摘要目的 探讨2次立体定向放射治疗(SBRT)胰腺癌的累积剂量和不良反应.方法 纳入24例接受了2次SBRT的胰腺癌患者.通过刚性及非刚性配准来计算各危及器官的累积剂量,并将所有剂量值均转换为2Gy一次分割等效剂量进行再次计算.结果 胃、十二指肠和小肠最大受照剂量(Dmax)、1cc 体积受照剂量(D1cc)的中位累积剂量分别为43.87、35.28 Gy3,35.53、26.59 Gy3,45.08、36.18 Gy3;10Gy剂量照射的体积(V10)中位数分别为107.40、23.98、169.26cc.脊髓Dmax和35%体积受照剂量(D0.35)的中位累积剂量分别为8.42、7.83Gy3.左、右肾总体积平均受照剂量(Dmean)和2/3体积受照剂量(D2/3)的中位累积剂量分别为5.18、3.65 Gy3,3.50、2.57 Gy3.肝脏Dmean和D1/2的中位累积剂量分别为5.18、3.64 Gy3.两次重叠照射野肿瘤靶区的中位累积剂量为93.38 Gy3.无3~4级不良反应发生.患者中位生存时间为17个月.结论 根据本研究所得出的各危及器官的累积剂量值来设定各器官受照剂量限值是安全、可接受的,可作为评估胰腺癌患者首次SBRT后能否再次行SBRT的参考指标.

abstractsObjective To assess the cumulative doses and side effects after two courses of stereotactic body radiation therapy (SBRT) for pancreatic cancer. Methods Twenty-four pancreatic cancer patients who received two courses of SBRT were enrolled. Organ endangering dose accumulations were calculated by rigid and non-rigid registration. All doses were recalculated to an equivalent dose of 2 Gy per fraction. Results The median of accumulated maximal dosage (Dmax) and dosage per 1cc(D1cc) of the stomach,duodenum and the bowel were 43.87 and 35.28 Gy 3,35.53 and 26.59 Gy3,45.08 and 36.18 Gy3; and the median volume under the dosage of 10Gy (V10) was 107.40,23.98 and 169.26cc, respectively. The median accumulated Dmaxand the dosage of 35% volume(D0.35) of the spinal cord was 8.42 and 7.83Gy3. The median cumulative Dmeanand D2/3of the left and right kidney were 5.18 and 3.65 Gy3, 3.50 and 2.57 Gy3, respectively. The median cumulative Dmeanand D50%of the liver was 5.18 and 3.64Gy3,respectively. The median summed dose to the overlapping radiation field of the two courses was 93.38 Gy3. No grade 3-4 toxicity occurred. Conclusions The cumulative doses to organs at risk as dose constraints were safe and acceptable,which could be used as a reference to evaluate whether a second SBRT could be done after initial SBRT for pancreatic cancer.