and method according to the invention. In particular, the device listed in FIG. 1 discloses a circuit 17 for a target material. This circuit comprises a radiation cell having a general reference number 1 and described above in accordance with various embodiments of each of FIGS. 2-4 and 5-8.

The principle of the invention is based on the target material circulating inside the circulation circuit and irradiating inside the irradiation cell 1. This target material enters the cell 1 via the inlet 4 and exits the cell through the outlet 5. In order to allow this circulation, a pump 16, preferably a high power pump, is installed in the circulation circuit 17.

According to the invention, a constant pressure maintaining means of the circuit is also provided.

In the embodiment shown in FIG. 1, the constant pressure holding means is generated via a "gas cushion" which acts as an expansion tank such that the constant pressure of the entire circuit 17 is maintained.

Finally, according to the invention, an external heat exchanger 15 is also provided in the circulation circuit 17 of the target material.

These elements, ie the assemblies corresponding to the external heat exchanger 15 and the pump 16, in a circulation inside the circuit, more particularly in a circulation inside the cell 1, in such a way that the target material is a fluid during irradiation. Disposed, and inevitably remains in a liquid state. This assembly is defined as external cooling means of the target material.

In other words, according to the invention, the configuration of the external means for cooling the target material in comparison with the other elements of the device is such that when the device is in operation, i.e. during irradiation, the target material has sufficient heat inside the heat exchanger 15. Allow movement in the circulation circuit 17 at a high speed sufficient to make the exchange.

In particular, the velocity as well as the pressure must be defined in such a way that the average temperature of the material circulating in the circulation circuit 17 is lower than the threshold temperature. Typically this temperature is less than 130 ° C.

Preferably, a second outlet is also provided to eliminate flooding of the target material. The outlet 6 is connected to the expansion tank 14.

This device further comprises a target material tank 12, a tank 10 for receiving the overflow and a syringe device 11. An outlet 13 is also provided which leads to the chemical synthesis module. The other elements are connected together by valves that prevent or allow circulation of the target material in the device.

In this example, the production of ¹⁸ F radioactive isotopes obtained from a target material consisting of ¹⁸ O-enriched water and irradiated by a proton beam is described. In this case, the outlet is a module for the synthesis of radiopharmaceuticals, such as the FDG module.

The first embodiment of the irradiation cell 1, which corresponds to a mechanical assembly during operation of the apparatus and is disclosed in FIGS. 2 to 4, irradiates the accelerated particle beam onto the target material to produce the radioisotope of interest.

As shown in FIGS. 2-4, the irradiation cell 1 comprises an insert 2 present in one or more metallic parts (elements) arranged such that an amount corresponding to the irradiation cavity 8 is produced.

Thus, the insert 2 comprises a cavity 8, which has a structure capable of receiving a target material which has been bombarded with particles of an accelerated particle beam. For this purpose, the cavity is closed (sealed) by the irradiation window 7 which transmits the accelerated particle beam.

The irradiation cell also includes an inlet 4 and an outlet 5 which allow the target material to enter / exit the irradiation cell. The inlet and outlet depend on the direction of the circulation in the circuit, providing inlet and outlet of the target material and vice versa.

An important point of the present invention is that it creates a necessarily turbulent vortex flow in the cavity. In other words, in the above invention, "flow vortex" means that a concave vortex occurs under certain conditions of the flowing fluid.

For this purpose, according to the embodiment shown in FIGS. 2 to 4, either the inlet duct or the outlet duct, the first duct is inevitably positioned in contact with the cavity. "Essentially tangentially" means that the first duct is an inlet duct that forms an angle of less than 25 ° and more preferably less than 15 ° relative to the physical tangent at the junction of its cavity. It is true.

The direction of the accelerated particle beam is represented by arrow X in the figures.

According to this embodiment, both the inlet duct 4 and the outlet ducts 5 and 6 are located more accurately on the outer periphery of the irradiation cell and along the "meridian". This means that at least the ducts 4 and 5 are arranged side by side along the imaginary meridians and therefore do not lie in the same cross section. Similarly, it is the difference between the slope of the first duct at the junction of the cavity and the slope of the second duct at the junction of the cavity. This structure allows to create a vortex flow that prevents the generation of areas that do not flow inside the cavity.

