Hearing Loss After Cisplatin-based Chemoradiotherapy for Locally Advanced Head and Neck Cancer: A Prospective Single-institution Study

Background/Aim: A single-institution prospective study was conducted to evaluate hearing loss rate after intensity modulated radiotherapy with concomitant cisplatin-based chemotherapy (CRT) for locally advanced head and neck cancer and identify cochlear dosimetric parameters associated with hearing loss risk. Patients and Methods: Hearing assessment, patients' characteristics, tumor-related variables, and cochlear quantitative dosimetric factors for adults with locally advanced head and neck cancer treated with CRT were prospectively collected. Each patient repeated audiometry at baseline (pre-CRT), 1 month after CRT, and then every 3 to 6 months. For each cochlea minimum dose (D-min), mean dose (D-mean), and maximum dose (D-max) were extracted from treatment plans. Logistic analysis was used for multivariate modeling. The relation between cochlear dosimetric factors and significant hearing loss was also analyzed with receiver operating characteristic (ROC) curves. Results: Between January 2016 and December 2018, 35 patients (70 cochleae) were included. Most patients (n=29; 82.9%) had primary cancer in a low-risk region (oral cavity, oropharynx, larynx). All patients completed the programmed CRT. During follow-up, significant hearing loss was recorded in 13 cases (37.1%). The ROC areas for significant hearing loss in relation to Dmin, Dmean, and Dmax were 0.70, 0.66, and 0.66, respectively. A dose-dependent relationship was noted between cochlear Dmin and significant hearing loss. Conclusion: Dmin <14.4 Gy is associated with reduced rates of significant hearing loss after concomitant cisplatin-based CRT in patients with locally advanced head and neck cancer. Definitive or adjuvant radiotherapy (RT) with concomitant cisplatin-based chemotherapy (CRT) is often recommended in the treatment of patients with locally advanced head and neck cancer (1, 2). Despite advances in RT technique, a significant number of patients will experience treatment related toxicities that negatively affect their quality of life (QoL). Over the years, dysfunction of hearing apparatus has become an important area of investigation for radiation oncologists, conscious that the RT damage to the cochlea is further aggravated by concurrent cisplatin systemic therapy (3). While it is well known that several factors - including patient's age and baseline hearing level, cumulative cisplatin dose, post-RT otitis media onset - affect the risk of hearing loss, it remains undefined which of the cochlear RT dose parameters - minimum dose (D-min), mean dose (D-mean), maximum dose (D-max) - are most predictive of sensorineural hearing loss (3, 4). Given the need to minimize the risk of severe hearing loss, we conducted a prospective study to quantify cochlear dose/hearing loss relationship aiming at a further improvement of counseling of patients with locally advanced head and neck cancer.