Table 1. NCI CTCAE v5.0 Ototoxicity Grading Scale.

Grade 1	Threshold shift >20 dB HL (i.e., 25 dB HL or greater); SNHL above 4 kHz (i.e., 6 or 8 kHz) in at least one ear
Grade 2	Threshold shift >20 dB at 4 kHz in at least one ear
Grade 3	HL sufficient to indicate therapeutic intervention, including hearing aids; threshold shift >20 dB at 2 to < 4 kHz in at least one ear
Grade 4	Audiologic indication for cochlear implant; > 40 dB HL (i.e., 45 dB HL or more); SNHL at 2 kHz and above

Abbreviations: HL, hearing loss; SNHL, sensorineural hearing loss.