|
| Authors, year | Cochlear implants tested (Nb tested) | Implant preparation | Irradiation method | Dose and fractionation scheme (total dose) | Measured parameter,
observed dysfunctions,
and critical dose |
|
| Ralston et al., 1999 [6] | 22 MCI (two processor generations)
24MCI (3p./model) | Two water equivalent plastic blocks (30 × 30 × 5 cm), separated by 1 cm thick Perspex blocks | Two parallel opposed 4 MV photon beams | 25 × 2 Gy, followed by 5 × 10 Gy and one fraction of 50 (150 Gy) | RF-lock and current output.
50> dose <150 Gy: gradual loss of RF link (CI22M).
CI24M changes in output current large at 150 Gy. |
|
| Baumann et al., 1999 [5] | Clarion 1.2 (4p.) | 10 cm synthetic block, covered by 0.5 cm thick Plexiglas | Cobalt radiation machine, gamma rays @ 1.2 MV | CI1: incr. sequential to (69 Gy)
CI2: 3 × 30 Gy (90 Gy)
CI3: 34 × 2 Gy (68 Gy)
CI4: 29 × 2 Gy (58 Gy) | RF-Lock (communication between ICS and speech processor) loss for dose <60 Gy. |
|
| Klenzner et al., 2004 [7] | Nucleus 24 K (1p.) | In situ implantation, cadaver head | Two parallel opposed 6 MV photon beams | 16.3, 6.2, and 20 Gy (42.5 Gy) | Impedance and current output.
No deficit at tested dose. |
|
| Klenzner et al., 2005 [8] | Nucleus CI24M (2p.)
Nucleus I24R (2p.) | Solid-water model simulating head tissue, serving as a phantom implanted device | Two parallel opposed 6 MV photon beams | Plan A: 50 × 2 Gy, followed by four fractions of 5 Gy. (120 Gy)
Plan B: 60 times 1.6 Gy, followed by four fractions of 5 Gy (116 Gy) | Impedance, current output, and charge balance of biphasic pulse.
No dysfunction 80 Gy.
Impedance fail at 111 Gy. |
|
| Markiewicz et al., 2006 [13] | Combi 40+ (1p.) | Single in situ case study | Total body irradiation, 6 MV photons | 3 × 4 Gy (12 Gy) | CI not used on TBI days.
No reported dysfunctions. |
|
| Reddy et al., 2012 [14] | Nucleus CI512 (1p.) | Single case study | 6 MV photons | 8 × 1.5 Gy (12 Gy) | No reported dysfunctions. |
|
| Current study | Digisonic SP (3p.)
Neuro CI (3p.) | Synthetic block, covered by 0.5 cm thick Plexiglas | 6 MV photons | 12 × 5 Gy (60 Gy) followed by two fractions of 50 (160 Gy)
16 × 5 Gy (80 Gy) followed by 20, 40, and 150 (total 290 Gy) | No more than 10% deviation in output currents at 60 or 80 Gy.
One device out of six dysfunctional after a 290 Gy cumulative dose. |
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