Can i use aloe vera for cervical cancer after surgery before radiation?

are there evidences that aloe vera destroys cancerous cells

I don't think aloe vera is going to "destroy" cancer cells. It's not quite that simple. While you are on radiation therapy it is best to not apply anything on your skin. Clean it with a damp cloth and dry.....

I think you should avoid this and talk to your radiation onchologist before doing it. Some substances are known to increase or decrease the effect of radation therapy.
Aloe vera is used to treat burns. I havent heard of anyone using it for that reason. Consult your doctor.
Internally, aloe vera is actually an extremely powerful laxiative. It's probably not something you want to be drinking. There are no studies that I'm aware of indicating the use of aloe for any type of neoplastic disease. In regards to herbal treatments, there is a herbal pack that can be applied directly to the cervix (a Bastyr Pack), but its effectiveness would depend on the staging of the cancer. If you have not reached N3 or M1 it might be benifical. Consult a qualified naturopathic physician if there is one in your area.
Update: In response to your question about the vaginal depletion pack, I referenced Murray and Pizzorno's "Textbook of Natural Medicine". It states that the pack is only good for cervical dysplasia, and it required daily treatments for up to several months, so perhaps it is too late in the game for this to work. In a nutshell, it consists of a tampon impregnated with a mixture of several chemicals and herbs that had been mixed together and then left to sit for several days. The ingredients were magnesium sulfate, glycerin, goldenseal, ceader leaf, and tea tree oil, bitter orange oil, and iron. The instructions are in appendix 11 of the second edition. I'm sorry, but I really don't think that this would be of any use to you at this point in time. Please disclose to your physician or oncologist the use of aloe vera.
I'm a naturopath