Sensorineural hearing loss after radiotherapy for head and neck tumors: a prospective study of the effect of radiation.

INTRODUCTION: In the treatment of head and neck cancers, the cochlea may be damaged if it is within the radiotherapy (RT) area; however, the severity and mechanism of such damage have yet to be clearly defined. The purpose of this study was to analyze the rates of early- and late-stage sensorineural hearing loss (SNHL) in patients receiving RT due to head and neck cancer and to investigate the reliability of distortion product otoacoustic emissions (DPOAEs) measurements and audiometric evaluation. STUDY DESIGN: Prospective. METHOD: The study included 38 ears of 19 patients scheduled for RT due to head and neck cancer diagnoses. The patients received RT at a fractioned dose of 200 cGy (5 d/wk) and were evaluated pretreatment and posttreatment (1st and 12th mo), both audiometrically and with DPOAE measurement. Any decrease greater than 10 dB was considered SNHL. The amplitudes of DPOAE measurements were statistically compared. RESULTS: The audiometric evaluation performed in the 1st posttreatment month showed no SNHL in any of the patients, whereas in the 12th month, 47% of the ears had SNHL. In all the patients that developed SNHL, the amplitudes obtained in DPOAE measurements in the first posttreatment month were statistically significantly lower. CONCLUSION: The results of the present study show that DPOAE measurement is a reliable method for determining which patients are at risk of developing SNHL in the early post-RT period.

[Prognostic factors and survival rates in oral cavity cancers]. / Oral kavite kanserlerinde prognostik faktörler ve sagkalim oranlari.

OBJECTIVES: We evaluated the treatment results and prognostic factors that might affect local control and survival in patients receiving radiotherapy for oral cavity cancers. PATIENTS AND METHODS: The study included 32 patients (16 men, 16 women; mean age 62 years; range 26 to 90 years) who received radiotherapy for oral cavity cancers. All the patients had squamous cell carcinoma, which involved the tongue in 15 patients (46.9%) and the lower lip in 13 patients (40.6%). Most of the patients (n=21, 65.7%) had T1 or T2 tumors. Neck lymph nodes were positive in 11 patients (34.4%). Fifteen patients had early stage (stage I, II), 17 patients had advanced stage (stage III, IV) tumors. Sixteen patients received primary radiotherapy and 16 patients received postoperative adjuvant radiotherapy, with doses ranging from 5000 cGy to 7000 cGy. The mean follow-up period was 68 months (range 5 to 147 months). RESULTS: Two-year and five-year survival rates were 53% and 39%, respectively. Age, sex, tumor differentiation, and the total radiotherapy dose were not found to affect survival (p>0.05), whereas tumor size, positive lymph nodes, stage, and treatment modality were found as significant prognostic factors (p=0.01). CONCLUSION: Our data show that tumor size, lymph node involvement, stage, and postoperative adjuvant radiotherapy are significant parameters that affect survival in oral cavity cancers.