Can MRI Surveillance Have an Impact in Detecting Recurrence of Soft Tissue Sarcomas?

In a new meta-analysis looking at soft tissue sarcoma recurrence, researchers noted a pooled proportion of 53 percent for local recurrence detected by high-intensity surveillance magnetic resonance imaging (MRI).

For the meta-analysis, published recently by the American Journal of Roentgenology, researchers reviewed 19 studies and compared imaging and clinical detection of local soft tissue sarcoma recurrence. The study authors also divided studies into subgroups of high-intensity surveillance (defined as at least one local surveillance imaging exam for low-risk tumors and at least three exams for high-risk or high-grade tumors) and low-intensity surveillance (imaging obtained at less frequency than above) two years after treatment.

The study authors saw mixed results with the majority of local recurrences (LRs) being discovered via clinical means in 11 studies and by imaging in eight studies. However, 11 studies noted that LRs diagnosed via imaging were clinically occult and the researchers found significant associations between surveillance intensity and the proportion of LRs diagnosed via imaging. Specifically, the study authors noted that high-intensity surveillance with MRI diagnosed 53 percent of the LRs whereas low-intensity surveillance with MRI detected six percent of LRs.

“We hypothesize that the probability of detecting (local recurrence of soft tissue sarcoma) depends on the frequency of MRI use,” wrote study co-author Soterios Gyftopoulos, M.D., MBA, MSc, the chief of radiology at New York University Langone Health in Brooklyn, N.Y., and colleagues. “This is supported by our data, which showed that LRs were more likely to be detected on MRI with high-intensity MRI use but more likely to be detected clinically with low-intensity MRI use. If MRI had been used more frequently in the studies that used it sparsely, more LRs may have been detected with MRI.”

Out of four studies that compared survival rates for imaging-detected LRs and clinically detected LRs, Gyftopoulos and colleagues said three studies noted better survival rates for patients with imaging-detected LRs but two of the studies lacked statistical significance for this finding. The researchers said another study did find a significant association between increased survival rates and more frequent locoregional imaging surveillance.

(Editor’s note: For related content, see “Surveillance MRI Study Shows Link Between Background Parenchymal Enhancement and Higher Risk of Second Breast Cancer” and “The Top Five MRI Articles of 2022.”)

In regard to study limitations, the study authors acknowledged variability with imaging techniques and the frequency of imaging and clinical exams with the surveillance protocols in the retrospective studies reviewed. While the small sample sizes in the reviewed studies reflect the rare incidence of soft tissue sarcoma, the researchers concede they may have had “excessive weight” on the study findings. Gyftopoulos and colleagues added that the inclusion of research dating back to 1982 may not reflect modern radiology practice nor recent advances with dynamic contrast-enhanced MRI or diffusion-weighted imaging.