“Supermassive” Intrahepatic Cholangiocarcinoma: The Role of Ablative Radiation Therapy

Abstract

<h3>Purpose/Objective(s)</h3> Ablative radiation therapy (RT) has been shown to improve clinical outcomes in patients with unresectable intrahepatic cholangiocarcinoma (ICC). Here we report on a cohort with "supermassive" ICC, and assess the role of ablative RT in the treatment of patients with such large lesions. <h3>Materials/Methods</h3> We retrospectively collected data from the University of Texas MD Anderson Cancer Center on patients presenting with ICC. We identified 63 patients with unresectable ICC, with tumors having a diameter of 10cm or more (34 received RT with or without chemotherapy, and 29 received chemotherapy alone). All patients in the RT cohort were treated with biologically effective doses (BED) higher than 80.5Gy. We analyzed overall survival (OS), tumor-related liver failure (TRLF), and treatment toxicity. <h3>Results</h3> Patients were followed-up to a median of 17.9 months. In total, 48 patients died (76.2%): 22 (64.7%) in the RT cohort and 26 (89.7%) in the chemotherapy cohort. Patients who received RT showed improved OS compared to patients in the chemotherapy cohort (Median OS 28.7 vs 11.9 months, respectively, log-rank <i>P</i>=0.003; aHR=0.3, 95%CI 0.1-0.7, <i>P</i>=0.01). Patients treated with chemotherapy alone had a higher rate of TRLF compared to those who received RT (47.1% vs 12.1%, respectively, log-rank <i>P</i>=0.01). No grade 3 or higher acute RT toxicity was noted. <h3>Conclusion</h3> Patients with "supermassive" ICC treated with ablative RT showed excellent clinical outcomes, with tolerable toxicity. Future studies are still needed to better assess the role of RT in this patient population.