MBCL-47. OTOTOXICITY IN MEDULLOBLASTOMA SURVIVORS FOLLOWING PROTON RADIATION. Issue 2 (22nd June 2018)

• Record Type: Journal Article
• Authors: Byun, John; Hess, Clayton B; Bajaj, Benjamin V M; Weyman, Elizabeth A; Lawell, Miranda P; Gallotto, Sara L; Ebb, David H; MacDonald, Shannon M; Tarbell, Nancy J; Yock, Torunn I
• Is Part Of: Neuro-oncology. Volume 20:Issue 2(2018)supplement 2
• Page Start: i127
• Page End: i127
• Publication Date: 2018-06-22
• Subjects: Brain Neoplasms -- Periodicals; Brain -- Tumors -- Periodicals; Brain -- Cancer -- Periodicals; Nervous system -- Cancer -- Periodicals; 616.99481
• DOI: 10.1093/neuonc/noy059.443
• Languages: English
• ISSNs: 1522-8517

Abstract

Abstract: BACKGROUND: Radiotherapy to the cochlea and cisplatin exposure are both associated with hearing loss (HL) in medulloblastoma survivors. Here we report late outcomes in survivors with ≥1 year audiogram testing. METHODS: Prospective medulloblastoma trial participants (clinicaltrials.gov: NCT01063114/NCT00105560) with ≥1 years of audiogram follow-up (FU, n=110 pts) comprised the study cohort. HL was graded using the SIOP-Boston ototoxicity scales (0-4) for each ear. Associations between grade 3 HL and mean cochlear radiation dose and cumulative cisplatin dose were evaluated. Target cisplatin dose was 450 mg/m2 but most patients did not receive full dose as dose reductions were used when ototoxicity was detected during chemotherapy. FINDINGS: Median follow-up was 4.0 years (range 1-10). At baseline, 10 ears (4.5%) had grade 3 HL. At latest FU, an additional 49 ears developed grade 3 HL (23.3%). There was no grade 4 HL. Median average cochlear dose across both ears was 29.9 Gy (20.8-50.6) and median cisplatin dose was 375.0 mg/m2 (60.0-583.0). Mean cochlear radiation dose for grade 3 HL (n=56) was 32.5Gy (24.1-47.0), compared with 31.8Gy (20.8-50.6, p=0.19). Mean cisplatin dose for grade 3 HL was 347.3mg/m2 (180.0-450.0), compared with 374.2mg/m2 for grade 0-2 ears (60.0-583.0, p=0.05). INTERPRETATION: Significant hearing deficits (SIOP-Boston grade 3) develop in approximately 23.3% of medulloblastoma patients. In this cohort, higher mean radiation dose did not affect HL rates. The lower mean cumulative cisplatin dose in pts with grade 3 HL suggests cisplatin ototoxicity is driving HL, and that host susceptibility may play a role.