宫颈癌腔内放射治疗的光子运输

Photon transport in pelvic radiotherapy for cervical cancer

子宫颈癌是我国常见的妇科恶性肿瘤之一,每年新发病例为13万左右,对妇女健康构成严重的威胁。目前临床治疗宫颈癌仍是行手术、放疗、化疗三者综合治疗,放疗扮演着重要的角色。只有提高放疗水平,才能提高患者的生存率,而准确的放疗剂量资料,来源于直接测量。由于女姓盆腔及周围组织的解剖学结构复杂,在实施放射测量过程中需要一系列测量设备、实验技术、照射参数等等,测量成本高,工作程序繁琐。本工作采用随机光子跟踪模拟方法,进行宫颈癌腔内放射治疗时组织中光子通量的计算,简单、灵活、准确、受条件影响不大,对复杂的女性盆腔结构、组织参数随能量的剧烈变化及散射各向异性均能很好地处理,值得推广。

At present clinical treatment of cervical cancer combines surgical intervention, radiotherapy and chemotherapy. Optimal doses in radiotherapy help improve survival of the patients, but the decision on such dose has to originate from direct measurement. Due to the complexity in the anatomic structure of female pelvic cavity and the adjacent tissues, quite an array of measure ment equipments, experimental techniques and radiation parameters have to be employed or determined during radiation measurements, which adds to the complexity of measurement as well as the costs. In this article, the author introduces random photon tracing simulation method to compute tissue photon flux during pelvic radiotherapy for cervical cancer. Besides the simplicity, flexibility and accuracy, this method also lessens the influences by the conditions of and is well adapted to complicated structure of the female pelvic cavity, drastic changes in tissue parameters, and anisotropic scattering.