Taku Inaniwa1, Masao Suzuki2, Shinji Sato1, Akira Noda1, Yoshiyuki Iwata1, Nobuyuki Kanematsu3, Toshiyuki Shirai1, Koji Noda4. 1. a Department of Accelerator and Medical Physics , National Institute of Radiological Sciences , Chiba , Japan. 2. b Department of Basic Medical Sciences for Radiation Damages , National Institute of Radiological Sciences , Chiba , Japan. 3. c Medical Physics Section, National Institute of Radiological Sciences , Chiba , Japan. 4. d National Institute of Radiological Sciences , Chiba , Japan.
Abstract
Purpose: A magnetic field longitudinal to an ion beam will potentially affect the biological effectiveness of the radiation. The purpose of this study is to experimentally verify the significance of such effects. Methods and materials: Human cancer and normal cell lines were exposed to low (12 keV/μm) and high (50 keV/μm) linear energy transfer (LET) carbon-ion beams under the longitudinal magnetic fields of B// = 0, 0.1, 0.2, 0.3, or 0.6 T generated by a solenoid magnet. The effects of the magnetic fields on the biological effectiveness were evaluated by clonogenic cell survival. Doses that would result in a survival fraction of 10% (D10s) were determined for each cell line and magnetic field. Results: For cancer cells exposed to the low (high)-LET beams, D10 decreased from 5.2 (3.1) Gy at 0 T to 4.3 (2.4) Gy at 0.1 T, while no further decrease in D10 was observed for higher magnetic fields. For normal cells, decreases in D10 of comparable magnitudes were observed by applying the magnetic fields. Conclusions: Significant decreases in D10, i.e. significant enhancements of the biological effectiveness, were observed in both cancer and normal cells by applying longitudinal magnetic fields of B// ≥ 0.1 T. These effects were enhanced with LET. Further studies are required to figure out the mechanism underlying the observed results.
Purpose: A magnetic field longitudinal to an ion beam will potentially affect the biological effectiveness of the radiation. The purpose of this study is to experimentally verify the significance of such effects. Methods and materials: Humancancer and normal cell lines were exposed to low (12 keV/μm) and high (50 keV/μm) linear energy transfer (LET) carbon-ion beams under the longitudinal magnetic fields of B// = 0, 0.1, 0.2, 0.3, or 0.6 T generated by a solenoid magnet. The effects of the magnetic fields on the biological effectiveness were evaluated by clonogenic cell survival. Doses that would result in a survival fraction of 10% (D10s) were determined for each cell line and magnetic field. Results: For cancer cells exposed to the low (high)-LET beams, D10 decreased from 5.2 (3.1) Gy at 0 T to 4.3 (2.4) Gy at 0.1 T, while no further decrease in D10 was observed for higher magnetic fields. For normal cells, decreases in D10 of comparable magnitudes were observed by applying the magnetic fields. Conclusions: Significant decreases in D10, i.e. significant enhancements of the biological effectiveness, were observed in both cancer and normal cells by applying longitudinal magnetic fields of B// ≥ 0.1 T. These effects were enhanced with LET. Further studies are required to figure out the mechanism underlying the observed results.
Entities:
Keywords:
Longitudinal magnetic field; biological effectiveness; carbon-ion radiotherapy
Authors: B Yudhistiara; K J Weber; P E Huber; A Ruehle; S Brons; P Haering; J Debus; H Hauswald Journal: Cancer Manag Res Date: 2019-09-12 Impact factor: 3.989
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Authors: Vincenzo Patera; Yolanda Prezado; Faical Azaiez; Giuseppe Battistoni; Diego Bettoni; Sytze Brandenburg; Aleksandr Bugay; Giacomo Cuttone; Denis Dauvergne; Gilles de France; Christian Graeff; Thomas Haberer; Taku Inaniwa; Sebastien Incerti; Elena Nasonova; Alahari Navin; Marco Pullia; Sandro Rossi; Charlot Vandevoorde; Marco Durante Journal: Front Phys Date: 2020-10-16