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Epstein L, Heger G, Roy A, Gannot I, Kelson I, Arazi L. The low-LET radiation contribution to the tumor dose in diffusing alpha-emitters radiation therapy. Med Phys 2024; 51:3020-3033. [PMID: 38096442 DOI: 10.1002/mp.16885] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/16/2023] [Accepted: 11/21/2023] [Indexed: 04/05/2024] Open
Abstract
BACKGROUND Diffusing alpha-emitters Radiation Therapy ("Alpha DaRT") is a new technique that enables the use of alpha particles for the treatment of solid tumors. Alpha DaRT employs interstitial sources carrying a few μ $\mu$ Ci of224 $^{224}$ Ra below their surface, designed to release a chain of short-lived atoms (progeny of224 $^{224}$ Ra) which emit alpha particles, along with beta, Auger, and conversion electrons, x- and gamma rays. These atoms diffuse around the source and create-primarily through their alpha decays-a lethal high-dose region measuring a few millimeters in diameter. PURPOSE While previous studies focused on the dose from the alpha emissions alone, this work addresses the electron and photon dose contributed by the diffusing atoms and by the atoms remaining on the source surface, for both a single Alpha DaRT source and multi-source lattices. This allows to evaluate the low-LET contribution to the tumor dose and tumor cell survival, and demonstrate the sparing of surrounding healthy tissue. METHODS The low-LET dose is calculated using the EGSnrc and FLUKA Monte Carlo (MC) codes. We compare the results of a simple line-source approximation with no diffusion to those of a full simulation, which implements a realistic source geometry and the spread of diffusing atoms. We consider two opposite scenarios: one with low diffusion and high212 $^{212}$ Pb leakage, and the other with high diffusion and low leakage. The low-LET dose in source lattices is calculated by superposition of single-source contributions. Its effect on cell survival is estimated with the linear quadratic model in the limit of low dose rate. RESULTS For sources carrying 3 μ $\umu$ Ci/cm224 $^{224}$ Ra arranged in a hexagonal lattice with 4 mm spacing, the minimal low-LET dose between sources is∼ 18 - 30 $\sim 18-30$ Gy for the two test cases and is dominated by the beta contribution. The low-LET dose drops below 5 Gy∼ 3 $\sim 3$ mm away from the outermost source in the lattice with an effective maximal dose rate of< 0.04 $<0.04$ Gy/h. The accuracy of the line-source/no-diffusion approximation is∼ 15 % $\sim 15\%$ for the total low-LET dose over clinically relevant distances (2-4 mm). The low-LET dose reduces tumor cell survival by a factor of∼ 2 - 200 $\sim 2-200$ . CONCLUSIONS The low-LET dose in Alpha DaRT can be modeled by conventional MC techniques with appropriate leakage corrections to the source activity. For 3 μ $\umu$ Ci/cm224 $^{224}$ Ra sources, the contribution of the low-LET dose can reduce cell survival inside the tumor by up to two orders of magnitude. The low-LET dose to surrounding healthy tissue is negligible. Increasing source activities by a factor of 5 can bring the low-LET dose itself to therapeutic levels, in addition to the high-LET dose contributed by alpha particles, leading to a "self-boosted" Alpha DaRT configuration, and potentially allowing to increase the lattice spacing.
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Affiliation(s)
- Lior Epstein
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
- Soreq Nuclear Research Center, Yavne, Israel
| | - Guy Heger
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
| | - Arindam Roy
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
| | - Israel Gannot
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Itzhak Kelson
- School of Physics and Astronomy, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Lior Arazi
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
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Heger G, Dumančić M, Luz I, Vatarescu M, Weizman N, Miller BW, Cooks T, Arazi L. First measurements of radon-220 diffusion in mice tumors, towards treatment planning in diffusing alpha-emitters radiation therapy. Med Phys 2024. [PMID: 38507254 DOI: 10.1002/mp.17020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 01/22/2024] [Accepted: 02/21/2024] [Indexed: 03/22/2024] Open
Abstract
BACKGROUND Diffusing alpha-emitters radiation therapy ("Alpha-DaRT") is a new method for treating solid tumors with alpha particles, relying on the release of the short-lived alpha-emitting daughter atoms of radium-224 from interstitial sources inserted into the tumor. Alpha-DaRT tumor dosimetry is governed by the spread of radium's progeny around the source, as described by an approximate framework called the "diffusion-leakage model". The most important model parameters are the diffusion lengths of radon-220 and lead-212, and their estimation is therefore essential for treatment planning. PURPOSE Previous works have provided initial estimates for the dominant diffusion length, by measuring the activity spread inside mice-borne tumors several days after the insertion of an Alpha-DaRT source. The measurements, taken when lead-212 was in secular equilibrium with radium-224, were interpreted as representing the lead-212 diffusion length. The aim of this work is to provide first experimental estimates for the diffusion length of radon-220, using a new methodology. METHODS The diffusion length of radon-220 was estimated from autoradiography measurements of histological sections taken from 24 mice-borne subcutaneous tumors of five different types. Unlike previous studies, the source dwell time inside the tumor was limited to 30 min, to prevent the buildup of lead-212. To investigate the contribution of potential non-diffusive processes, experiments were done in two sets: fourteen in vivo tumors, where during the treatment the tumors were still carried by the mice with active blood supply, and 10 ex-vivo tumors, where the tumors were excised before source insertion and kept in a medium at37 ∘ C $37^\circ {\text{C}}$ with the source inside. RESULTS The measured diffusion lengths of radon-220, extracted by fitting the recorded activity pattern up to 1.5 mm from the source, lie in the range0.25 - 0.6 mm ${0.25-0.6}\nobreakspace {\text{mm}}$ , with no significant difference between the average values measured in in-vivo and ex-vivo tumors:L R n i n - v i v o = 0.40 ± 0.08 mm $L_{Rn}^{in-vivo}=0.40{\pm }0.08\nobreakspace {\text{mm}}$ versusL R n e x - v i v o = 0.39 ± 0.07 mm $L_{Rn}^{ex-vivo}=0.39{\pm }0.07\nobreakspace {\text{mm}}$ . However, in-vivo tumors display an enhanced spread of activity 2-3 mm away from the source. This effect is not explained by the current model and is much less pronounced in ex-vivo tumors. CONCLUSIONS The average measured radon-220 diffusion lengths in both in-vivo and ex-vivo tumors are consistent with published data on the diffusion length of radon in water and lie close to the upper limit of the previously estimated range of0.2 - 0.4 mm $0.2-0.4\nobreakspace {\text{mm}}$ . The observation that close to the source there is no apparent difference between in-vivo and ex-vivo tumors, and the good agreement with the theoretical model in this region suggest that the spread of radon-220 is predominantly diffusive in this region. The departure from the model prediction in in-vivo tumors at large radial distances may hint at potential vascular contribution, which will be the subject of future works.
