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Qi Y, He L, Wang Z, Liu Y, Liu H, Huo W, Xu XG, Chen Z. EVALUATION OF SECONDARY DOSE AND CANCER RISK FOR OUT-OF-FIELD ORGAN IN ESOPHAGEAL CANCER IMRT IN A CHINESE HOSPITAL USING ATOM PHANTOM MEASUREMENTS. RADIATION PROTECTION DOSIMETRY 2017; 177:389-396. [PMID: 28472430 DOI: 10.1093/rpd/ncx057] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 04/11/2017] [Indexed: 06/07/2023]
Abstract
There have been few studies on the secondary cancer after radiation treatment in Chinese hospitals. This study has measured out-of-field absorbed organ doses from intensity-modulated radiation therapy (IMRT) radiotherapy for esophageal cancer in a Chinese hospital and evaluated the risks of secondary cancer. The dose measurements were based on the thermo-luminescence dosemeter (TLD) and the ATOM® phantom, which represents an adult male. Over 100 TLD chips were placed in 35 different organ sites and one group of the same TLDs was set as background contrast. All TLDs were calibrated against the same Linac accelerator performing an IMRT plan for esophageal cancer. The measured doses were used to calculate the secondary cancer risks according to biological effects of ionizing radiation (BEIR) VII methodology. The baseline risks and survival data were based on relevant statistics for the Chinese population. It is found that the out-of-field organ doses depended greatly on the distance between organ sites and the target isocenter. The organ doses decreased exponentially as the distance from the target isocenter increased, and, for distances <15 cm, the organ doses fell off more rapidly and almost decreased by 99.55%. When compared with the calculation results by the Pinnacle treatment planning system (TPS), most of the out-of-field organ doses were underestimated in the TPS and the percentage of underestimation reached 100% for distant organs such as the bladder, prostate and testis. These trends are due to a known fact that out-of-field organs received secondary radiation resulted from patients and collimator scattering as well as leakage in the gantry head. The higher lifetime attribute risks (LARs) per 100 000 population were in the lower esophagus (186) and lungs (93.2) near the target. But all LARs of considered organs were found to be less than the baseline cancer risks. Results in this article can help to provide a database about the effect of radiotherapy-induced secondary cancer incidence during esophageal cancer treatment in China.
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Affiliation(s)
- Yaping Qi
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui Province, PR China
| | - Lijuan He
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui Province, PR China
| | - Zhi Wang
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui Province, PR China
- Department of Radiation Oncology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, PR China
| | - Yuanyuan Liu
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui Province, PR China
| | - Hongdong Liu
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui Province, PR China
| | - Wanli Huo
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui Province, PR China
| | - X George Xu
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui Province, PR China
- Nuclear Engineering Program, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Zhi Chen
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui Province, PR China
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