In addition, in an advantageous manner, internal cooling means are provided inside the cavity to prevent excessive heat of the target material in the cavity. These means are represented by a duct 9 through a cooling fluid that can flow through the inlet 3.

According to the second embodiment shown in FIGS. 5 to 7, the inlet 4 is located in the direction of the collision point of the approximately accelerated particle beam X, ie the inlet 4 is the center of the irradiation cell 1. While inevitably conforming to the axis of symmetry xx, the outlet ducts 5 and 6 are located at the edges (outer periphery) of the cell.

This embodiment creates a vortex inside the cavity so that there is no inevitable area that does not flow. In addition, the inlet duct is located adjacent to the collision point of the beam, which allows a displacement tolerance of approximately 1 mm with respect to the beam.

In addition, in a particularly advantageous manner, this second embodiment allows to give a symmetrical circulation to the target material in the cavity 8. Similarly, the inlet duct 4 in contact with the irradiation window in the opposite direction of the irradiation beam X causes the window to cool, thus preventing overheating of the window by the accelerated particle beam.

According to this structure, the inlet duct corresponds to the axial duct 4 and the outlet duct corresponds to the peripheral duct, but not vice versa.

According to both embodiments shown in FIGS. 2 to 7, internal cooling means of the target material are generally provided in the irradiation cell. Typically and as disclosed in document BE-A-1011263, the internal cooling means 9 may be provided in the form of a double-walled jacket surrounding the irradiation cell, and as shown in FIGS. Allow circulation

According to the second embodiment shown in FIGS. 5 to 7, an indirect internal cooling means 9 can be provided. This means that the insert 2 or part of its elements are cooled. Therefore, no direct or close contact is provided between the cavity 8 and the internal cooling means 9.

According to the embodiment shown in FIGS. 5 to 7, the flow rate and pressure can be optimized to be completely independent from the presence of the internal cooling means 9.

Similarly, cooling means using gaseous helium may be provided to cool the irradiation window 7. In this case, it is suggested to use a double window made of Havar with a total thickness between 50 and 200 μm as the irradiation window.

According to the second embodiment, it is also not possible to make use of such window cooling means. In such cases, it is suggested to use a single window with a total thickness between 25 and 50 μm as the irradiation window.

Another embodiment of the device according to the invention can also be drawn, in which the accelerated charged particle beam hits the cavity window 7 at the point of impact and the inlet 4 is at the target fluid inlet, so that the inlet is And toward the collision point in such a way that the window collides face to face. In this embodiment, in contrast to the second embodiment mentioned above, it is meant that the collision point of the accelerated particle beam does not necessarily have a direction that necessarily coincides with the central axis (x-x) of the cavity 8. In other words, the second embodiment as mentioned above should be considered as a specific case of the other embodiment which is more general.

The material for manufacturing the device according to the invention must be chosen in a careful way. Advantageously, they are chosen to be resistant to radiation and pressure. Similarly, they must be chemically inert relative to the fluoride ions. For example, the external heat exchanger 15 may be formed of a pipe made of silver or any other material that is chemically inert and resistant to radiation and pressure. For this application, copper cannot be used and niobium is difficult to apply to the machine. Therefore, silver and / or titanium are the best compromises; It is possible to use tantalum and / or palladium to make any part of the device.

Likewise, the choice of insert material is of particular importance. There is a need to substantially prevent the production of undesirable byproducts during the investigation. For the purposes of the examples, there is a need to prevent the production of radioisotopes that give by-products that affect the subsequent synthesis of radioactive tracers to be distinguished by radioisotopes and that are disrupted by high-energy gamma particle radiation. For example, Ti gives ⁴⁸ V which does not have a negative secondary effect in synthesis, whereas silver does not produce chemical fluctuations other than gamma rays.

In addition, when selecting the type of material for the insert of the device according to the invention, another important parameter is its thermal conductivity. Thus, silver has good conductors or shortcomings. After several investigations, silver forms silver compounds that can become contaminants.

Titanium produces ⁴⁸ V which is chemically inert but has a half-life of 16 days. Thus, in the case of titanium, there are serious problems in which technicians are exposed to ionizing radiation if the target window violates its replacement cycle.

Finally, the use of niobium for inserts is also possible, which conducts twice as much as titanium but less than silver. Niobium (Nb) produces isotopes with few long half-lives.

