Real-World Data Yield Positive Outcomes of SBRT in Oligometastatic Ovarian Cancer

Patients with oligometastatic ovarian cancer who received stereotactic body radiotherapy (SBRT) experienced positive outcomes and minimal toxicity, according to results from a poster presented at the 2026 American College of Radiation Oncology (ACRO) Summit.

The overall survival (OS) rate at 1 year was 85.6%, at 2 years if was 73.8%, and 3 years it was 59.0%. The median OS was not reached. Additionally, the progression-free survival (PFS) rate at 1 year was 76.4%, at 2 years it was 54.0%, and at 3 years it was 48.0%. The median PFS was 28.9 months.

A total of 54.5% of patients experienced progression. The in-field progression rate was 9.1% and deemed by authors as “rare”, and most treatment failures occurred out of the field. The out-of-field progression rate was 36.4%.

“Most disease progression occurred outside the treated field, supporting the role of SBRT in durable local disease control. These real-world data support SBRT as a safe and effective treatment option in carefully selected patients,” Lifei Zhu, MD, PhD, a postdoctoral fellow at Washington University and colleagues wrote in the poster.

This single-institution analysis occurred between January 2011 and September 2025. The authors cited that the purpose of the study was to determine local control, recurrence patterns, survival outcomes, and toxicity associated with SBRT in patients with oligometastatic ovarian cancer.

A total of 22 patients were enrolled, and 90.9% were oligoprogressive after surgery and systemic therapy. At presentation, 4.5% of patients were oligometastatic, and 4.5% were oligometastatic after surgery. At the time of SBRT, 5 or fewer sites of disease were noted.

The primary end point was in-field progression, out-of-field progression, OS, and PFS. Secondary end points included the worst toxicity 6-months post-SBRT per CTCAE v5.0 criteria and ECOG performance status change.

Of note, 85.7% of patients had preserved or improved ECOG performance status. This included 6 patients who improved, 12 who were stable, and 3 who declined. Additionally, 6 patients had baseline ECOG performance status of 1 and then transitioned to ECOG performance status of 0.

No grade 3 or higher toxicities were observed. Within 6 months, the toxicity rates showed 86.4% of patients having grade 0 to 1, and 13.6% had grade 2. The most common adverse effects included none (22.7%), respiratory (4.5%), skin (4.5%), gynecologic (4.5%), genitourinary (9.1%), fatigue/general (4.5%), and gastrointestinal (about 50%).

“Oligometastatic ovarian cancer remains challenging following surgery and systemic therapy. SBRT enables delivery of high-dose focal radiation while sparing surrounding normal tissues. Prior studies have demonstrated encouraging outcomes, but real-world data on recurrence patterns, survival, and toxicity remain limited,” the authors concluded.

Reference

Zhu L, Tang JY, Mehta KJ, et al. Stereotactic body radiation therapy (SBRT) for oligometastatic ovarian cancer. Presented at the 2026 American College of Radiation Oncology Summit; Orlando, FL. February 4-6, 2026.