Introduction/Background*The management of recurrent adult granulosa cell tumour (AGCT) of the ovary is a challenging therapeutic scenario. When surgery and hormonal therapies are no longer feasible, further treatment options are limited since there are low response rates to chemotherapy. Traditionally radiotherapy has not been widely used, but with recent advances in radiotherapy techniques this may provide a further option for either localised disease or palliative treatment.

Aim To evaluate the response to radiotherapy in recurrent AGCT.

Methodology A retrospective analysis was undertaken of patients who received radiotherapy for recurrent AGCT. Descriptive statistics were used to describe baseline characteristics, treatment and outcomes.

Result(s)*A total of 11 patients with AGCT were treated between 2012-2020. The mean age at diagnosis was 49 (28-57). 7(64%) patients had multi-site disease. 8 (50%) had pelvic disease, 6 (33) upper abdominal and 4 (17%) nodal disease. Most patient had large volume tumours with range 37.8-5942.7cm³. In total, 21 sites were treated with radiotherapy with 5(45%) patients receiving multiple courses of radiotherapy, including one who had re-irradiation of 3 sites. One patient had post-operative RT and one died soon after pelvic radiotherapy due to progressive upper abdominal disease. Nine patients with 16 sites were evaluable for response assessment at first irradiation. Technique: Stereotactic radiotherapy for 2 sites, IMRT/conformal 10 sites, large volume palliative fields to 4 sites. Radiation dose ranged from 20 to 45Gy in 5-20 fractions. There was a response in 100% sites with median reduction in tumour volume by 80% (range 18-100%) after 3 months and by 88% (range 24-100%) at 12 months demonstrating continued regression. Two patients had a complete radiological response, and two had <1% residual disease. One patient had progression within the irradiated field after 47 months and overall local control was 89% with median follow up 32.4 months. One patient had grade 2 acute bowel toxicity and two patients had grade 1 bowel toxicity.

Conclusion*Radiotherapy is a very effective treatment for recurrent AGCT, achieving maintained local control. This demonstrates that chemo-refractory tumours can still be very sensitive to radiation treatment, which should be considered for selected patients.