Chemoradiotherapy With or Without Metformin in Locally Advanced Cervical Cancer

Patients randomized to the metformin group will start taking metformin within 1 day after group allocation. They will take one tablet of metformin (850 mg) once daily for three consecutive days. Subsequently, they will take metformin orally twice daily throughout the entire external and internal irradiation period, with each administration consisting of one tablet.

The study requires all subjects to sequentially undergo external beam radiotherapy (EBRT) and intracavitary brachytherapy (BT). All radiotherapy must be completed within 7-8 weeks after treatment initiation. The total prescribed dose EQD2 for EBRT combined with BT should be ≥80 Gy; for subjects with squamous carcinoma with lesions ≤4 cm, the HR-CTV D90 should be ≥80 Gy; for subjects with adenocarcinoma or lesions \>4 cm, it is recommended that HR-CTV D90 should be ≥85 Gy. When the prescribed dose is limited by organs at risk (OAR), priority should be given to covering HR-CTV. The radiotherapy plan in this study is based on image guidance. Imaging scans can use MRI or CT, and the scanning area should extend at least 5 cm above and below the PTV.

The dosage of cisplatin is 40 mg/m2, administered once weekly during radiotherapy for a duration of 5 weeks. Prior to and following cisplatin administration, 1-2 liters of fluid should be given for adequate hydration. Treatment should continue until disease progression or intolerable toxicity occurs.

Using 68Ga-NY104 as a small molecule targeted imaging agent for CA-IX, two CA-IX PET/CT scans will be conducted in patients: one upon enrollment and another one week after randomization.