Abstract:
The purpose of this study was to determine the maximum tolerated dose (MTD) for stereotactic body radiation therapy (SBRT) in the treatment of non-metastatic prostate cancer. This study was a phase 1 dose escalation trial conducted in Japan. Patients with histologically proven prostate cancer without lymph nodes or distant metastases were enrolled. The prescribed doses were 42.5, 45, or 47.5 Gy in five fractions. Dose-limiting toxicity (DLT) was defined as grade (G) 3+ gastrointestinal or genitourinary toxicity within 180 days after SBRT completion, and a 6 plus 6 design was used as the method of dose escalation. A total of 16 patients were enrolled, with 6 in the 42.5 Gy group and 10 in the 45 Gy group. No DLT was observed in the 42.5 Gy group. In the 45 Gy group, one patient experienced G3 rectal hemorrhage, and another had G4 rectal perforation, leading to the determination of 42.5 Gy as the MTD. None of the patients experienced biochemical recurrence or death during the follow-up period. We concluded that SBRT for non-metastatic prostate cancer at 42.5 Gy in five fractions could be safely performed, but a total dose of 45 Gy increased severe toxicity.
摘要:
这项研究的目的是确定立体定向身体放射疗法(SBRT)治疗非转移性前列腺癌的最大耐受剂量(MTD)。该研究是在日本进行的1期剂量递增试验。纳入经组织学证实无淋巴结或远处转移的前列腺癌患者。处方剂量为五个部分的42.5、45或47.5Gy。剂量限制性毒性(DLT)定义为SBRT完成后180天内的(G)3级胃肠道或泌尿生殖系统毒性,6+6设计作为剂量递增的方法。共纳入16例患者,42.5Gy组6个,45Gy组10个。在42.5Gy组中没有观察到DLT。在45Gy组中,一名患者出现G3直肠出血,另一个有G4直肠穿孔,导致测定42.5Gy作为MTD。在随访期间,没有患者出现生化复发或死亡。我们得出的结论是,在五个部分中42.5Gy的非转移性前列腺癌的SBRT可以安全地进行,但总剂量为45Gy会增加严重毒性。