Ovary Sparing Intensity Modulated Radiation Therapy Following Ovarian Transposition: A Single Institution Retrospective Dosimetric Analysis of Patients With Cervical Cancer Treated With External Beam Radiation Therapy After Oophoropexy.

Abstract

Ovarian transposition before the start of pelvic radiation therapy can potentially preserve ovarian function. However, it remains unclear what reasonable dose constraints are and how soon following transposition it is safe to start radiation therapy. We performed a retrospective review of patients aged <50 years diagnosed with cervical cancer who underwent ovarian transposition before pelvic radiation therapy between 2010 and 2023. Endpoints examined included the incidence of premature ovarian insufficiency (POI), relapse in the ovary, and acute surgical complications. Seventeen patients met the inclusion criteria. Median age at diagnosis was 32 years. Median follow-up was 52.2 months. POI incidence was 71%. Among patients with POI, the median mean dose (Dmean) and maximum dose (Dmax) to the least-exposed ovary were 12.0 Gy (IQR, 2.8-19.2 Gy) and 19.3 Gy (IQR, 4.7-42.9 Gy), respectively. Among patients with no evidence of POI, the median Dmean and Dmax to the least-exposed ovary were 4.4 Gy (IQR, 1.5-6.8 Gy) and 5.9 Gy (IQR, 2.4-11.4 Gy), respectively. All patients with a Dmean to the least-exposed ovary >8 Gy developed POI compared with 50% of patients with a Dmean to the least-exposed ovary <8 Gy (P = .03). All patients with a Dmax to the least-exposed ovary >16 Gy developed POI compared with 54.5% of patients with a Dmax <16 Gy (P = .05). Patients with POI had a smaller median distance between the more superior ovary and the planning target volume (2.55 cm vs 4.00 cm). There was one relapse in the ovary; however, this patient was noted to have widely metastatic disease at the time of relapse. The median time from surgery to start of radiation therapy was 40 days (IQR, 20-57 days). Three patients started radiation therapy within 1 week; none had an acute surgical complication. Our data suggest that patients receiving a mean dose >8 Gy or a maximum dose >16 Gy to the least-exposed ovary following ovarian transposition are at higher risk of POI. Starting radiation therapy within 1 week of transposition was not associated with any identifiable increase in acute surgical complications.