Potentiation of inner ear damage following electron beam irradiation with CDDP administration.

This study was designed to examine the combined ototoxic effects of cisplatin, an antitumor platinum compound, administration and electron beam irradiation on the inner ear of guinea pigs, histopathologically. One group received saline solution 4 ml/kg/day and the other group received cisplatin of 2 mg/4 ml/kg/day for five consecutive days. The right temporal bones of all animals of both groups were exposed to the electron beam of 14 Gy/day 3 hours after the daily injection of saline or cisplatin. All animals were sacrificed for inner ear histopathological findings 21 days after the last injection. A combination of cisplatin administration and electron beam irradiation produced a severe potentiation of the outer hair cell damage with no inner hair cell damage. Therefore, in treatment of head and neck carcinomas, it is important to pay attention to inner ear damage caused by combination therapy of cisplatin and electron beam irradiation which involves the inner ear.