We evaluated the efficacy and safety of stereotactic body
radiation therapy (SBRT) for patients with head and neck
tumors. From April 2005 through April 2008, 34 patients with head and neck
tumors were treated with CyberKnife SBRT. Twenty-one of them had prior
radiotherapy. Treatment sites were orbit (n = 7), cervical lymph nodes (n = 6), nasopharynx (n = 5), oropharynx (n = 4) and others (n = 12). The prescribed dose ranged from 19.5 to 42 Gy (median, 30 Gy) in 3-8 fractions for consecutive days. The target volume ranged from 0.7 to 78.1 cm(3) (median, 11.6 cm(3)). The median follow-up was 16 months. Treatment was well tolerated without significant acute complications in any cases. Complete response rate and partial response rate were 32.4% and 38.6%, respectively. The overall survival rates were 70.6% and 58.3% at 12 and 24 months, respectively. The overall survival was better in patients without prior
radiotherapy within the previous 24 months or in case of smaller target volume. Six patients suffered severe late complications. All these patients had prior
radiotherapy, and 2 of them developed massive
hemorrhage in the pharynx and both died of this complication 5 and 28 months, respectively, after SBRT. Our preliminary results suggest that SBRT is an effective treatment modality for head and neck
tumors. However,
re-irradiation has significant risk of severe and even fatal late complications in the form of
necrosis and
hemorrhage in re-irradiated areas.