Liver transplantation for perihilar cholangiocarcinoma after neoadjuvant chemoradiation with brachytherapy versus stereotactic beam radiotherapy: Pretransplant toxicity and posttransplant outcomes

Introduction Liver transplantation (LT) is the only curative treatment for patients with unresectable perihilar cholangiocarcinoma (pCC). Before listing, patients undergo neoadjuvant chemoradiation (CT-RT) according to the Mayo Clinic protocol (radiosensitizing chemotherapy + brachytherapy). In 2020, at our center we substituted brachytherapy with stereotactic beam radiotherapy (SBRT). Aim To compare pretransplant toxicity and post-transplant outcomes of LT for pCC after brachytherapy versus SBRT. Materials & Methods We performed a retrospective analysis of patients who underwent LT for pCC at our center between 2011 and 2023. Pre-LT adverse events were graded according to the Common Terminology Criteria for Adverse Events (CTCAE). Results Eight patients underwent LT: 4 after brachytherapy and 4 after SBRT (4, 50% women, median age 52 in brachytherapy and 62.5 in SBRT). CT-RT-related adverse events ≥ grade 3 occurred in all after brachytherapy and in one patient after SBRT (p=0.028). Median post-LT length of stay was 16.5 days (range, 9 - 25) for brachytherapy and 12 (range, 10-12) for SBRT. Post-LT 90-day complications occurred in 2 (50%) patients after brachytherapy (Clavien Dindo grade II and IVa) and one after SBRT (grade IIIa). In the brachytherapy group, one patient had microfoci of pCC on the bile duct margin; all LT in the SBRT group were R0. One brachytherapy patient and one SBRT patient had positive lymph nodes at histology. Overall survival at 1-, 3- and 5- years for the entire cohort was 100%, 80% and 40. No differences in survival were observed between the two groups. After a median follow-up of 146 months for brachytherapy and 12 months for SBRT, recurrences were 3 for brachytherapy and one for SBRT. Two deaths occurred in the brachytherapy group, none in the SBRT group. Conclusion Preliminary data suggest that neoadjuvant SBRT is comparable to brachytherapy regarding post-LT outcomes, but with lower pre-LT toxicity.