International Journal of Hematology and Oncology 2020, Vol 30, Num 2 Page(s): 190-199
DAILY HIGH DOSE PER FRACTION RADIOTHERAPY IN EARLY GLOTTIC LARYNGEAL TUMORS WITH CONCURRENT ANALYSIS OF VOICE QUALITY AND VOCAL FUNCTION

UĞUR SELEK1, FADIL AKYOL1, ENİS ÖZYAR1, SAİT SARI1, TAŞKIN YÜCEL1, ESRA ÖZCEBE1

Hacettepe University Department of Radiation Oncology, ANKARA

Keywords: laryngeal cancer, radiation therapy, acoustic voice analysis, videolaringostroboscopy
We prospectively assessed the outcome of daily high dose per fraction radiotherapy schema in early stage glottic carcinoma patients, along with objective analysis of vocal cord function and functional voice preservation. Between June 1998 and February 2001, 61 patients with early stage (T1-2N0M0) squamous cell glottic carcinoma, who received definitive radiation therapy at Hacettepe University, were analyzed. Patients were treated homogeneously by Co 60 photon beams, with parallel-opposed laryngeal ports, at daily fractionation doses of 2.3 Gy over 27 fractions to 62.1Gy for T1 and 28 fractions to 64.4 Gy for T2 tumors. A longitudinal voice quality (VQ) and vocal function (VSL) study were prospectively conducted before, in the middle of and after radiotherapy, and every 3 months up to 9 months follow up. Acoustic measures of the fundamental frequency (FF, vocal cord vibration in Hz.), jitter (perturbation of vibration), shimmer (perturbation of loudness), and harmonic-to-noise ratio (HNR) were objectively calculated. Function of vocal cords was visually evaluated by videostrobolaringoscopy (VSL) with Hirano & Bless criteria. Median follow-up was 4 years (range, 3 - 67 months). Actuarial local control at 5-years was 90.1 % for T1 tumors (T1a, 90.1%; T1b, 85.7%) and crude local control was 6/9 (66.6%) for T2 tumors. Five year actuarial survival for T1N0M0 patients was 92.9%. The pre-treatment objective voice quality values of the irradiated patients, in comparison with normal population values, showed elevated median scores for FF (154.8 Hz. ± 41.3 Hz.), jitter (%4.5 ± %4.3), shimmer (8.9 dB ± 6 dB), and HNR (0.25 dB ± 0.20 dB). Subsequently, at 3 and 6 months follow up after radiotherapy, the comparison of objective voice parameters with pretreatment values showed an overall significant decrease for FF, jitter, shimmer and HNR. Pretreatment VSL displayed irregularity of vocal cords and mucosal wave distortion; however both parameters improved by radiotherapy significantly. Irregularity in each cord recovered significantly in comparison to preradiotherapy observation (left cord p= 0.03, right cord p= 0.01); as well as significantly better mucosal waves with better vibration were detected on both sides (left mucosa p= 0.03, right mucosa p= 0.02). Grade I or II acute morbidity (RTOG/EORTC) with dysphagia was observed at median 13th day of treatment (range, 10th-23rd days), but no grade 3 or 4 acute morbidity occurred. No late complications of grade 2-4 were detected in follow up. Our altered fractionation radiotherapy seems to be a highly tolerable and effective treatment modality, with less than normal but improved objective voice scores after irradiation in comparison to those prior to treatment. The outcome of different treatment alternatives in local control and voice quality must be an important issue for the best therapeutic option for early glottic larynx tumors, and irradiation appears to be a reasonable first choice.