Radiation from CBCT scans

[logan]

So I've requested a preliminary plan from the two surgeons I consulted with. One hasn't gotten back to me since I emailed (and the receptionist sounded confused when I called, which isn't a good sign); the other says that I need a CT or cone beam CT first to make a preliminary plan. As a sanity check:

1. Does that sound right, that a CT scan is needed to make a preliminary surgical plan?

2. The CT will definitely have to be repeated ~6 months from now, right before surgery following pre-surgical orthodontics, and I'm assuming another CT scan is standard AFTER surgery to make sure things are in the right place. So I'd be opting now for a 3rd non-essential CT scan to my head. Should I be concerned about radiation levels? I looked up the numbers, and there is a wide range but a rough estimate is 200 uSv per CBCT, but it could be as high as 1000 uSv. This compares to ~10 uSv for 2D panoramic xrays, and 3000 uSv average exposure per year (spread over the body, not concentrated in the head). I have a growth in my thyroid that has so far tested benign but clearly I'd like it to stay that way.

Thoughts?

[kavan]

A prelim plan to give you an idea of what they have in mind can be made from an X ray ceph.

[Lefortitude]

ive thought about this too. 

https://pubmed.ncbi.nlm.nih.gov/31502516/


Minimize exposure, but sometimes its needed.  Thats the best advice i got.

[InvisalignOnly]

I was only asked to do one CBCT scan in the beginning and the surgeon based his plan on that. Just before the surgery, they did a normal x-ray to see the new position of the teeth (after pre-surgical orthodontic treatment), and after surgery they did another normal x-ray to check that all is okay with the plates and bones etc. So no more CBCT, but it might depend on the surgeon. Most surgeons do not ask for a CBCT scan at all, but personally I'd not go to those because they obviously do not use the latest planning technology.

[GJ]

A girl who used to post here recently got thyroid cancer, and she thinks it could be due to exposure. Maybe, maybe not. But avoid all them that you can, imo.

[kavan]

CBCT scans are needed for '3-d' type planning technology programs, especially custom implants  and 3-D surgical planning having to do with rotations involving down grafts and other more complex surgical displacements. However, there are many many cases that can be considered straight forward enough where just a ceph can be used to plan out a surgery.

[Lefortitude]

It may be worth it to take a round of potassium iodide after your cbct scans.  especially if female or have some risk factors (like a thyroid mass?)

[thedude]

I think the medical profession is reckless with CT scans in general. It's easy not to worry about something when the effects from it aren't seen for 25 years. It looks harmless when you compare it to the amount of background radiation you receive but I'm far from convinced that a targeted burst of radiation in a small area is the same as the broad intake of radiation you get from the sun. They have tried to study it though and haven't found much of an increase in cancer. Cancer diagnoses are so absurdly common today though that I think it's hard to study right.

That said, it would take 100 CBCT scans to get the amount of radiation you get from one chest or abdominal CT scan you would get at a hospital without a second thought from them. So it's not that much radiation if you look at it that way.