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Affiliation(s)
- Guy Heger
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Beersheba, Israel
| | - Mirta Dumančić
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Beersheba, Israel
- Now at Gerald Bronfman Department of Oncology, Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada
| | - Ishai Luz
- The Shraga Segal Department of Microbiology, Immunology, and Genetics, Ben-Gurion University of the Negev, Beersheba, Israel
| | - Maayan Vatarescu
- The Shraga Segal Department of Microbiology, Immunology, and Genetics, Ben-Gurion University of the Negev, Beersheba, Israel
| | - Noam Weizman
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Beersheba, Israel
- Oncology Department, Radiation Therapy Unit, Hadassah - Hebrew University Medical Center, Jerusalem, Israel
| | - Brian W Miller
- College of Medicine, Department of Radiation Oncology, Department of Medical Imaging, The University of Arizona, Tucson, Arizona, USA
| | - Tomer Cooks
- The Shraga Segal Department of Microbiology, Immunology, and Genetics, Ben-Gurion University of the Negev, Beersheba, Israel
| | - Lior Arazi
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Beersheba, Israel
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Nissim S, Brandis M, Aviv O, Arazi L. Characterization of a 4παβ(LS)-γ(HPGe) prototype system for low-background measurements. Appl Radiat Isot 2023; 198:110866. [PMID: 37235985 DOI: 10.1016/j.apradiso.2023.110866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 04/22/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023]
Abstract
A ground-level prototype system for low-background measurements was developed and tested. The system consists of a high-purity germanium (HPGe) detector used for detecting γ rays and coupled to a liquid scintillator (LS) used for detecting α and β particles. Both detectors are surrounded by shielding materials and anti-cosmic detectors ("veto") used to suppress background events. The energy and timestamp of detected α, β and γ emissions are recorded event-by-event and analyzed offline. By requiring timing coincidence between the HPGe and LS detectors, background events originating from outside the volume of the measured sample can be effectively rejected. The system performance was evaluated using liquid samples containing known activities of an α emitter (241Am) or a β emitter (60Co) whose decays are accompanied by γ rays. The LS detector was found to provide a solid angle of almost 4π for α and β particles. Compared to the traditional γ-singles mode, operating the system in coincidence mode (i.e., α-γ or β-γ) reduced the background counts by a factor of ∼100. Consequently, the minimal detectable activity for 241Am and 60Co was improved by a factor of 9, being 4 mBq and 1 mBq for an 11-d measurement, respectively. Furthermore, by applying a spectrometric cut in the LS spectrum that corresponds to α emission from 241Am, a background reduction factor of ∼2400 (compared to γ-singles mode) was achieved. Beyond low-background measurements, this prototype exhibits additional compelling features, such as the ability to focus on certain decay channels and study their properties. This concept for a measurement system may be of interest to laboratories that monitor environmental radioactivity, studies involving environmental measurements and/or trace-level radioactivity.
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Affiliation(s)
- S Nissim
- Soreq Nuclear Research Center, Yavne, 81800, Israel; Unit of Nuclear Engineering, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - M Brandis
- Soreq Nuclear Research Center, Yavne, 81800, Israel
| | - O Aviv
- Soreq Nuclear Research Center, Yavne, 81800, Israel.
| | - L Arazi
- Unit of Nuclear Engineering, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
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Heger G, Roy A, Dumančić M, Arazi L. Alpha dose modeling in diffusing alpha-emitters radiation therapy-Part I: single-seed calculations in one and two dimensions. Med Phys 2023; 50:1793-1811. [PMID: 36464914 DOI: 10.1002/mp.16145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 09/01/2022] [Accepted: 09/29/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Diffusing alpha-emitters Radiation Therapy ("DaRT") is a new method, presently in clinical trials, which allows treating solid tumors by alpha particles. DaRT relies on interstitial seeds carrying μCi-level 224 Ra activity below their surface, which release a chain of short-lived alpha emitters that spread throughout the tumor volume primarily by diffusion. Alpha dose calculations in DaRT are based on describing the transport of alpha emitting atoms, requiring new modeling techniques. PURPOSE A previous study introduced a simplified framework, the "Diffusion-Leakage (DL) model", for DaRT alpha dose calculations, and employed it to a point source, as a basic building block of arbitrary configurations of line sources. The aim of this work, which is divided into two parts, is to extend the model to realistic seed geometries (in Part I), and to employ single-seed calculations to study the properties of DaRT seed lattices (Part II). Such calculations can serve as a pragmatic guide for treatment planning in future clinical trials. METHODS We derive a closed-form asymptotic solution for an infinitely long cylindrical source, and extend it to an approximate time-dependent expression that assumes a uniform temporal profile at all radial distances from the source. We then develop a finite-element one-dimensional numerical scheme for a complete time-dependent solution of this geometry and validate it against the closed-form expressions. Finally, we discuss a two-dimensional axisymmetric scheme for a complete time-dependent solution for a seed of finite diameter and length. Different solutions are compared over the relevant parameter space, providing guidelines on their usability and limitations. RESULTS We show that approximating the seed as a finite line source comprised of point-like segments significantly underestimates the correct alpha dose, as predicted by the full two-dimensional calculation. The time-dependent one-dimensional solution is shown to coincide to sub-percent-level with the two-dimensional calculation in the seed midplane, and maintains an accuracy of a few percent up to ∼2 mm from the seed edge. CONCLUSIONS For actual treatment plans, the full two-dimensional solution should be used to generate dose lookup tables, similarly to the TG-43 format employed in conventional brachytherapy. Given the accuracy of the one-dimensional solution up to ∼2 mm from the seed edge it can be used for efficient parametric studies of DaRT seed lattices.
