Objective To determine the maximum tolerated dose ( MTD) and dose-limiting toxicity (DLT) of hypofractionat-ed conformal radiotherapy ( HFRT) with concurrent weekly medium-dose gemcitabine ( GEM) in patients with unresectable pancreatic cancer. Methods Ten patients with previously untreated, locally advanced, or asymptomatic-metastatic pancreatic adenocarcinoma were enrolled in this study. GEM at a dose of 600 mg/m2 was given intravenously over 30 minutes starting 2 hours before radiotherapy weekly for 7 weeks. The initial radiation dose was 48 Gy in 12 fractions (3 fractions/week) with three patients (level 1). Radiation dose was escalated by 4Gy increments in successive cohorts of 3 to 6 additional patients until DLT was observed. Toxicities were graded using the Radiation Therapy Oncology Group and National Cancer Institute Common Toxicity Criteria, version 3.0. Results In general, therapy was well tolerated in patients treated at the first two dose levels of 48Gy/12 fractions and 52Gy/13 fractions. The DLT of HFRT with concurrent weekly medium-dose GEM were neutropenia (2 patients), thrombocytopenia (2 patients), at the dose level of 56Gy/14 fractions. Of the 10 patients eligible for a median follow-up of 10 months, 1 complete response, 3 partial response, and 5 with stable disease, and the median overall survival time was 12 months. Conclusion The final radiation dose investigated (52Gy/13 fractions,3 fractions/week) is recommended for further study considering the occurrence toxicity.%目的 探讨低分割、高剂量适形放疗同步吉西他滨治疗不可切除胰腺癌的放疗靶区最大耐受剂量和剂量限制性毒性反应.方法 采用“3+3”试验设计模式,10例经病理组织学证实不可手术切除的初治胰腺癌患者接受同步放化疗,放疗采用低分割、高剂量适形放疗,单次剂量为4Gy,3次/周,靶区累积照射剂量以4Gy逐渐累加,直至出现限制性剂量毒性反应,靶区累积剂量DT 48Gy～56Gy/12～14f；同步给予吉西他滨每周600mg/m2,静滴,1次/周,共7周.观察治疗疗效和毒性反应,并进行生存随访.结果 当靶区DT达到56Gy/14f时,出现剂量限制性毒性反应,主要表现为血3～4级血小板减少或粒细胞减少,故终止试验.获CR 1例,PR 3例,SD 5例,PD 1例,中位生存期为12个月.结论 对于不可切除胰腺癌,推荐采用吉西他滨600mg/m2,1次/周同步放疗,三维适形放疗采用低分割、高剂量模式,靶区最大耐受剂量为DT 52Gy/13f,3次/周.
展开▼
