Most CCC have a multidisciplinary team, including a nutritionist, who will access his nutritional needs, and a speech and swallow therapist, who will instruct on exercises to do for the mouth, amongst other info, both who should see him before starting treatment, during, and after. If not, maybe inquire about them. Besides hearing, some chemos can effect vision, although uncommon maybe, I suggest the same in seeing an opthmologist before, during and after treatment to monitor any changes, in addition to letting the treatment doctors know.

Good luck with everything.