MRI and Ultrasound May Be Best Used in Tandem for Surveillance Imaging in Soft Tissue Sarcoma

MRI is the gold standard for detecting local recurrence in soft tissue sarcoma (STS) because it affords superior soft tissue resolution, but data published in the Journal of Surgical Oncology suggest that ultrasound could be capable of comparable diagnostic performance, according to R. Lor Randall, MD, FACS.1,2

“Ultrasound could play a larger role in STS surveillance, either as a compliment or a substitute to MRI, but we really do need further, high-quality, prospective data to inform this pursuit further,” Randall said in an interview with OncLive®. Randall is the David Linn Endowed Chair for Orthopedic Surgery, the chair of the Department of Orthopedic Surgery, and a professor at UC Davis Comprehensive Cancer Center in Sacramento, California.

In the interview, Randall discussed the use of ultrasound vs MRI for extremity STS surveillance, the differences between the 2 modalities, and findings from an extensive literature review comparing the accuracy, recurrence detection, cost-effectiveness, and clinical outcomes of both approaches.

OncLive: Is there a definitive standard of care when it comes to surveillance imaging for extremity STS?

Randall: STS accounts for approximately 1% of adult cancers and 15% of pediatric cancers, and 60% or so arise in the extremities. As orthopedic oncologists, we see a fair load of STS. Despite advances in surgery, adjuvant treatments, and neoadjuvant treatments, local recurrence rates can range anywhere from 10% to 30%, and surveillance in the postoperative period is important.

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, such as if there’s metal in the body in critical areas like the brain, etc. 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.

We decided to perform a review to look at diagnostic accuracy, recurrence rates, cost effectiveness, and outcomes of ultrasound vs MRI in extremity STS. [Our paper was] published [in September 2025] in the Journal of Surgical Oncology. We performed a PRISMA Scoping Review using PubMed, Embase, and Scopus. The range on the Scopus was 1990 to 2025. Post-resection surveillance studies using ultrasound and/or MRI [were included]. We identified 366 studies, but only 8 met the criteria. Two were prospective, 4 were retrospective, and there were 2 reviews in total, [amounting to] approximately 856 patients across all 8 studies.

In terms of diagnostic performance, both had similar accuracy. The sensitivity rate [range] for MRI was 83% to 100% with a specificity [rate range] of approximately 93% to 98%. Ultrasound had a lower sensitivity rate [range] at 75% to 100%, but the specificity rate [range] was 79% to 98%. There was no statistically significant difference across the studies. Hybrid protocols where MRI and ultrasound are utilized together achieve 100% recurrence detection vs 65% with MRI alone.

How do the costs and clinical outcomes compare between the imaging tools?

There are limited data on this. In fact, most of comes from the European literature. One study did report that ultrasound was approximately 79% cheaper than an MRI, which was 60 euros vs 280 euros, respectively. That cost per recurrence in that study was 493 euros when ultrasound was used vs 2305 euros for an MRI, which is a pretty large difference.

In terms of clinical outcomes, the recurrence rates were 10% to 46%. The median detection [ranged from] 1 year to 22 months, and imaging detection was done mostly before clinical exam. This means that most of these patients will get their studies before they see their provider. Their provider will then know the imaging results before they perform a physical exam, so we are not bringing clinical examination into this assessment in any way. Adding ultrasound between MRIs did allow for earlier average detection of 3 to 6 months.

The take-home message is that ultrasound and MRI have comparable diagnostic accuracy. Ultrasound brings substantial cost savings and may increase accessibility. We should be considering potentially hybrid strategies to combine the strengths of both [modalities] to optimize surveillance. The real weakness in the literature is a lack of multicenter, randomized controlled trials. I’m going to start pitching this sort of study to some of our cooperative groups. It [wouldn’t be] an interventional study, so it [would face its own set of] challenges, but it could shed robust light on all this.

There have been limited cost-effective analyses, but there’s a substantial difference between ultrasound and MRI, and there are no quality-of-life data in any of the literature. That’s an opportunity as well.

What might an ideal hybrid approach look like?

This is something we are implementing now here at UC Davis in our sarcoma program. For high-grade extremity STS, we’re getting baseline MRIs at 3 months post-operation and then following with ultrasounds. If we notice any changes on the ultrasound, we will move to an MRI. This is not ironclad. There are some particularly high-risk cases, so if we have positive margins, or if we know [the tumor is] in an area where local recurrence could mean a devastating result for the patient, we will continue with MRI. But for the more straightforward cases where we have an R0 resection, we will use that algorithm.

Could insurance barriers pose an issue for those who are looking to augment or replace MRI with ultrasound in this scenario?

I think insurance companies will favor this as more of the literature comes out about the utility of ultrasound, because it’s a cheaper tool.

References

1. Smith J, Dallas-Orr D, Todi N, Brown D, Randall DR. Ultrasound versus magnetic resonance imaging for extremity soft tissue sarcoma surveillance: a scoping review. J Surg Oncol. Published online September 3, 2025. doi:10.1002/jso.70079
2. Hussein M, Gupta H, Ahuja A, Thaker S. Imaging recommendations for soft-tissue sarcomas: model guidelines from diagnosis to post-treatment follow-up. Clin Radiol. 2024;79(12):881-891. doi:10.1016/j.crad.2024.08.023