RU2738005C2 - RESERVOIR FOR A REPLENISHED HOMOGENEOUS GAMMA-RADIATION SOURCE BASED ON AQUEOUS SOLUTION OF SODIUM 99MTc-PERTECHNETATE AND A METHOD FOR CONTOURING A PATIENT'S BODY FOR INDIRECT PLANAR LYMPHOSCINTIGRAPHY IN "WHOLE BODY" MODE - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: group of inventions relates to medicine. Container for replenished homogenous gamma-radiation source based on aqueous solution of sodium ^99mTc-pertechnetate characterized in that the container is made in the form of a parallelepiped of acrylic plastic with size of 51×51×4 cm and volume of 5,000 cm³. On upper edge of reservoir there are two round holes with thread ∅ 8.8 mm for metal bolts with silicone gaskets. On rear surface of container there are symmetrically arranged four ledges at distance of 4.5 cm from side faces with size of 5×5 cm for installation of container into "holder for homogeneous source". Method for contouring a patient's body for indirect planar whole body lymphoscintigraphy involves administering to a patient a preparation based on ^99mTc-labeled colloidal nanoparticles with activity of up to 110 MBq, and 30 minutes after the introduction, the gamma-camera is used for indirect planar lymphoscintigraphy in the "whole body" mode. Two-detector rotary gamma-ray monitor is used to specify the protocol of indirect planar lymphoscintigraphy. Signal is recorded only by upper detector. Lower detector is switched off and a holder with solution of sodium ^99mTc-pertechnetate, uniformly distributed in 5 l of distilled water, is placed on it. After the examination is completed, the obtained images are evaluated, wherein the patient's body is defined as a homogeneous section which does not transmit a signal to the detector, and the injection site and the lymph drainage path - in the form of high-signal centers and zones, wherein the sentinel lymph node is visualized on the lymphoscintigram as a bright RPA hyper fixation center in the projection of the potential lymphatic drain zone.

EFFECT: use of this group of inventions is cost-effective, easy to implement, has high throughput capacity, since it does not require long time for preparation and postprocessor processing, and enables to obtain data from the entire region of interest.

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Description

The invention relates to medicine, namely to radiology, and can be used within the framework of personalization in planning the surgical treatment of patients with malignant melanoma of the skin.

Currently, the indication for biopsy of the sentinel lymph node in confirmed malignant melanoma of the skin is stage 0-IIC, in which there are no clinical and instrumental signs of regional and distant metastasis. For this group of patients, the scope of the surgical intervention consists in radical excision of the primary tumor within the healthy tissue with regional lymphadenectomy, which can be limited to removal of the sentinel lymph node, the topic of which is specified, including using indirect planar lymphoscintigraphy.

To determine the localization of the sentinel lymph node, it is necessary to establish clear anatomical landmarks of the potential pathways of lymph outflow. For this purpose, in world practice, the technique of contouring the patient's body using a planar homogeneous source of gamma radiation is used. The patient's body, against the background of uniformly distributed homogeneous activity in the scanning field of the gamma camera, is visualized as a homogeneous photopenic zone with clear contours.

In the routine practice of most oncological clinics in the world, a planar source of cobalt-57 (⁵⁷Co) (BRKrynyckyi, CKKim, MRGoyenechea, PTChan, Z.-Y. Zhang, and J. Machac, “Clinical breast lymphoscintigraphy: optimal techniques for performing studies, image atlas, andanalysis of images,” Radiographics, vol. 24, no. 1, pp. 121-139,2004; MV Mar, RL Dickinson, WD Erwin, and RE Wendt III, “Optimal 57Co fl ood source activity and acquisition time for Olymphoscintigraphy localization images,” Journal of Nuclear Medicine Technology, vol. 36 , no. 2, pp. 82–87, 2008).

However, this method has certain disadvantages, namely:

- ⁵⁷ Co belongs to cyclotron radionuclides, has a high cost, which makes it difficult to use it in the routine practice of most hospitals providing oncological care;

- for the use of ⁵⁷ Co, specially designed premises, approved by urban planning standards, are required to comply with radiation safety, both in the hospital and outside.

A known method of using indirect planar lymphoscintigraphy with contouring the patient's body in the area of interest using a homogeneous source of gamma radiation replenished with an aqueous solution of ^99m Tc-sodium pertechnetate in patients with malignant melanoma of the skin of various localization (Sentinel lymph node scintigraphy in cutaneous melanoma using a planar calibration phantom filled with Tc-99m pertechnetate solution for body contouring / Peştean C, Bărbuş E, Piciu A, Larg MI, Sabo A, Moisescu-Goia C, Piciu D. -. Clujul Medical journal, 2016; 89 (4): 480–485. Published online 2016 Oct 20), where a calibration phantom is used for contouring, filled with a homogeneous solution of ^99m Tc-sodium pertechnetate, with an activity of 37 MBq, placed behind the patient. This technique involves obtaining a series of planar images of one anatomical region (corresponding to one field of view of a gamma camera), where the primary focus is located.

