Influence of Ionizing Radiation on Two Generations of Cochlear Implants.
The purpose of the present study was to test the behavior of two different generations of cochlear implant systems subjected to a clinical radiotherapy scheme and to determine the maximal acceptable cumulative radiation levels at which the devices show out-of-specification behaviors. Using stereotactic irradiation (Cyberknife, 6 MV photon beam), three Digisonic SP and three Neuro devices were submitted to 5 Gy doses that cumulated to 60 Gy (12 sessions) and 80 Gy (16 sessions), respectively. A follow-up series of irradiation was then applied, in which Digisonic SP devices received two additional fractions of 50 Gy each, cumulating to 160 Gy, and Neuro devices three additional fractions of 20, 40, and 150 Gy, cumulating to 290 Gy. Output current values were monitored during the treatment. At clinical doses, with 60 or 80 Gy cumulative radiation exposure, no single measurement showed more than 10% divergence from the reference measure. The cochlear implants tested in this study showed high resistance to clinically relevant cumulative radiation doses and showed no out-of-bounds behavior up to cumulative doses of 140 or 160 Gy. These observations suggest that cochlear implant users can undergo radiotherapy up to cumulative doses well above those currently used in clinical situations without risk of failure.
Department of Head and Neck Surgery, CHU Nice, 06100 Nice, France.
Nicolas
N
Guevara
Department of Radiation Oncology/IBDC CNRS UMR 6543, Cancer Center Antoine-Lacassagne, University Nice Sophia-Antipolis, 06189 Nice, France.
Anaïs
A
Gérard
Clinical and Scientific Research Department, Oticon Medical-Neurelec, 06220 Vallauris, France.
Jeanne
J
Dupré
Clinical and Scientific Research Department, Oticon Medical-Neurelec, 06220 Vallauris, France.
Delphine
D
Goursonnet
Clinical and Scientific Research Department, Oticon Medical-Neurelec, 06220 Vallauris, France.
Michel
M
Hoen
Clinical and Scientific Research Department, Oticon Medical-Neurelec, 06220 Vallauris, France.
Dan
D
Gnansia
Department of Head and Neck Surgery, CHU Nice, 06100 Nice, France.
Gaëlle
G
Angellier
Department of Head and Neck Surgery, CHU Nice, 06100 Nice, France ; Department of Radiation Oncology/IBDC CNRS UMR 6543, Cancer Center Antoine-Lacassagne, University Nice Sophia-Antipolis, 06189 Nice, France.
Juliette
J
Thariat
D003054:Cochlear Implants; D006801:Humans; D008422:Materials Testing; D011839:Radiation, Ionizing