Cancer risk from CT scans may be lower than thought

Radiation-induced cancer is a big fear as the use of CT scans for all kinds of medical diagnoses increases. Clearly, unnecessary radiation should be avoided. But a new study suggests that the cancer risk may have been overestimated.

Researchers from Stanford analyzed 10 million records from Medicare claims from 1998 to 2005 to determine the radiation exposure from CT scans and the cancer risk among this population. They found that radiation exposure doubled from 1998 to 2001 compared with 2002 to 2005 as CT use became more common.

However, the incidence of cancer related to radiation from CT was estimated to be 0.02% for those scanned in the earlier time period compared with 0.04% for those scanned in the later time period. Previous estimates have put the cancer risk from CT radiation at 1.5% to 2% of the population.

The study was presented Wednesday at the annual meeting of the Radiological Society of North America.

Two studies published last year in the Archives of Internal Medicine asserted that CT scans deliver far more radiation than has been believed and may contribute to 29,000 new cancers each year, along with 14,500 deaths.

Related: CT scan use rising in emergency rooms, study says

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