The next time your doctor orders a scan, know what the benefits are, but don’t forget to ask about the harms | Ranjana Srivastava
“And one more thing: what do you want to do about this?”
The intern looks so apologetic that I suspect a medical error regarding our eighty-year-old patient who was admitted overnight with confusion. As I scroll through the images on the computer, I can see the problem even without the arrows pointing to an “ill-defined abnormality” around the colon.
I’m slightly irritated.
“Who had a CT done of his abdomen to investigate the confusion?” I ask. The intern groans.
“He had a pan scan, but we didn’t order that.”
A ‘pan scan’ is a scan from head to toe, colloquially known as a fishing expedition. It is the poor cousin of a targeted scan, performed to confirm or rule out a clinical diagnosis.
A conversation with the patient’s son quickly reveals that the cause of the confusion is an underlying dementia and a drug misadventure (sedatives mistaken for antihypertensives). The patient is recovering well, but unfortunately the ‘fishing expedition’ brings with it a net of incidental findings.
In addition to the possible intestinal abnormality, his prostate looks jagged and the pancreas looks strange – and this is just the abdominal scan. The chest CT scan discovers a ‘lesion’, the benign description of which is accompanied by the warning to have a follow-up scan – destroying any chance of it being left alone.
“Please tell me the brain CT scan is flawless,” I beg.
“It shows an old stroke that the patient can’t remember.”
At the bedside, my happy observation that his confusion has disappeared is drowned out by questions from concerned relatives about ‘all those forms of cancer’.
Being wary of easily harming an elderly patient, I recommend:
“If there are no symptoms, I would avoid the risks of a colonoscopy.
“A prostate biopsy has major consequences, even if it reveals cancer.
“An MRI brain will confuse him and provide no useful information.”
The family thinks:
“They say no to everything, but we want the best for our father.”
Their desire to investigate the incidental findings causes other specialists to rush past. No one really worries about it, but in the fragmented way of modern medicine, everyone eventually suggests something. Surgery says the patient can have a colonoscopy if they want; urology recommends a blood test; breathing says repeat scan in a few months; and neurology laments that sometimes it’s just easier to do an unnecessary MRI.
The only surprised person is the intern, who is still reconciling textbook medicine with real life.
A very precious week later, on the eve of discharge, the patient falls and miraculously walks away with only a bruised ego. He secretly asks me if he really needs all that outpatient “stuff” when he most appreciated my original advice to leave him alone. But now I’m stunned and I just want him in a safer environment, so I tell him to talk to his kids.
If I were to guess, I’d say he got all those tests – at great cost and with negligible benefit to him or the system. As for the damage, I wouldn’t know because I never saw him again.
after newsletter promotion
There was a time in my training when I needed permission to even request an MRI, approval of which was dependent on the appropriateness of the request. Those were also the days when radiologists asked physicians questions like, “How will this change your management?”
My favorite radiologist would ask trainees carrying out the orders of their superiors to “come back after examining the patient so you can order the appropriate test.” Today, when physicians “talk” to each other via electronic commands and tend to stay in “our line,” such sensible questions would probably be considered impertinent.
As I read, I thought about these issues a thoughtful article in the Medical Journal of Australia about the harm of incidental imaging findings.
The authors note that “incidentalomas” (purely incidental findings on imaging) occur in up to one-third of all tests and as many as 40% in CTs and MRIs. Most findings are benign and clinically insignificant, but in the absence of risk stratification based on patient factors, clinical context and better description, patients end up receiving unnecessary – and harmful – interventions.
On an individual level, it may seem useful for a scan to detect a mass that could later become cancerous. But on a population basis, a substantial increase in the incidental detection of cancers, including those of the kidney, thyroid, prostate and breast, has not led to a reduction in cancer-related mortality, but has led to an increase in the number of major surgeries.
An earlier Australian study found that approximately 11,000 cases of cancer occur in women and 18,000 cases of cancer in men each year. may be overdiagnosed. This figure sticks in my memory because I regularly see the trauma of being diagnosed with cancer, even when it doesn’t endanger your life.
As our universal healthcare system feels the strain, low-value medical care should concern us all.
Some of the authors’ advice is aimed at radiologists. The use of more specific reporting, consensus guidelines, and explicit follow-up recommendations has been shown to reduce overmanagement by anxious physicians.
An excellent suggestion is to include “incidentaloma outcomes” in the growing number of clinical trials to provide prospective data on the natural history of these findings.
As a doctor who spends a lot of time ordering tests, but also struggles with the results of scans I never ordered, I’m particularly drawn to the appeal of two suggestions.
First, the public needs to be made more aware of the potential harm. Patients are rarely informed about the frequency of incidental imaging findings, but physicians have a duty of care to discuss this explicitly. In turn, patients must recognize that demanding a scan (yes, it happens) is not a given replacing a thorough history and examination.
But by far the best advice is simple: avoid unfounded images. If doctors order fewer scans, we will find fewer incidentalomas. We can limit the damage by acting less reflexively and using more validated decision rules, supported by artificial intelligence.
Limiting the harm from imaging cannot be an idea limited to PowerPoint presentations and scientific publications when the consequences for patients are so great. This is another area where shared decision-making is possible.
So, the next time your doctor orders a scan, note the benefits, but don’t forget to ask about the harms.