The disadvantages of the presented technique include a limited amount of visualization of potential pathways of lymph drainage, which significantly reduces the possibility of determining the localization of the sentinel lymph node, and as a result, can lead to incorrect surgical tactics.

There is a known method of performing indirect planar lymphoscintigraphy in the "whole body" mode with contouring the patient's body using a ⁵⁷ Co plate as a homogeneous planar source of gamma radiation in patients with malignant melanoma of the skin (Whole-Body Lymphoscintigraphy Using Transmission Scans-Martha "authors Vallejo Mar, BBA, CNMT, Sonia Gee-Johnson, BS, CNMT, E. Edmund Kim, MD and Donald A. Podoloff, MD / J. Nucl. Med. Technol. March 1, 2002 vol. 30 no. 1 12-17). A disadvantage presented method is the use of the plate ⁵⁷ Co, which has a high cost, which makes it difficult to use in routine practice in most hospitals.

The technical solution is the development of a container for filling with an aqueous solution^99mTc-sodium pertechnetate and method contouring the patient's body during an indirect planar lymphoscintigraphy in full body mode".

For the technical solution, as well as in the known method, a container filled with an aqueous solution of ^99m Tc-sodium pertechnetate is used.

A feature of the proposed method is that the container is made of acrylic plastic, measuring 51x51x4cm and a volume of 5000 cm ³ , and on one of the side faces of the container there are two round holes with a thread Ø 8.8 mm for metal bolts with silicone gaskets, on the back surface of the container there are four symmetrically located protrusions at a distance of 4.5 cm from the side faces measuring 5x5 cm for installing the container into the "holder for a homogeneous source". 30 minutes after the introduction of the RFP, the patient is examined, on the monitor of a two-detector rotary gamma camera and the protocol for indirect planar lymphoscintigraphy is set, these parameters are recorded only by the upper detector with active "body contour", the lower detector is turned off and a holder with the declared capacity is installed on it and after at the end of the study, the obtained images are assessed, where the patient's body is defined as a homogeneous area that does not transmit a signal to the detector, and the injection site and lymph drainage pathways are in the form of foci and zones of a high signal, and the sentinel lymph node is visualized on the lymphoscintigram as a bright focus of RFP hyperfixation in the zone projection potential lymphatic drainage.

The invention is illustrated by a detailed description, a clinical example and illustrations, which depict:

Fig. 1 - diagram of the capacitance of a homogeneous source (back view):one - capacity; 2 - protrusions; 3 - holes; 4 - metal bolts.

FIG. 2 - diagram of the capacity of a homogeneous source (side view): 1 - capacity; 2 - protrusions; 4 - metal bolts; 6 - holder.

FIG. 3 - diagram of the container of a homogeneous source (View on the holder): 1 - container; 2 - projections; 3 - holes; 4 - metal screws; 6 - holder.

Fig. 4 is a diagram of the capacity of a homogeneous source (Sectional view): 1 - capacity; 3 - hole; 4 - metal bolts; 5 - silicone gasket.

Fig. 5 is a photo: General view of the holder.

6 is a photo of a funnel for filling with water.

Fig. 7 is a photo of a bolt with a silicone gasket.

Fig. 8 - photo: a, b) introduction of activity into the liquid contents of the container.

Fig.9 - Scheme of the image of the patient's body: a) with contouring of the body; b) without contouring the body.

FIG. 10 is an image of an indirect planar lymphoscintigraphy of patient B.

FIG. 11 is an image of an indirect planar lymphoscintigraphy of patient A.

FIG. 12 is an image of an indirect planar lymphoscintigraphy of patient C.

The device (Fig. 1) consists of a container in the form of a parallelepiped 1, made of acrylic plastic, 51x51x4cm in size and with a volume of 5000 cm ³ (5L). On one of the side faces of the container there are two round holes with threads 3 (8.8 mm in diameter), closed with metal bolts 4 (Fig. 2) with silicone gaskets 5 (Fig. 4) (to ensure tightness). On the back surface of the container, four protrusions 2 (Fig. 1) are symmetrically located at a distance of 4.5 cm from the side edges, with dimensions of 5x5 cm. These protrusions 2 are designed to install the container in the "holder for a homogeneous source" 6 (Fig. 3), which included in the delivery set of the gamma camera (Fig. 5).

