This advice was posted on the internet by Paul Galioni in the US.

I am a firm believer in Aloe Vera Gel for use during all phases of XRT (radiation treatment). While it may seem very hippy-dippy there is firm medical evidence that it helps prevent scarring and helps reduce the swelling that goes along with all kinds of burns.

When I was undergoing XRT I was using aloe vera a couple to a few times a day (morning-noon-evening) and when I would run out, I found that my voice which had remained very near ‘normal’ was suddenly ‘raspy’.
When resumed the Aloe Vera (about 2 ounces three times a day — ALWAYS AFTER RADIATION) I found that within a few days my voice returned to near normal again.

This is PURE Aloe Vera gel or gel mixed with something like Spanish moss as a thickener. Don’t drink Aloe Vera sun cream or aloe vera shampoo etc — just plain aloe vera. You can buy it at a health food store, and it should come in a dark glass bottle. This keeps the air and the sunlight from changing the chemical structures of the substances which help you. It also keeps it from going rancid on you.

The texture is sometimes a turn off and often people find the taste not to their liking. I found, however, over time, that I came to enjoy both. Like my mother said about Scotch: it is an acquired taste which drives men mad” — and I found the same is true of aloe vera, much as with pasta or rice — a day without aloe vera is a day without the sun.
It will not work magic overnight — but it will reduce a lot of the swelling and you should notice that the voice has become noticeably less raspy over the course of several days to a week.

Sometimes people may experience loose bowels after using aloe vera in elevated amounts. This is because the layer right under the skin is a substance which was the main ingredient in laxatives until well into this century and many laxatives still use it as one of the active ingredients. But some companies use more of it than others — either the cutting and slicing is done by machine, or they are trying to exploit as much of the product as they can. It will not give you loose bowel movements if just used as a topical (on the skin) lotion, but if you drink it, the aloe vera that has the layer right under the skin may give you loose bowels. Just use less.

It can be mixed with other juices if you find that sipping it cold and straight from a shot glass isn’t pleasant.
I liked mine very cool, and would let it just dribble down my throat — it helped cool the burn and I imagined that it was sticking there and doing more good than if I had just slammed back a couple of ounces. Radiation burns make tissue swell up, and that includes the tissue that makes up your vocal chords. Aloe Vera not only helps take away this swelling, it also prevents scarring of the area — which might lead to a very radically hoarse voice post XRT. Aloe Vera is not a wonder drug — it just happens to be one of the many botanicals which has a good history of helping and a past history of actual scientific trials which support the two abilities I mentioned above: anti-inflammatory and anti-scarring.

So, no wild claims here — just that Aloe Vera will probably help more than it would hurt — and of course the proviso: tell your doc. Most likely aloe vera will be viewed as a very benign thing and the doc will say: well if you want to waste your money go ahead. Some might recognise it’s potential and say: well It won’t hurt the process. I would be surprised to see any doc say NO! WHAT A STUPID IDEA. But it is only courteous to ask your doctor.
Good luck. Don’t worry, it is common to swell and scar a little during XRT.