A birthday party for a kid with cancer?

My brother was just diagnosed with medulloblastoma and will be starting chemotherapy in 3 weeks, after his surgery on tuesday. It's brain surgery so I know he won't be feeling great after that, plus all the nausea from the chemo afterwards. His birthday is February 3rd. My dad is a wreck right now because of the diagnosis and the loss of my mother. The last thing he's thinking about is throwing my brother a party. But my brother is going to be 7 years old and I don't want him to miss out on anything just because he's sick. Is there anything I could do? Any ideas? Or should I just get him a gift and that's it? Thanks for the help.