How do they decide how much radiotherapy to give?

I see from other postings that ladies quote how many nodes out of how many removed were positive and that this decides things. I had sentinel node biopsy in July. 2 nodes removed, both positive. Had chemo after 5 weeks and now am having radiotherapy to chest wall, armpit and collarbone area - 15 lots. For all I - or they - know I might have had 20 nodes affected. I have tried asking but just get told of the horrors of lymphoedema. The procedure was never discussed at the time. I know that for me it would have been better to have had all the nodes removed - after all they knew the tumour was large.
Not much use for prognosis purposes not knowing how many nodes were involved.

I dont realy know how they decide how may doses of radiation we have to have. in my case i had a grade 3 tumour and no nodes affected but am still haveing four and a half weeks of radiation after haveing chemo. Everyone seems to have different courses though .
Best Wishes
Lindiloo x

there is a limit to how much radiation in total you can have to one area and if I remember it is measured in grays.

The normal amount is 50 grays. this is split into fractions. If you have only 15 sessions each session has more grays than if you have a greater number of sessions with smaller amounts of radiation per session. i was told that if you have small non pendulous breasts they can give higher doses for shorter times, don’t know why this is, unless pendulous ones cause the skin to rub together and the rays are more difficult to control. I had the small pert kind of bosoms, perfect for only 15 sessions apparently.

I think the side effects can be worse if you have fewer sessions but these don’t last that long. Once the treatment ends your skin will cook for a short while but then get better. That is, if you have skin reactions. Most people don’t (only 1 in 5 gets severe problems). I was unfortunate in having quite sore skin and swelling which lasted quite a long time. I think the main reason they give you fewer doses is to speed up the through put of women, but it does avoid having to have a lot of visits to the hospital for short periods of time. I would rather have had more sessions personally to avoid painful skin reactions but I was told what I was having, no choice

Hi sarcath,
I am really surprised that with a sentinel node biopsy and having 2 nodes positive you didn’t have total axillary clearance. I was dx in Jan 2003, had a WLE and 8 sample nodes removed as sentinel biopsy was not available then at my breast care centre. 3 of the 8 nodes were positive and I went back a month later for total axillary clearance. Luckily for me, as another node was positive, so 4/18.

I had 6 x FEC chemo and 25 Gys rads with 2 boosters. I questioned why I needed chemo and rads and was told the chemo would zap any microscopic cancer cells that had gotten through the lymph nodes (which we already knew had been affected) and the rads would deal with any cells remaining in the breast where the tumour was. Made sense to me, so I went ahead. I had rads over 5 and a half weeks and it was easy, except for the travelling. I only got slight sunburn at the end of the treatment. However, some 4 yrs later, I find I have lymphodoema in that breast, which is very puffy and swollen, but not painful. I can live with that. My bc surgeon at my 5 yrly review last week said these changes can occur up to 40 yrs after radiotherapy. Wish someone had told me of these long term effects of rads and I wouldn’t have worried so much about a recurrence


Thank you. That is very informative. Where do you all get your info? I never seem to get any to speak of! I don’t think breast size comes into it for me - I had a mastectomy. But what you say still makes sense. Only had 5 doses so far and as yet no problems.

I got my information from the cancer backup site, they sent me a booklet on radiotherapy, I also asked loads of questions as I didn’t like the idea of radiotherapy at all - especially the fewer sessions larger doses. My surgeon knew less than I did - he was surprised the doses were higher if you had fewer sessions.

I also bought a book from amazon on radiotherapy - it also included lots on chemo which I didn’t have.

I like to know everything but not everyone is like me


just thought - I think the reason you didn’t have lymph nodes cleared is that your hospital is giving radiotherapy instead, this is an alternative treatment, but I think it has slightly greater risks of causing lymphoedema and some other rarer side effects of radiotherapy

Maybe ask for rationale for this treatment. They do try and give a treatment plan which is very much tailored to the nature of your breast cancer so this may be more effective for you


Thank you all for your information - I shall be looking for some of these books to help me.

You are right, Mole, when you say I should have an explanation but I have failed to get one. After the mastectomy, so when they were in possession of all the facts, I asked why I couldn’t have the nodes removed and was told ‘after the chemo’. When I mentioned it again - I asked why it was considered safe to leave the nodes there when some more were almost certainly affected. His response was’ have them out if you want but it will delay the radiotherapy to the chest’ He also went on about the horrors of Lymphoedema.

I wonder who makes these decisions. At the outset I thought the treatment was decided by the MDT. This was semingly not so in my case - at first the surgeon did not want to operate yet and sent me to the oncologist to have chemo first. I was quite OK with this until the oncologist said she was not in favour because I had previously had chemo for a different cancer - it seems that even if the drugs are different the chemo is not as effective as the first time round. So back I went to the surgeon who - grudgingly, I think, - went ahead.
After surgery I did have chemo but fear that these accursed nodes might have been busy sending out more cancer if the chemo was not doing much.
If only the surgeon had bothered to discuss options with me I would have chosen axillary clearance in the first place, never mind the sentinel node biopsy. For me, a bit neurotic as I am, I know I would have been happier, especially in the absence of any real rationale as you put it. Just hoping the radiotherapy does the trick but I have to wonder what has been going on in the meantime.

Sorry I’ve gone on a bit and could go on more!!