光子刀治疗恶性肿瘤207例临床研究

Photo knife for cancer:an study of 207 patients

目的:观察分析光子刀在肿瘤放疗中的应用情况及技术特点,以进一步指导临床实践。方法:总结207例光子刀治疗的恶性肿瘤患者的靶区部位、治疗方针、治疗计划设计(计划靶体积、剂量分割、照射方式)、实施方法及不良反应。结果:照射部位:头颈部49例、体部158例。靶区分布前三位分别是:肺(24.6%)、颅脑(14.5%)和肝(13.5%)。治疗方针:单纯放疗190例(根治103例、姑息87例)和缩野推量17例。治疗计划:计划靶体积(PTV):1～246.5cm3,中位值66.7cm3。射野数目:2～11个,中位数目6个。照射剂量:单次分割剂量1.2～9.56Gy,中位剂量6Gy;总量12～70Gy,中位剂量48Gy。分割方式:每周5次190例,每周(5次17例;分割次数:3～30次,中位数9次。不良反应:全组共发生16例1～2级放射不良反应(RTOG/EORCT标准),占7.7%,无3级以上不良反应发生。结论:高精度、高剂量、高疗效和低损伤是光子刀治疗的临床优势,"小而精"的剂量学特点是优势形成的关键因素,推荐计划靶体积(PTV)≤216cm3,临床以单放和常规分割照射为主的方式较为常用且安全,应用范围广并可望成为胰腺癌新的治疗选择,但摆位误差等问题亟待解决。

Objective：In order to further improve the clinical project the clinical application and technical character of photon knife in cancer treatment was observed and analyzed. Methods：The target position, treatment choice and planning （target volume,dose and fractionation） , implementation and side-effect of 207 patients suffered from different cancers treated by photon knife were summarized. Results：Irradiation position： head and neck 49 ,body 158. The first three target position were lung （24. 6% ） , encephalocoele （14. 5% ） and liver （13.5%） respectively, radiotherapy alone 190（radical 103, palliative 87）, and 17 cases as boost. Dose-fraction： single dose 1.2-9. 56Gy, median 6Gy; total dose： 12-70Gy, median 48Gy; dose fractionation： 5/W for 190, 〈 5/W for 17; fraction ：3-30, median 9 ; irradiation fields 2-11, median 6 ; planning target volume （PTV） ： 1-246cm^3 , median 66. 7cm^3 ; side-effect ： 1-2 grade side-effect of radiation（RTOG/EORTC） was found in 16 cases（7.7% ） , without any side-effect over 3 grade in total cases. Conclusion ：The clinical advantage of Photon knife are being more accuracy ,dosage and effect but less damage. The dosage character of ＂small and accuracy＂ is the key factor and PTV ≤216cm^3 is recommended. The application of radiation alone and 5/W fraction is usual and safe. The photon knife can be used widely in clinical and would even become a new choice for pancreatic carcinoma, but the error of position setting should be solved.