Preliminary analyses of efficacy and safety of Cyberknife stereotactic body radiotherapy for 26 patients with recurrent cholangiocellular carcinoma after surgery

Objective To evaluate the efficacy and safety of stereotactic body radiation therapy (SBRT) using Cyberknife in the treatment of patients with recurrent cholangiocellular carcinoma (RCC) after surgery. Methods Clinical data of 26 patients with recurrent RCC after surgery undergoing Cyberknife SBRT from 2010 to 2015 were retrospectively analyzed. The median recurrence time was 10 months (range 2.0-63.0 months) and the median tumor diameter was 2.8 cm (range 1.2-4.8 cm). The median prescription dose/fraction was 45 Gy/5f (range 40-50 Gy/3-8 f). The tumor progression was evaluated based on enhanced CT or MRI. Overall survival (OS), progression-free survival (PFS) and local control rate (LC) were analyzed by Kaplan-Meier method. Toxicity was assessed using the common terminology criteria for adverse events version 4.0. Results For the entire cohort, the median OS and PFS were 13.5 months and 6.5 months at a median follow-up of 29.3 months (range 2.1-62.0 months). The 1-and 2-year OS and PFS rates were 52% and 21% as well as 28% and 15%, respectively. Among them, 4 patients (4/26, 15%) were recurrent in situ after SBRT. Three patients experienced grade Ⅲ adverse reactions including 1 case of gastrointestinal reaction, 1 case of liver dysfunction and 1 case of biliary tract infection. Only 1 patient suffered from ≥grade IV gastrointestinal bleeding during the advanced stage. Conclusions SBRT using Cyberknife is a safe and effective treatment for patients with recurrent RCC after surgery. The adverse reactions can be tolerated by patients. Key words: Cholangiocellular neoplasm/stereotactic body radiotherapy; Cyberknife; Treatment outcome