Room: Exhibit Hall | Forum 7
Purpose: Patientsâ€™ post-surgical anatomy and tumor location might often render the use of standard applicators suboptimal. However, 3D printing patient-specific moulds to guide needle insertion enables the optimum placement of needles to produce better treatment plans. A technique to 3D-print personalized needle-moulds based on patient-specific geometry is presented here.
Methods: The patient was CT-scanned with contrast-soaked gauzes packed inside the vaginal vault . The DICOM structure of the vault was then 3D printed. This â€œdraftâ€? mould was inserted inside the patient to test the fit and perform an MRI scan. High-risk CTV and organs at risk were delineated on the MR images. Needle paths within the mould were designed to allow optimal dose delivery adapting to target geometry and organs at risk anatomy, and making sure that the exit path of the needles should be accessible to the physician during the insertion. Lastly, an optimum plan was created. The needle paths through the mould were converted to RT structures. The final mould design was drawn in a CAD software subtracting the needle paths from the mould creating smooth and precise holes. A handle with suturing eyes was added to the mould before printing it. The needle paths of the final mould were compared to the ones created on the TPS and numbered.
Results: Two patient-specific vaginal moulds were created. One â€œdraftâ€? mould was used for testing, whereby it was sutured inside a chickenâ€™s cavity and a mock insertion ensued. The plastic needles were inserted according to the plan. Delivery of the source was performed smoothly. Initial department approval to use the 3D printed mould for patient treatment was obtained pending writing an internal protocol and related documents.
Conclusion: 3D printing allows creating patient-specific moulds that facilitate and enable personalized brachytherapy treatments adapting to patientâ€™s anatomy and tumor geometry.