For patients with cervical or endometrial cancer, the vagina is a common site of metastasis. Although vaginal cancer is rare, it still claims the lives of hundreds of women each year. Brachytherapy treatment approaches for gynecological cancers vary based on tumour size and location, employing intracavitary (using an applicator) or hybrid intracavitary-interstitial (using both an applicator and catheters) brachytherapy. The hybrid approach has shown notable improvements in local control for large tumours and decreases in morbidity related to organs at risk (OARs) when compared to intracavitary brachytherapy alone. However, due to limited infrastructure and insufficient training of radiation oncologists, many patients are not offered this technique, despite its favourable outcomes. Moreover, conventional radiation sources in brachytherapy offer rotationally symmetric dose distributions, potentially leading to dose spillage to surrounding tissues due to the non-symmetrical shape of tumours. One solution is Intensity Modulated Brachytherapy (IMBT). With IMBT, high-density metallic shields rotate during treatment, modulating emitted radiation to focus it on the tumour while shielding healthy tissues. Implementation of IMBT is anticipated to allow for effective tumour coverage in complex cases, removing the need for invasive interstitial needle placement and minimizing morbidity associated with surrounding OARs. In less complicated cases, IMBT is expected to reduce the radiation dose delivered to OARs, thereby enhancing patient outcomes.

The overall goal of this research project is to design and manufacture a novel dynamically rotating high-density shield for an HDR-BT applicator for vaginal treatment, alongside a rotational system and compare the efficacy of vaginal IMBT versus intracavitary and hybrid intracavitary/interstitial brachytherapy.