Table 4.

Overview of literature on radiation-induced ear toxicity

	Study design	Number of patients (n)	Concurrent chemotherapy	Mean cochlear dose	Radiation induced ear toxicity
Pan et al. [5]	Prospective	31	No	47.4 Gy	Significant hearing loss for cochlear dose ≥ 45 Gy	Older patients more susceptible to hearing loss
Chen et al. (2006)	Retrospective	22	yes	48.5 Gy	57% SNHL	21% serous otitis
Van der Putten et al. [8]	Retrospective	52	No	36.1 Gy	32% hearing loss	39% tinnitus
Hitchcock et al. [39]	Prospective	62	34% RT only 66% yes	33.1 Gy	RT only group: SNHL for cochlear dose ≥ 40 Gy	Chemoradiation group: SNHL for cochlear dose ≥ 10 Gy
Chan et al. [26]	Retrospective	97	yes	48.9	9.4% low frequency SNHL	51.2% high frequency SNHL
Nutting et al. [30]	Prospective	110	No	56.2 Gy (3D-CRT) vs. 35.7 Gy (IMRT)	SNHL: 39% (3D-CRT) vs. 35% (IMRT)	Tinnitus: 58% (3D-CRT) vs. 44% (IMRT)
Bass et al. [31]	Retrospective	473	n.a	Exposure defined as cochlear dose > 1 Gy	22% Mild hearing impairment	38% severe hearing impairment