Liauw Stanley L, Ni Lisa, Wu Tianming, Arif Fauzia, Cloutier Denise, Posner Mitchell C, Kozloff Mark, Kindler Hedy L
Department of Radiation Oncology, University of Chicago Medical Center, Chicago, IL, USA.
Department of Surgical Oncology, University of Chicago Medical Center, Chicago, IL, USA.
J Gastrointest Oncol. 2020 Dec;11(6):1399-1407. doi: 10.21037/jgo-20-187.
We explored the safety and efficacy of ablative doses of stereotactic body radiation therapy (SBRT) for unresectable pancreatic cancer.
This phase I/II trial included patients with unresectable pancreatic cancer previously treated with any number of cycles of induction chemotherapy. Patients were enrolled according to a 3+3 dose escalation design at 10, 12.5, and 15 Gy ×3, with subsequent patients at the maximally tolerated dose (MTD). Treatment was delivered to gross tumor delineated with MRI fusion using image-guidance to fiducial markers. Dose-limiting toxicity (DLT) was defined as grade 3+ toxicity within 30 days. Secondary endpoints included late gastrointestinal (GI) toxicity, freedom from local failure (FFLF), and survival.
Fifteen patients received a median 10 cycles of chemotherapy. There were no DLTs, and the MTD was 15 Gy ×3. Thirty-day toxicity included grade 2 nausea (46%) and grade 2 diarrhea (7%). Median survival after SBRT was 12.8 months (23 months after diagnosis) and median relapse-free survival was 7 months. At 1-year, FFLF was 80%. Four patients had grade 3+ GI bleeding after 30 days (median 6 months). Grade 3+ GI bleeding was associated with tumor volume (P=0.01), heterogeneity of dose within the planning target volume (PTV) (V120, P=0.03), and duodenal dose (V26-30 Gy, P<0.2).
This aggressive SBRT regimen demonstrated limited 30-day morbidity, a moderate degree of local control, and a moderate risk for late GI bleeding. Further work is necessary to define the most appropriate hypofractionated radiation therapy (RT) regimen in the ablative dose range.
我们探讨了立体定向体部放射治疗（SBRT）消融剂量用于不可切除胰腺癌的安全性和有效性。
这项I/II期试验纳入了先前接受过任意周期诱导化疗的不可切除胰腺癌患者。患者按照3+3剂量递增设计入组，剂量分别为10、12.5和15 Gy×3，后续患者接受最大耐受剂量（MTD）。使用图像引导将治疗照射至通过MRI融合勾勒出的大体肿瘤，并以基准标记物为准。剂量限制毒性（DLT）定义为30天内3级及以上毒性。次要终点包括晚期胃肠道（GI）毒性、无局部失败生存期（FFLF）和总生存期。
15例患者接受了中位10周期化疗。未出现DLT，MTD为15 Gy×3。30天毒性包括2级恶心（46%）和2级腹泻（7%）。SBRT后的中位总生存期为12.8个月（诊断后23个月），中位无复发生存期为7个月。1年时，FFLF为80%。4例患者在30天后出现3级及以上胃肠道出血（中位6个月）。3级及以上胃肠道出血与肿瘤体积（P=0.01）、计划靶体积（PTV）内剂量的异质性（V120，P=0.03）以及十二指肠剂量（V26 - 30 Gy，P<0.2）相关。
这种积极的SBRT方案显示30天发病率有限，局部控制程度中等，晚期胃肠道出血风险中等。有必要进一步开展工作，以确定消融剂量范围内最合适的大分割放射治疗（RT）方案。