The overall activity of the insert 2 is measured after irradiation and the lack of the entire insert should be as low as possible.

Wherein - in the examples described in accordance with one embodiment stated in two, radioisotope production apparatus ¹⁸ O- concentrated and used for the production of ¹⁸ F from the water, the energy, one between 5 and 30 MeV range 150 μA It is exposed to a proton beam with a beam intensity of 1 and an irradiation time ranging from 1 minute to 10 hours.

In this embodiment, the concentrated water should have a minimum flow rate of 200 ml per minute, but this flow rate can easily be reached with about 500 ml of valves per minute or higher valves of the first embodiment, while this flow rate is per minute Easily reach about 1000 ml of valve, and more preferably 1500 ml per minute, or even higher valves of the second embodiment. This flow rate can be obtained, for example, through the use of a pump, such as the pump 120 series supplied by Micro Pump Ltd. (http://www.micropump.com) . This gear pump is equipped with a gear set N21 with a delivery capacity of 900 ml per minute at a pressure of 5 to 6 bars. Another example of a pump that can be used is TS057G.APPT.G02.3230 from Tuthill (http://pump.tuthill.com/) with the ability to deliver a flow rate of about 1100 ml per minute at a differential pressure of 6 bar. The pump corresponds to the model.

The total amount of target contained in the whole apparatus of the invention should not exceed 20 ml, which means that the dead vloume of the pump should be used as low as possible.

An external heat exchanger 15 which comprises a very small amount of target material, typically less than 10 ml, preferably less than 5 ml, is also generally intended to dissipate heat generated by irradiation of the target fluid in the irradiation cell 1. Connected to secondary cooling circuit (not shown).

The irradiation cell 1 is necessarily located along the axis of the incident beam. Therefore, the material that made it must be able to withstand ionizing radiation. However, it is possible to position the pump 16, the external heat exchanger 15 and the valve V ₅ so that they are offset for the purpose of protecting against such radiation. Applicants could devise a solution in which these components could be protected from ionizing radiation by flux return of cyclotron magnetic force.

Various types of exchangers known to those skilled in the art can be used. Without being limited, we refer to coil exchangers or exchangers with double wall pipes or even tube exchangers or plate exchangers. The only constraints on these exchangers are very low dead volume not exceeding a few ml, extremely low head loss and, of course, maximum heat-exchange capacity (between 1 and 2.5 kW), while other products due to irradiation, ¹⁸ O- Resistance to concentrated water and acid pH values (between 2 and 7).

Schematically, the device according to the invention allows radioisotopes to be produced from a target material irradiated by a beam of charge particles produced by cyclotrons. Thanks to its design, the device according to the invention has the advantage of optimizing the use of the irradiation capabilities of modern cyclotrons. This means that although the irradiation window 7 of the presently known technique cannot withstand the pressure due to the irradiation current greater than 45 μA, however, the device according to the preferred embodiment is the maximum usable current of the cyclotron currently used in nuclear medicine. That is, because it allows the use of a current of about 100 μA.

In general, the device makes it possible to use the current cyclotron's maximum ability to produce irradiation currents in excess of 100 μA, until the temperature rise can be controlled. Therefore, the target inevitably remains in a liquid state allowing to be recycled at high speed without depriming of the pump.

The fact that the target material with 80 μA can be investigated rather than 40 μA allows economically very advantageous production of more ¹⁸ F.

8A, B and C show the means of conveying, producing and draining target material into the irradiation cell. The valve V ₆ allows a backpressure of helium, argon or nitrogen to be provided to form a "gas cushion" that acts as an expansion tank. Helium, argon or nitrogen generally makes it possible to keep the pressure in the whole circuit constant, especially via valves V ₁ and V ₃ . Valves V ₂ and V ₄ are used to charge the system.

