Affiliations 

  • 1 Sunway University, School of Healthcare and Health Sciences, Centre for Biomedical Physics, No. 5, Jalan Universiti, Bandar Sunway, Petaling Jaya, Selangor, Malaysia
  • 2 Department of Basic Medical Sciences for Radiation Damages; National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba, Japan
  • 3 Radiation Effect Research Team, Department of Accelerator and Medical Physics, NIRS, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba, Japan
  • 4 Heavy-Ion Radiotherapy Promotion Unit & Department of Accelerator and Medical Physics, NIRS, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba, Japan
  • 5 Gray Laboratory, CRUK/MRC Oxford, Oncology Institute, University of Oxford, ORCRB-Roosevelt Drive, Oxford, UK
  • 6 Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, UK
J Radiat Res, 2019 Mar 01;60(2):178-188.
PMID: 30624699 DOI: 10.1093/jrr/rry099

Abstract

The effects of the charged ion species 4He, 12C and 20Ne on glioblastoma multiforme (GBM) T98G, U87 and LN18 cell lines were compared with the effects of 200 kVp X-rays (1.7 keV/μm). These cell lines have different genetic profiles. Individual GBM relative biological effectiveness (RBE) was estimated in two ways: the RBE10 at 10% survival fraction and the RBE2Gy after 2 Gy doses. The linear quadratic model radiosensitivity parameters α and β and the α/β ratio of each ion type were determined as a function of LET. Mono-energetic 4He, 12C and 20Ne ions were generated by the Heavy Ion Medical Accelerator at the National Institute of Radiological Sciences in Chiba, Japan. Colony-formation assays were used to evaluate the survival fractions. The LET of the various ions used ranged from 2.3 to 100 keV/μm (covering the depth-dose plateau region to clinically relevant LET at the Bragg peak). For U87 and LN18, the RBE10 increased with LET and peaked at 85 keV/μm, whereas T98G peaked at 100 keV/μm. All three GBM α parameters peaked at 100 keV/μm. There is a statistically significant difference between the three GBM RBE10 values, except at 100 keV/μm (P < 0.01), and a statistically significant difference between the α values of the GBM cell lines, except at 85 and 100 keV/μm. The biological response varied depending on the GBM cell lines and on the ions used.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.