“The possible solutions to a given problem emerge as the leaves of a tree, each node representing a point of deliberation and decision.“
-Niklaus Wirth
His treatment had gone well and the large mass in his neck had completely receded during six weeks of radiation therapy. Now, I had recommended a CT scan to make certain that his cancerous lymph nodes had completely disappeared. I was surprised by his initial response.
“No way, Doctor! I don’t want a CT scan!”
“Really?” I asked.
“Why?” “I heard that CT scans CAUSE cancer. I don’t want one!” Indeed, he had heard news reports of a
study in
The New England Journal of Medicine highlighting the explosive growth in CT usage and warning that the radiation exposure might have real, long term consequences. Over 60 million CT scans were done in the United States in 2006, up from 3 million in 1980. Although no long term studies of people undergoing CT scans have been done, atomic blast survivors and atomic industry workers who were exposed to similar dosages of radiation have an increased risk of cancer, and the younger the age of exposure, the greater the risk. The authors estimate that up to 2 percent of cancers might be caused by CT scans.
Having a patient refuse a CT scan was a new experience for me; usually, I am the one telling patients that they do not need a scan that they want. Unlike scheduled mammograms for breast cancer survivors, no studies have ever shown a benefit of routine CT scans for survivors of head and neck cancer. The financial costs, as well as the emotional toll chasing down inconsequential or equivocal findings, can be enormous. Adding to the confusion, some physicians now skip the “routine CT” and go right to the much more expensive PET/CT scans.
On the other hand, the studies DO occasionally identify findings that respond to early intervention; for example, the images of the neck CT scan might pick up a new cancer or non-symptomatic lung nodule. Not frequently, mind you.
After assuring my patient that, in his particular situation, the benefits of potentially identifying residual cancer outweighed the cancer risk from an additional scan, he decided to go ahead with the study. A few days later, we called to tell him that the scan looked great.
Follow-up testing for cancer survivors can pose real dilemmas. Patients and families crave good news, and, for some, that requires more certainty than I can provide with a physical examination. My patient who was worried about the risks of CT scans reminded me that each test requires thought and each result requires a deliberate reaction.
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Ref: Brenner DJ, Hall EJ, Computed Tomography – An Increasing Source of Radiation Exposure,
New Engl J Med 2007 (Nov 29); 357:2277-2284.
The following is feedback received for this blog:
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Good post. I wondered how you and other cancer docs were having to deal with this.
- rlbates
http://rlbatesmd.blogspot.com/
I was just discussing this with a friend, who also happens to be my mom's oncologist. For us, the benefits outweigh the risks...as her latest followup CT found a cancer in her ureter. Part of the risk of being HNPCC+.
- angela marie
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