2846 - Relationship between RTOG Criteria of Ototoxicity and Sensorineural Hearing Loss Based on Pure Tone Audiometry in Nasopharyngeal Carcinoma Patients Delivered by Intensity Modulated Radiotherapy
Presenter(s)
X. Song1, and M. Shi2; 1Department of Radiation Oncology, First Affiliated Hospital of Air Force Medical University, Xi’an, Shaanxi, China, 2Department of Radiation Oncology, First Affiliated Hospital of Air Force Medical University, Xi'an, Shaanxi, China
Purpose/Objective(s): Radiation-induced sensorineural hearing loss (SNHL) is a severe manifestation of ototoxicity, characterized by delayed onset and progressive deterioration. Currently, there were no effective drugs to prevent or treat SNHL. Radiation Therapy Oncology Group (RTOG) criteria, based on subjective patient-reported hearing loss, primarily reflects acute auditory toxicity during radiotherapy (RT). However, the long-term recovery of hearing beyond 1 year after intensity-modulated radiotherapy remains unclear. In contrast, SNHL is objectively quantified by pure tone audiometry (PTA), providing a precise measure of hearing loss. SNHL seriously affects patients' quality of life. The correlation between RTOG ototoxicity levels and SNHL has been rarely reported. This study we used single-center retrospective data to analyze whether RTOG toxicity criteria can predict SNHL.
Materials/Methods: 619 patients with nasopharyngeal carcinoma (NPC) in our institution from 2013 to 2023 were included in the study. Ototoxicity and PTA of 65 patients (130 ears) were recorded in detail at 1 year and 2 years after RT. Ototoxicity was evaluated with RTOG 0617. SNHL was assessed with 1997 WHO hearing loss criteria, based on PTA results showing elevated air and bone conduction thresholds (> 25 dB) at 0.5, 1, 2, and 4 kHz (high frequency), with an air-bone conduction thresholds gap < 10 dB. Correlation and comparative analysis were performed using statistical software.
Results: The incidence of ototoxicity in 619 NPC patients was 37.8%, 44.9%, 50.9%, 47.8%, and 45.9% at 3, 6, 12, 18, and 24 months after RT, respectively. 12.1%, 18.1%, 23.1%, 21%, and 20.2% of patients exhibited RTOG ototoxicity grade = 2. Patients' hearing levels at 1 year and 2 years recovered to 78.9% and 87% of the levels observed at 3 months after RT. Ototoxicity was observed in 56.2% (73/130) and 60.9% (56/92) of ears at 1 and 2 years after RT. High frequency SNHL occurred in 31.5% (41/130) and 57.6% (53/92) of ears at 1 and 2 years after RT, while low frequency SNHL was observed in 8.5% (11/130) and 19.6% (18/92). The proportion of high and low frequency SNHL in the RTOG grade = 2 group gradually increased at 1 and 2 years after RT (66.67% vs 89.6%; 23.3% vs 29.9%). High frequency SNHL positively correlated with ototoxicity after 1 and 2 years (Spearman coefficients: 0.414, p < 0.001; 0.676; p < 0.001). Low frequency SNHL also correlated with ototoxicity (Spearman coefficients: 0.392, p < 0.001; 0.491, p < 0.001). Kruskal-Wallis H test and post-hoc analysis revealed significant differences in high frequency SNHL with different RTOG grades (RTOG grade 0 vs1: p=0.002; grade 0 vs 2: p<0.001; grade 1 vs 2: p=0.043).
Conclusion: RTOG ototoxicity grades may be a reliable predictor for the occurrence of SNHL. It enables clinicians to identify SNHL early and implement prevention and treatment strategies.