PMID- 34203882
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20240402
IS  - 2072-6694 (Print)
IS  - 2072-6694 (Electronic)
IS  - 2072-6694 (Linking)
VI  - 13
IP  - 12
DP  - 2021 Jun 15
TI  - Impact of Hypoxia on Relative Biological Effectiveness and Oxygen Enhancement 
      Ratio for a 62-MeV Therapeutic Proton Beam.
LID - 10.3390/cancers13122997 [doi]
LID - 2997
AB  - This study uses the yields of double-strand breaks (DSBs) to determine the 
      relative biological effectiveness (RBE) of proton beams, using cell survival as a 
      biological endpoint. DSB induction is determined when cells locate at different 
      depths (6 positions) along the track of 62 MeV proton beams. The DNA damage 
      yields are estimated using Monte Carlo Damage Simulation (MCDS) software. The 
      repair outcomes are estimated using Monte Carlo excision repair (MCER) 
      simulations. The RBE for cell survival at different oxygen concentrations is 
      calculated using the repair-misrepair-fixation (RMF) model. Using (60)Co gamma-rays 
      (linear energy transfer (LET) = 2.4 keV/mum) as the reference radiation, the RBE 
      for DSB induction and enzymatic DSB under aerobic condition (21% O(2)) are in the 
      range 1.0-1.5 and 1.0-1.6 along the track depth, respectively. In accord with RBE 
      obtained from experimental data, RMF model-derived RBE values for cell survival 
      are in the range of 1.0-3.0. The oxygen enhancement ratio (OER) for cell survival 
      (10%) decreases from 3.0 to 2.5 as LET increases from 1.1 to 22.6 keV/mum. The RBE 
      values for severe hypoxia (0.1% O(2)) are in the range of 1.1-4.4 as LET 
      increases, indicating greater contributions of direct effects for protons. 
      Compared with photon therapy, the overall effect of 62 MeV proton beams results 
      in greater cell death and is further intensified under hypoxic conditions.
FAU - Chan, Chun-Chieh
AU  - Chan CC
AUID- ORCID: 0000-0002-1156-9791
AD  - Department of Electrical Engineering, National Chung Hsing University, Taichung 
      40227, Taiwan.
FAU - Chen, Fang-Hsin
AU  - Chen FH
AUID- ORCID: 0000-0002-1671-4863
AD  - Department of Medical Imaging and Radiological Sciences, Chang Gung University, 
      Taoyuan 33302, Taiwan.
AD  - Radiation Biology Research Center, Institute for Radiological Research, Chang 
      Gung University, Taoyuan 33302, Taiwan.
AD  - Department of Radiation Oncology, Chang Gung Memorial Hospital-Linkou Branch, 
      Taoyuan 33305, Taiwan.
FAU - Hsiao, Ya-Yun
AU  - Hsiao YY
AUID- ORCID: 0000-0001-7494-8767
AD  - Department of Radiology, Chung Shan Medical University Hospital, Taichung 40201, 
      Taiwan.
AD  - Department of Medical Imaging and Radiological Sciences, Chung Shan Medical 
      University, Taichung 40201, Taiwan.
LA  - eng
GR  - CSMU-INT-109-08/Chung Shan Medical University/
GR  - CMRPD1H0473/Chang Gung Memorial Hospital, Linkou/
GR  - 109-2314-B-182-078-MY3/Ministry of Sciences and Technology, Taiwan/
GR  - 109-2628-B-182-008/Ministry of Sciences and Technology, Taiwan/
PT  - Journal Article
DEP - 20210615
PL  - Switzerland
TA  - Cancers (Basel)
JT  - Cancers
JID - 101526829
PMC - PMC8232608
OTO - NOTNLM
OT  - cell survival
OT  - double strand break
OT  - enzymatic double strand break
OT  - hypoxia
OT  - relative biological effectiveness
COIS- The authors report no conflict of interest. The authors alone are responsible for 
      the content and writing of the paper.
EDAT- 2021/07/03 06:00
MHDA- 2021/07/03 06:01
PMCR- 2021/06/15
CRDT- 2021/07/02 01:18
PHST- 2021/04/27 00:00 [received]
PHST- 2021/06/07 00:00 [revised]
PHST- 2021/06/09 00:00 [accepted]
PHST- 2021/07/02 01:18 [entrez]
PHST- 2021/07/03 06:00 [pubmed]
PHST- 2021/07/03 06:01 [medline]
PHST- 2021/06/15 00:00 [pmc-release]
AID - cancers13122997 [pii]
AID - cancers-13-02997 [pii]
AID - 10.3390/cancers13122997 [doi]
PST - epublish
SO  - Cancers (Basel). 2021 Jun 15;13(12):2997. doi: 10.3390/cancers13122997.