The radiation effects usually begin after the 2nd week, 10-14 days of starting treatment, beginning with neck redness, and radiation continue to work several weeks after treatment completion, and have acute, and long term toxicities. Chemo effects start much sooner, usually 3 days after infusion, but cease sooner after treatments are completed. I never had Cisplatin alone, but did with two other chemo's in a high dose induction cocktail, which didn't go well. With radiation, in other subsequent treatments, I believe I had more nausea from pain meds, mucus, canned nutrition from tube feeding, bad taste than anything else. I tried a number of anti-nausea meds through the years.

With Cisplatin, maybe you already know, there are several toxicities that may or may not occur, but if they do to let the staff, oncologist know right away for any neuropathy, hearing, and vision changes, which can become permanent, if not addressed. The creatinine, blood count will be checked weekly in the blood test prior to infusions, and adequate water should be consumed after infusions to flush the kidneys.

The key to getting through treatments are Adequate nutrition, hydration, impeccable oral care, mucocitis, infection, pain, nausea, and vomit control and treatment, neck care, mouth exercises, sleep.

Good luck, and hope this helps.