子宫颈癌高剂量率192铱源腔内放射治疗的剂量学临床意义

目的探讨子宫颈癌高剂量率192铱源腔内放射治疗的剂量与疗效、放疗副反应的关系。方法68例子宫颈癌采用体外照射与Micro-Selectron高剂量率192铱后装机腔内照射治疗，由治疗计划系统制定个体化治疗方案，并按国际辐射剂量与测量委员会38号文件的建议，计算参考点和参考体积。结果体外及腔内照射A点总剂量为65～72Gy，B点53.8～60.2Gy，膀胱和直肠参考点平均剂量分别为A点剂量的40.27％和57.68％，A点100％剂量水平的参考体积为98.39cm3。结论子宫颈癌的治疗效果与A点剂量有关，但不是惟一影响预后的因素，放射性膀胱炎、直肠炎的发生与膀胱、直肠的放射剂量有关。

The Clinical Significance of High Dose Rate Intracavltary Radiotherapy for Cervlcal Cancer

Objective To explore the relationship between the dose of high dose rate 192 source intracavitary radiotherapy in cervical cancer and the clinical results and the side effect of radiotherapy.Methods 68 patients with cervical cancer were treated by combined external with intracavitary radiotherapy.The intracavitary therapy was delivered by Micro Selectron high dose rate afterloading unit containing 192 iridium source.Before the treatment the individual treatment scheme was formulated for every patient and the absorbed dose at reference points and reference volume were calculated according to the method recommended by ICRU report (No 38).Results The total dose at point A and B were 65-72 Gy and 53.8-60.2 Gy,respectively.In the intracavitary therapy the mean doses of bladder and rectal reference point were 40.27% and 57.68%,respectively.The mean reference volume was 98.39 cm 3 at the 100% dose level of point A.Conclusions The clinical results of cervical cancer was correlated with the dose of point A.The delayed reactions of urinary bladder and rectum were correlated with the dose of irradiation.