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Affiliation(s)
- Guy Heger
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
| | - Arindam Roy
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
| | - Mirta Dumančić
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
| | - Lior Arazi
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
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Heger G, Dumančić M, Roy A, Arazi L. Alpha dose modeling in diffusing alpha-emitters radiation therapy. Part II: Lattice studies. Med Phys 2023; 50:1812-1823. [PMID: 36517936 DOI: 10.1002/mp.16155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Diffusing alpha-emitters radiation therapy ("DaRT") is a new method, presently in clinical trials, which allows treating solid tumors by alpha particles. DaRT relies on interstitial seeds carrying μCi-level 224 Ra activity on their surface, which release a chain of short-lived alpha emitters that spread throughout the tumor volume primarily by diffusion. Alpha dose calculations in DaRT are based on describing the transport of alpha emitting atoms, requiring new modeling techniques. PURPOSE A previous study introduced a simplified framework, the "diffusion-leakage (DL) model," for DaRT alpha dose calculations, and employed it to a point source, as a basic building block of arbitrary configurations of line sources. The aim of this work, which is divided into two parts, is to extend the model to realistic seed geometries (in Part I), and to employ single-seed calculations to study the properties of DaRT seed lattices (Part II). Such calculations can serve as a pragmatic guide for treatment planning in future clinical trials. METHODS We employ the superposition of single-seed solutions, developed in Part I, to study the alpha dose in DaRT seed lattices and investigate the sensitivity of the required seed activity and spacing to changes in the DL model parameters and to seed placement errors. RESULTS We show that the rapid fall-off of the dose, which guarantees sparing healthy tissue already 2-3 mm away from the tumor, strongly favors a hexagonal, rather than square, seed placement pattern. Realistic variations in the seed manufacturing parameters (224 Ra activity and emission rate of its daughters) are shown to have a negligible effect on the required lattice spacing. On the other hand, tumor parameters (i.e., diffusion lengths and 212 Pb leakage probability), as well as seed placement errors, have a significant effect. CONCLUSIONS In most cases, hexagonal lattice spacing on the scale of ∼3.5-4.5 mm using seeds carrying a few μCi/cm 224 Ra will enable overcoming realistic uncertainties in measured tumor environment parameters, as well as seed placement errors, and result in therapeutically relevant alpha dose levels.
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Affiliation(s)
- Guy Heger
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
| | - Mirta Dumančić
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
| | - Arindam Roy
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
| | - Lior Arazi
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
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Carrier JF, Boudam K, Arazi L, Kamio Y, Taussky D. PHSOR10 Presentation Time: 1:15 PM. Brachytherapy 2022. [DOI: 10.1016/j.brachy.2022.09.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Nishri Y, Vatarescu M, Luz I, Epstein L, Dumančić M, Del Mare S, Shai A, Schmidt M, Deutsch L, Den RB, Kelson I, Keisari Y, Arazi L, Cooks T, Domankevich V. Diffusing alpha-emitters radiation therapy in combination with temozolomide or bevacizumab in human glioblastoma multiforme xenografts. Front Oncol 2022; 12:888100. [PMID: 36237307 PMCID: PMC9552201 DOI: 10.3389/fonc.2022.888100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 09/02/2022] [Indexed: 11/13/2022] Open
Abstract
Glioblastoma multiforme (GBM) is at present an incurable disease with a 5-year survival rate of 5.5%, despite improvements in treatment modalities such as surgery, radiation therapy, chemotherapy [e.g., temozolomide (TMZ)], and targeted therapy [e.g., the antiangiogenic agent bevacizumab (BEV)]. Diffusing alpha-emitters radiation therapy (DaRT) is a new modality that employs radium-224-loaded seeds that disperse alpha-emitting atoms inside the tumor. This treatment was shown to be effective in mice bearing human-derived GBM tumors. Here, the effect of DaRT in combination with standard-of-care therapies such as TMZ or BEV was investigated. In a viability assay, the combination of alpha radiation with TMZ doubled the cytotoxic effect of each of the treatments alone in U87 cultured cells. A colony formation assay demonstrated that the surviving fraction of U87 cells treated by TMZ in combination with alpha irradiation was lower than was achieved by alpha- or x-ray irradiation as monotherapies, or by x-ray combined with TMZ. The treatment of U87-bearing mice with DaRT and TMZ delayed tumor development more than the monotherapies. Unlike other radiation types, alpha radiation did not increase VEGF secretion from U87 cells in culture. BEV treatment introduced several days after DaRT implantation improved tumor control, compared to BEV or DaRT as monotherapies. The combination was also shown to be superior when starting BEV administration prior to DaRT implantation in large tumors relative to the seed size. BEV induced a decrease in CD31 staining under DaRT treatment, increased the diffusive spread of 224Ra progeny atoms in the tumor tissue, and decreased their clearance from the tumor through the blood. Taken together, the combinations of DaRT with standard-of-care chemotherapy or antiangiogenic therapy are promising approaches, which may improve the treatment of GBM patients.
