Brachytherapy treatment in gynecological cancers is an essential component to delivering adequate doses of radiation to a tumour while sparing normal tissue. Interstitial and intracavitary brachytherapy is often needed in advanced or recurrent disease, in cases where intrauterine brachytherapy may not deliver the optimal outcome. Interstitial brachytherapy is based on a defined template-and-needle system, and the procedure relies on clinical examination and pre-treatment imaging to guide needle insertion. There is currently no standard image-guided process to help direct needles in the pelvis. The investigators propose a 3D ultrasound device that will provide real-time imaging for the brachytherapy procedure which will aid in avoiding needle insertion into pelvic organs and result in optimal dose coverage to the tumour.

This is an efficacy study to optimize the use of three-dimensional ultrasound imaging for interstitial and intracavitary brachytherapy. In this study, 3DUS images will be acquired during the regular clinical procedure to assess the quality of the images, anatomical detail and location of needles. The acquired images will be analyzed post-treatment and fused with pre-treatment MRI, and post-treatment CT scans to develop a virtual simulated radiation treatment plan, and to verify the applicator positions.

Inclusion Criteria:

• Patients with locally advanced or recurrent gynecological malignancies who are offered interstitial or intracavitary brachytherapy treatment. These typically would include patients with primary or recurrent vaginal cancers, endometrial cancers or cervical cancers. Histologies of these cancers are typically adenocarcinomas or squamous cell carcinomas

Exclusion Criteria:

• Above patients who are not offered interstitial or intracavitary brachytherapy as a treatment modality

Females patients with locally advanced or recurrent gynecological malignancies who are offered interstitial or intracavitary brachytherapy treatment.