This study is an exploratory study based on the previous study " A prospective, multicenter, randomized, parallel arm-controlled, superiority clinical study to evaluate the role of hydrogel spacer in reducing rectal radiation dose in cervical cancer radiation therapy", in which additional follow up study on the subjects of the previous study were conducted. Subjects (6 subjects in Phase I; 100 subjects in Phase II, 50 in the test group and 50 in the control group) who completed the pre-study will be enrolled in this study if they are willing to participate in the long-term follow-up by signing the informed consent form.

The purpose of this study is to evaluate the long-term benefit of hydrogel spacer when hydrogel is injected between the rectum and cervix in women undergoing radiation therapy.

Inclusion Criteria:

• Karnofsky score ≥ 70. Subjects aged ≥ 18 years and ≤ 75 years. Subjects must be able to cooperate in completing the entire study. The subjects' pelvic and abdominal cavity and joints are free of metal implants and can tolerate MRI.

No contraindications to CT scanning. Subjects must be able to understand the purpose of the trial, voluntarily participate and sign an informed consent form

Exclusion Criteria:

• Subjects whose target tumors have been previously treated (chemotherapy, immunotherapy, surgical treatment, etc.) Subjects with other primary malignancies Subjects with contraindications to radiotherapy, as determined by the investigators Subjects with injection site infections. Subjects who are allergic to the ingredients of the device. Subjects whose tumors invade the injection site and affect the injection process and injection safety, as determined by the investigators Persons with severe mental illness, cognitive impairment and thinking disorders.

Participants in other drug clinical trials or medical device clinical trials 1 month prior to screening Pregnant or lactating women or those who plan to get pregnant within the last six months Subjects who cannot be followed up as prescribed by the doctor Other conditions that, in the judgment of the investigator, make the subject unsuitable for enrollmen