EP-4735916-A1 - ALPHA SPECTROMETRY SCANNER

Abstract

The present invention relates to an alpha spectrometry scanner for measuring one or more characteristics of radiation particles received from a radioactive sample under test, which sample is comprised in a radiopharmaceutical, said scanner comprising: detector means comprising a pixelated detector comprising a two dimensional array of detector pixels sensitive to said radiation particles received from said sample; a readout circuit in electric communication with said detector means, arranged to readout each pixel of said array, and wherein said readout circuit is arranged to generate, based on said readout of each of said detector pixels, a charge pattern for each hit of a radiation particle on said detector means, said charge pattern comprising spatial data, temporal data and energy deposited for each detector pixel of said array; spectroscopic analyser means in electric communication with said readout circuit to receive each charge pattern generated by said readout circuit, wherein said spectroscopic analyser means are arranged with a selective algorithm to extract features from said charge pattern and to identify and quantify a corresponding alpha particle of said sample based on said extracted features; a collimator arranged for selecting radiation particles that are on a path from said radioactive sample under test, towards said detector means, wherein said collimator is positioned in front of said detector means, and is comprised of an alpha particle vacuum collimator or an alpha particle air-flush collimator, said vacuum collimator or air-flush collimator is arranged to restrict the passage of said radiation particles and select particles on the path towards the pixels of the array of the pixelated detector.

Inventors

• PLOMP, Jeroen
• DENKOVA, Antonia Georgieva
• DE BLOIS, Reinier Hendrik
• VAN LIESHOUT, Erik
• VAN DER WAL, Ernst Mattijs

Assignees

• Technische Universiteit Delft
• Erasmus University Medical Center Rotterdam

Dates

Publication Date

20260506

Application Date

20240628

Claims (16)

1. 1. An alpha spectrometry scanner for measuring one or more characteristics of radiation particles received from a radioactive sample under test, which sample is comprised in a radiopharmaceutical, said scanner comprising: detector means comprising a pixelated detector comprising a two dimensional array of detector pixels sensitive to said radiation particles received from said sample; a readout circuit in electric communication with said detector means, arranged to readout each pixel of said array, and wherein said readout circuit is arranged to generate, based on said readout of each of said detector pixels, a charge pattern for each hit of a radiation particle on said detector means, said charge pattern comprising spatial data, temporal data and energy deposited for each detector pixel of said array; spectroscopic analyser means in electric communication with said readout circuit to receive each charge pattern generated by said readout circuit, wherein said spectroscopic analyser means are arranged with a selective algorithm to extract features from said charge pattern and to identify and quantify a corresponding alpha particle of said sample based on said extracted features; a collimator arranged for selecting radiation particles that are on a path from said radioactive sample under test, towards said detector means, wherein said collimator is positioned in front of said detector means, and is comprised of an alpha particle vacuum collimator or an alpha particle air-flush collimator, said vacuum collimator or air-flush collimator is arranged to restrict the passage of said radiation particles and select particles on the path towards the pixels of the array of the pixelated detector.
2. 2. The alpha spectrometry scanner of claim 1 , wherein said spectroscopic analyser means is further arranged with said selective algorithm to extract features from said charge pattern and to identify and quantify a corresponding beta minus particle of said sample.
3. 3. The alpha spectrometry scanner according to any of the previous claims, wherein said spectroscopic analyser means is further arranged to identify with said selective algorithm and based on said charge pattern corresponding alpha and beta minus particles for generating an alpha spectrum and a beta minus energy distribution of said sample.
4. 4. The alpha spectrometry scanner according to any of the previous claims, wherein said readout circuit is arranged for continuous readout of each pixel.
5. 5. The alpha spectrometry scanner according to any of the previous claims, wherein said charge pattern generated by said readout circuit is arranged for comprising pixel coordinates, time of arrival and time over threshold data for detector pixel of said array.
6. 6. The alpha spectrometry scanner according to any of the previous claims, wherein said readout circuit is arranged for filtering said energy deposited in said charge pattern, wherein said filtering comprises pixel grouping to generate charge peaks in said pattern with high contrast.
7. 7. The alpha spectrometry scanner according to any of the previous claims, wherein said spectroscopic analyser means comprises a programmable logic device configured for executing said selective algorithm.
8. 8. The alpha spectrometry scanner according to claim 7, wherein a programmable logic device is a Field Programmable Gate Array, FPGA.
9. 9. The alpha spectrometry scanner according to claim 7 or 8, wherein said FPGA is configured for one or more functions of noise filtering, signal amplification, baseline correction, and data formatting, and wherein one or more of these functions are implemented into said FPGA as one or more logic circuits.
10. 10. The alpha spectrometry scanner according to claim 7, 8, or 9, wherein said FPGA is configured for one or more functions of data transformation, event identification, particle tracking, and wherein one or more of these functions are implemented into said FPGA as one or more logic circuits.
11. 11. The alpha spectrometry scanner according to claim 7, 8, 9, or 10, wherein said FPGA is configured for performing pattern recognition to determine one or more characteristics of each charge pattern as a particle event, by identing each particle’s spatial data, temporal data and energy deposited and wherein the pattern recognition function is implemented into said FPGA as one or more logic circuits.
12. 12. The alpha spectrometry scanner according to any of the previous claims, wherein said collimator is a 3D printed collimator.
13. 13. The alpha spectrometry scanner according to any of the previous claims, wherein said collimator comprises a plurality wave guides.
14. 14. The alpha spectrometry scanner according to any of the previous claims, wherein said collimator is a collimator system to enhance resolution by path definition said radiation particles onto said pixels of the array of the pixelated detector.
15. 15. The alpha spectrometry scanner according any of the previous claims, wherein said vacuum collimator further comprises vacuum means comprising a vacuum port in fluid communication with vacuum channels and arranged for connecting a vacuum pump to generate a vacuum in said particle channels of said collimator during use of said alpha spectrometry scanner.
16. 16. The alpha spectrometry scanner according to any of the claims 1-14, wherein said air-flush collimator further comprises air-flush system means, such as an air pump, comprising an above ambient pressure compartment that is in fluid communication with air channels to flush said above ambient pressure compartment and said air channels.

