Neoadjuvant radiation case volume and associated with margin-negative resection rates in patients with pancreatic cancer.

e16281 Background: High surgical case volume (SCV) is associated with improved outcomes. Whether radiation case volume (RCV) is associated with outcomes is unknown, but of potentially increased importance given the recent results of the PREOPANC trial. We examined the impact of RCV on pathologic outcomes among patients (pts) with pancreatic cancer (PC) receiving neoadjuvant therapy (NAT). Methods: Pts with PC who received any NAT between 2009-2018 were identified from the National Cancer Database. Institutions were defined by SCV (low: < 9, medium:9-35, high:≥36 pts/year) and by RCV (nil:none, low:1-6, high:≥7 pts/year). Pathologic outcomes were node (N0/N1) and margin (R0/R1) status. Results: In total, 10,893 pts received NAT at 890 institutions; 3,522 (32%) received radiation at 562 (63%) institutions. Among all 10,893 pts, 2,896 (26%) were treated at low-SCV, 5,421 (50%) at medium-SCV, and 2,576 (24%) at high-SCV institutions. Among all 10,893 pts, 904 (8%) were treated at nil-RCV institutions, 7,736 (71%) at low-RCV, and 2,253 (21%) at high-RCV institutions. N0 resections were accomplished in 1,210 (54%) of 2,253 pts at high-RCV institutions, 3,732 (48%) of 7,736 at low-RCV, and 339 (38%) of 904 at nil-RCV institutions ( p values < 0.001). Similarly, R0 margins were achieved in 1,979 (88%) of 2,253 pts at high-RCV, 6,380 (82%) of 7,736 at low-RCV, and 671 (74%) of 904 at nil-RCV institutions ( p values < 0.001). Among 3,522 pts that received radiation, N0 resections were not different by RCV: 769 (62%) of 1,241 at high-RCV institutions and 1,461 (64%) of 2,281 at low-RCV institutions ( p= 0.22). Pts treated with radiation at high-RCV institutions had higher proportions of R0 margins: 1,120 (90%) of 1,241 at high-RCV and 1,931 (85%) of 2,281 at low-RCV institutions ( p< 0.001). High-RCV and low-RCV institutions were each associated with N0 resections (Table) and were not different from each other ( p= 0.33). High-RCV and low-RCV institutions were each associated with R0 margins, however high-RCV was more strongly associated than low-RCV ( p< 0.001). Conclusions: Pts at high-RCV facilities had greater odds of R0 margins independent of surgical case volume. As radiation techniques evolve, the value of high-RCV experience is likely to become increasingly important.[Table: see text]