Apr 09th 2022

Determining When to Use SBRT to Treat Oligometastatic Cancer

Recent advances in radiation oncology treatments offer promising alternatives for the nearly 2 million patients diagnosed with cancer in the U.S. each year. One of these treatments is stereotactic body radiation therapy (SBRT). Also known as stereotactic ablative body radiation (SABR), this type of radiation was first used in the early 1990s.

SBRT is a specialized way of delivering radiation that is akin to surgical resection of a tumor. It is often used for patients with early-stage lung cancer who are not surgical candidates.

It's now being used to treat a variety of cancers, particularly among patients with oligometastatic cancer—those who don't have widespread metastatic disease and have just a few localized malignant growths.

How does SBRT work to treat oligometastatic cancer?

SBRT employs very focused high-dose radiation delivered over one to five days, whereas more traditional types of radiation therapy—such as external beam radiation (EBRT)—are delivered in daily sessions over several weeks or months.

Historically, SBRT has been used primarily in cases where one would otherwise consider a surgical resection of the metastatic lesion. Though not a proven technique for all situations, it is being used for frequently to treat oligometastatic lesions (e.g., from colorectal cancer). The popularity of SBRT is understandable: it’s an easier form of treatment that is relatively well tolerated with a fairly good success rate, which is attractive to patients and providers alike—even more so because the course of treatment is so much shorter (3-5 days versus 35+ days).

Encouraging results and increased ease in treating certain types of cancerous lesions with SBRT have led to an expansion of its use. However, there isn't an overwhelming body of evidence to support the extent of this expansion, particularly for those patients whose symptoms mimic oligometastatic disease but do not truly have oligometastatic disease. In addition, SBRT may not always be the most effective treatment path, especially for patients with certain types of oligometastatic cancer that may require repeatedly treating lesions as they pop up—particularly if doing so would not impact the overall prognosis.

SBRT as part of a holistic approach for oligometastatic cancer

While data are still emerging and further evidence would be beneficial in determining the when SBRT is the best approach, there are enough outcomes that demonstrate its efficacy with certain types of cancer and certain patient populations.

SBRT has been very valuable and successful for patients with tumors in places such as the liver and lungs where surgery is often a riskier option. In certain cases when outcomes are equivalent, it's the best course of treatment.

Still, a holistic, multidisciplinary approach can offer exceptional value in establishing the appropriate course of treatment—and whether SBRT is part of it.

Such decisions can be facilitated by the eviCore onConnect Tumor Board, which brings medical oncologists, radiation oncologists, and other oncology professionals together to determine the most appropriate treatment for the patient's journey—for example, if systemic treatment like chemotherapy is preferred over radiation or if it should be offered concurrently or prior to/following surgery.

Rather than fast-tracking approval for SBRT when it may not be the best option for a particular patient, Tumor Board discussions offer oncology professionals a chance to see a case from all sides and get insights and input on how to move forward.

eviCore's experts, alongside oncology professionals, consider SBRT and other options to reach the same goal—to deliver the best patient outcomes possible in a cost-effective manner.