Dr Randall on the Benefits and Limitations of MRI in Soft Tissue Sarcoma Surveillance

“MRIs tend to be the gold standard. They’re superior for soft tissue resolution and therefore detection, but they are costly, less accessible, and there are a few contraindications, Ultrasound is cheaper, faster, and is widely available, but historically, it’s been underutilized due to operator dependence and limitations for deep-seated surgical beds.”

R. Lor Randall, MD, FACS, the David Linn Endowed Chair for Orthopedic Surgery, the chair of the Department of Orthopedic Surgery, and a professor at the University of California Davis Comprehensive Cancer Center, discussed the rationale for conducting a study comparing ultrasound vs MRI for post-resection disease surveillance in patients with soft tissue sarcoma (STS) of the extremities.

Orthopedic oncologists see a significant volume of STS cases, Randall began. STS is a relatively uncommon malignancy, accounting for approximately 1% of adult cancers, though it represents a much higher percentage—approximately 15%—of pediatric cancers, he explained. Most of these sarcomas originate in the extremities, he said.

Despite ongoing advances in surgical techniques and the use of adjuvant and neoadjuvant treatments, local recurrence rates for STS remain substantial, Randall stated. Due to this high recurrence risk, surveillance in the postoperative period is critically important, he emphasized. A common question in this field revolves around determining the most effective, accessible, and cost-efficient surveillance method, he said.

Historically, MRI has been considered the gold standard imaging modality, Randall stated. This reliance stems from MRI’s known superiority in soft tissue resolution, which enhances the detection of potential recurrences, he reported. However, MRI presents several challenges in a routine surveillance setting: it is costly, less accessible than other imaging types, and has certain contraindications, such as when metal is present in critical areas of the body, such as the brain, he summarized.

Ultrasound is a highly attractive alternative because it is cheaper, faster, and is widely available, Randall continued. Nevertheless, ultrasound has traditionally been underutilized for STS surveillance due to limitations associated with operator dependence and difficulties in accurately visualizing deep-seated surgical beds, he noted.

To rigorously address the clinical and economic debate regarding the efficacy of these surveillance methods, Randall and colleagues performed a review comparing the diagnostic accuracy, recurrence rates, cost-effectiveness, and clinical outcomes of ultrasound vs MRI in extremity STS. This evaluation was published in the Journal of Surgical Oncology.