晚近的研究显示,给予前列腺癌较高的放射剂量疗效较好。但如果采用手工制定三维治疗计划,肿瘤剂量达81Gy时,已超过周围组织的耐受剂量,限制了肿瘤剂量的提高。作者采用一组逆向治疗计划(inverse planing)参数以求制定出更满意的治疗方案。 作者从以前用野视图(Beam’s eye view)计划,接受剂量达81Gy的46例病人中,挑选出6例病人换用逆向放疗计划系统重新设计,并将两种方法进行比较。①野视图(BEV)方法:病人俯卧,用6野照射(2个前斜、2个后斜、2个侧野),前列腺、精囊72Gy,用手调BEV显示模型,调节多叶光栅形成适形的靶体积,随后只加量照射前列腺9Gy,并用2个60°楔形板后野取代2个前斜野,以提高剂量的均匀性,并调节准直器孔径以避开直肠壁。②自动逆向计划系统的计算机优化方案:采用Bortfeld创造的优 Recent studies have shown that giving higher doses of radiation to prostate cancer is better. However, if a three-dimensional treatment plan is manually formulated, when the tumor dose reaches 81 Gy, it has exceeded the tolerated dose of the surrounding tissue, limiting the increase in tumor dose. The authors used a set of inverse planing parameters to develop a more satisfactory treatment plan. Authors from the previous plan with Beam’s eye view, 46 patients receiving a dose of 81Gy, select six patients to switch to reverse radiotherapy planning system redesign, and compare the two methods. 1Wild view (BEV) method: The patient was lying on his face in a prone position, with 6 fields (2 anterior oblique, 2 posterior oblique, and 2 lateral fields), 72 Gy of prostate and seminal vesicle, and BEV display model adjusted by hand to adjust the formation of multi-leaf grating. The target volume was shaped, and then only 9Gy of the prostate was irradiated, and two 60° wedge plates were used to replace the two front oblique fields to increase the uniformity of the dose and adjust the collimator aperture to avoid the rectal wall. 2 computer optimization program of automatic reverse planning system: using the advantages created by Bortfeld