Stereotactic body radiation therapy (SBRT) in recurrent, persistent or oligometastatic gynecological cancers

Abstract

Objective: SBRT is a well-tolerated technique and provides local-regional control in a variety of metastatic and recurrent tumor types. The role of SBRT in extracranial recurrent, persistent, or oligometastatic gynecological tumors is not well-studied. We therefore retrospectively analyzed a sizeable number of patients in this setting.

Methods: We performed a retrospective review of 86 patients with 209 tumors treated at our institution with SBRT for recurrent, persistent, or oligometastatic extracranial gynecological tumors. The median follow-up was 20 months (range 1-91). The median SBRT dose was 24 Gy (range 10-50) delivered in a median of 4 fractions (range 1-6). The Kaplan-Meier curves and log rank tests were used to assess local control (LC) and overall survival (OS). Cox proportional hazards model was used to evaluate for covariates associated with LC and OS.

Results: The 1- and 3-year LC were 80% and 68% respectively. The 1- and 3-year OS were 70% and 39%. 32% of the lesions demonstrated complete response, 23% partial response and 20% stable disease. SBRT achieved better local control in smaller tumors. Toxicity was typically mild with grade 1 gastrointestinal toxicity and fatigue being the most common. Only 4.3% of treatments resulted in grade 2 or greater toxicity. There was only one case of grade 3 and no grade 4 or 5 toxicities.

Conclusions: SBRT offers a high rate of local control with low incidence of toxicity, mainly grade 1 GI toxicity and fatigue, and provides effective salvage therapy for oligometastatic extracranial pelvic and extra-pelvic gynecological tumors.

Keywords: Gynecologic cancer; Oligometastatic; Persistent; Recurrent; SBRT; Stereotactic body radiation therapy.