Diluted gadoteridol (ProHance®) causes mild ototoxicity in cochlear outer hair cells.

CONCLUSION Administration of diluted solutions of gadoteridol might cause considerably less toxic effects on cochlear outer hair cells (OHCs). OBJECTIVES Visualization of endolymphatic hydrops is done by intratympanic injection of gadolinium-based contrast agents (GBCAs) and three-dimensional fluid-attenuated inversion recovery (3-D FLAIR) magnetic resonance imaging. Here, we investigated the physiological and morphological responses of guinea pig cochlear cells to gadoteridol. METHODS Distortion product otoacoustic emission (DPOAE) levels were measured before and 1, 2, and 4 weeks after intratympanic injection of 1/8 or 1/16 dilution of gadoteridol in guinea pigs. Morphological changes in isolated cochlear OHCs were observed after application of gadoteridol and GdCl3. RESULTS At the highest frequency (F2 = 12 000 Hz), DPOAE level was significantly (p < 0.05) lower in the 1/8 diluted gadoteridol group than in the control group. Cell shape changes were observed in 24% (6/25) and 3% (1/33) of OHCs after application of 1/8 and 1/16 diluted gadoteridol, respectively. The occurrence of morphological damage was significantly lower after application of saline compared with 1/8 diluted gadoteridol. Morphological damage was significantly lower after application of 1/16 diluted gadoteridol compared with 1/8 diluted gadoteridol (p < 0.05). Morphological damage was observed at a high rate (8/10 cells, 80%) after application of GdCl3.