Ablation radiation dose

[Hamish5]

I accepted a cryo ablation when I got a cancellation at days notice. I was worried about the radiation dosage but the consultant reassured me it would be equivalent to a few months natural radiation. My procedure took about an hour. I've since researched the radiation factor and was shocked to find the dose is likely to be equivalent to from 5 to 20 years. I requested information from the radiologist and was told my procedure had a dose area product of 377mgy and skin dose of 30 mgy. From what I can find, that is equivalent to 37.7 msv total body dose! This is more than 12 years natural radiation! I am really annoyed and angry about this! Can anyone explain how the consultant could get it so wrong?

[BobD Volunteer]

I suspect that you think the radiation is constant during the whole hour of the procedure. It is not since it is a pulsed xray not constant. Like the old fashioned TV it is so many "lines" per second.

I have had total of four ablations (three within four years and the fourth about eight years later) all RF not cryo and all around four hours and still alive and kicking some 20 years after the first.

[Teresa156]

Hi Hamish,

Are you absolutely certain you are reading documentation or studies that have been done recently? From what I can see on line, there are a lot of procedures in place nowadays to extensively lower radiation exposure during cryoblations and it looks like there are many very recent studies about it. I’ve never really even thought about it before I read your post, but I can’t find anything controversial.

[Hamish5 in reply to Teresa156]

Thanks Bob and Teresa, It was the ablation team radiologist who gave me the DAP figure of 377 mgy. I found it difficult to convert this to a whole body effective dose , but the best ( or worst!) estimate I can find is by using a conversion figure of 0.1 which gives me 37. 7msv😕

[secondtry]

A very valid point to seek clarification on. As a patient I need to know the bottom line on all risks before proceeding.

[Ppiman]

Leicester has moved to PFA but I suspect the radiation dose is similar. I shall follow this thread with interest.

Steve

[Gfern]

Are you saying that you wouldn’t have had the ablation if you had known this? What problems are you expecting that this radiation dose will cause you?

[Hamish5 in reply to Gfern]

I am most definitely saying that! 37msv is equivalent to over 300 chest X-rays. Radiation, even at low levels, damaged cells. This can lead to cancer and other health problems which I'd rather not risk. You didn't know this?

[Gfern in reply to Hamish5]

No I didn’t know, but I am not sure now that i do know I am happier with the knowledge. It’s a bit late after all the x-rays, ablations , angiograms and radiation therapy over the last twenty years. But at least my stents are working, my new knee is good, my cancer has gone and I am now afib free , non of which would have been possible without radiation involved in the treatment. So I suppose ignorance has helped in that I had the treatment without the attendant anxiety that you are facing, and my health is better than it would have been without the treatment. Whoever said Ignorance is Bliss had a good point.

[Cavalierrubie]

Very interesting post. If this is the case, l feel concerned having had lots of ct scans and chest x-rays over the past twelve months, so the radiation from those, coupled with an ablation, the figures would be even higher.

I have an appointment with EP on 14th March with a view to ablation, lt has made me somewhat hesitant in going ahead.

[Cliff_G in reply to Cavalierrubie]

By all means ask, but see the post lower down which I just added, ChatGPT output

[Espeegee]

Easy he didn't know so gave you an ottohh number, "off the top of his head". A failing of many medics is not admitting they don't know so they make it up. Unlucky for him you were more interested than he was and now you're armed and dangerous lol. Chances are of course you probably won't see him again so won't have the opportunity to ask why he got it so wrong.

[Cliff_G]

ChatGPT's answer on this as follows (ChatGPT is getting much more reliable):

"The radiation dose during an atrial fibrillation (AF) ablation varies depending on the technique, equipment, and duration of the procedure. Here are the typical radiation doses and associated risks:

1. Radiation Dose

Effective Dose:

5–25 millisieverts (mSv) is the typical range.

For context:

A single chest X-ray delivers about 0.1 mSv.

