[ RadSafe ] Increase in Cancer Risk due to Cardiac Imaging

[Scott, Bobby]

Hi All:

The study focused on medical records for 82,861 patients that underwent
cardiac imaging after acute myocardial infarction. The study design is
seriously flawed, including the way in which the Cox proportional hazard
model was applied. The LNT-related risk estimates presented should not
be considered credible. For example, the latent period for
radiation-induced solid tumors is more than 10 years while the average
follow-up time for the study was only 5 years. Thus, solid tumors
attributed to radiation from cardiac imaging procedures are more likely
due to other causes. It appears that most of the patients whose medical
records were studied were more than 50 years of age. Thus, the 12,020
diagnosed cancers among the study population may be significantly less
than would be expected (baseline rate) had the patients not undergone
cardiac imaging procedures that used radiation. If so, then this would
implicate a reduction in cancers as a result of the imaging. Concerned
scientist plan to submit a joint Letter to the Editor related to the
paper. The paper represents but one among a growing number of
poorly-designed studies of cancer among irradiated human populations
that managed to get published in peer-reviewed journals and have adverse
impacts on the general public because of the misinformation transmitted.
These papers being published in peer-reviewed journals point to a broken
peer-review system for such studies.

Bobby
B. R. Scott
Lovelace Respiratory Research Institute
2425 Ridgecrest Drive SE
Albuquerque, NM 87108 USA

-----Original Message-----
From: Leo M. Lowe [mailto:llowe at senes.ca] 
Sent: Wednesday, February 09, 2011 12:03 PM
To: radsafe at agni.phys.iit.edu
Subject: [ RadSafe ] Increase in Cancer Risk due to Cardiac Imaging

Hello,

A recent study on cardiac imaging of heart attack patients by 
Eisenberg et al. in the Canadian Medical Association Journal 
(7Feb2011) reports a dose-dependent response and a cancer risk of 3% 
per 10 mSv in the patients.  This seems quite high.  A minimum 
exposure-to-cancer onset delay of one year was used in the analysis 
to assess potentially attributable cancers.

See the CBC News report at 
http://www.cbc.ca/health/story/2011/02/07/heart-cancer-radiation-tests.h
tml

An on-line version of the paper is available on the CMAJ web site.

Any comments?

Regards,


Leo M. Lowe, Ph.D., P.Phys., CRadP