378 Background: Induction chemotherapy (iC) followed by concurrent chemoradiation has been shown to improve overall survival (OS) for locally advanced pancreatic cancer (LAPC). A recent National Cancer Data Base (NCDB) analysis has also shown improved OS with the use of stereotactic body radiation therapy (SBRT) versus conventionally fractionated radiation therapy (CFRT). This NCDB analysis evaluated outcomes of concurrent chemoradiation with SBRT compared to CFRT, following iC. Methods: The NCDB was queried for primary stage III, cT4N0-1M0 unresected pancreatic adenocarcinoma treated with concurrent chemoradiation following iC (2004-2015). CFRT was defined as 1.8-2.5 Gy per fraction up to a total dose of 45-70 Gy, whereas SBRT was defined as > 4.0 Gy per fraction up to a total dose of 20-60 Gy. Baseline patient, tumor, and treatment characteristics were examined. The primary endpoint was overall survival (OS). Kaplan-Meier analysis, Cox proportional hazards method, logistic regression, and propensity score matching were used. Results: Among 872 patients, 738 patients underwent CFRT and 134 patients received SBRT. Median follow-up was 24.3 months and 22.9 months for the CFRT and SBRT cohorts, respectively. The use of SBRT showed improved survival in the multivariable analysis compared to CFRT (HR 0.78, p = 0.025). Using 1:1 propensity score matching, a total of 240 patients were matched, with 120 patients in each cohort. The receipt of SBRT remained statistically significant for improved OS, including median OS (18.1 months vs 15.9 months) and 2-year OS (37.3% vs 25.5%) compared to the CFRT (p = 0.0040). Conclusions: This NCDB analysis shows a significant survival benefit with the use of SBRT versus CFRT, in the setting of definitive management for LAPC following iC. Further prospective studies evaluating the use of SBRT in the definitive treatment of this challenging population are warranted.
Single-fraction Stereotactic Body Radiation Therapy versus Conventionally Fractionated Radiation Therapy for the Treatment of Prostate Cancer Bone Metastases