Case report: Short-course hypofractionated radiation therapy combined with immune checkpoint inhibitors for the treatment of advanced ovarian mucinous cystadenocarcinoma.

Background: Ovarian mucinous cystadenocarcinoma is a rare subtype of ovarian epithelial carcinoma that is resistant to platinum-based chemotherapy and has a poor prognosis, and there is no standard treatment plan for patients for whom multiline treatment has failed. Case presentation: oma with FIGO stage IVB disease who was sequentially treated with paclitaxel liposomes+carboplatin, 5-Fu+CF+oxaliplatin, capecitabine+oxaliplatin, bevacizumab+FOLFOX4, S-1, and bevacizumab+oxaliplatin+raltitrexed chemotherapy. After the progression of the disease, a combination of short-course hypofractionated radiation therapy and immune checkpoint inhibitors was used. The radiotherapy target area was the metastatic lymph nodes in the right posterior part of the hepatic artery, with a radiation dose of 30 Gy/10 F. Camrelizumab, an immune checkpoint inhibitor, was administered intravenously every three weeks at a dose of 200 mg each time. The therapeutic effect was significant, with CA125 levels within the normal range. Metastatic lymph nodes disappeared from the abdominal cavity. The therapeutic effect achieved a complete response (CR). Currently, CA125 levels are within the normal range, and abdominal CT reveals no tumor recurrence or metastasis. The duration of response (DoR) reached over four years. Conclusion: Ovarian mucinous cystadenocarcinoma is a rare tumor with poor treatment efficacy and poor prognosis. Short-course hypofractionated radiation therapy combined with PD-1 inhibitors may be an effective and safe treatment strategy.