Phase I trial of stereotactic body radiation therapy (SBRT) for limited site locoregional recurrences of ovarian cancer.

IMPORTANCE

Radiation therapy is infrequently used in the treatment of advanced ovarian cancer due to the propensity for peritoneal spread and dose limitations of classical large field techniques. However, for patients with limited sites of recurrence, advanced radiation techniques such as SBRT may offer an effective treatment option.

OBJECTIVE

To evaluate the safety, preliminary efficacy, quality-of-life outcomes, and tumor perfusion changes in patients with limited locoregional recurrences of ovarian cancer treated with SBRT.

METHODS

Patients with ovarian, fallopian tube, or primary peritoneal cancer and ≤ 3 total sites of disease were eligible for this phase I 3 + 3 dose-escalation study.

RESULTS

Fifteen patients were accrued and SBRT dose was safely escalated to dose-level 3 (30 Gy in 3 fractions) without dose-limiting toxicity. There were no grade 2 or higher SBRT-related toxicities. One-year LC, PFS, and OS were 95 %, 45 %, and 100 %, respectively. The majority of patients received SBRT on study in lieu of systemic therapy (67 %), and 70 % of these patients remained off systemic therapy at one-year follow-up. At one year after completion of SBRT, global health status/QOL patient reported outcomes were maintained from baseline values. Perfusion imaging demonstrated increases in tumor blood flow (p = 0.02) after delivery of the first fraction of SBRT and decreases in blood flow (p < 0.01) and blood volume (p < 0.01) from fraction 1 to 6 weeks after SBRT.

CONCLUSIONS AND RELEVANCE: This Phase I trial offers preliminary evidence that SBRT can be safe and effective for limited site locoregional recurrences of ovarian cancer.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03325634.