Guideline and preliminary clinical practice results for dose specification and target delineation for postoperative radiotherapy for oral cavity cancer.

Background: Surgery followed by radiotherapy (RT) is indicated for patients with high-risk oral cavity cancer (OCC). Based on multi-institutional reports, we developed a guideline for postoperative RT for patients with OCC.

Methods: A multidisciplinary OCC team was recruited to develop a questionnaire concerning details of risk-factor categorization, target delineation, and dose specification. Thirty-one radiation oncologists from 18 institutions completed the questionnaire, and data were subjected to extensive review to establish the guideline by expert meeting. In this study, we also report the results for patients treated in accordance with the guideline at our institution between 2007 and 2011.

Results: Forty-one patients received RT compatible with this guideline with a median 26.8-month follow-up. Thirty-two patients (78%) remained disease-free, 6 (15%) developed locoregional recurrence (4 in-field, 1 marginal, and 1 out-field) and 4 (10%) developed distant metastasis. The overall 2-year survival rate was 86.7%.

Conclusion: This guideline is promising and should be validated and refined in further clinical practice.