IMRT in hypopharyngeal tumors.
OBJECTIVE
Intensity-modulated radiation therapy (IMRT) data on hypopharyngeal cancer (HC) are scant. In this study, the authors report on early results in an own HC patient cohort treated with IMRT. A more favorable outcome as compared to historical data on conventional radiation techniques was expected.


METHODS
29 consecutive HC patients were treated with simultaneous integrated boost (SIB) IMRT between 01/2002 and 07/2005 (mean follow-up 16 months, range 4-44 months). Doses of 60-71 Gy with 2.0-2.2 Gy/fraction were applied. 26/29 patients were definitively irradiated, 86% received simultaneous cisplatin-based chemotherapy. 60% presented with locally advanced disease (T3/4 Nx, Tx N2c/3). Mean primary tumor volume measured 36.2 cm(3) (4-170 cm(3)), mean nodal volume 16.6 cm(3) (0-97 cm(3)).


RESULTS
2-year actuarial local, nodal, distant control, and overall disease-free survival were 90%, 93%, 93%, and 90%, respectively. In 2/4 patients with persistent disease (nodal in one, primary in three), salvage surgery was performed. The mean dose to the spinal cord (extension of > 5-15 mm) was 26 Gy (12-38 Gy); the mean maximum (point) dose was 44.4 Gy (26-58.9 Gy). One grade (G) 3 dysphagia and two G4 reactions (laryngeal fibrosis, dysphagia), both following the schedule with 2.2 Gy per fraction, have been observed so far. Larynx preservation was achieved in 25/26 of the definitively irradiated patients (one underwent a salvage laryngectomy); 23 had no or minimal dysphagia (G0-1).


CONCLUSIONS
Excellent early disease control and high patient satisfaction with swallowing function in HC following SIB IMRT were observed; these results need to be confirmed based on a longer follow-up period. In order to avoid G4 reactions, SIB doses of < 2.2 Gy/fraction are recommended for large tumors involving laryngeal structures.
Studer
Gabriela
G
Radiotherapie, USZ, Universitätsspital Zürich, Rämistrasse 100, 8091, Zürich, Switzerland. gabriela.studer@usz.ch
Lütolf
Urs Martin
UM
Davis
Jacques Bernard
JB
Glanzmann
Christoph
C
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003680:Deglutition Disorders / Q000209:etiology* / Q000517:prevention & control*; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000209:etiology / Q000517:prevention & control; D020266:Radiotherapy, Conformal / Q000009:adverse effects* / Q000379:methods*; D018570:Risk Assessment; D016896:Treatment Outcome