【摘要】 目的比较不同射野数目对宫颈癌调强放疗计划的剂量学特点。方法选取我院2020年8月至12月20例接受调强放疗的宫颈癌患者,每个病例分别设计5野和7野两组调强放疗治疗计划,5野入射度为45°、115°、180°、245°、315°（PlanA）;7野入射角度为0°、50°、100°、150°、210°、260°、310°（PlanB）,采用等效均匀剂量优化法,在膀胱、直肠以及小肠罚分值≠0时,尽量使骨盆剂量降低,使100%等剂量线刚好覆盖95% 靶体积,比较其靶区和危及器官的剂量学差异。结果两组放疗计划靶区的适形度指数CI和均匀性指数HI,PlanB优于PlanA,且均具有统计学意义（P<0.001）。危及器官直肠V₁₀、V₅₀以及膀胱V₁₀、V₅₀无统计学意义（P> 0.05）;直肠V₂₀、V₃₀、V₄₀、D_mean、膀胱V₂₀、V₃₀、V₄₀、D_mean、小肠V₃₀、V₄₀、V₅₀、D_mean、骨盆V₂₀、V₃₀、V₄₀、V₅₀、D_mean,PlanB优于PlanA;对于小肠V₁₀、V₂₀以及骨盆V₁₀,PlanA优于PlanB,且均具有统计学意义（P<0.05）;机器跳数和出束时间PlanA略少于PlanB,且具有统计学意义（P <0.001）。结论两组计划均能满足临床需要,小肠及骨盆在高低剂量区各自具有其优势,但是综合考虑发生放射损伤相关性研究结果以及剂量学结果PlanB更适合于临床应用。更多还原

【Abstract】 Objective To investigate the dosimetric characteristics of different field numbers in intensity-modulated radiotherapy for cervical cancer.Methods A total of 20 patients with cervical cancer who received intensity-modulated radiotherapy in our hospital from August to December 2020 were enrolled;and two intensity-modulated radiotherapy plans with 5 and 7 fields were designed for each patient.The incidence angles were 45°,115°,180°,245°,and 315° in the plan with 5 fields（Plan A） and were 0°,50°,100°,150°,210°,260°,and 310° in the plan with 7 fields（Plan B）.The equivalent uniform dose optimization method was used;and when the cost values of the bladder;the rectum;and the small intestine were not equal to zero and the dose of the pelvis was minimized so that the 100% isodose contour covered 95% of the target volume;the target area and the organs at risk were compared in terms of dosimetry.Results Plan B had significantly better conformity index and homogeneity index of the planning target than Plan A（P <0.001）.There were no significant differences in V₁₀ and V₅₀ of the organs at risk（rectum and bladder） between the two plans（P> 0.05）.Compared with Plan A,Plan B had significantly better V₂₀,V₃₀,V₄₀,and D_mean of the rectum;V₂₀,V₃₀,V₄₀,and D_mean of the bladder,V₃₀,V₄₀,V₅₀,and D_mean of the small intestine and V₂₀,V₃₀,V₄₀,V₅₀,and D_mean of the pelvis;while Plan A had significantly better V₁₀ and V₂₀ of the small intestine and V₁₀ of the pelvis than Plan B（P <0.05）.Compared with Plan B;Plan A had a significantly lower number of monitor units and a significantly shorter beam-on time than Plan B（P <0.001）.Conclusion Both plans can meet clinical needs and have their own advantages in the high-and low-dose areas of the small intestine and the pelvis;however,considering the association with radiation injury and the results of dosimetric analysis,Plan B is more suitable for clinical application.更多还原