3D Printed Custom Applicators for HDR BT (DISCO)

Successful treatment of gynaecological HDR brachytherapy patients with 3D printed intracavitary applicators.

To demonstrate the feasibility of successfully simulating, planning and treating a HDR BT gynaecological patient with a 3D-printed internal mould, such that there is a dosimetric and/or clinical benefit for the patient relative to the current standard of care (cylindrical vaginal applicator). Successful treatment indicated by achieving no adverse events or difference to standard of care, and dosimentic comparisons of the 3D printed applicator plan to the cylinder plan are equivalent or better. Feasibility also determined by achieving no logistical or design issues in using the 3D printed applicators clinically.

To assess the patients radiation therapy acute and late toxicities using the CTCAE criteria

RT acute and late side effects will be assessed and quantified using CTCAE criteria via clinician assessment and PROs

To compare quality of treatment plans generated for 3D-printed moulds and cylindrical applicators assessed by dosimetric indices, statistical analysis (p-value) and comparison with international guidelines.

The plan quality of treatment plans generated for 3D-printed moulds and cylindrical applicators will be compared using dosimetric indices including target coverage (D90, Dose Homogeneity index) and organs at risk doses (D2cc, D1cc and point max) as well as patient comfort. statistical analysis (p-value) and comparison with international guidelines will be used to assess the quality of the treatment plans.

Determine feasibility of a pre-planned MR-only procedure

Feasibility of a pre-planned MR-only procedure will be determined using any of the patients that are accrued to the study who have both a CT and MRI performed at the time of simulation. The applicator and treatment plan will be generated based on the MRI and both compared to the CT-based plan and applicator. Feasibility will be indicated by generating equivalent plan quality and applicators from both methods.

To determine the feasibility of an initial CT-only process by comparing initial and final CT plan dosimetry assessed by dosimetric indices, clinical tolerances, and statistical analysis (p-value).

The initial and final CT plan dosimetry will be compared to determine the feasibility of an initial CT-only process. Clinically insignificant differences between the plan dosimetry metrics and all within clinical tolerances will be used to quantify the difference. statistical analysis (p-value) will be used to assess the quality of the treatment plans.