The use—and misuse—of full-body MRI scans for tumor detection

In recent years, whole-body MRI (WB-MRI) has emerged as an attractive screening modality for some, with the goal of detecting disease before it becomes symptomatic. The thought is that early detection of brain, lung, renal, colon, liver, bone, and soft-tissue cancers, as well as aneurysms and other cardiovascular diseases, could improve prognosis.^[]

WB-MRI screening is offered by several private companies. For example, US-based Ezra offers a full-body MRI scan for $1,950, which visualizes the head, neck, spine, pelvis, and abdomen. Another company, Prenuvo, offers a similar package for a whopping $2,499.

Detailing WB-MRI

WB-MRI is radiation-free and is usually performed without contrast media. It assesses soft-tissue and bone marrow pathology in different types of cancers. As discussed in a review of WB-MRI for preventive health screening, the images combine “functional images” and high-quality morphological sequences. They are usually taken from the skull base to the mid-thigh.^[]

This can compromise image quality, and it also deters wider adoption, as the patient needs to be able to tolerate a long MRI confinement.^[]

Researchers in Italy evaluated the interaction between patients and imaging, stating that this is “often overlooked in favor of evaluating diagnostic efficacy.” Despite the improvements, they write, “there is the possibility that imaging creates a major psychological and physical burden, especially on cancer patients. As various whole-body imaging modalities can be used for diagnosis and follow-up in different settings, understanding the patient experience may be beneficial in particular in modern healthcare where it is crucial to recognize and meet patients' needs and preferences.”^[]

Something to keep in mind, the authors point out, is that “WB-MRI is usually used on cancer patients, who are often older than the general population, have age-related disabilities, are more likely to develop painful bone metastases, and are subjected to higher physiological pressures. All of these factors can affect a patient's ability to perform a WB-MRI scan.”  

 When to use WB-MRI

Various guidelines support the use of WB-MR for cancer screening in patients with cancer-predisposition syndromes such as Li-Fraumeni syndrome, where it is coupled with contrast-enhanced brain MRI (and breast MRI in adult women).^[] It is also recommended in patients with hereditary paraganglioma and pheochromocytoma syndromes. 

It is also used to detect the volume, number, and distribution of neurofibromas in patients with neurofibromatosis. The National Comprehensive Cancer Network (NCCN) also recommends introducing WB-MRI as a means to detect malignant peripheral nerve sheath tumors.

Aside from its use in patients with a predisposition to cancer, WB-MRI is also used to evaluate patients with advanced prostate cancer, multiple myeloma, and metastatic disease. 

WB-MRI in asymptomatic patients

The use of WB-MRI in asymptomatic patients is contentious. The authors of the WB-MRI review conducted a meta-analysis to assess the WB-MRI findings in asymptomatic adults. They found a high proportion of indeterminate incidental results (13.9%), and this number was significantly higher in studies that included cardiovascular or colon MRI. In total, 6 studies suggested a pooled proportion of false-positive findings of 16.0%.

“Many people attach high value to the incidental MRI findings of disease that ‘can save lives,’” the authors averred. “However, there is a need for balance between the benefit and harm of whole‐body screening in asymptomatic subjects. Based on current evidence, healthcare providers should not offer whole‐body MRI for preventive health screening to asymptomatic subjects outside of a research setting. Asymptomatic subjects undergoing whole‐body MRI should be informed about the substantial prevalence of critical and indeterminate incidental findings, the lack of verification data, and the apparent substantial proportion of false‐positive findings.”

Indeterminate incidental and false-positive findings can result in unnecessary additional exams and treatments, along with the negative psychological impact. 

Professional guidance

Professional societies discourage the use of WB-MRI in asymptomatic patients.

The American College of Radiology (ACR) “does not believe there is sufficient evidence to justify recommending total body screening for patients with no clinical symptoms, risk factors or a family history suggesting underlying disease or serious injury.”^[]

They added, “To date, there is no documented evidence that total body screening is cost-efficient or effective in prolonging life. In addition, the ACR is concerned that such procedures will lead to the identification of numerous non-specific findings that will not ultimately improve patients' health but will result in unnecessary follow-up testing and procedures, as well as significant expense.”

The American Academy of Family Practice offers similar guidance.^[] It extends this advice to whole-body CT and PET:

“Whole-body scanning with a variety of techniques (magnetic resonance imaging, single-photon emission computed tomography, positron emission tomography, CT) is marketed by some to screen for a wide range of undiagnosed cancers. However, there are no data suggesting that these imaging studies will improve survival or improve the likelihood of finding a tumor (estimated tumor detection is less than 2% in asymptomatic patients screened). 

“Whole-body scanning has a risk of false-positive findings that can result in unnecessary testing and procedures with additional risks, including considerable exposure to radiation with positron emission tomography and CT, a very small increase in the possibility of developing cancer later in life, and accruing additional medical costs as a result of these procedures. Whole-body scanning is not recommended by medical professional societies for individuals without symptoms, nor is it a routinely practiced screening procedure in healthy populations.”