(P116) Pain and Radiographic Control After Stereotactic Radiosurgery for Spinal Metastases From Hepatocellular Carcinoma: A Comparison With Other Radioresistant Histologies

Todd J. Carpenter, MD, Michael H. Buckstein, MD, PhD, Eddie Zhang, BS, Seth Blacksburg, MD, MBA, Isabelle M. Germano, MD, Sheryl Green, MBBCH; Department of Radiation Oncology, Department of Neurosurgery, Icahn School of Medicine at Mount Sinai; Department of Radiation Oncology, Winthrop University Hospital

PURPOSE: We sought to determine the relative radioresistance of hepatocellular carcinoma (HCC) by evaluating the clinical efficacy of stereotactic radiosurgery (SRS) for spinal metastases from HCC compared with outcomes in patients with classically radioresistant histologies in terms of local control (LC) and pain control.

MATERIALS AND METHODS: We performed a retrospective review of all patients treated at our institution with spine SRS for metastatic HCC, renal cell carcinoma, melanoma, and sarcoma from January 2007 through May 2014. Radiographic control and patient-reported pain control were analyzed as a function of various patient- and treatment-related parameters.

RESULTS: Of 134 lesions in 96 patients treated with spine SRS during the study period, 41 were radioresistant histologies, including 18 HCC, 1 mixed HCC/cholangiocarcinoma, 15 renal cell carcinoma, 6 melanoma, and 1 leiomyosarcoma. Median age was 61 years. Extraosseous disease was present in 63% overall (74% and 55% in HCC and non-HCC patients, respectively; P = NS). Spinal cord compression was present in 29% (32% and 27% in HCC and non-HCC patients, respectively; P = NS), and 24% had decompressive surgery prior to SRS (26% and 23% in HCC and non-HCC patients, respectively; P = NS). Median dose was 18 Gy (range: 14–18 Gy), with no difference between groups. Follow-up imaging was available for 35 patients. With a median follow-up of 6.4 months, actuarial 3-, 6-, and 12-month LC rates for HCC and non-HCC patients were 74%, 65%, and 35% and 94%, 94%, and 85%, respectively (P = .0383). Median time to local failure was 3.5 months for HCC patients and 10.7 months for non-HCC patients. On multivariate analysis (MVA), there was significantly worse LC with HCC histology (P = .0257). Of the 29 patients reporting pretreatment pain, initial pain relief was achieved in 27 (93%); both patients who did not experience initial pain relief had HCC. Actuarial 3-, 6-, and 12-month pain control rates for HCC and non-HCC patients were 73%, 61%, and 23% and 100%, 90%, and 90%, respectively (P = .0405). This interaction remained significant on MVA (P = .0414).

CONCLUSIONS: When treated with SRS to the spine, metastatic HCC has worse pain and radiographic control than other highly radioresistant histologies, suggesting that HCC should be included in the category of highly radioresistant tumors. Whether these lesions may benefit from further dose escalation and/or alternate treatment strategies will be the subject of future studies.

Proceedings of the 97th Annual Meeting of the American Radium Society - americanradiumsociety.org