In a single-institution cohort study reported in the Journal of Clinical Oncology, Keilty et al identified factors associated with an increased risk of hearing loss in pediatric patients receiving radiation therapy and chemotherapy for central nervous system and head and neck tumors.
The study involved data from 2,420 longitudinal hearing assessments in 340 ears from 171 patients aged ≤ 18 years treated with radiation with or without chemotherapy at the Hospital for Sick Children, Toronto, between 2005 and 2017. Hearing assessments were evaluated according to International Society of Pediatric Oncology-Boston (SIOP) grading.
On multivariate analysis, mean cochlea radiotherapy dose (odds ratio [OR] = 1.04 per Gy, P < .001), time since radiotherapy (OR = 1.21 per year, P < .001), cisplatin dose (OR = 1.48 per 100 mg/m2, P < .001), and carboplatin dose (OR = 1.41 per 1,000 mg/m2, P =.002) were independently associated with increasing SIOP grade of hearing loss.
Risk of severe hearing loss (SIOP grade 3–4) was also significantly associated with mean cochlea radiotherapy dose (OR = 1.05 per Gy, P < .001), time since radiotherapy (OR = 1.18 per year, P < .001), cisplatin dose (OR = 1.23 per 100 mg/m2, P = .029), and carboplatin dose (OR = 1.45 per 1,000 mg/m2, P =.019), as well as radiotherapy at < 3 vs ≥ 3 years of age (OR = 2.86, P = .019).
No synergistic effect on hearing loss was observed for radiotherapy and cisplatin (P = .53 for interaction) or for radiotherapy and carboplatin (P = .85 for interaction).
The cumulative incidence of high-frequency hearing loss (> 4 kHz) was ≥ 50% at 5 years after radiotherapy for mean cochlea radiotherapy doses > 30 Gy. The incidence of hearing loss across all frequencies continued to increase at > 5 years after radiotherapy.
The investigators formulated a nomogram to model the risk of severe hearing loss based on age at radiotherapy, years since radiotherapy, cisplatin dose, carboplatin dose, and cochlea radiotherapy dose. The nomogram has been adapted for a computer-based calculator.
The investigators concluded, “Children treated with radiation and chemotherapy experience a high incidence of hearing loss over time, with associations found between more severe hearing loss and cisplatin or carboplatin dose as well as mean cochlea dose. Mean cochlea dose of ≤ 30 Gy is proposed as a goal to reduce the risk of hearing loss; a lower threshold (20–25 Gy) may be considered in patients receiving platinum chemotherapy to reduce cumulative hearing loss burden.”
Derek S. Tsang, MD, MSc, of the Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by the Mount Sinai Hospital-University Health Network Academic Health Sciences Centre Innovation Fund, Department of Radiation Oncology Academic Enrichment Fund, and Princess Margaret Cancer Foundation. For full disclosures of the study authors, visit ascopubs.org.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.