You do need to get your rest but it doesn't have to be all at one time!
I am a very active person with sports, work, volunteering, and spending time with friends. I know I needed my rest so I arranged my schedule by including naps during my day. I did work through my treatment but I was able to close my eyes for a few minutes at lunch. I also made sure I had time for a nap after work before heading out for the evening. Weekends I spent a lot of time relaxing and napping.
I think as long as you build in naps and rest into your schedule, and most importantly, listen to your body, there is no harden rule of enough sleep per evening.