Surviving hypopharynx-larynx carcinoma in the era of IMRT

Outcome in locoregionally advanced laryngeal carcinoma and hypopharyngeal carcinoma after conventional radiation techniques is known for modest disease control and considerable late toxicity. Considering the lack of standardization in prescription dose for intensity-modulated radiotherapy (IMRT), we aimed to compare the results after our methods of simultaneously integrated boost IMRT with published results.

Between March 2002 and December 2008, 65 hypopharyngeal, 31 supraglottic, and 27 locoregionally advanced glottic tumor patients underwent definitive IMRT (with simultaneous chemotherapy in 86%). Of these, 64% presented with locoregionally advanced disease. Mean follow-up was 26 months (range, 3-83 months), with a median of 21 months. Treatment (2.0-2.2 Gy per fraction, 66-72.6 Gy) followed a prospectively defined protocol. If the boost volume included more than half of the larynx or a substantial part of the pharynx, dose was limited to 2.0 Gy per fraction.

The 2-year local, nodal, and locoregional control (LRC) rates for the entire cohort were 82%, 90%, and 77%, respectively; the disease-free and overall survival rates were 75% and 83%, respectively. The ultimate 2-year LRC rate, including salvage surgery, was 86%. Laryngectomy was required in 2 LRC patients needing tracheostoma already before; 2 further LRC patients needed tracheostomy before IMRT and remained tracheostoma dependent, and 3 patients remained feeding tube dependent after IMRT. Salvage laryngectomy was successful in 8 of 11. Of all 123 patients, 91 patients (74%) are locoregionally controlled and live with a functional laryngopharynx.

Simultaneously integrated boost IMRT with limited acceptance of dose inhomogeneity resulted in very satisfactory disease control despite a slight left shift of planning target volume curves on the dose-volume histogram. Considering the treatment tolerance, a careful increase in dose in our patients seems possible. Dose-volume comparisons remain difficult because no international standards have been defined for contouring and volume-related dose distribution.