Stereotactic Body Radiation Therapy in Gynecologic Oligometastases: An Effective but Underutilized Approach

SIMPLE SUMMARY: Stereotactic body radiation therapy (SBRT) allows for the high-precision delivery of a large dose of radiation to a small area. SBRT has shown overall survival benefits in a variety of oligometastatic cancers in recent trials. However, prospective data in recurrent or oligometastatic gynecologic cancer are limited. The current literature shows that SBRT in gynecologic oligometastases is safe and effective, resulting in 2-year local control rates exceeding 80%. However, progression outside of the radiated field remains a significant issue despite local control. This review discusses the advantages, limitations, and future directions of SBRT in gynecologic oligometastases including a discussion on the synergistic effects of combination with immunotherapy. ABSTRACT: Historically, the role of radiation in gynecological metastatic disease involved palliation for pain or bleeding. Stereotactic Body Radiation Therapy (SBRT) has shown survival benefits in oligometastatic disease from varying primary histologies in recent randomized trials. However, gynecologic primary oligometastases have been underrepresented in these trials. Recent studies across gynecological malignancy types have similarly shown favorable outcomes and acceptable toxicities from treating recurrent or oligometastatic gynecologic cancer (ROMGC) patients with definitive radiation therapy. The largest body of literature reported on the use of SBRT in ovarian cancer, which was found to be an effective option, especially in the setting of chemo-resistant disease. Despite the encouraging outcomes using SBRT in oligometastatic gynecologic malignancies, SBRT remains underutilized given the lack of randomized studies studying ROMGC with long term follow-up. While waiting for future prospective trials to establish the role of SBRT as the standard of care in ROMGC patients, this review focuses on reporting the advantages and drawbacks of this technique and examines the current literature to help guide patient centered treatment decisions.