Afterloading high dose rate intracavitary vaginal cylinder

Area of Science:

• Gynecologic Oncology
• Radiation Oncology
• Medical Physics

Background:

• Total abdominal hysterectomy is a common treatment for gynecologic malignancies.
• Post-hysterectomy brachytherapy is often required for vaginal cuff or vault recurrences.
• Existing brachytherapy applicators may have limitations in treating the vaginal vault effectively.

Purpose of the Study:

• To design and evaluate a novel afterloading vaginal cylinder for high dose rate (HDR) brachytherapy.
• To ensure the applicator is suitable for treating the vaginal vault after total abdominal hysterectomy.
• To optimize dose distribution and coverage for HDR brachytherapy in the vaginal vault.

Main Methods:

• A nylon vaginal cylinder was designed with multiple source loading channels.
• Channel positioning was optimized to achieve broader isodose surfaces and mitigate linear source brachytherapy end effects.
• A central channel was incorporated for advanced treatment of the tented vault or cervical stump, with options for peripheral sources for vaginal wall plaque therapy.

Main Results:

• The designed applicator facilitates HDR brachytherapy for the vaginal vault, proximal vagina, or entire vagina.
• Treatment planning allows precise control over the treated isodose surface through source positioning and dwell time adjustments.
• The design accommodates treatment of tented vaults and cervical stumps, expanding therapeutic capabilities.

Conclusions:

• The developed HDR vaginal cylinder demonstrates significant potential for treating gynecologic cancers, particularly after hysterectomy.
• Its versatility supports various treatment scenarios, including vaginal cuff, proximal, and entire vaginal wall irradiation.
• This applicator offers a valuable tool for radiation oncologists managing post-surgical gynecologic cancer patients.