Laryngeal long-term morbidity after supraglottic laryngectomy and postoperative radiation therapy

Purpose: This study was performed to investigate factors associated with la ryngeal morbidity when postoperative radiation therapy (RT) is added to sup raglottic laryngectomy. Materials and Methods: From 1980 to 1994, 56 patients affected with T1 to 4 N0 to 2c supraglottic squamous cell carcinoma selected for standard (59%) or extended (41%) supraglottic laryngectomy at 2 different institutions wer e retrospectively analyzed. Most of the patients (91%) also underwent neck dissection. Approximately 80% of the patients had stage T4 primary lesions or N2 neck disease. Postoperative RT was added for presumed microscopic dis ease at the primary site (13 patients), regional nodes (23 patients), or bo th (20 patients). Median delivered doses to the larynx and to the neck were 50 Gy (range, 40 to 64 Gy) and 46 Gy (range, 40 to 64 Gy), respectively. M edian follow-up for living patients is 11 years (range, 2.8 to 16.9 years). Laryngeal complication was defined as the appearance of grade 2 or higher toxicity according to the European Organization for Research and Treatment of Cancer (EORTC) and the Radiation Therapy Oncology Group (RTOG) scoring s ystems. Results: Two- and 5-year actuarial locoregional control rates were 85 +/- 5 % and 83 +/- 5%, respectively. Thirty patients (54%) developed laryngeal co mplications. However, just one patient experienced grade 4 laryngeal oedema requiring permanent tracheostomy. Estimated actuarial survival without lar yngeal complications were 50 +/- 7%, 43 +/- 7%, and 39 +/- 7% at 2, 5, and 10 years, respectively. At univariate analysis, treated volumes (P = .03) a nd total dose to the larynx (P = .03) were significantly associated with lo cal toxicity. A trend was observed also for. the maximum dose to the neck ( P = .06) and dose per fraction (P = .09). A multivariate Cox proportional h azards model showed total dose to the larynx tb be the only independent pre dictor of toxicity (P = .03). The hazard ratio of laryngeal toxicity was 2. 2 (95% confidence interval: 1.1 divided by 4.6), for a total dose to the la rynx greater than 50 Gy. Conclusion: After supraglottic laryngectomy, postoperative RT to the neck d oes not affect local morbidity, but careful RT treatment planning is necess ary to avoid delivering a total dose to the larynx greater than 50 Gy. (Am J Ototaryngol 2000;21:14-21. Copyright (C) 2000 by W.B. Saunders Company).