Delayed sodium thiosulfate as an otoprotectant against carboplatin-induced hearing loss in patients with malignant brain tumors.

Abstract

Carboplatin is effective in the treatment of malignant brain tumors. However, when administered in conjunction with osmotic opening of the blood-brain barrier (BBB), carboplatin is ototoxic. The purpose of this study was to determine whether delayed administration of sodium thiosulfate (STS), given after BBB closure, provided protection against carboplatin ototoxicity. Patients underwent monthly treatment with intra-arterial carboplatin (200 mg/m2/day x 2) in conjunction with osmotic opening of the BBB, for up to 1 year. Audiological assessment was conducted at baseline and within 24 h before each monthly treatment. STS was administered i.v. as one (20 g/m2) or two (20 g/m2 and 16 g/m2) 15-min doses, depending on baseline hearing status. The initial group received the first STS dose 2 h (or 2 and 6 h) after carboplatin (STS2) and a subsequent group received STS 4 h (or 4 and 8 h) after carboplatin (STS4). Audiological data were compared with a historical comparison group (HCG) treated with carboplatin without STS. Spearman correlation coefficients comparing STS 2 (n = 24), STS4 (n = 17), and HCG (n = 19) indicated significantly lower rates of ototoxicity with increased delay in STS (P = 0.0006). On the basis of the analysis of hearing levels, there were significant differences among the two STS groups and HCG at 8000 Hz (P = 0.0010) and at 4000 Hz (P = 0.0075). The log-rank test for time to ototoxicity indicated a significant difference between STS4 and HCG (P = 0.0018). Delayed STS was effective in protecting against carboplatin-induced hearing loss. STS delayed to 4 h after carboplatin significantly decreased time to development of ototoxicity and rate of ototoxicity when compared with HCG.

• Authors: N D Doolittle, L L Muldoon, R E Brummett, R M Tyson, C Lacy, J S Bubalo, D F Kraemer, M C Heinrich, J A Henry, E A Neuwelt
• Journal: Clinical cancer research : an official journal of the American Association for Cancer Research (Clin Cancer Res) Vol. 7 Issue 3 Pg. 493-500 (Mar 2001) ISSN: 1078-0432 [Print] United States
• PMID: 11297239 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Thiosulfates
• Carboplatin
• sodium thiosulfate

Topics

• Adolescent
• Adult
• Aged
• Blood-Brain Barrier (drug effects)
• Brain (drug effects, pathology)
• Brain Neoplasms (drug therapy)
• Carboplatin (adverse effects)
• Child
• Child, Preschool
• Deafness (chemically induced)
• Dose-Response Relationship, Drug
• Female
• Humans
• Male
• Middle Aged
• Quality of Life
• Thiosulfates (therapeutic use)
• Time Factors