Stereotactic body radiation therapy induces fast tumor control and symptom relief in patients with iliac lymph node metastasis.

The CyberKnife is a robotic stereotactic body radiotherapy (SBRT) system which has shown promising results for many malignances with good efficacy and low toxicity. This study aims to evaluate the response and local control (LC) obtained with CyberKnife in the management of iliac lymph node metastases (ILNM). Twenty-two patients with 27 ILNM were treated by CyberKnife from May 2010 to May 2016. Median follow-up time was 33 months (8-97). The complete response, partial response, stable disease and progression disease rates were 37.0%, 48.0%, 7.5% and 7.5% respectively. The 1-, 2-, and 3-year LC rates were all 90.6%, and overall survival rates were 78.8%, 60.6%, and 43.3% respectively. All patients with pelvic pain and ureter obstruction achieved good and fast symptom relief, while leg edema persisted in 2 patients. The general treatment tolerance was acceptable and no severe toxicities were reported. No factors were found correlated with local failure. While overall survival (OS) was better for patients who had received a total dose more than 30 Gy or prior systemic treatment, and whose symptoms were relieved. Taken together, CyberKnife is an effective therapeutic option for ILNM, providing high LC rate and good symptom relief with minimal toxicity.