Description

Title: alpha spectrometry scanner Description: BACKGROUND The present invention relates to an alpha spectrometry scanner. Alpha spectrometry scanners are used in alpha radionuclide therapy. Alpha radionuclide therapy, also known as alpha particle therapy, is a type of targeted radiation therapy that utilizes alpha particles to treat certain types of cancer. It involves the administration of radionuclides that emit alpha particles to selectively destroy cancer cells while aiming to minimizing damage to surrounding healthy tissues. Alpha particles are high-energy particles consisting of two protons and two neutrons, essentially the nucleus of a helium atom. They have a large mass and a positive charge, which gives them high linear energy transfer (LET) characteristics. Due to their size and charge, alpha particles have a short range in tissue and deposit a large amount of energy along their path, making them highly effective in damaging cancer cells. Radionuclides used in alpha radionuclide therapy are chosen based on their ability to emit alpha particles. These radionuclides can be produced artificially or obtained from natural sources. Commonly used alpha-emitting radionuclides include Actinium-225 (Ac-225), Radium-223 (Ra-223), and Bismuth-213 (Bi-213). These radionuclides are typically attached or bound to targeting molecules, such as antibodies or peptides, to specifically deliver them to cancer cells. The radionuclides are combined with specific targeting molecules that have an affinity for cancer cells. These targeting molecules can recognize and bind to specific receptors or antigens present on the surface of cancer cells, allowing the alpha-emitting radionuclides to be delivered directly to the tumour sites. This targeted approach minimizes damage to healthy tissues and maximizes the radiation dose to cancer cells. When the alpha-emitting radionuclides decay, they emit alpha particles that deposit their energy within a short distance in the surrounding tissue. This localized energy deposition causes significant DNA damage in the targeted cancer cells, leading to cell death. Additionally, the high LET characteristics of alpha particles can induce bystander effects, where neighbouring cancer cells are also affected by radiation-induced damage. Alpha radionuclide therapy can be administered through various routes, depending on the specific radionuclide and cancer type. It can be given intravenously, as an injection or infusion, or directly targeted to specific tumour sites using techniques such as radioimmunotherapy. The treatment is usually performed in specialized centers by trained medical professionals. Alpha radionuclide therapy has shown promise in the treatment of certain cancers, such as metastasised tumours, particularly those with limited treatment options or resistant to conventional therapies. The highly localized and potent radiation delivered by alpha particles offers the potential for effective tumor control while minimizing damage to healthy tissues. Ongoing research and clinical trials aim to further refine this therapy and expand its applications in cancer treatment. A promising radioisotope for this therapy is 225Ac which is a part of a decay chain having daughter radionuclides that also emit alpha radiation making it very potent with a total of four alpha particles. This decay unfortunately also has a downside, the emission of the alpha particles also results in breaking of the chemical bond holding the alpha emitter to the molecule targeting the cancer cells, which can result in many adverse side effects. This breaking of bonds due to the alpha emission as well as the destructive power of the alpha particles themselves can also destroy the radiopharmaceutical, therefore it is of great importance to perform quality control tests (e.g., accurate measurement of the activity) as fast as possible and just before administering in the patient. It is an object of the present invention to provide a device that is able to reduce the time to perform the quality control activity measurements from hour(s) to minutes making the treatment four times more efficient and with that saving costs and be able to treat more patients. The device should be able to enable fast and very accurate measurement of the activity of 225Ac. SUMMARY OF THE INVENTION In a first aspect, there is provided, an alpha spectrometry scanner for measuring one or more characteristics of radiation particles received from a radioactive sample under test, which sample is comprised in a radiopharmaceutical, said scannercomprising: detector means comprising a pixelated detector comprising a two dimensional array of detector pixels sensitive to said radiation particles received from said sample; a readout circuit in electric communication with said detector means, arranged to readout each pixel of said array, and wherein said readout circuit is arranged to generate, based on said readout of each of said detector pixels, a charge