前列腺癌调强计划改变多叶准直器角度对直肠和膀胱剂量的影响

目的:常规放疗的前列腺癌,由于直肠和膀胱的剂量限制,治疗结束后活检阳性率较多。剂量递增实验证明,高剂量照射能提高前列腺癌的局部控制率和生存率。本文以前列腺癌为例,在保证肿瘤区域剂量的前提下,探讨调强计划中改变多叶准直器角度对减少直肠和膀胱剂量的影响。材料方法:选取10例已放疗患者的CT作为研究对象,用调强技术比较改变多叶准直器角度对直肠和膀胱的剂量影响。结果:直肠的D25、D50、V60和膀胱的D30、D50、V60在改变多叶准直器角度后都有明显减少。结论:在前列腺癌靶区复杂,且计划因肿瘤剂量和正常组织剂量不能同时满足时,应用此方法可以一定程度上减少正常组织的受照剂量。

The Impact of Change Angle of Multi-leaf Collimator on the Dose Distribution of the Intensity-modulated Radiation Therapy Plan for Prostate Cancer

purpose： Common radiation therapy for prostate cancer, positive rate were more after treatment due to the rectum and bladder dose limit. Dose escalation experiments show that high doses of radiation can improve local control of prostate cancer rate and survival rate. In this paper, in ensuring the dose of tumor, explores the impact of change angle of multi-leaf collimator on the dose distribution of the intensity-modulated radiation therapy plan for prostate cancer. Material Methods： Select 10 eases had radiotherapy patient＇s CT as an object of study, compared with the impact of change angle of multi-leaf collimator on the dose distribution of the intensity-modulated radiation therapy plan for prostate cancer. Results： The rectum D25,D50, V60 and bladder D30、D50, V60 all decreased significantly after changed the angle of multi-leaf collimator. Condusion： The application of this method can to some extent reduce the dose to normal tissue for complex target volume plans when plans fail to satisfy the tumor dose and normal tissue simultaneously.