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Affiliation(s)
- Yossi Nishri
- Translational Research Laboratory, Alpha Tau Medical, Jerusalem, Israel
| | - Maayan Vatarescu
- Translational Research Laboratory, Alpha Tau Medical, Jerusalem, Israel
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
| | - Ishai Luz
- Translational Research Laboratory, Alpha Tau Medical, Jerusalem, Israel
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
| | - Lior Epstein
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Radiation Protection Department, Soreq Nuclear Research Center, Yavne, Israel
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Mirta Dumančić
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Sara Del Mare
- Translational Research Laboratory, Alpha Tau Medical, Jerusalem, Israel
| | - Amit Shai
- Translational Research Laboratory, Alpha Tau Medical, Jerusalem, Israel
| | | | - Lisa Deutsch
- Biostatistics Department, BioStats Statistical Consulting Ltd., Maccabim, Israel
| | - Robert B. Den
- Translational Research Laboratory, Alpha Tau Medical, Jerusalem, Israel
- Department of Radiation Oncology, Urology, and Cancer Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Itzhak Kelson
- School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Yona Keisari
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Lior Arazi
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- *Correspondence: Lior Arazi, ; Tomer Cooks, ; Vered Domankevich,
| | - Tomer Cooks
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
- *Correspondence: Lior Arazi, ; Tomer Cooks, ; Vered Domankevich,
| | - Vered Domankevich
- Translational Research Laboratory, Alpha Tau Medical, Jerusalem, Israel
- *Correspondence: Lior Arazi, ; Tomer Cooks, ; Vered Domankevich,
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Nissim S, Aviv O, Brandis M, Weissman L, Sasson R, Yungrais Z, Datz H, Arazi L. Evaluating the intensity of the 'prompt' 140.5 keV γ-ray of 99Mo using a 4παβ(LS)-γ(HPGe) measurement system. Appl Radiat Isot 2022; 188:110367. [PMID: 35834892 DOI: 10.1016/j.apradiso.2022.110367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 07/04/2022] [Accepted: 07/05/2022] [Indexed: 11/15/2022]
Abstract
The absolute intensity for the 'prompt' 140.5 keV gamma-ray of 99Mo was evaluated using the β-γ coincidence technique. A liquid sample of 99Mo was prepared from a99Mo/99mTc generator and measured in a 4παβ(LS)-γ(HPGe) system that comprises a Liquid Scintillator (LS) detector and a High-Purity Germanium (HPGe) detector. The sample was introduced into scintillation fluid embedded in a photo-reflector assembly that provides almost 100% efficiency for detecting β particles (in the energy range of intreset). The combination of the HPGe and the LS detectors provided a highly effective rejection mechanism for non-coincident events. Thereby, the distinction between the detected 140.5 keV events originating from decays of 99mTc (IT) and those from transitions bypassing the metastable state could be obtained and the 'prompt' intensity was evaluated directly. The system was calibrated for detecting β particles and γ-rays using radioactive sources of known activities and having identical geometry as the sample containing 99Mo. The absolute intensity of the 'prompt' 140.5 keV was found to be (5.21 ± 0.02stat±0.16sys)%, in good agreement with results from more recently reported works.
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Affiliation(s)
- S Nissim
- Soreq Nuclear Research Center, Yavne, 81800, Israel; Unit of Nuclear Engineering, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - O Aviv
- Soreq Nuclear Research Center, Yavne, 81800, Israel.
| | - M Brandis
- Soreq Nuclear Research Center, Yavne, 81800, Israel
| | - L Weissman
- Soreq Nuclear Research Center, Yavne, 81800, Israel
| | - R Sasson
- Radiopharmaceutical Division, ISORAD Ltd, Yavne, 811010, Israel
| | - Z Yungrais
- Soreq Nuclear Research Center, Yavne, 81800, Israel
| | - H Datz
- Soreq Nuclear Research Center, Yavne, 81800, Israel
| | - L Arazi
- Unit of Nuclear Engineering, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
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Arazi L. Diffusing Alpha Emitters Radiation Therapy: Theoretical Modeling. Int J Radiat Oncol Biol Phys 2020. [DOI: 10.1016/j.ijrobp.2020.07.802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Abstract
Diffusing alpha-emitters radiation therapy ('DaRT') is a new cancer-treatment modality, which enables treating solid tumors by alpha particles. The treatment utilizes implantable seeds embedded with a low activity of radium-224. Each seed continuously emits the short-lived alpha-emitting daughters of radium-224, which spread over several mm around it, creating a 'kill region' of high alpha-particle dose. DaRT is presently tested in clinical trials, starting with locally advanced and recurrent squamous cell carcinoma (SCC) of the skin and head and neck, with promising results with respect to both efficacy and safety. This work aims to provide a simple model which can serve as a zero-order approximation for DaRT dosimetry, allowing for calculating the macroscopic alpha particle dose of a point source, as a basis for more realistic source geometries. The model consists of diffusion equations for radon-220, lead-212 and bismuth-212, with the other short-lived daughters in local secular equilibrium. For simplicity, the medium is assumed to be homogeneous, isotropic and time-independent. Vascular effects are accounted for by effective diffusion and clearance terms. To leading order, the alpha particle dose can be described by simple analytic expressions, which shed light on the underlying physics. The calculations demonstrate that, for a reasonable choice of model parameters, therapeutic alpha-particle dose levels are obtained over a region measuring 4-7 mm in diameter for sources carrying a few [Formula: see text]Ci of radium-224. The model predictions served as the basis for treatment planning in the SCC clinical trial, where treatments employing DaRT seeds carrying 2 [Formula: see text]Ci of radium-224 and spaced 5 mm apart resulted in ∼[Formula: see text] complete response of the treated tumors with no observed radiation-induced toxicity. The promising results of the SCC clinical trial indicate that in spite of its approximate nature, the simple diffusion-based dosimetry model provides a quantitative starting point for DaRT treatment planning.
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Affiliation(s)
- Lior Arazi
- Unit of Nuclear Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negav, POB 653 Beer-Sheva 8410501, Israel
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Popovtzer A, Rosenfeld E, Mizrachi A, Bellia SR, Ben-Hur R, Feliciani G, Sarnelli A, Arazi L, Deutsch L, Kelson I, Keisari Y. Initial Safety and Tumor Control Results From a "First-in-Human" Multicenter Prospective Trial Evaluating a Novel Alpha-Emitting Radionuclide for the Treatment of Locally Advanced Recurrent Squamous Cell Carcinomas of the Skin and Head and Neck. Int J Radiat Oncol Biol Phys 2019; 106:571-578. [PMID: 31759075 DOI: 10.1016/j.ijrobp.2019.10.048] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 10/04/2019] [Accepted: 10/21/2019] [Indexed: 11/30/2022]
Abstract
PURPOSE Our purpose was to report the feasibility and safety of diffusing alpha-emitter radiation therapy (DaRT), which entails the interstitial implantation of a novel alpha-emitting brachytherapy source, for the treatment of locally advanced and recurrent squamous cancers of the skin and head and neck. METHODS AND MATERIALS This prospective first-in-human, multicenter clinical study evaluated 31 lesions in 28 patients. The primary objective was to determine the feasibility and safety of this approach, and the secondary objectives were to evaluate the initial tumor response and local progression-free survival. Eligibility criteria included all patients with biopsy-proven squamous cancers of the skin and head and neck with either primary tumors or recurrent/previously treated disease by either surgery or prior external beam radiation therapy; 13 of 31 lesions (42%) had received prior radiation therapy. Toxicity was evaluated according to the Common Terminology Criteria for Adverse Events version 4.03. Tumor response was assessed at 30 to 45 days at a follow-up visit using the Response Evaluation Criteria in Solid Tumors, version 1.1. Median follow-up time was 6.7 months. RESULTS Acute toxicity included mostly local pain and erythema at the implantation site followed by swelling and mild skin ulceration. For pain and grade 2 skin ulcerations, 90% of patients had resolution within 3 to 5 weeks. Complete response to the Ra-224 DaRT treatment was observed in 22 lesions (22/28; 78.6%); 6 lesions (6/28, 21.4%) manifested a partial response (>30% tumor reduction). Among the 22 lesions with a complete response, 5 (22%) developed a subsequent local relapse at the site of DaRT implantation at a median time of 4.9 months (range, 2.43-5.52 months). The 1-year local progression-free survival probability at the implanted site was 44% overall (confidence interval [CI], 20.3%-64.3%) and 60% (95% CI, 28.61%-81.35%) for complete responders. Overall survival rates at 12 months post-DaRT implantation were 75% (95% CI, 46.14%-89.99%) among all patients and 93% (95% CI, 59.08%-98.96%) among complete responders. CONCLUSIONS Alpha-emitter brachytherapy using DaRT achieved significant tumor responses without grade 3 or higher toxicities observed. Longer follow-up observations and larger studies are underway to validate these findings.
