摘要目的 测量腭部125I放射性粒子义齿基托布源器的剂量分布(组织吸收剂量),为腭部恶性肿瘤临床治疗提供客观依据.方法 利用头颈部仿生模型进行模拟实验,配戴125I粒子义齿基托布源器,对腭部直径2 cm模拟肿瘤进行局部切除术后放射治疗.义齿基托布源器共含125I粒子11粒,活度29.6 MBq/粒,处方剂量(周缘匹配剂量)为80 Gy.利用热释光剂量学方法测量瘤区及周围组织的剂量分布情况.结果 瘤区内及距肿瘤边缘0.5、1.0 cm的腭黏膜下剂量分别为317.25、176.55和105.71 Gy,均达到了临床设计要求80 Gy;瘤区外正常组织除舌体外接受剂量均明显低于瘤区剂量,位于耐受剂量内(口腔黏膜TD5/560 Gy,骨TD5/55 Gy).结论 利用125I粒子义齿基托布源器对腭部恶性肿瘤进行术后近距离治疗可取得满意的剂量分布,但需要对舌体进行适当的放射防护.

abstractsObjective To measure the dose distribution (tissue absorbed dose) of palatal denture applicator containing 125I. Methods Simulated model of head and neck was used to wear the palatal dental applicator containing I for the postoperative brachytherapy of a simulated tumor at a diameter of 2 cm in the palate. The denture contained 11 125I seed with radioactivity of 29. 6 MBq per seed. The prescribed dose (edge matched dose) was 80 Gy. The absorbed dose in the simulated target and its adjacent area was measured by thermoluminescence dosimeters. Results The dose in the target area reached the value of treatment needs, and the dose absorbed by tissue around the target was lower except tongue. Conclusions Using palatal denture applicator containing 125I for postoperative brachytherapy of malignant tumors of palate can get satisfied dose distribution, but the tongue needs to be protected.