Concordance between the chang and the International Society of Pediatric Oncology (SIOP) ototoxicity grading scales in patients treated with cisplatin for medulloblastoma

Background: Reporting ototoxicity is frequently complicated by use of various ototoxicity criteria. The International Society of Pediatric Oncology (SIOP) ototoxicity grading scale was recently proposed for standardized use in reporting hearing loss outcomes across institutions. The aim of this study was to evaluate the concordance between the Chang and SIOP ototoxicity grading scales. Differences between the two scales were identified and the implications these differences may have in the clinical setting were discussed. Procedures: Audiological evaluations were reviewed for 379 patients with newly diagnosed medulloblastoma (ages 3-21 years). Each patient was enrolled on one of two St. Jude clinical protocols that included craniospinal radiation therapy and four courses of 75mg/m² cisplatin chemotherapy. The latest audiogram conducted 5.5-24.5 months post-protocol treatment initiation was graded using the Chang and SIOP ototoxicity criteria. Clinically significant hearing loss was defined as Chang grade ≥2a and SIOP ≥2. Hearing loss was considered serious (requiring a hearing aid) at the level of Chang grade ≥2b and SIOP ≥3. Results: A strong concordance was observed between the Chang and SIOP ototoxicity scales (Stuart's tau-c statistic=0.89, 95% CI: 0.86, 0.91). Among those patients diagnosed with serious hearing loss, the two scales were in good agreement. However, the scales deviated from one another in classifying patients with less serious or no hearing loss. Conclusions: Although discrepancies between the Chang and SIOP ototoxicity scales exist primarily for patients with no or minimal hearing loss, the scales share a strong concordance overall. Pediatr Blood Cancer 2014;61:601-605.