Objectives: Few reports addressed radiosurgery of calvarial metastases. We evaluated efficacy and toxicity of CyberKnife Radiosurgery (CKR) for symptomatic calvarial metastases (SCM).

Methods: We treated with CKR for 8 patients with SCM from May 2008 to August 2015. Primary sites were lung cancer(3), hepatocellular carcinoma(3), esophageal cancer(1) and maxillary sinus cancer(1). The median target volume was 25.9 mL (range, 8.0 - 74.5 mL). The median marginal dose was 25Gy (range, 18 – 30Gy) and the median fractions were 5 (range, 1 – 5 fractions). The median maximum dose and fraction were 26.9 Gy and 5 fractions at the scalp surface. The SCM presented with local swelling (4/8 patients), local pain or headache (6/8 patients) and no neurologic deficit.

Results: All patients had died during the observation. The 50% survival and 6 months survival rate from CKR were 2.5 months and 12.5%. Pain relief was 100% after CKR. Four of 6 patients improved completely local pain during the CKR treatment. We confirmed tumor shrinkage in 2 of 4 patients with local swelling. CKR treatment caused no grade 3 - 5 toxicities in CTCAE v4.0. All patients had local alopecia at the scalp.

Conclusions: Our results indicated that CKR was a safe and effective treatment option for SCM.