Effectiveness of brachytherapy and fractionated stereotactic radiotherapy boost for persistent nasopharyngeal carcinoma.

Background: Nasopharyngeal carcinoma (NPC) with local persistence after primary radiotherapy carries a high risk of treatment failure. We compared the effectiveness of brachytherapy and a fractionated stereotactic radiotherapy (SRT) boost in improving tumor control.

Methods: We retrospectively reviewed the records of 755 patients with NPC treated from 1994 to 2001. Fifty-two patients (7%) had persistent local disease, but seven of them were unsuitable for radiotherapy boost. Overall, 24 patients received brachytherapy boost at a median dose of 20 Gy, and 21 patients received an SRT boost at a median dose of 15 Gy.

Results: Despite the radiotherapy boost, the overall 3-year local failure-free control rate was still significantly lower for patients with persistent disease than for the rest (71% vs 86%, p < .01). Only the SRT subgroup achieved a local failure-free control rate close to that of the complete responders (82% vs 86%, p = .71).

Conclusions: SRT boost is more effective in reverting the poor prognostic influence of local persistent disease.