Natural background radiation exposure is approximately 3 mSv per year.

Factors Influencing Dose:

Length and complexity of the procedure.

Operator experience.

Use of advanced imaging techniques like fluoroscopy or 3D mapping systems, which can reduce fluoroscopy time and, consequently, radiation exposure.

2. Associated Risks

Cancer Risk:

The risk of cancer from ionizing radiation is cumulative and depends on the total dose over a lifetime.

The linear no-threshold (LNT) model estimates:

5–25 mSv may increase lifetime cancer risk by 0.025–0.125% (based on general risk estimates of 5% per 1,000 mSv).

Skin and Tissue Damage:

Rare at these doses, but prolonged or excessive fluoroscopy can lead to skin burns or tissue injury.

Threshold for deterministic effects like skin burns: 2,000 mSv (2 Gy) to the skin, much higher than typical AF ablation doses.

Eye Cataracts:

Lens exposure may increase the risk of cataracts with high cumulative doses, but modern shielding significantly reduces this risk.

Risk Reduction Strategies

3D Mapping Systems: Significantly reduce fluoroscopy time and radiation exposure.

Reduced Fluoroscopy Protocols: Use pulsed fluoroscopy or "zero fluoroscopy" techniques.

Operator Experience: Experienced electrophysiologists typically use less fluoroscopy.

Protective Measures: Lead aprons, thyroid shields, and proper shielding reduce risks to both the patient and medical staff.

In summary, the typical radiation dose of 5–25 mSv during AF ablation is relatively low but not negligible. The associated cancer risk is minimal but should still be considered, particularly in younger patients or those undergoing multiple procedures.

-----

I would personally add that AF is not benign, contrary to original thinking on this, and the radation exposure should be balanced against these risks. ChatGPT again provided me a good summary on the morbidity and mortality risks of remaining in AF.

[CliveP]

If only I’d known about this I could have spent the 8 years I’ve been free of AF since my ablation worrying rather than getting on with my life.

[Hamish5 in reply to CliveP]

Congratulations on that. I'd love to get on with my life but unfortunately, since my ablation just 6 weeks ago, I've already had 3 AF episodes lasting 12 to 15 hours each time. This is worse than before the procedure when I had an episode about once a month.

[CliveP in reply to Hamish5]

Try to be positive. Worrying won’t help. It’s quite common and not surprising to have episodes like that immediately after an ablation. Mine was all over the place at the same point. I’m sure things will improve as you recover.

Troubling yourself over how much radiation you might have had is just stress that you don’t need. You’ve had it now and that’s not changing. Worrying about what the doctor said or didn’t say or what might or might not happen serves no useful purpose.

[wilsond in reply to Hamish5]

Extremely common to experience increased AFib activity in the first 12 weeks. It's called the blanking period. Its also possible to take longer to settle down.

The Patient Leaflet on here contains excellent information.

[AsparagusLover in reply to CliveP]

Made me smile!

Had no inkling about radiation during cryotherapy ablation. Bit late to worry now as I had it beginning of Aug 2024 & thus far it’s worked! 🫣

[Model52]

A point that is too often overlooked is the radiation dose involved in heart-related procedures such as bypasses, stent placements, ablations and device placements like pacemakers and Watchmans .

X-ray radiation is harmful for human tissue and can cause cancer. That is why all hospital personnel working in the vicinity of X-ray devices permanently have to carry a dosimeter.

The radiation dose is time dependent, but for example for procedures like catheter ablation it varies between the equivalent of 250 to 1000 static X-rays. Very high, in any case. Placing a few stents equals about 400 X-rays.

My friend radiologist calls it ‘unbelievable’ that the total dose/lifetime per patiënt is not registered in this country (Belgium), and in most other countries, for that matter. I agree with him wholeheartedly. Personnel working around X-ray equipment in hospitals all carry a recorder to monitor their radiation dose. Why is this not recorded and registered for patients?

Is this registered where you live? And if not, don’t you think it should be?