Claims (21)

In a device for producing a radioisotope of interest from an irradiated target fluid using a beam of accelerated charged particles, the device included in the circulation circuit 17 is: An irradiation cell (1), at least one inlet (4) and at least one outlet (5) comprising a metallic insert capable of forming a cavity (8) closed by the irradiation window (7) and designed to receive the target fluid The cavity (8) comprising; A pump 16 for circulating the target fluid inside the circulation circuit 17; An external heat exchanger 15; The pump (16) and the external heat exchanger (15) forming external cooling means of the target fluid; Characterized in that it further comprises means for maintaining the constant pressure 14 of the circulation circuit 17 and external cooling means of the target fluid arranged in such a way that the target fluid inevitably remains inside the cavity in a liquid state during irradiation. Device. 2. The apparatus of claim 1, wherein the pump generates a sufficient flow rate to maintain the target fluid at an average temperature of less than 130 ° C. 3. Apparatus according to claim 1 or 2, characterized in that the pump (16) generates a flow rate of greater than 200 ml per minute. The device of claim 1, wherein the pump generates a flow rate greater than 500 ml per minute, preferably 1000 ml per minute, more preferably 1500 ml per minute. Apparatus according to any of the preceding claims, characterized in that the cavity (8) can contain between 0.2 and 5.0 ml of target fluid volume. Apparatus according to any one of the preceding claims, characterized in that it contains an overall target fluid amount of less than 20 ml in its circulation circuit. Apparatus according to any of the preceding claims, characterized in that the inlet (4) and outlet (5) are arranged in such a way as to create a vortex in the flow of the target fluid inside the cavity (8). Apparatus according to any of the preceding claims, characterized in that one of the inlet (4) or the outlet (5) is necessarily located tangentially to the cavity (8). Apparatus according to any one of the preceding claims, characterized in that the inlet and outlet are located on the side surface of the cavity (8) on the same meridion. 10. The inlet (4) according to any of the preceding claims, wherein the inlet (4) defines the impact point of the charged particle beam accelerated in the cavity window in such a way that the target fluid inflow causes the window to face the window using the beam. Device arranged to face. 11. The cavity (8) according to any of the preceding claims, wherein the cavity (8) exhibits a central axis around the deployed side surface, the outlet (5) is connected to the side surface, and the inlet (4) is connected to the central axis. Device characterized in that it follows. Apparatus according to any of the preceding claims, characterized in that the irradiation cell (1) comprises internal cooling means. Apparatus according to any one of the preceding claims, characterized in that the internal cooling means is in the form of a double wall jacket surrounding the cavity (8). The device according to claim 12, wherein the internal cooling means is an indirect cooling means of the cavity (8). Apparatus according to any one of the preceding claims, characterized in that it comprises helium-based cooling means for cooling the irradiation window (7) of the irradiation cell (1). In a method for producing a radioactive isotope of interest from a target fluid used as a precursor of the radioactive isotope of interest irradiated inside the irradiation cell using a beam of accelerated charged particles, the irradiation cell 1 comprises: 7) a metallic insert 2, which is sealed by 7 and can form a cavity 8 designed to receive a target fluid, the cavity 8 having at least one inlet 4 and at least one outlet ( 5) is provided; The method is characterized in that it comprises an external heat exchanger 15 and at least one pump 16 for the circulation of the material in addition to the irradiation cell 1 to circulate the target fluid inside the circulation circuit 17. ; The method is characterized in that the external heat exchanger 15 is arranged in such a way that the pressure of the circuit is such that the constant pressure holding means 14 of the circulation circuit, i. And controlled by the pump (16). 17. The method according to claim 16, wherein the vortex in the flow of target fluid is induced inside the cavity (8). 18. The method according to claim 16 or 17, wherein the pump (16) generates a flow rate sufficient to maintain the target fluid at an average temperature of less than 130 ° C. 19. The method according to claim 18, wherein the pump (16) generates a flow rate of greater than 200 ml per minute. A irradiation cell (1) comprising a metallic insert (2) comprising at least one inlet (4) and at least one outlet (5) and capable of forming a cavity designed to receive a target fluid, said cavity (8) is defined by the central axis of the circumference of which the side surface is deployed, the cavity (8) being opposed by the irradiation window (7) and by the second surface and the irradiation window (7) which are necessarily perpendicular to the central axis. Closed, Said inlet connected to said second surface, which is essentially perpendicular to said central axis, while said outlet is connected to a side surface. Use of a device according to any one of claims 1 to 15 or a method according to any one of claims 16 to 19 or preparation of a radiopharmaceutical compound, particularly for medical applications such as positron emission tomography. Irradiation cell according to claim 20.