Hearing Assessment after Treatment of Nasopharyngeal Carcinoma with CRT and IMRT Techniques

Abstract

Objectives. This study analyzed the long-term hearing loss after treatment of primary nasopharyngeal carcinoma to elucidate its causal factors. Methods. Ninety-two nasopharyngeal carcinoma patients were treated with radiotherapy or chemoradiotherapy. Pure tone audiometry was performed before the therapy and annually up to 9 years after completing treatment. The hearing thresholds were corrected for age-related deterioration and compared to the results without adjusting for age. Results. The mean air and bone conduction threshold with and without correction for age-related deterioration differed significantly 2–9 years after completing radiotherapy (p < 0.05). The audiometry results with age correction showed a flattened configuration compared to the results without age correction. The total radiation dose and radiation modality showed a causal relationship with a greater incidence of hearing loss after therapy (p < 0.05). There was more deterioration in the air and bone hearing thresholds with conformal radiotherapy than intensity-modulated radiotherapy (p < 0.001). A radiation dose >72 cGy resulted in more severe hearing loss than <72 cGy (p < 0.05). Conclusion. Hearing loss after completing therapy should be corrected for age-related hearing deterioration to reveal the true extent to which the loss is a therapeutic complication. Both the radiation modality used and the dose were significantly associated with hearing loss.

Treatment of late sequelae after radiotherapy for head and neck cancer

“…In addition to a radiation dose of 47 Gy or more to the cochlea, the main factors affecting the risk of SNHL are the patient’s age and baseline hearing level, cisplatin dose, post-RT otitis media, and follow-up time [178,179,183–185]. In addition, the deterioration in air conduction caused by RT-induced Eustachian tube dysfunction and middle air fibrosis may accompany persistent SNHL, indicating mixed hearing impairment [186]. …”

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

“…Findings in the current literature suggest that persistent high-frequency SNHL is common after NPC treatment, and combining cisplatin-based chemotherapy with radiotherapy increases the incidence and severity of SNHL [ 5 , 6 , 9 ]. However, the existing literature is inconclusive on the nature of long-term progression of SNHL after chemoradiotherapy.…”

“…It was reported that high-frequency SNHL can occur any time after the initiation of NPC treatment with occurrence probability reaching the plateau between 18 and 24 months after treatment [ 6 ]. One study suggested that treatment-induced SNHL can continue to increase with time [ 9 ]. It is noted that some of the early studies on SNHL after NPC treatment were based on short follow-up time [ 5 ].…”

Avaliação de toxicidades tardias em pacientes com carcinoma epidermoide de cabeça e pescoço submetidos a quimiorradiação concomitante baseada em cisplatina

“…Modalidades de tratamento que visam minimizar a ototoxicidade devem ser estimuladas e o emprego de IMRT parece ser protetor contra a perda auditiva induzida pela radioterapia, pois permite poupar a cóclea dos efeitos das altas doses de radiação (143)(144)(145) .…”

“…as audiometrias e os padrões de perda auditiva devem ser interpretados após ajuste para o que é esperado naquela faixa etária do paciente. Desse modo, podemos evidenciar a perda auditiva que é, verdadeiramente, uma complicação terapêutica (144) .…”