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Affiliation(s)
- A Popovtzer
- Rabin Medical Center Petah Tiqva, Petah Tiqva, Israel; Tel Aviv University, Tel Aviv, Israel.
| | - E Rosenfeld
- Rabin Medical Center Petah Tiqva, Petah Tiqva, Israel
| | - A Mizrachi
- Rabin Medical Center Petah Tiqva, Petah Tiqva, Israel; Tel Aviv University, Tel Aviv, Israel
| | - S R Bellia
- Instituto Scientifico Romagnolo per Lo Studio e la Cura dei Tumori, (IRST)-IRCCS, Meldola, Italy
| | - R Ben-Hur
- Rabin Medical Center Petah Tiqva, Petah Tiqva, Israel
| | - G Feliciani
- Instituto Scientifico Romagnolo per Lo Studio e la Cura dei Tumori, (IRST)-IRCCS, Meldola, Italy
| | - A Sarnelli
- Instituto Scientifico Romagnolo per Lo Studio e la Cura dei Tumori, (IRST)-IRCCS, Meldola, Italy
| | - L Arazi
- Ben-Gurion University of the Negev, Beersheba, Israel
| | - L Deutsch
- BioStats Statistical Consult, Merkez Renanim, Maccabim Israel
| | - I Kelson
- Tel Aviv University, Tel Aviv, Israel
| | - Y Keisari
- Tel Aviv University, Tel Aviv, Israel
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Sadetskii I, Symon Z, Farkash A, Schmidt M, Magen O, Arazi L, Fleisher E, Kelson I, Keisari Y. Animal Study of Histopathology in Response to Implantation of DART (Diffusing Alpha-emitters Radiation Therapy) Seeds, a New Form of Alpha-Particle Brachytherapy Source in Normal Tissues. Int J Radiat Oncol Biol Phys 2019. [DOI: 10.1016/j.ijrobp.2019.06.566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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13
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Keisari Y, Etzyoni R, Bittan H, Lazarov E, Efrati M, Schmidt M, Cooks T, Arazi L, Kelson I. PO-0960: Radiobiological effectiveness and its role in modelling secondary cancer risk for proton therapy. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)31397-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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14
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Aprile E, Aalbers J, Agostini F, Alfonsi M, Anthony M, Arazi L, Arisaka K, Arneodo F, Balan C, Barrow P, Baudis L, Bauermeister B, Breur PA, Brown A, Brown E, Bruenner S, Bruno G, Budnik R, Bütikofer L, Cardoso JMR, Cervantes M, Coderre D, Colijn AP, Contreras H, Cussonneau JP, Decowski MP, de Perio P, Di Giovanni A, Duchovni E, Fattori S, Ferella AD, Fieguth A, Fulgione W, Gao F, Garbini M, Geis C, Goetzke LW, Grignon C, Gross E, Hampel W, Hasterok C, Itay R, Kaether F, Kaminsky B, Kessler G, Kish A, Landsman H, Lang RF, Le Calloch M, Lellouch D, Levinson L, Levy C, Lindemann S, Lindner M, Lopes JAM, Lyashenko A, Macmullin S, Marrodán Undagoitia T, Masbou J, Massoli FV, Mayani D, Melgarejo Fernandez AJ, Meng Y, Messina M, Micheneau K, Miguez B, Molinario A, Murra M, Naganoma J, Ni K, Oberlack U, Orrigo SEA, Pakarha P, Persiani R, Piastra F, Pienaar J, Plante G, Priel N, Rauch L, Reichard S, Reuter C, Rizzo A, Rosendahl S, Dos Santos JMF, Sartorelli G, Schindler S, Schreiner J, Schumann M, Scotto Lavina L, Selvi M, Shagin P, Simgen H, Teymourian A, Thers D, Tiseni A, Trinchero G, Tunnell C, Wall R, Wang H, Weber M, Weinheimer C, Zhang Y. Search for Event Rate Modulation in XENON100 Electronic Recoil Data. Phys Rev Lett 2015; 115:091302. [PMID: 26371638 DOI: 10.1103/physrevlett.115.091302] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Indexed: 06/05/2023]
Abstract
We have searched for periodic variations of the electronic recoil event rate in the (2-6) keV energy range recorded between February 2011 and March 2012 with the XENON100 detector, adding up to 224.6 live days in total. Following a detailed study to establish the stability of the detector and its background contributions during this run, we performed an unbinned profile likelihood analysis to identify any periodicity up to 500 days. We find a global significance of less than 1σ for all periods, suggesting no statistically significant modulation in the data. While the local significance for an annual modulation is 2.8σ, the analysis of a multiple-scatter control sample and the phase of the modulation disfavor a dark matter interpretation. The DAMA/LIBRA annual modulation interpreted as a dark matter signature with axial-vector coupling of weakly interacting massive particles to electrons is excluded at 4.8σ.
