Inclusion Criteria:

1. The patient is fully voluntary and has the capacity for autonomy, signing the informed consent form 30 days prior to enrollment
2. Age ≥18 and ≤75 years
3. FIGO stage IB-IIIB cervical cancer; IIIC1 (lymph node metastasis ≤2 cm, without common iliac lymph node metastasis)
4. Pathologically diagnosed as squamous cell carcinoma, adenocarcinoma, or adenosquamous carcinoma
5. Concurrent weekly cisplatin therapy ± immunotherapy
6. Able to undergo brachytherapy
7. ECOG performance status of 0-1, with an expected ability to tolerate lying flat for half an hour.

Exclusion Criteria:

1. Patients who have undergone cervical cancer surgery, excluding pelvic lymphadenectomy or pelvic lymph node dissection, or cervical conization
2. FIGO stages IA, IIIC2, IVA, or IVB
3. FIGO stage IIIC1 with lymph nodes >2 cm, or with common iliac lymph node metastasis
4. History of prior abdominal or pelvic radiotherapy
5. Pregnant or breastfeeding women
6. Patients with active infections or fever
7. Other severe diseases that may significantly affect clinical trial compliance, such as unstable heart disease, kidney disease, chronic hepatitis requiring treatment, poorly controlled diabetes, or mental disorders.