Diagnosis of recurrent ovarian cancer: Recurrent ovarian cancer generally refers to patients who have achieved complete remission of ovarian cancer after initial treatment and whose lesions are found again more than 6 months after discontinuation of chemotherapy. Recurrence can occur at any time after the initial remission, with 2-3 years being the most common. Patients may again experience symptoms such as abdominal distention and discomfort, often with varying amounts of ascites. Patients with severe recurrence may also have symptoms depending on the site of recurrence, such as hematuria in the bladder, blood in the stool in the rectum, or hydronephrosis in the ureter. If the recurrent lesions are extensive and severe, the patient may be directly diagnosed with intestinal obstruction. Gynecologic triage often reveals recurrent lesions in the pelvis, especially those above the vaginal dissection; serum CA125 and other tumor markers may be progressively elevated; imaging examination often reveals recurrent lesions in the liver, spleen, kidney, adrenal gland, lung, mediastinum, and peritoneum, lymph nodes, etc. It is important to note that some patients do not have any symptoms or imaging changes at the beginning of recurrence, but have elevated serum markers. In these patients, the markers should be rechecked once a month, and if they are progressively and exponentially increased three times in a row, recurrence can be considered and an appropriate imaging method should be selected to further clarify the diagnosis. Premature use of imaging may not only be unhelpful in detecting recurrent lesions, but may also add to the patient’s financial and emotional burden. Elevated markers alone are not usually an indication for treatment initiation, and it is generally considered appropriate to begin treatment after a lesion has been detected. Among imaging methods, ultrasound, especially color ultrasound, is preferred because it is noninvasive and inexpensive, and most recurrent ovarian cancer lesions are still located in the pelvic and abdominal cavities. CT is sensitive to lesions in the liver, spleen, peritoneum and lung, while MRI is more sensitive than CT in diagnosing recurrence in the soft tissues of the pelvis; ECT and PET/CT are superior to other methods in determining the number and location of recurrent lesions due to the combination of anatomical and functional imaging. The diagnostic rate and positive predictive value of PET/CT, in particular, can reach more than 90%, which is the most accurate localization and diagnosis method at present. However, the instrument is not yet popular and expensive, which are its defects. Patients who meet the following criteria should be considered for surgical treatment: 1. patients aged ≤75 years; 2. patients in remission for ≥6 months after initial treatment; 3. isolated resectable lesions that can be satisfactorily resected, preferably without visual residue; 4. no unresectable extra-abdominal or liver metastases; 5. no intestinal obstruction (palliative surgery to relieve intestinal obstruction is not 6. no clinical contraindications to surgery; 6. Karnofsky score ≥ 60; 7. patient consent and personal financial permission to apply chemotherapy or radiation therapy after recovery from surgery.