The method is performed as follows.

For contouring the patient's body during indirect planar lymphoscintigraphy in the "whole body" mode in patients with malignant melanoma of the skin, a source based on an aqueous solution was proposed^99mTc-sodium pertechnetate. 1 ml was used as a radiation source.^99mTc - sodium pertechnetate with an activity of 50-60 mBq, dissolved in distilled water with a volume of 5 liters. Half life^99mTc is 6.01 hours. After 6 half-lives^99mTc, the solution is disposed of as household waste.

To implement the method, a two-detector rotary gamma camera was used, combined with an X-ray computed tomograph - Discovery NM / CT 670, manufactured by GE Healthcare (Israel) with installed parallel low-energy high-resolution collimators (LEHR).

Stages of patient and system preparation:

A solution of ^99m Tc-sodium pertechnetate is prepared. In a sterile evacuated vial with a volume of 15 cm ^{3, 99m} Tc - sodium pertechnetate is eluted from the generator. Then, ^99m Tc-sodium pertechnetrate in a volume of 1 ml with an activity of 50 mBq measured in a dosage calibrator is taken from this vial with an insulin syringe. In the conditions of the radionuclide support unit, the source is prepared on a stainless steel table. The container 1 is placed in a vertical position with holes 3 on the upper edge (Fig. 1). Next, unscrew two bolts 4 and insert a funnel into any hole 3 and fill a container with distilled water with a volume of 5 liters. (Fig. 6) After filling the container 1, a bolt 4 with a silicone gasket 5 is screwed into one of the holes 3 (Fig. 7). An insulin syringe with activity is placed into the open hole 3 and a solution of ^99m Tc-sodium pertechnetate is injected into the container 1 (Fig. 8). Then, after the introduction of the entire volume of the solution, the syringe plunger is reciprocated to ensure maximum evacuation of activity from the syringe. The second hole 3 is tightened with a second screw 4 with a silicone gasket 5 (Fig. 7). Container 1 is placed horizontally on the table surface to ensure that the holes are tight 3. Next, the contents of container 1 are stirred by rotating 180 degrees clockwise and counterclockwise around the horizontal axis to evenly distribute the ^99m Tc-sodium pertechnetate solution throughout the entire volume of container 1.

A drug based on colloidal albumin nanoparticles labeled with ^99m Tc, with an activity of up to 110 MBq, is administered to the patient subcutaneously / intradermally. 2-4 injections are made around the tumor, and 30 minutes after the injection of RP, a study is carried out on a gamma camera.

The patient is placed in a supine position with the legs directed towards the gantry, the arms are fixed along the body or behind the head, on the interactive ruler of the gamma camera table, the scanning zone boundaries corresponding to the patient's height are indicated, then the table is brought into working position by pressing the buttons on the gamma remote control - cameras. The detector located under the patient is brought to the lowest position using the remote control. On top of this detector, a holder with a container of a homogeneous source is installed (Fig. 5). Thus, a source with a ^99m Tc-sodium pertechnetate solution is placed behind the patient.

Description of the method for contouring the patient's body in the "whole body" mode.

30 minutes after the introduction of the RFP, the patient is examined with these parameters. Registration of the received signals is carried out in the front projection. The projection registration time is 18 minutes. A protocol of indirect planar lymphoscintigraphy with parameters is set on the monitor of a two-detector rotary gamma camera: data is recorded only by the upper detector with active “body contour”, the lower detector is turned off, a holder with a container of a homogeneous source is installed on it ”(Fig. 5), the speed of the tabletop is 15 cm / min, LEHR collimator.

After the end of the study, the images obtained are evaluated at a specialized workstation. On the received lymphoscintigram, a homogeneous background with a low signal level is clearly visualized. The patient's body is defined as a homogeneous area that does not transmit a signal to the detector, against the background of which the injection site and lymph drainage pathways are determined in the form of foci and zones of a high signal. Due to this difference in incoming signals against the background of the anatomical projection of the patient's body with a clear contour, the picture of the distribution of the RFP along the lymphatic tract is determined (Fig. 9 a). When performing an indirect planar lymphoscintigraphy in the "whole body" mode without contouring the body, the injection site and lymph drainage pathways are visualized as foci and zones of a high signal against a uniform background of a missing signal. As a consequence, there are no anatomical landmarks for the sentinel lymph node topic (Fig. 9 b). The sentinel lymph node is visualized on the lymphoscintigram as a bright focus of RFP hyperfixation in the projection of the area of potential lymph outflow (Fig. 9 a).