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Affiliation(s)
- E Aprile
- Physics Department, Columbia University, New York, New York 10027, USA
| | - J Aalbers
- Nikhef and the University of Amsterdam, Science Park, 1098XG Amsterdam, Netherlands
| | - F Agostini
- INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, 67100 L'Aquila, Italy
- Department of Physics and Astrophysics, University of Bologna and INFN-Bologna, 40126 Bologna, Italy
| | - M Alfonsi
- Nikhef and the University of Amsterdam, Science Park, 1098XG Amsterdam, Netherlands
- Institut für Physik & Exzellenzcluster PRISMA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - M Anthony
- Physics Department, Columbia University, New York, New York 10027, USA
| | - L Arazi
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - K Arisaka
- Physics & Astronomy Department, University of California, Los Angeles, California 90095, USA
| | - F Arneodo
- New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - C Balan
- Department of Physics, University of Coimbra, 3004-516, Coimbra, Portugal
| | - P Barrow
- Physik-Institut, University of Zurich, 8057 Zurich, Switzerland
| | - L Baudis
- Physik-Institut, University of Zurich, 8057 Zurich, Switzerland
| | - B Bauermeister
- Institut für Physik & Exzellenzcluster PRISMA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - P A Breur
- Nikhef and the University of Amsterdam, Science Park, 1098XG Amsterdam, Netherlands
| | - A Brown
- Nikhef and the University of Amsterdam, Science Park, 1098XG Amsterdam, Netherlands
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - E Brown
- Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
- Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
| | - S Bruenner
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - G Bruno
- INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, 67100 L'Aquila, Italy
- Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
| | - R Budnik
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - L Bütikofer
- Albert Einstein Center for Fundamental Physics, University of Bern, 3012 Bern, Switzerland
| | - J M R Cardoso
- Department of Physics, University of Coimbra, 3004-516, Coimbra, Portugal
| | - M Cervantes
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - D Coderre
- Albert Einstein Center for Fundamental Physics, University of Bern, 3012 Bern, Switzerland
| | - A P Colijn
- Nikhef and the University of Amsterdam, Science Park, 1098XG Amsterdam, Netherlands
| | - H Contreras
- Physics Department, Columbia University, New York, New York 10027, USA
| | - J P Cussonneau
- SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Université de Nantes, Nantes 44307, France
| | - M P Decowski
- Nikhef and the University of Amsterdam, Science Park, 1098XG Amsterdam, Netherlands
| | - P de Perio
- Physics Department, Columbia University, New York, New York 10027, USA
| | - A Di Giovanni
- New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - E Duchovni
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - S Fattori
- Institut für Physik & Exzellenzcluster PRISMA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - A D Ferella
- INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, 67100 L'Aquila, Italy
| | - A Fieguth
- Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
| | - W Fulgione
- INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, 67100 L'Aquila, Italy
| | - F Gao
- Department of Physics & Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - M Garbini
- Department of Physics and Astrophysics, University of Bologna and INFN-Bologna, 40126 Bologna, Italy
| | - C Geis
- Institut für Physik & Exzellenzcluster PRISMA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - L W Goetzke
- Physics Department, Columbia University, New York, New York 10027, USA
| | - C Grignon
- Institut für Physik & Exzellenzcluster PRISMA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - E Gross
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - W Hampel
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - C Hasterok
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - R Itay
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - F Kaether
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - B Kaminsky
- Albert Einstein Center for Fundamental Physics, University of Bern, 3012 Bern, Switzerland
| | - G Kessler
- Physik-Institut, University of Zurich, 8057 Zurich, Switzerland
| | - A Kish
- Physik-Institut, University of Zurich, 8057 Zurich, Switzerland
| | - H Landsman
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - R F Lang
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - M Le Calloch
- SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Université de Nantes, Nantes 44307, France
| | - D Lellouch
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - L Levinson
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - C Levy
- Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
- Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
| | - S Lindemann
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - M Lindner
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - J A M Lopes
- Department of Physics, University of Coimbra, 3004-516, Coimbra, Portugal
| | - A Lyashenko
- Physics & Astronomy Department, University of California, Los Angeles, California 90095, USA
| | - S Macmullin
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | | | - J Masbou
- SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Université de Nantes, Nantes 44307, France
| | - F V Massoli
- Department of Physics and Astrophysics, University of Bologna and INFN-Bologna, 40126 Bologna, Italy
| | - D Mayani
- Physik-Institut, University of Zurich, 8057 Zurich, Switzerland
| | | | - Y Meng
- Physics & Astronomy Department, University of California, Los Angeles, California 90095, USA
| | - M Messina
- Physics Department, Columbia University, New York, New York 10027, USA
| | - K Micheneau
- SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Université de Nantes, Nantes 44307, France
| | - B Miguez
- INFN-Torino and Osservatorio Astrofisico di Torino, 10125 Torino, Italy
| | - A Molinario
- INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, 67100 L'Aquila, Italy
| | - M Murra
- Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
| | - J Naganoma
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
| | - K Ni
- Department of Physics & Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - U Oberlack
- Institut für Physik & Exzellenzcluster PRISMA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - S E A Orrigo
- Department of Physics, University of Coimbra, 3004-516, Coimbra, Portugal
| | - P Pakarha
- Physik-Institut, University of Zurich, 8057 Zurich, Switzerland
| | - R Persiani
- Department of Physics and Astrophysics, University of Bologna and INFN-Bologna, 40126 Bologna, Italy
- SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Université de Nantes, Nantes 44307, France
| | - F Piastra
- Physik-Institut, University of Zurich, 8057 Zurich, Switzerland
| | - J Pienaar
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - G Plante
- Physics Department, Columbia University, New York, New York 10027, USA
| | - N Priel
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - L Rauch
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - S Reichard
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - C Reuter
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - A Rizzo
- Physics Department, Columbia University, New York, New York 10027, USA
| | - S Rosendahl
- Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
| | - J M F Dos Santos
- Department of Physics, University of Coimbra, 3004-516, Coimbra, Portugal
| | - G Sartorelli
