Long-Term Progression of Sensorineural Hearing Loss and Tinnitus after Combined Intensity-Modulated Radiation Therapy and Cisplatin-Based Chemotherapy for Nasopharyngeal Carcinoma: A Case Report

Sensorineural hearing loss (SNHL) is a common adverse effect for nasopharyngeal carcinoma (NPC) patients treated with chemoradiotherapy. We report a case of 12-year follow-up from a patient with stage IIB NPC, treated in 2004 with intensity-modulated radiotherapy and cisplatin-based chemotherapy. Pure-tone audiograms were conducted before treatment and at two other points in the 12-year period after treatment. Analysis of the patient's audiograms reveals that the development of high-frequency SNHL started after treatment and reached a plateau accompanied by tinnitus approximately 32 months after treatment conclusion. After the plateau, high-frequency SNHL continued to develop slowly in the next 10 years, possibly a long-term effect from radiation-induced microvascular change of the hearing apparatus. The continuous high-frequency hearing decline is associated with increased tinnitus pitch in the patient. With experience learned from this case, we recommend hearing tests at regular intervals for at least 3-5 years for NPC patients treated with chemoradiotherapy. Patients need to be educated about tinnitus and counseling can be offered when they begin to feel inconvenienced by tinnitus. These patients also need to be advised against exposure to noise that can aggravate the already compromised hearing apparatus, leading to further hearing loss and worsening tinnitus. Limiting the peak dose and total cumulative dose of cisplatin should be considered based on the patients' risk factors to achieve a balance between treatment efficacy and long-term adverse effects.