Sensorineural hearing loss after radiotherapy and chemoradiotherapy: a single, blinded, randomized study

Area of Science:

• Otolaryngology
• Radiation Oncology
• Medical Oncology

Background:

• The combined ototoxic effects of radiation and cisplatin (CDDP) are not well understood.
• Nasopharyngeal carcinoma (NPC) treatment often involves radiotherapy, with or without chemotherapy.

Purpose of the Study:

• To compare sensorineural hearing outcomes in NPC patients receiving radiotherapy alone versus those receiving concurrent and postradiotherapy CDDP.
• To investigate the ototoxicity of chemoradiotherapy in NPC patients.

Main Methods:

• Newly diagnosed NPC patients were randomized to radiotherapy or chemoradiotherapy.
• Bone conduction hearing thresholds were measured pre-treatment and at multiple time points post-radiotherapy (1 week, 6 months, 1 year, 2 years).
• Statistical analysis was performed using the Mann-Whitney U test.

Main Results:

• Chemoradiotherapy patients exhibited poorer hearing thresholds at 1 and 2 years post-radiotherapy compared to radiotherapy-alone patients (P = .001 and P = .03, respectively).
• High-frequency (4 kHz) hearing thresholds were significantly worse in the chemoradiotherapy group at all post-treatment time points.
• While hearing thresholds in the radiotherapy group initially improved then worsened, the chemoradiotherapy group's hearing deterioration stabilized by 1 year.

Conclusions:

• Concurrent/adjuvant CDDP with radiotherapy for NPC leads to greater sensorineural hearing loss than radiotherapy alone, particularly affecting high-frequency sounds.
• Current definitions of normal inner ear tissue tolerance for radiotherapy should be revised for chemoradiotherapy patients.