恶性肿瘤调强适形放射治疗质量保证的研究

目的：探讨调强适形放射治疗的质量保证方法。方法：用CMS放射治疗计划系统设计调强适形放射治疗计划。采用CT模拟的方法验证射野等中心位置，比较各照射野实际胶片调强图与治疗计划系统得到的相应照射野的测强图的一致性，采用多通道剂量仪验证多点绝对剂量。结果：射野等中心位置误差在3mm以内。各射束垂直方向测得的调强图与计划系统计算的调强图一致。等中心点实测剂量与计划剂量的误差在3％以内，其余偏离点的实测剂量与计划剂最误差在5％以内。近期疗效为完全缓解（CR）58．8％（10／17），部分缓解（PR）17．6％（3／17），无变化（NR）23．5％（4／17），总有效率（CR＋PR）为76．5％（13／17），所有17例患者均能耐受放射治疗，按计划完成调强透形放射治疗。结论：上述质量保证措施切实可行。调强适形放射治疗对恶性肿瘤有较好的近期疗效。

Clinical Effects and Quality Assurance of Intensity Modulated Radiation Therapy for Carcinoma

Objective: To study the quality assurance of intensity modulated radiation therapy(IMRT) for carcinoma.Method: CMS radiation therapy planning system was used to provide optimized IMRT treatment plans for carcinoma.The center point position of each beam was measured by CT simulation.The actual film intensity map of each beam was compared with that predicted by planning.The MOSFET dosimetry was used to measure the center point dose and another eccentric point dose.Results: The error of center point position of each beam was less than 3mm.The intensity map measured by the film was well consistent with that predicted by the planning.The errors between the measured dose and predicted dose in the central point were less than 3%,whereas the errors in another eccentric point were less than 5%.The complete response rate was 58.8%(10/17),the part response rate was 17.6%(3/17),the no response rate was 23.5%(4/17),the overall response rate(CR+PR) was 76.5%(13/17).All of the 17 patients tolerated IMRT and completed the radiotherapy planning.Conclusions: The procedures for quality assurance of IMRT are feasible in our experience.IMRT can be considered as an effective approach to treat carcinoma.