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PURPOSE: 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. METHODS AND MATERIALS: 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. RESULTS: 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%. CONCLUSIONS: 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.
RESUMO
BACKGROUND: The National Accreditation Program for Rectal Cancer (NAPRC) emphasizes a multidisciplinary approach for treating rectal cancer and has developed performance measures to ensure that patients receive standardized care. We hypothesized that rectal cancer patients receiving care at multiple centers would be less likely to receive timely and appropriate care. STUDY DESIGN: A single institution retrospective review of a prospectively maintained database was performed. All patients undergoing proctectomy and ≤1 other treatment modality (eg radiation and/or chemotherapy) for Stage II/III rectal adenocarcinoma were included. Unified care was defined as receiving all modalities of care at our institution, and fragmented care was defined as having at least 1 treatment modality at another institution. RESULTS: From 2009 to 2019, 415 patients met inclusion criteria, with 197 (47.5%) receiving fragmented care and 218 (52.5%) receiving unified care. The unified cohort patients were more likely to see a colorectal surgeon before starting treatment (89.0% vs 78.7%, p < 0.01) and start definitive treatment within 60 days of diagnosis (89.0% vs 79.7%, p = 0.01). On adjusted analysis, unified care patients were 2.78 times more likely to see a surgeon before starting treatment (95% CI 1.47-5.24) and 2.63 times more likely to start treatment within 60 days (95% CI 1.35-5.13). There was no difference in 90-day mortality or 5-year disease-free survival. CONCLUSIONS: This retrospective cohort study suggests patients with rectal cancer receiving fragmented care are at an increased risk of delays in care without any impact on disease-free survival. These findings need to be considered within the context of ongoing regionalization of rectal cancer care to ensure all patients receive optimal care, irrespective of whether care is delivered across multiple institutions.