Short- and Long-Term Outcomes of Neoadjuvant Stereotactic Body Radiation Therapy vs. Neoadjuvant Conventional Radiation Therapy in Patients with Pancreatic Cancer

Abstract

<h3>Purpose/Objective(s)</h3> While neoadjuvant chemotherapy is widely accepted in treatment of pancreatic cancer, there is no consensus on the modality of neoadjuvant radiotherapy (NRT) with neoadjuvant Stereotactic Body Radiation Therapy (SBRT) gaining more interest. Our goal was to compare SBRT versus conventional radiation therapy (CRT). <h3>Materials/Methods</h3> A retrospective analysis of NCDB data from 2004 – 2018 was conducted. Patients who underwent NRT followed by surgical resection with known radiation and survival data were included. The primary outcome was overall survival (OS) and secondary outcomes include 30- and 90-day postoperative mortality, pathologic complete response (pCR) and R0 resection. <h3>Results</h3> The SBRT group (average 33Gy/5fx) comprised 392 patients, and 467 patients received CRT (average 45Gy/25fx). Median OS for patients undergoing CRT compared to SBRT group was 22 vs 34 months (p<0.001). The SBRT group had better median OS among AJCC clinical stage 1, 2 and 3 compared to CRT (32 vs 26 months, p = 0.078), (34 vs 21 months, p< 0.001) and (37 vs 23 months, p < 0.001), respectively. The 30- and 90-day postoperative mortality for CRT compared to SBRT group was 5% vs 2% (p = 0.02) and 12% vs 6% (p = 0.002), respectively. R0 resection and pCR rate for CRT compared to SBRT was 85% vs 87% (p = 0.96), and 3.7% vs 3.8% (p=0.77), respectively. <h3>Conclusion</h3> Patients who underwent neoadjuvant SBRT compared with CRT had superior OS, particularly in AJCC stage 2 and 3, along with decreased post operative mortality. Further randomized controlled trials are warranted.