Gynecological pelvic tumors primarily include ovarian cancer, cervical cancer, and endometrial cancer. Radiotherapy (RT) is one of the key treatment modalities for gynecological tumors. It is a necessary therapeutic approach for 80% to 90% of cervical cancer patients and 60% of endometrial cancer patients . The vagina, as a target organ and critical vulnerable organ for RT, may be affected by radiation, leading to adverse effects such as vaginal mucosal changes, adhesions, stenosis, or atresia . Vaginal stenosis (VS) is a common yet often overlooked side effect in female patients undergoing pelvic tumor RT, frequently causing symptoms such as dyspareunia, pain, vaginal dryness, or vaginal bleeding . Brand AH et al. prospectively recorded VS data from 179 cervical cancer patients receiving RT, with an average follow-up of 9.6 months, and found that 38% of patients developed VS. Park HS et al. documented VS data from endometrial cancer patients undergoing intravaginal brachytherapy, with an average follow-up of 12.9 months, and reported a VS incidence of 33%. Thais de Morais Siqueira et al. recorded subsequent VS in patients who underwent pelvic RT, with VS prevalence rates of 79% in cervical cancer patients and 67% in endometrial cancer patients. The occurrence of vaginal stenosis can impair patients' later sexual quality of life and comfort satisfaction, which is a crucial factor affecting marital relationship . Failure to prevent or address vaginal stenosis promptly may lead to psychological issues such as anxiety and depression in patients, while both physical and psychological distress can result in a decline in overall quality of life . When progressing to severe vaginal stenosis or vaginal atresia, it not only increases the discomfort during gynecological examinations but also reduces the probability of early detection of tumor recurrence, thereby affecting long-term patient survival .

Current research in China regarding the contributing factors and preventive measures for vaginal stenosis remains in the exploratory phase, with insufficient attention paid to this condition. Current clinical practice predominantly emphasizes the preventive role of vaginal irrigation against infections . During vaginal irrigation, dilators are only briefly used as a substitute for dilation. For cervical cancer patients undergoing radical radiotherapy, routine vaginal irrigation is performed both during and after the treatment. Post-radiotherapy, patients are advised to undergo routine vaginal dilation therapy.

The most commonly used method for preventing vaginal stenosis is the application of vaginal dilators or related molds. Bakker et al. demonstrated that regular use of finger dilation, vaginal dilators, or other types of dilators can improve female patients' sexual function and gradually restore normal vaginal size. Law et al. confirmed that persistent use of vaginal dilators for 6 months significantly restored vaginal size to pre-radiotherapy levels. A study investigating the use of vaginal dilators in patients undergoing pelvic tumor radiotherapy found that 80.0% of patients did not develop vaginal stenosis at 12 months post-radiotherapy, demonstrating that consistent use of vaginal dilators effectively reduces the severity of vaginal stenosis . Martins J et al. conducted a trial comparing local estrogen, local testosterone, placebo, and vaginal dilators for the prevention of vaginal stenosis (VS) in women undergoing radiotherapy for cervical cancer. After 12 months of follow-up, among 142 patients, the prevalence of VS was 11% in those treated with vaginal dilators, 57% in placebo users, and 56.8% in estrogen-treated women, confirming the efficacy of vaginal dilators in reducing VS incidence. Stahl JM et al. enrolled 243 patients who received high-dose brachytherapy (HDR) in the vagina, all of whom were treated with vaginal dilators. At 12 months, the rate of no VS occurrence was 63.5% in non-adherent patients, 70.2% in standard-adherent patients, and 81.2% in extended-adherence patients, further validating the effectiveness of persistent vaginal dilator use in reducing vaginal stenosis. Jiang Song et al. retrospectively analyzed 80 cervical cancer patients who underwent radical radiotherapy at Xuzhou Cancer Hospital from January 2017 to December 2018. The patients were divided into two groups: the control group (40 cases) received only vaginal irrigation, while the observation group (40 cases) received vaginal irrigation combined with vaginal mold application. The incidence of vaginal stenosis was compared between the two groups at 3 months post-radiotherapy. Results: The vaginal stenosis rate in the observation group was 32.50%, while that in the control group was 70.00%, with a statistically significant difference (P <0.05). The use of vaginal mold was associated with a reduced incidence of radiation-induced vaginal stenosis in cervical cancer patients.

Inclusion Criteria:

1. women aged 18 to 70 years.
2. After radiotherapy for pelvic tumors, the tumor is well controlled (no macroscopically visible tumor). At least 1 week after radiotherapy, regular vaginal dilation and irrigation are expected to be performed subsequently.
3. ECOG 0-2.
4. prospected survival greater than 6 months.
5. Good communication skills, no history of mental illness.
6. Consent to participate in this trial and voluntarily sign the informed consent form.

Exclusion Criteria:

1. Malignant tumors in other parts of the body.
2. congenital vaginal stenosis or pre-enrollment confirmed vaginal stenosis.
3. Allergic to silica gel and polyvinyl chloride materials.
4. active vaginal bleeding.
5. It is anticipated that cooperation with the treatment will not be possible.
6. The disease may cause difficulties in treatment and evaluation (e.g., sepsis, inability of the patient to tolerate treatment, etc.).
7. pregnant and lactating women.
8. Participated in other clinical trials involving drugs or medical devices within the past 3 months.
9. The investigators consider other conditions unsuitable for participation in this trial.