Mazeron J J, Crook J M, Marinello G, Walop W, Pierquin B
Département de cancérologie, Hôpital Henri Mondor, Créteil, France.
Int J Radiat Oncol Biol Phys. 1990 Aug;19(2):281-5. doi: 10.1016/0360-3016(90)90535-r.
The results of Iridium 192 implantation for 121 node negative T1 or T2 squamous carcinomas of mobile tongue were reviewed to look for predictors of local control and necrosis. Age, sex, total dose, dose rate, linear activity, and intersource spacing were examined. Minimum follow-up was 2 years but no patient with local recurrence or necrosis was excluded. There were 57 T1N0 tumors, 45 T2aN0 (2.1-3.0 cm), and 19 T2bN0 (3.1-4.0 cm). Local failures occurred in 14% of T1, 11% of T2a, and 26% of T2b. Univariate analysis showed that local control increased with increasing dose (55-60 Gy: 73%; 65-75 Gy: 92%, p = 0.005), whereas multivariate analysis revealed both sex and total dose to be significant. Radiation necrosis occurred in 17% of T1, 29% of T2a, and 47% of T2b (p = 0.034). Half were limited to soft tissue and the majority healed with conservative management. Univariate analysis showed that necrosis increased with increasing dose (55-60 Gy: 16%; 65-75 Gy: 33%, p = 0.037), as well as increasing dose rate, linear activity, and intersource spacing. With multivariate analysis only stage, dose rate, and spacing remained predictive of necrosis. Total dose was not adjusted for dose rate or tumor volume. This analysis suggests that within the therapeutic range of low dose rate brachytherapy, correction of total dose according to dose rate is unnecessary. We recommend 65 Gy. Lower dose rate (0.4-0.5 Gy/hr) and closer intersource spacing (12-14 mm) should be aimed for to minimize necrosis.
回顾了192铱植入治疗121例舌活动部T1或T2期鳞癌且淋巴结阴性患者的结果，以寻找局部控制和坏死的预测因素。研究了年龄、性别、总剂量、剂量率、线性活度和源间距离。最小随访时间为2年，但未排除局部复发或坏死的患者。其中有57例T1N0肿瘤、45例T2aN0（2.1 - 3.0 cm）和19例T2bN0（3.1 - 4.0 cm）。T1期局部失败率为14%，T2a期为11%，T2b期为26%。单因素分析显示，局部控制率随剂量增加而提高（55 - 60 Gy：73%；65 - 75 Gy：92%，p = 0.005），而多因素分析显示性别和总剂量均具有显著性。T1期放射性坏死发生率为17%，T2a期为29%，T2b期为47%（p = 0.034）。一半局限于软组织，大多数经保守治疗愈合。单因素分析显示，坏死发生率随剂量增加而升高（55 - 60 Gy：16%；65 - 75 Gy：33%，p = 0.037），也随剂量率、线性活度和源间距离增加而升高。多因素分析中，仅分期、剂量率和间距可预测坏死。总剂量未根据剂量率或肿瘤体积进行调整。该分析表明，在低剂量率近距离放射治疗的治疗范围内，无需根据剂量率校正总剂量。我们推荐65 Gy。应采用较低的剂量率（0.4 - 0.5 Gy/小时）和更近的源间距离（12 - 14 mm），以尽量减少坏死。
