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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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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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Vatarescu M, Bechor S, Haim Y, Pecht T, Tarnovscki T, Slutsky N, Nov O, Shapiro H, Shemesh A, Porgador A, Bashan N, Rudich A. Adipose tissue supports normalization of macrophage and liver lipid handling in obesity reversal. J Endocrinol 2017; 233:293-305. [PMID: 28360082 PMCID: PMC5457504 DOI: 10.1530/joe-17-0007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 03/30/2017] [Indexed: 12/21/2022]
Abstract
Adipose tissue inflammation and dysfunction are considered central in the pathogenesis of obesity-related dysmetabolism, but their role in the rapid metabolic recovery upon obesity reversal is less well defined. We hypothesized that changes in adipose tissue endocrine and paracrine mechanisms may support the rapid improvement of obesity-induced impairment in cellular lipid handling. C57Bl-6J mice were fed ad libitum either normal chow (NC) or high-fat diet (HFF) for 10 weeks. A dietary obesity reversal group was fed HFF for 8 weeks and then switched to NC for 2 weeks (HFF→NC). Whole-body glucose homeostasis rapidly nearly normalized in the HFF→NC mice (fasting glucose and insulin fully normalized, glucose and insulin tolerance tests reversed 82% to the NC group levels). During 2 weeks of the dietary reversal, the liver was significantly cleared from ectopic fat, and functionally, glucose production from pyruvate, alanine or fructose was normalized. In contrast, adipose tissue inflammation (macrophage infiltration and polarization) largely remained as in HFF, though obesity-induced adipose tissue macrophage lipid accumulation decreased by ~50%, and adipose tissue MAP kinase hyperactivation was reversed. Ex vivo, mild changes in adipose tissue adipocytokine secretion profile were noted. These corresponded to partial or full reversal of the excess cellular lipid droplet accumulation induced by HFF adipose tissue conditioned media in hepatoma or macrophage cells, respectively. We propose that early after initiating reversal of nutritional obesity, rapid metabolic normalization largely precedes resolution of adipose tissue inflammation. Nevertheless, we demonstrate a hitherto unrecognized contribution of adipose tissue to the rapid improvement in lipid handling by the liver and by macrophages.
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Affiliation(s)
- Maayan Vatarescu
- The Department of Clinical Biochemistry and PharmacologyFaculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- The National Institute of Biotechnology in the Negev (NIBN)Ben-Gurion University, Beer-Sheva, Israel
| | - Sapir Bechor
- The Department of Clinical Biochemistry and PharmacologyFaculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- The National Institute of Biotechnology in the Negev (NIBN)Ben-Gurion University, Beer-Sheva, Israel
| | - Yulia Haim
- The Department of Clinical Biochemistry and PharmacologyFaculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- The National Institute of Biotechnology in the Negev (NIBN)Ben-Gurion University, Beer-Sheva, Israel
| | - Tal Pecht
- The Department of Clinical Biochemistry and PharmacologyFaculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- The National Institute of Biotechnology in the Negev (NIBN)Ben-Gurion University, Beer-Sheva, Israel
| | - Tanya Tarnovscki
- The Department of Clinical Biochemistry and PharmacologyFaculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Noa Slutsky
- The Department of Clinical Biochemistry and PharmacologyFaculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ori Nov
- The Department of Clinical Biochemistry and PharmacologyFaculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Hagit Shapiro
- The Department of Clinical Biochemistry and PharmacologyFaculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Avishai Shemesh
- The Shraga Segal Department of MicrobiologyImmunology and Genetics, Ben-Gurion University, Beer-Sheva, Israel
| | - Angel Porgador
- The Shraga Segal Department of MicrobiologyImmunology and Genetics, Ben-Gurion University, Beer-Sheva, Israel
| | - Nava Bashan
- The Department of Clinical Biochemistry and PharmacologyFaculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Assaf Rudich
- The Department of Clinical Biochemistry and PharmacologyFaculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- The National Institute of Biotechnology in the Negev (NIBN)Ben-Gurion University, Beer-Sheva, Israel
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