Early screening is not without risk

UCSF Radiologist Dr. Brett Elicker describes the effect of multiple CT scans and what UCSF is doing to limit the amount of radiation when screened with CT.


  • Overall morality difference?
  • Would these early lung cancers have caused a problem?
  • Side effects of screening (radiation)?

A lung nodule is round in the lung, which is unusual.  However, the vast majority aren’t cancer. However, the recommendation is that doctors will follow-up the patients with multiple CTs, to prove after 2 years that it isn’t cancerous. The sum of the radiation of four CTs for screening over the two years could potentially cause cancer.


  • Background: 1-3 mSv
  • Chest CT: 8 mSv
  • Low dose chest CT: 1 mSv
  • Follow up-low dose radiation.
  • After 2 year four scans: 11-26 mSv, not necessary a benign process. 




Division Chief, Cardiothoracic Imaging
Professor Clinical Radiology

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