复发性直肠癌CT引导^(125)I粒子植入的剂量学验证

Dosimetric Verification of CT-guided ^(125)I Seed Implant ation in Recurrent Rectal Cancer

[目的]探讨复发性直肠癌CT引导125I粒子植入的剂量分布。[方法]选择10例接受CT引导125I粒子植入的复发性直肠癌患者。计划靶区D90(90%体积接受的剂量)为100Gy。CT引导进针和植入粒子,粒子针间距1cm,平行排列,粒子间隔1cm均匀植入。术后即刻行CT扫描和剂量学验证。[结果]计划靶区平均体积为101cc,平均植入粒子80颗,单颗粒子活度为0.5～0.8mCi。计划靶区平均植入粒子活度0.69mCi/cc。平均D90为91.5Gy,平均V100(计划靶区接受100%处方剂量的体积百分比)为85.5%。平均V150和V200分别是68.9%和52.1%,平均最小周边剂量是38.5Gy。[结论]复发性直肠癌CT引导125I粒子植入可以实现预期的剂量分布。均匀植入粒子靶区剂量不均匀,部分患者因骨骼和危及器官限制,靶区周边剂量偏低。

[Purpose] To investigate dose distribution in recurrent rectal cancer patients treated with CT-guided 125I seed implantation. [Methods] Ten recurrent rectal cancer patients treated with CT-guided 125I seed implant atron were enrolled in this study. D90 (the dose received by 90% of the target) for planning target volume (PTV) was 100 Gy. Implanted needles were inserted with the interval of 1cm and in parallel to each other under CT guidance. The seeds were implanted 1cm center to center uniformly. Postimplan...