DIFFERENCE IN DEGREE OF SUB-LETHAL DAMAGE RECOVERY BETWEEN CLINICAL PROTON BEAMS AND X-RAYS

Yoshitaka Matsumoto; Koichi Ando; Takamitsu A Kato; Yuta Sekino; Hitoshi Ishikawa; Takeji Sakae; Koji Tsuboi; Hideyuki Sakurai

doi:10.1093/rpd/ncy270

DIFFERENCE IN DEGREE OF SUB-LETHAL DAMAGE RECOVERY BETWEEN CLINICAL PROTON BEAMS AND X-RAYS

Radiat Prot Dosimetry. 2019 May 1;183(1-2):93-97. doi: 10.1093/rpd/ncy270.

Authors

Yoshitaka Matsumoto^{1

2}, Koichi Ando³, Takamitsu A Kato⁴, Yuta Sekino^{1

2}, Hitoshi Ishikawa^{1

2}, Takeji Sakae^{1

2}, Koji Tsuboi^{1

2}, Hideyuki Sakurai^{1

2}

Affiliations

¹ Radiation Oncology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan.
² Radiation Biology, Proton Medical Research Center, University of Tsukuba Hospital, 2-1-1 Amakubo, Tsukuba, Ibaraki, Japan.
³ Medicine & Biology Division, Heavy Ion Medical Center, Gunma University, 3-39-22 Showa-machi, Maebashi, Gunma, Japan.
⁴ Radiation Cancer Biology and Oncology, Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA.

PMID: 30576477
DOI: 10.1093/rpd/ncy270

Abstract

Fractionated proton beam radiotherapy is spreading worldwide these days. However, biological data of sub-lethal damage recovery (SLDR) after proton irradiation is not known yet. We here conducted split-dose experiments (20-360 min intervals) to clarify SLDR kinetics, and also compared the kinetics between cells with different repairability of DNA double-strand breaks. CHO and 51D1 cell lines but not V3 cell line showed significant SLDR, which reached plateau in 4-6 h. The recovery rates and recovery halftime of SLDR after X-rays were significantly higher and shorter than proton beams for CHO and 51D1 cells, respectively. Additionally, the frequency of remaining gamma-H2AX foci after two fractions was remarkably higher for X-rays than proton beams. These data suggest that there is a difference between proton beam and X-rays in SLDR and the retained DNA double-strand breaks after split-dose irradiation.

MeSH terms

Animals
Cell Survival / radiation effects
Cells, Cultured
Cricetulus
DNA Breaks, Double-Stranded / radiation effects*
DNA Repair / physiology*
Dose-Response Relationship, Radiation
Immunohistochemistry
In Vitro Techniques
Kinetics
Linear Energy Transfer
Microscopy, Fluorescence
Proton Therapy*
Relative Biological Effectiveness
X-Rays