I'm sorry this is playing on your mind Ineedabreak.
Like most medical tests, there are some possible risks but your doctor/medical team would make sure the benefits of having a CT scan outweigh these risks.
If you'd like to talk this through with someone please don't hesitate in giving our cancer nurses a call on 0808 800 4040 (Monday - Friday between 9a.m -5p.m) as they're very insightful and will do all they can to work through your concerns with you and hopefully put your mind at ease.
When I read your question, I became intrigued because this question has been asked before, and I did some reading around. I'm not an expert in this area.
I'm not sure how much you know about radiation dose, so please forgive me if I'm telling you something you already know.
Radiation dose is measured in milliSieverts, or mSv. Each procedure gives the patient a certain amount of radiation; if the scanner head make multiple passes (eg one pass normal and a second pass after injection of contrast medium) then you have to add each pass separately. So a typical abdomenal scan is 8 mSv, but this is increased to 16 mSv if a second pass is made with contrast. I've had 2 of these so far, so my estimated dosage is 32 mSv. But to put that in context, living in the UK the average background radiation dose is around 2.7 mSv a year, so each of my CT scans is broadly equivalent to around 6-7 years of background radiation. Not all CT scans need the same amount of radiation. For instance a brain CT is just 2 mSv, which is less than one year's background radiation.
So, how does this all relate to future cancer risk? I found a calculator which estimates the additional risk you have of getting radiation induced cancer from any particular medical procedure, based on your age, sex, and the procedure type. So for my 32 mSv exposure at ages 65 and 66 (I'll simplify that to 65), it calculates my chance of radiation induced cancer at... 1/934. Basically, it's 1 in a thousand. Since we all have a 1/4 or 0.25 lifetime risk of dying from cancer, adding a further 0.0001 to that figure doesn't worry me at all. However, if I were aged 25 and I'd just had these CTs, then the risk would be higher... 1/311 or 0.0032. That's because I would normally have a lot more years to live, giving any radiation induced cancer more time to manifest.
By comparison, the lifetime risk of dying in a road accident is about 1/240 in the UK, and most of us don't worry unduly about that possibility. Personally, I start to get concerned at about 1/100. In terms of CT scans, it's roughly equivalent to a male aged 30 getting 100 mSv exposure, or a male aged 60 getting 200 mSv exposure.
Maybe that's the way forward for you? The calculator will accumulate your estimated exposure from all your procedures, and give you an estimate of the chance of radiation induced cancer. You know where your own personal fear threshold lies, but I suggest 1/100 or 0.01 (1%) is a good starting point. Once you have a clear idea of what the risk is from your previous exposure, you'll be in a better position to decide whether you want to continue having scans into the future.
Sorry to ask this dumb question, but you're sure this is CT and not MRI? MRI doesn't carry any risk of radiation exposure, but it's a lot slower than CT. CT is over in a matter of seconds whereas MRI takes 30 minutes or even longer.
According to the calculator, a chest abdomen & pelvis exam is 21 mSv, which I guess is doubled if you have a second pass with contrast (I did say I'm not an expert at this). If you've already had 7 such scans then this sounds like a significant amount of exposure, which seems to continuing year on year.
I think in your shoes I would express my concerns to the consultant and ask whether a CT is really necessary, and if so, are they aware of your cumulative exposure so far? Could they maybe find what they need from conventional X-rays, which only use a fraction of the radiation dose of a CT scan? Or an MRI, which doesn't have risk, although it does take a lot longer.
Please keep us posted. You are not the first person to raise this issue here, but I don't think we've ever gone into any detail. Anything you can feed back from the radiographer would be really useful, both now and for future questioners.
I rang and had a word with the radiographer and raised my concerns. She said well there are some people who have had as many scans as you have had while they are actually in hospital at any one time if they need them.
I also had a word with a GP who said she'd recently had this conversation with a radiographer for another patient and many years down the line, like 20 years there's a slight risk of it causing cancer.
Amazingly I wasn't waiting weeks for the result this time either. Just over a week and I recieved the letter.
