Patients with inoperable pancreatic adenocarcinoma have limited options, with traditional chemoradiation providing modest clinical benefit and an otherwise poor prognosis. Stereotactic body radiation therapy for pancreatic cancer is limited by proximity to organs-at-risk (OAR). However, stereotactic magnetic resonance-guided adaptive radiation therapy (SMART) has shown promise in delivering ablative doses safely. We sought to demonstrate the benefits of SMART using a 5-fraction approach with daily on-table adaptation. Patients with locally advanced, nonmetastatic pancreatic adenocarcinoma were treated with 50 Gy in 5 fractions (biologically effective dose10 100 Gy) with a prescribed goal of 95% planning target volume coverage by 95% of prescription, prioritizing hard OAR constraints. Daily online adaptation was performed using magnetic resonance-guidance and on-table reoptimization. Patient outcomes, treatment factors, and daily adaptation were evaluated. Forty-four patients were treated with SMART at our institution from 2014 to 2019. Median follow-up from date of diagnosis was 16 months (range, 6.7-51.6). Late toxicity was limited to 2 (4.6%) grade 3 (gastrointestinal ulcers) and 3 (6.8%) grade 2 toxicities (duodenal perforation, antral ulcer, and gastric bleed). Tumor abutted OARs in 35 patients (79.5%) and tumor invaded OARs in 5 patients (11.1%). Reoptimization was performed for 93% of all fractions. Median overall survival was 15.7 months (95% confidence interval, 10.2-21.2), while 1-year and 2-year overall survival rates were 68.2% and 37.9%, respectively. One-year local control was 84.3%. This is the first reported experience using 50 Gy in 5 fractions for inoperable pancreatic cancer. SMART allows this ablative dose with promising outcomes while minimizing toxicity. Additional prospective trials evaluating efficacy and safety are warranted.
1 December 2017 in International Journal of Radiation Oncology, Biology, Physics
The objective of this study was to present the treatment technique and evaluate clinical outcomes after intensity modulated radiation therapy (IMRT) for vulvar cancer. This retrospective study included 39 patients with squamous cell carcinoma of the vulva treated with IMRT from 2005 to 2015. There were 21 patients treated with postoperative IMRT, 13 with definitive IMRT, and 5 with preoperative IMRT. Tumor staging was Federation of Gynecology and Obstetrics stage I in 6, stage II in 7, stage III in 19, and stage IV in 7 patients. Concurrent chemotherapy was administered to 14 patients. Brachytherapy was delivered in 8 patients. The median follow-up was 34 months (range, 3.3-71). Median IMRT dose to patients receiving pre- or postoperative IMRT was 5040 cGy (range, 5040-6080). Median combined IMRT and brachytherapy dose to gross tumor was 7000 cGy (range, 5040-7520) in those treated with definitive RT. The 3-year locoregional control (LRC) and overall survival for those receiving postoperative RT were 89% and 67%, respectively. The 3-year LRC and overall survival for those receiving definitive IMRT were 42% and 49%, respectively. In patients receiving definitive or neoadjuvant IMRT, 69% had complete clinical response and 44% had complete pathologic response. The actuarial 3-year inguinal recurrence rate was 7%. There were no acute grade 3-4 hematological, gastrointestinal, or genitourinary toxicities. There were no late grade 3-4 gastrointestinal or genitourinary toxicities. IMRT for vulvar cancer is associated with high rates of LRC in the postoperative setting and limited radiation-related toxicity. Durable LRC of disease after definitive IMRT remains challenging, and several refinements to our treatment technique are suggested.