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目的比较宫颈癌术后前后对穿照射,四野盒式照射,三维适形放疗和调强技术的剂量分布方法收集8例宫颈癌术后放疗患者,勾画PTV,小肠,直肠和左右股骨颈。分别设计前后对穿照射,四野盒式照射,三维适形放疗和调强放疗计划;比较各种计划的靶区适形指数(comformal index,CI)和均匀指数(homogeneity indes,HI),小肠,股骨颈与直肠最大剂量和受照40Gy以上的体积百分比(V40)。结果前后对穿照射,四野盒式照射,三维适形放疗以及调强技术靶区适形指数(CI)平均值分别为:0.32±0.31,0.35±0.27,0.61±0.33和0.83±0.42。均匀指数(HI)平均值分别:1.07±0.12,1.08±0.07,1.12±0.32和1.05±0.21。小肠最大受照剂量和V40平均值分别为5158±180,5145±153,5102±209,5078±214;78±13%,57±21%,34±24%,29±11%。直肠最大剂量各类计划间相差最大为140cGy,V40在IMRT计划中均值为45%,其余三计划全为100%。左右股骨颈最大受照剂量在四野盒式照射中最大,为5058cGy;在IMRT最小,为4762cGy;V40以三维适形放疗计划最小,平均为6%;四野盒式照射最大,平均为19%。结论从各指标上看,调强计划剂量分布最好,三维适形放疗计划次之;对与尚未具备条件开展调强的放疗单位开展三维适形放疗也将使患者受益。
Objective To compare 8 patients with postoperative radiotherapy of cervical cancer with PTD, small intestine, rectum and left and right femoral neck by comparing the dose distribution before and after radiotherapy of uterine cervix cancer with radiotherapy, Shino capsule irradiation, three-dimensional conformal radiotherapy and intensity modulation technique. The radiofrequency, radiotherapy, radiotherapy and IMRT were performed before and after the radiotherapy. The comformal index (CI) and homogeneity indels (HI), intestine, The maximum femoral neck and rectum dose and the volume above 40Gy (V40). The results showed that the mean values of CI of the three groups were 0.32 ± 0.31,0.35 ± 0.27,0.61 ± 0.33 and 0.83 ± 0.42, respectively. Mean values of homogeneity index (HI) were 1.07 ± 0.12, 1.08 ± 0.07, 1.12 ± 0.32 and 1.05 ± 0.21, respectively. The maximum dose of the small intestine and the mean V40 were 5158 ± 180, 5145 ± 153, 5102 ± 209, 5078 ± 214; 78 ± 13%, 57 ± 21%, 34 ± 24%, 29 ± 11%, respectively. The largest rectal dose of each type of plan the difference between the maximum 140cGy, V40 in the IMRT plan mean 45%, the remaining three plans were all 100%. The maximum dose of the left and right femoral neck was the largest in the four-field cassette irradiation, 5058cGy; in the IMRT the smallest was 4762cGy; V40 three-dimensional conformal radiotherapy the smallest, with an average of 6%; Conclusion From the various indicators, IMRI best dose distribution, followed by three-dimensional conformal radiotherapy plan; and have not been qualified to carry out three-dimensional radiotherapy unit radiotherapy unit will also benefit patients.