Yasuo Takiguchi1, Tadaaki Miyamoto, Keiichi Nagao, Takayuki Kuriyama. 1. Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, Anagawa, 4-9-1, Inage-ku, Chiba, 263-8555, Japan. takiguchiyasuo@yahoo.co.jp
Abstract
PURPOSE: The aim of this study was to assess the radiosensitivities and homogeneous efficacy in the spread-out Bragg peak (SOBP) for lung cancer cell lines exposed to carbon ions. MATERIALS AND METHODS: The dose-dependent survival rates of seven cell lines exposed to carbon ions, fast neutrons, and photons were obtained using colony-forming assays in vitro. The relative biological effectiveness (RBE) of carbon ions and fast neutrons to photons was determined by comparing the doses at the 10% and 1% survival levels. RESULTS: The RBEs at 13, 40, 50, and 80 keV/microm were 1.20-1.29, 1.55-1.80, 1.57-2.00, and 1.69-2.58, respectively, at the 10% survival level. The RBE of 290 MeV carbon ions increased with increasing linear energy transfer. The biological dose (relative physical dose x RBE) distributions in the SOBP did not statistically differ at the proximal, mid, or distal points at the 10% (p = 0.945) and 1% (p = 0.211) survival levels, respectively; however, deviation of the biological dose at 10% and 1% survival were 3%-16% and 6%-24%, respectively. Furthermore, 290 MeV carbon ions at 80 keV/microm in the SOBP were nearly equivalent to 30 MeV fast neutrons. CONCLUSION: Our results demonstrate nearly homogeneous effectiveness in the SOBP, although we are aware of the deviation in some cell lines.
PURPOSE: The aim of this study was to assess the radiosensitivities and homogeneous efficacy in the spread-out Bragg peak (SOBP) for lung cancer cell lines exposed to carbon ions. MATERIALS AND METHODS: The dose-dependent survival rates of seven cell lines exposed to carbon ions, fast neutrons, and photons were obtained using colony-forming assays in vitro. The relative biological effectiveness (RBE) of carbon ions and fast neutrons to photons was determined by comparing the doses at the 10% and 1% survival levels. RESULTS: The RBEs at 13, 40, 50, and 80 keV/microm were 1.20-1.29, 1.55-1.80, 1.57-2.00, and 1.69-2.58, respectively, at the 10% survival level. The RBE of 290 MeV carbon ions increased with increasing linear energy transfer. The biological dose (relative physical dose x RBE) distributions in the SOBP did not statistically differ at the proximal, mid, or distal points at the 10% (p = 0.945) and 1% (p = 0.211) survival levels, respectively; however, deviation of the biological dose at 10% and 1% survival were 3%-16% and 6%-24%, respectively. Furthermore, 290 MeV carbon ions at 80 keV/microm in the SOBP were nearly equivalent to 30 MeV fast neutrons. CONCLUSION: Our results demonstrate nearly homogeneous effectiveness in the SOBP, although we are aware of the deviation in some cell lines.
Authors: S B Curtis; W A Schilling; T S Tenforde; K E Crabtree; S D Tenforde; J Howard; J T Lyman Journal: Radiat Res Date: 1982-05 Impact factor: 2.841
Authors: G Stewart; T W Griffin; B R Griffin; G Laramore; K J Russell; R G Parker; M N Maor; L W Davis Journal: Am J Clin Oncol Date: 1989-08 Impact factor: 2.339
Authors: Shubhankar Suman; Kamal Datta; Daniela Trani; Evagelia C Laiakis; Steven J Strawn; Albert J Fornace Journal: Radiat Environ Biophys Date: 2012-05-05 Impact factor: 1.925