Abstract：Objective To study Monte Carlo simulation to guide the dose optimization of intra-operative radiotherapy (IORT) for breast cancer, and evaluating its effects of clinical application. Methods The MCBEAM program of MCTP is used to establish the model of the accelerator using for breast cancer patients′ IORP. The preoperative CT images are edited to intra-operative states using independent developed editor, then determing the target at the intra-operative states and setting equivalent material and lead of different thicknesses in front of and behind the target. Calculating with the MCSIM program to get the optimal combination of the equivalent material and lead. There are 23 patients who accepted IORT with the optical combination of themselves, and the situations of wounds healing, reactions of radiotherapy, cosmetic effects and the recurrence of cancer are observed. Results By adding 2-3 mm equivalent material in front of the target and 5 mm equivalent material and 2 mm lead behind the target, the 90% isodose curve almost wraps around the target volume;and the V90>90% and the V110<4%. The average dose of lung is less than 1 Gy. The 23 patients′ wounds healed well, and there are no wounds′ infection and radiotherapy reaction;after the healing of wounds and half a year after the operation, the excellent rate of breasts′ appearance is over 80%, and no tumor recurrence was found. Conclusions The method of MC guided dose optimization of IORT for breast cancer is reliable, the dose distribution of target volume is uniform. There were no adverse reactions to radiotherapy and the cosmetic effect is satisfying. This method is well worthy of clinical popularizing.
Yang Bo*,Wang Zhenwu,Kong Xudong et al. Monte carlo simulation based dose optimization of intra-operative radiotherapy for breast cancer and its clinical application[J]. Chinese Journal of Radiation Oncology, 2015, 24(3): 310-313.
[1] Veronesi U, Orecchia R, Luini A,et al. Intraoperative radiotherapy during breast conserving surgery:a study on 1,822 cases treated with electrons[J]. Breast Cancer Res Treat,2010,124(1):141-151.DOI:10.1007/s10549-010-1115-5. [2] Holmes DR, Baum M, Joseph D. The TARGIT trial:targeted intraoperative radiation therapy versus conventional postoperative whole-breast radiotherapy after breast conserving surgery for the management of early-stage invasive breast cancer (a trial up-date)[J]. Am J Surg,2007,194(4):507-510. [3] 章青,傅深.乳腺癌的术中放疗[J].中国癌症杂志,2013,23(8):590-595.DOI:10.3969/j.issn.1007-3969.2013.08.005. [4] Vaidya JS, Josepo DJ, Tobias JS,et al. Targeted intraoperative radiotherapy versus whole breast radiotherapy for breast cancer (TARGIT-A trial):an international, prospective, randomized, non-inferiority phase 3 trial[J]. Lancet,2010,376(9735):91-102.DOI:10.1016/S0140-6736(10)60837-9. [5] 张绍刚,王连元,田丽红.术中放疗的吸收剂量测算方法的研究[J].中华放射医学与防护杂志,2001,21(5):371-374. [6] 孙春雷,周士福,时伟锋,等.保乳手术术中电子线照射的近期效果[J].江苏医药,2010,36(18):2173-2175. [7] 赵于天,周士福,杨波,等.乳腺癌保乳手术加术中放疗32例临床观察[J].实用临床医药杂志,2011,15(19):73-75.DOI:10.3969/j.issn.1672-2353.2011.19.023. [8] Ahnesjo A, Aspradakis MM. Dose calculations for external photon beams in radiotherapy[J]. Phys Med Biol,1999,44(11):99-155. [9] Kuerer HM, Julian TB, Strom EA,et al. Accelerated partial breast irradiation after conservative surgery for breast cancer[J]. Ann Surg,2004,239(3):338-351. [10] Veronesi U, Orecchia R, Luini A,et al. Full-dose intraoperative radiotherapy with electrons during breast conserving surgery:experience with 590 Cases[J]. Ann Surg,2005,242(1):101-106. [11] Lemanski C, Azria D, Gourgon-Bourgade S,et al. 1ntraoperative radiotherapy in early-stage breast cancer:results of the montpellier phase Ⅱ trial[J]. Int J Radiat Oncol Biol Phys,2010,76(3):698-703.DOI:10.1016/j.ijrobp.2009.02.039. [12] Veronesi U, Orrechia R, Luini A, et al. A preliminary report of intraoperative radiotherapy IORT in limited stage breast cancers that are conservatively treated[J]. Eur J Cancer,2001,37(17):2178-2183. [13] Kraus-Tiefenbacher U, Schfda A, Steil V,et al. Intraoperative radiotherapy (IORT) for breast cancer using the intrabeam system[J].Tumori,2005,91(4):339-345. [14] Bernard D, Chu JC, Rozenfeld M,et al. Design optimization of intraoperative radiotherapy cones[J]. Inter J Radiat Oncol Biol Phys,2005,55(5):1446-1457. [15] Report of the AAPM Task Group No.105. Issues associated with clinical implementation of Monte Carlo-based photon and electron external beam treatment planning[J].Med Phys,2007,34(12):4818-4853. [16] 李士骏.电离辐射剂量学基础[M].苏州:苏州大学出版社,2010. [17] 俞伟,鞠忠建,李席如,等.早期乳腺癌保乳手术联合术中放疗临床分析[J].军医进修学院学报,2010,31(9):874-876.
2015, Vol. 24 
