Clinical outcomes of Cyberknife in brain metastases / 中华放射肿瘤学杂志

ABSTRACT

Objective To retrospectively analyze clinical outcomes of brain metastases treated with Cyberknffe. Methods From Aug. 2006 to Aug. 2007, 40 patients with brain metastases treated with Cy-berknife in Tianjin Cancer Hospital were included. Totally 68 brain metastatic lesions were treated. The maximal diameter was 0.4 -7.5 cm (average 1.9 cm). The primary tumor of 35 patients was partial re-ponse or stable to the previous treatment at the diagnosis of brain metastasis. The geometric center of target volume was set as the isocenter and the nominal standard dose point. More than 95% target volume was cov-ered by 80% isodose surface. Hypofractionated radiation was 18 -36 Gy given in 1 -5 fractions of 5 -25 Gy. Results The Follow-up rate was 95%. The clinical symptom remission rate (including complete and partial remission) at one week after Cyberknife treatment was 90% (36/40). The therapeutic effective rate (CR + PR + SD) was 94% (64/68) after three months follow-up, which was evaluated by contrast-en-hanced CT or MRI. The 3-month local control and 1-year survival rates were 78% (53/68) and 68% (27/40). New brain metastatic lesions outside the radiation field occurred in 14 patients within 3 months, which was independent of age, whole brain irradiation, number or maximal diameter of original lesions, frac-tion dose, frequency or total dose of Cyberknife treatment. Conclusions Cyberknife, used as the primary treatment of brain metastases, can achieve good clinical outcomes.