Heike, I know that you can buy Ensure powder in 900gm tins from pharmacies in Australia. It costs about $22 maybe $24 per tin
Ensure is what most of us in NZ and Australia are recommended to eat/drink by hospital Dieticians as we go through this treatment.
Most of us get the ready to drink cans of Ensure plus. You can make this up yourself . The Ensure powder tells you to add 6 scoops but to make it equivalent to Ensure Plus you just add 9 scoops per serve.
This formula will provide your husband with all the calories, protein, carbohydrates and vitamins etc. that he will need . Make sure he drinks the equivalent of 6 - 8 ensure plus drinks per day. Of course you can add fruit, yoghurt, nut butters, oils and / or anything else you want to this .
Also make sure that he has some medication to help with constipation. He will get constipated. everybody going through this treatment does.
Hope this helps,
Tammy.

Caregiver/advocate to Husband Kris age 59@ diagnosis
DX Dec '10 SCC BOT T4aN2bM0 HPV+ve.Cisplatin x3 35 IMRT.
PET 6/11 clear.
R) level 2-4 neck dissection 8/1/11 to remove residual node - necrotic with NED
Feb '12 Ca back.. 3/8/12 total glossectomy/laryngectomy/bilat neck dissection/partial pharyngectomy etc. clear margins. All nodes negative for disease. PEG in.
March 2017 - 5 years disease free. Woohoo!