Role of involved-site radiation in the management of recurrent ovarian malignancies: a single institutional experience

Abstract

Objectives: Radiation therapy is commonly used to preserve local control in patients with oligometastatic disease. The objective of this study was to evaluate our institutional experience utilizing involved-site radiation (ISRT) in the management of recurrent ovarian cancer. Methods: Twenty-eight patients with recurrent ovarian cancer treated with ISRT between 2008-2019 were identified from our institutional database. A retrospective review of patient charts was performed. ISRT was delivered to sites of gross disease for all the patients who developed localized oligorecurrence following prior lines of chemotherapy to preserve local control. Results: The median age of diagnosis was 53 years range (23-70 years). Serous cystadenocarcinoma was the most common histological type (60.7%), followed by endometroid (14.3%) and clear cell subtypes (10.7%). Most patients had stage 3C (46.4%) at initial diagnosis. Many patients (79%) underwent initial optimal debulking, followed by platinum-based adjuvant chemotherapy. ISRT was considered mostly for patients who had recurrent disease confined to the pelvis (85.7%). The median time from the initial diagnosis to the initiation of ISRT was 49 months, and the median follow-up time after ISRT was 9.5 months (range 0-51 months). Most of the patients had a median of 2 recurrences (range 0-8) before receiving ISRT. The median radiation dose was 48 Gy (range 38-66 Gy). The median time to initiate additional chemotherapy after the ISRT was 2 months (range 0-23 months). The one-year rates of local control and distal progression following ISRT were 78% and 64.7%, respectively. The one-year overall survival rate after completion of ISRT was 72.5%. A majority of patients with recurrent disease following ISRT were treated with additional chemotherapy (10/19), and one patient with an out of field recurrence was managed with complete resection of distal metastases. The median time to initiate additional chemotherapy after the ISRT was 2 months (range 0-23 months). All patients tolerated ISRT well, and no ≥ grade 3 toxicities were observed. Conclusions: ISRT in recurrent ovarian cancer offers reasonable local control in well-selected patients with oligo-recurrences of ovarian cancer. Treatment was well-tolerated and may offer an alternative to interval-debulking surgery or chemotherapy in selected patients.