- Department of Physics and Astrophysics, University of Bologna and INFN-Bologna, 40126 Bologna, Italy
| | - S Schindler
- Institut für Physik & Exzellenzcluster PRISMA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - J Schreiner
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - M Schumann
- Albert Einstein Center for Fundamental Physics, University of Bern, 3012 Bern, Switzerland
| | - L Scotto Lavina
- SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Université de Nantes, Nantes 44307, France
| | - M Selvi
- Department of Physics and Astrophysics, University of Bologna and INFN-Bologna, 40126 Bologna, Italy
| | - P Shagin
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
| | - H Simgen
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - A Teymourian
- Physics & Astronomy Department, University of California, Los Angeles, California 90095, USA
| | - D Thers
- SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Université de Nantes, Nantes 44307, France
| | - A Tiseni
- Nikhef and the University of Amsterdam, Science Park, 1098XG Amsterdam, Netherlands
| | - G Trinchero
- INFN-Torino and Osservatorio Astrofisico di Torino, 10125 Torino, Italy
| | - C Tunnell
- Nikhef and the University of Amsterdam, Science Park, 1098XG Amsterdam, Netherlands
| | - R Wall
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
| | - H Wang
- Physics & Astronomy Department, University of California, Los Angeles, California 90095, USA
| | - M Weber
- Physics Department, Columbia University, New York, New York 10027, USA
| | - C Weinheimer
- Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
| | - Y Zhang
- Physics Department, Columbia University, New York, New York 10027, USA
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Reitkopf-Brodutch S, Confino H, Schmidt M, Cooks T, Efrati M, Arazi L, Rath-Wolfson L, Marshak G, Kelson I, Keisari Y. Ablation of experimental colon cancer by intratumoral 224Radium-loaded wires is mediated by alpha particles released from atoms which spread in the tumor and can be augmented by chemotherapy. Int J Radiat Biol 2015; 91:179-86. [PMID: 25179346 DOI: 10.3109/09553002.2015.959666] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE We developed (224)Ra-loaded wires, which release by recoil alpha emitting nuclei into solid tumors and cause tumor cell killing. This research examined if the major damage was inflicted by alpha particles emitted from these atoms or by direct gamma and beta emissions from the inserted wires. We also examined the efficacy of this treatment against colon cancer in combination with chemotherapy. MATERIALS AND METHODS Mouse colon carcinomas (CT-26 xenografts), treated by intra-tumoral radioactive wires loaded with (224)Ra atoms were monitored for effects on tumor growth, intratumoral tissue damage and distribution of alpha emitting atoms. The effects were compared with those of (224)Ra-loaded wires coated with poly methyl methacrylate (PMMA), which blocks atom recoil. Similar experiments were performed with radioactive wires combined with systemic 5-FU. RESULTS (224)Ra-loaded wires inhibited tumor growth and formed necrotic areas inside the tumor. PMMA coated wires did not inhibit tumor growth, and caused minor intratumoral damage. Autoradiography images of tumors treated with (224)Ra-loaded wires revealed a spread of alpha emitters over several mm, whereas PMMA-coated wires showed no such spread. Injection of 5-FU with (224)Ra-loaded wires augmented tumor growth retardation and cure. CONCLUSIONS (224)Ra-loaded wires ablate solid tumors by the release of alpha-particle emitting atoms inside the tissue, an effect that can be enhanced by combining this method with chemotherapy.
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Affiliation(s)
- Shira Reitkopf-Brodutch
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University , Tel Aviv , Israel
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Cooks T, Tal M, Raab S, Efrati M, Reitkopf S, Lazarov E, Etzyoni R, Schmidt M, Arazi L, Kelson I, Keisari Y. Intratumoral 224Ra-loaded wires spread alpha-emitters inside solid human tumors in athymic mice achieving tumor control. Anticancer Res 2012; 32:5315-5321. [PMID: 23225432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND We developed a new method of brachytherapy, termed diffusing alpha-emitters radiation therapy (DaRT), based on the use of intratumoral (224)Ra-loaded wires, which release short-lived alpha-emitting atoms by recoil. Here, we examined their ability to destroy and control the development of several human-derived tumors implanted in athymic mice. MATERIALS AND METHODS The experiments were performed on athymic mice bearing malignant human-derived tumors including prostate (PC-3), glioblastoma (GBM, U87-MG), colon (HCT15), squamous cell carcinoma (FaDu) and melanoma (C32). One or more (224)Ra-loaded wires were inserted into the tumors, and mice were assessed for tumor growth rate and survival. RESULTS In vivo studies showed that DaRT can effectively destroy the tumors, and in vitro tests confirmed the sensitivity of the studied cells to alpha particles. While the C32 cells were relatively resistant, other tumor types (e.g. HCT15) exhibited sensitivity in both measured aspects. CONCLUSION DaRT could potentially be combined with chemotherapy or other treatment modalities to effectively treat non-resectable tumors.
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Affiliation(s)
- Tomer Cooks
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine. Tel Aviv University, Israel
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Lazarov E, Arazi L, Efrati M, Cooks T, Schmidt M, Keisari Y, Kelson I. ComparativeIn VitroMicrodosimetric Study of Murine- and Human-Derived Cancer Cells Exposed to Alpha Particles. Radiat Res 2012; 177:280-7. [DOI: 10.1667/rr2664.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Horev-Drori G, Cooks T, Bittan H, Lazarov E, Schmidt M, Arazi L, Efrati M, Kelson I, Keisari Y. Local control of experimental malignant pancreatic tumors by treatment with a combination of chemotherapy and intratumoral 224radium-loaded wires releasing alpha-emitting atoms. Transl Res 2012; 159:32-41. [PMID: 22153808 DOI: 10.1016/j.trsl.2011.08.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2011] [Revised: 08/24/2011] [Accepted: 08/27/2011] [Indexed: 12/21/2022]
Abstract
We developed (224)Ra-loaded wires that when inserted into solid tumors, release radioactive atoms that spread in the tumor and irradiate it effectively with alpha particles (diffusing alpha-emitters radiation therapy [DaRT]). In this study, we tested the ability of intratumoral (224)Ra-loaded wires to control the local growth of pancreatic tumors and the enhancement of this effect by chemotherapy. Pancreatic mouse tumors (Panc02) were treated with (224)Ra-loaded wire(s) with or without gemcitabine. The tumor size and survival were monitored, and autoradiography was performed to evaluate the spread of radioactive atoms inside the tumor. Mouse and human pancreatic cancer cells, irradiated in vitro by alpha particles with or without chemotherapy, were evaluated for cell growth inhibition. The insertion of (224)Ra-loaded wires into pancreatic tumors in combination with gemcitabine achieved significant local control and was superior to each treatment alone. A dosimetric analysis showed the spread of radioactive atoms in the tumor around the wires. Alpha particles combined with gemcitabine or 5-FU killed mouse and human cells in vitro better than each treatment alone. DaRT in combination with gemcitabine was proven effective against pancreatic tumors in vivo and in vitro, and the process may be applicable as a palliative treatment for patients with pancreatic cancer.
