Fractionated stereotactic radiotherapy as reirradiation for locally recurrent head and neck cancer.

Purpose: We report early preliminary experience with CyberKnife radiosurgery (RS) as salvage treatment for locally recurrent head and neck cancer (HNC).

Methods And Materials: Between March 2004 and August 2006, 36 patients (44 sites) were treated with CyberKnife RS as reirradiation for locally recurrent HNC. Treatment sites were as follows: nasopharynx (8), maxillary sinus (8), neck lymph nodes (8), skull base (7), nasal cavity (4), retropharyngeal lymph nodes (3), orbit (2), and others (4). Total doses administered were 18-40 Gy (median, 30 Gy) in 3 to 5 fractions to the 65%-85% isodose line for 3-5 consecutive days. Previous external radiation dose ranged from 39.6 to 134.4 Gy (median, 70.2 Gy). Gross tumor volume ranged from 0.2 to 114.9 cm(3) (median, 22.6 cm(3)). Median follow-up was 17.3 months.

Results: Thirty-five of 44 sites were evaluated for response. Fifteen (42.9%) sites achieved complete response, 13 sites (37.1%) achieved a partial response, 3 (8.6%) sites maintained stable disease, and 4 sites (11.4%) showed tumor progression. Grade III acute complications were noted in 13 patients. Late complications were observed in three patients (1 bone necrosis, 2 soft tissue necrosis) during follow-up.

Conclusion: These preliminary results suggest that fractionated stereotactic radiosurgery is an effective treatment modality as a salvage treatment with good short-term local control. The early overall response rate is encouraging. However, more experience and a longer follow-up are necessary to determine the role of fractionated stereotactic radiosurgery as a salvage treatment of locally recurrent HNC and to define long-term complications.