terrib

Since you are planning on doing the radiation, certainly eating a healthy diet is a good thing. We've had a lot of discussion here on OCF about diets and various books on diet and cancer.
Personally my wife and I had a very strict no sugar diet for over 20 years (and I mean strict: no sugar substitutes and shopping in organic stores)and we found it to be very healthy although it did not prevent me from getting cancer.
Your use of the word "alternative" is worrisome, and I echo Christine's cautionary words that there is NO alternative to radiation, chemo and/or surgery (except death).
Unfortunately, the Internet is full of bogus promises on the wondrous almost magical results of various "alternatives".
For what it is worth, I have never seen any study or article indicating any harmful effects from not eating sugar, eating raw veggies, and drinking tea . I'm skeptical about detox claims or "magic" teas (like essiac or other frauds). But eating an alternative diet to fast food, fatty food, fried food, junk food, does have demonstrable health results.
Even now, I make sure to have one ultra healthy meal in my Vitamix to supplement the canned nutrients as there is no substitute for fresh healthy food.
Charm