Will I get cancer as a result of CT scan?

Question

Hi doctor,

I am a 50 year old male. My height is 5'11" and weight is 170 lbs. I do not have any major health issue, but my brother and mother had recently come down with leukemia. Recently had a CT scan of the abdomen and pelvis repeated with and without contrast material. Before four years, I also had three CT scans due to kidney stones. I had one CT scan in my age of 12 or 13 for chest. I am walking around all day thinking that will I get cancer as a result of the CT scan that I had. I am very upset with what had taken place. Furthermore, I searched in internet and it is more scarier to look at the dose levels and the corresponding moderate risk equal to just one CT scan. If just one scan is equal to moderate risk, then what about the total risk of all the scans that I have had? Some additional information that I obtained regarding the scans are, the recent scan is 87 DLP which is equal to 14 milligray. Two scans in three years are 564 DLP and 785 DLP respectively. I do not know the dose of the scans taken for kidney and chest. Well, I hope to hear from you soon and I hope that my question and concerns are clear for a good answer. Thank you very much.

Answer 1

Hi,

Welcome to icliniq.com.

The recent computed tomography (CT) scan of abdomen and pelvis has a radiation dose of 12.366 mSv which means it is causing an additional cancer risk of 0.06 percent. This is quite low and not a reason to get worried.

The radiation dose from the three CT scans for kidney stones are 10.15 mSv, 14.13 mSv and ?10 mSv dose length product (DLP) not mentioned. Therefore, the total dose from four CT scans in recent times is 46.64 mSv in four years. This gives you additional cancer risk of 0.23 percent.

I am not accounting for the scan taken for chest because it is long back and dose is not available. You are 99.76 percent safe.

There is no serious problem if radiation from last scan has given you additional risk of 0.06 percent. This is acceptable if you have any medical condition which required the CT scan for evaluation. However, I support your views that CT scan should not be done unless required.

For further information consult a radiologist online.

Answer 2

Hi,

Welcome back to icliniq.com.

There is recent research which shows that in males the probability of developing a cancer is 44.9 percent and dying from one is 25 percent.

Therefore, the baseline probability of having a cancer is 44.9 + 0.28 percent and is 45.18 percent for you including the earlier scan. Anyway this risk is not significantly high from those who have not got scan done and not a problem.

The conversion factor for DLP to mSv is chest CT scan multiplies DLP with 0.018, abdomen CT scan multiplies DLP with 0.018 and pelvis CT scan multiplies DLP with 0.018.

Several sources show conversion factors from 0.015, 0.017, 0.018 or 0.019 depending on research study and area of scan. I am using 0.018 for your calculations. The numbers vary slightly because of the new research and machine types.

For further information consult a radiologist online.