This method has advantages over the traditional technique using the ⁵⁷ Co plate due to the imaging of the whole body within a single scan, rather than a single anatomical region, and the wide availability of the ^99m Tc isotope compared to ⁵⁷ Co.

Clinical example 1.

Patient V., 72 years old. I consulted an oncodermatologist for an increase in the size and color change of a nevus on the anterior abdominal wall. After examination, she was diagnosed with melanoma. An indirect planar lymphoscintigraphy was performed in the "whole body" mode using the proposed capacity and contouring method. Based on the recorded data, an image was obtained (Fig. 10).

The above image shows a photopenic area corresponding to the patient's body contours against a homogeneous background of a moderately increased signal. Within the body contour, areas of RP hyperfixation are visualized: on the anterior abdominal wall - the injection site (corresponding to the primary tumor) and in the right inguinal and right axillary regions, with a fragmentarily traced radioactive "path" from the injection site - sentinel lymph nodes.

Clinical example 2.

Patient A., 38 years old. I went to the oncological dispensary for damage to the nevus on the lateral surface of the abdomen. After examination, she was diagnosed with melanoma. An indirect planar lymphoscintigraphy was performed in the "whole body" mode using the proposed capacity and contouring method. Based on the recorded data, an image was obtained (Fig. 11).

The above image shows a photopenic area corresponding to the patient's body contours against a homogeneous background of a moderately increased signal. Within the body contour, areas of RP hyperfixation are visualized: on the left lateral part of the abdomen - the injection site (corresponds to the primary tumor) and in the left axillary region, with a traced reactive "path" from the injection site - the "sentinel" lymph node.

Clinical example 3.

Patient N., 40 years old. I went to an oncological dispensary for an increase in the size and color change of a nevus, after prolonged exposure to ultraviolet radiation, on the anterior abdominal wall. After examination, she was diagnosed with melanoma. An indirect planar lymphoscintigraphy was performed in the "whole body" mode using the proposed capacity and contouring method. Based on the recorded data, an image was obtained (Fig. 12).

The above image shows a photopenic area corresponding to the patient's body contours against a homogeneous background of a moderately increased signal. Within the body contour, areas of RP hyperfixation are visualized: on the anterior abdominal wall - the injection site (corresponds to the primary tumor) and in both inguinal and both axillary regions, with a fragmentarily traced reactive "path" from the injection site - sentinel lymph nodes.

The proposed indirect planar lymphoscintigraphy in the "whole body"body contouring using a homogeneous rechargeable gamma-ray source based on an aqueous solution^99mTc-sodium pertechnetate makes it possible to determine the localization and intensity of RP accumulation in all possible lymphatic collectors, and to provide the surgeon with a complete picture for carrying out the appropriate volume of surgical intervention.

The proposed invention is cost-effective, simple to implement, has a high throughput, since it does not require much time for preparation and post-processing, and allows obtaining data from the entire area of interest.

Claims (2)

1. A container for a replenished homogeneous source of gamma radiation based on an aqueous solution of ^99m Tc-sodium pertechnetate, characterized by the fact that the container is made in the form of a parallelepiped of acrylic plastic with a size of 51 × 51 × 4 cm and a volume of 5000 cm ³ , and on the upper edge of the container there are two round holes with a thread ∅ 8.8 mm for metal bolts with silicone gaskets, on the back surface of the container there are four symmetrically located protrusions at a distance of 4.5 cm from the side edges measuring 5 × 5 cm for installing the container in the "holder for a homogeneous source ". 2. A method of contouring the patient's body for indirect planar lymphoscintigraphy in the "whole body" mode, comprising administering to the patient a preparation based on colloidal albumin nanoparticles labeled with ^99m Tc, with an activity of up to 110 MBq, and 30 minutes after administration, a study is performed on a gamma camera indirect planar lymphoscintigraphy in the "whole body" mode, characterized in that the protocol of indirect planar lymphoscintigraphy is set on the monitor of the two-detector rotary gamma camera, the signal is recorded only by the upper detector, the lower detector is turned off and a holder with a capacity according to claim 1 with a solution of ^99m is installed on it Tc-sodium pertechnetate, evenly distributed in 5 liters of distilled water, after the end of the study, the obtained images are assessed, where the patient's body is defined as a homogeneous area that does not transmit a signal to the detector, and the injection site and lymphatic drainage pathways are in the form of foci and zones of a high signal, and the sentinel lymph node is visualized on lymphoscintigram as a bright focus of RFP hyperfixation in the projection of the zone of potential lymph outflow.

Images