Spine stereotactic radiosurgery as a promising modality in patients with metastatic hepatocellular and cholangiocarcinoma.

Abstract

e13551 Background: While stereotactic body radiation therapy (SBRT), a form of high-dose rate radiation therapy, is often used in the local management of early-stage hepatocellular carcinoma (HCC), its role in managing metastatic hepatobiliary malignancies is currently unclear. Here, we investigate the role of spine stereotactic radiosurgery (SSRS), a form of SBRT that targets spinal metastases, in the management of late-stage HCC or cholangiocarcinoma. Methods: We retrospectively reviewed a total of 28 patients with 43 HCC or cholangiocarcinoma metastases treated with SSRS between 2004 and 2017 at our institution. We used Kaplan-Meier curves to estimate overall survival (OS) and local control (LC), and Cox regression analysis to identify potential predictive factors of the two. Results: The median patient age was 63 (range 28 to 78) years old. Four patients had a histology-proven diagnosis of metastatic cholangiocarcinoma, while 39 had hepatocellular carcinoma. Of the patients with HCC, 47% had predisposing viral hepatitis, while 53% had either non-alcoholic steatohepatitis (NASH) or no known predisposing factors. Twenty-nine cases were treated with 24Gy in 1 fraction, 11 with 27Gy in 3 fractions, 2 with 18Gy in 2 fractions, and 1 with 30Gy in 5 fractions. The 1-year actuarial OS and LC rates were 23% and 75%, respectively. The median OS was 6.3 months, while the median time to local failure was not reached. On univariate modeling, negative predictors of LC included history of prior RT to the site of metastasis (p < 0.005) and tumor volume > 60cc (p = 0.03), while biologic equivalent dose (BED) > 52Gy was the only positive predictive factor (p < 0.05). Presence of epidural disease, Bilsky grade, presence of viral hepatitis, or type histology were not predictors of LC (all p > 0.05). In patients who had pain or neurologic findings at presentation, 56% reported improvement in their symptoms on follow up. Three patients (11%) developed compression deformity and one patient (4%) developed radiation-induced neuritis. Conclusions: SSRS provides promising and durable local control in patients with metastatic hepatobiliary disease, and early intervention with high BED are necessary to ensure high level of local control, improvement in symptoms, and a low rate of long-term toxicity.