Koot R W, Maarouf M, Hulshof M C, Voges J, Treuer H, Koedooder C, Sturm V, Bosch D A
Department of Neurosurgery, Academic Medical Center, Amsterdam, The Netherlands.
Cancer. 2000 Jun 15;88(12):2796-802.
In the current study, the authors describe and compare two different strategies of brachytherapy for the treatment of patients with primary glioblastoma multiforme (GBM).
The study was comprised of 84 patients. Forty-five patients were implanted with permanent or temporary low activity iodine-125 ((125)I) seeds in Cologne and 21 patients were implanted with temporary iridium-192 ((192)Ir) wires in Amsterdam. Both groups received external beam radiation therapy (EBRT); the (125)I group received 10-30 grays (Gy) with the implant in situ and the (192)Ir group received 60 Gy before implantation. In Cologne, implantation was performed after a diagnostic stereotactic biopsy whereas in Amsterdam implantation took place after cytoreductive diagnostic surgery. In addition, 18 patients in Amsterdam served as a control group. This group received only EBRT after cytoreductive surgery.
In both groups the mean age of the patients was between 50-55 years, with 80% of the patients age > 45 years. The mean implantation volume encompassed by the referenced isodose was 23 cm(3) for (125)I and 48 cm(3) for (192)Ir. Initial dose rates were 2. 5-2.9 centigrays (cGy)/hour for permanent (125)I, 4.6 cGy/hour for temporary (125)I, and 44-100 cGy/hour (mean, 61 cGy) for (192)Ir. A total dose of 50-60 Gy, 60-80 Gy, and 40 Gy, respectively, was administered at the outer margins of the tumor. The median survival was approximately 16 months for both the (125)I group and the (192)Ir group. This was 6 months longer than the median survival in the control group. Reoperations were performed in 4 patients in the (125)I group (9%) versus 7 patients in the (192)Ir group (33%). No complications or late reactions were reported in the (125)I group, whereas one case of hemorrhage and three cases of delayed stroke were observed in the (192)Ir group.
The equal median survival times in these two brachytherapy groups with such different dose rate radiation schedules support the hypothesis that dose rate does not play a major role in the survival of patients with primary GBM.
在本研究中，作者描述并比较了两种不同的近距离放射治疗策略，用于治疗原发性多形性胶质母细胞瘤（GBM）患者。
该研究纳入了84例患者。45例患者在科隆接受了永久性或临时性低活度碘-125（¹²⁵I）种子植入，21例患者在阿姆斯特丹接受了临时性铱-192（¹⁹²Ir）导线植入。两组均接受了外照射放疗（EBRT）；¹²⁵I组在植入物原位时接受10 - 30戈瑞（Gy），¹⁹²Ir组在植入前接受60 Gy。在科隆，植入在诊断性立体定向活检后进行，而在阿姆斯特丹，植入在减瘤诊断性手术后进行。此外，阿姆斯特丹的18例患者作为对照组。该组仅在减瘤手术后接受EBRT。
两组患者的平均年龄均在50 - 55岁之间，80%的患者年龄大于45岁。参考等剂量线所包围的平均植入体积，¹²⁵I组为23 cm³，¹⁹²Ir组为48 cm³。初始剂量率，永久性¹²⁵I为2.5 - 2.9厘戈瑞（cGy）/小时，临时性¹²⁵I为4.6 cGy/小时，¹⁹²Ir为44 - 100 cGy/小时（平均61 cGy）。分别在肿瘤外缘给予的总剂量为50 - 60 Gy、60 - 80 Gy和40 Gy。¹²⁵I组和¹⁹²Ir组的中位生存期约为16个月。这比对照组的中位生存期长6个月。¹²⁵I组有4例患者（9%）进行了再次手术，而¹⁹²Ir组有7例患者（33%）进行了再次手术。¹²⁵I组未报告并发症或晚期反应，而¹⁹²Ir组观察到1例出血和3例迟发性中风。
这两个近距离放射治疗组采用如此不同的剂量率放疗方案却有相等的中位生存期，支持了剂量率在原发性GBM患者生存中不起主要作用这一假说。