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Affiliation(s)
- Galit Horev-Drori
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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Arazi L, Cooks T, Schmidt M, Keisari Y, Kelson I. The treatment of solid tumors by alpha emitters released from224Ra-loaded sources—internal dosimetry analysis. Phys Med Biol 2010; 55:1203-18. [DOI: 10.1088/0031-9155/55/4/020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Keisari Y, Cooks T, Bittan H, Lazarov E, Reitkopf S, Horev G, Arazi L, Etzyoni R, Schmidt M, Kelson I. 2044 Tumor growth inhibition and necrosis following treatment of experimental solid malignant tumors by intra-tumoral Ra-224 loaded sources. EJC Suppl 2009. [DOI: 10.1016/s1359-6349(09)70560-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Cooks T, Schmidt M, Bittan H, Lazarov E, Arazi L, Kelson I, Keisari Y. Local Control of Lung Derived Tumors by Diffusing Alpha-Emitting Atoms Released From Intratumoral Wires Loaded With Radium-224. Int J Radiat Oncol Biol Phys 2009; 74:966-73. [DOI: 10.1016/j.ijrobp.2009.02.063] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2008] [Revised: 02/24/2009] [Accepted: 02/24/2009] [Indexed: 11/25/2022]
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Cooks T, Arazi L, Efrati M, Schmidt M, Marshak G, Kelson I, Keisari Y. Interstitial wires releasing diffusing alpha emitters combined with chemotherapy improved local tumor control and survival in squamous cell carcinoma-bearing mice. Cancer 2009; 115:1791-801. [PMID: 19197995 DOI: 10.1002/cncr.24191] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND The objective of this study was to examine the combined effect of diffusing alpha-emitter radiation therapy (DART) together with the chemotherapeutic agent cisplatin on tumor development. METHODS BALB/c mice bearing squamous cell carcinoma tumors were treated with radium 224 ((224)Ra-)-loaded stainless steel wires, releasing short-lived, alpha-emitting atoms from their surface. A concomitant regimen of cisplatin doses (5 mg/kg per dose) was given intravenously for the evaluation of the combined effect. Animals were monitored for tumor growth and survival. RESULTS First, the authors observed that alpha particles and cisplatin inhibited SQ2 cell proliferation in vitro and promoted apoptosis. Treatment of tumor-bearing mice indicated that, when a regimen of 2 separate doses of cisplatin was given concomitantly with a single intratumoral (224)Ra-loaded wire, there was moderate tumor growth inhibition relative to what was observed from each treatment alone. When tumors were treated with 2 radioactive wires positioned near the tumor base and a similar drug administration, the growth arrest effect intensified, and there also was a significant increase in survival rates. The combined treatment reduced both local tumor growth and metastatic spread to the lungs. CONCLUSIONS Antitumor activity and overall survival of metastatic tumor-bearing mice were improved significantly by the combined treatment. These results highlight the potential benefit of alpha radiation-based radiotherapy in combination with chemotherapeutic drugs for anticancer treatment.
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Affiliation(s)
- Tomer Cooks
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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Cooks T, Horev G, Reitkopf S, Marshak G, Arazi L, Kelson I, Keisari Y. Intratumoral 224Ra-loaded Wires Combined with Chemotherapy can Destroy Solid Malignant Tumors of Various Histological Types in Mice, and Prolong Survival. Int J Radiat Oncol Biol Phys 2008. [DOI: 10.1016/j.ijrobp.2008.06.560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Cooks T, Efrati M, Bittan H, Schmidt M, Arazi L, Kelson I, Keisari Y. Growth retardation and survival prolongation of experimental lung carcinoma by interstitial Ra-224 loaded wires releasing diffusing alpha-emitting atoms. EJC Suppl 2008. [DOI: 10.1016/s1359-6349(08)71387-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Etzyoni R, Cooks T, Tal M, Schmidt M, Arazi L, Kelson I, Keisari Y. Radiotherapy of solid malignant human tumors in athymic mice by intratumoral 224Ra-loaded wires releasing alpha emitting atoms can achieve local tumor control. EJC Suppl 2008. [DOI: 10.1016/s1359-6349(08)71394-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Cooks T, Arazi L, Schmidt M, Marshak G, Kelson I, Keisari Y. Growth retardation and destruction of experimental squamous cell carcinoma by interstitial radioactive wires releasing diffusing alpha-emitting atoms. Int J Cancer 2007; 122:1657-64. [DOI: 10.1002/ijc.23268] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
A new method utilizing alpha particles to treat solid tumors is presented. Tumors are treated with interstitial radioactive sources which continually release short-lived alpha emitting atoms from their surface. The atoms disperse inside the tumor, delivering a high dose through their alpha decays. We implement this scheme using thin wire sources impregnated with (224)Ra, which release by recoil (220)Rn, (216)Po and (212)Pb atoms. This work aims to demonstrate the feasibility of our method by measuring the activity patterns of the released radionuclides in experimental tumors. Sources carrying (224)Ra activities in the range 10-130 kBq were used in experiments on murine squamous cell carcinoma tumors. These included gamma spectroscopy of the dissected tumors and major organs, Fuji-plate autoradiography of histological tumor sections and tissue damage detection by Hematoxylin-Eosin staining. The measurements focused on (212)Pb and (212)Bi. The (220)Rn/(216)Po distribution was treated theoretically using a simple diffusion model. A simplified scheme was used to convert measured (212)Pb activities to absorbed dose estimates. Both physical and histological measurements confirmed the formation of a 5-7 mm diameter necrotic region receiving a therapeutic alpha-particle dose around the source. The necrotic regions shape closely corresponded to the measured activity patterns. (212)Pb was found to leave the tumor through the blood at a rate which decreased with tumor mass. Our results suggest that the proposed method, termed DART (diffusing alpha-emitters radiation therapy), may potentially be useful for the treatment of human patients.
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Affiliation(s)
- L Arazi
- School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
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