3D printing of individual skin brachytherapy applicator: design, manufacturing, and early clinical results
Grzegorz Bielęda, Adam Chicheł, Marek Boehlke, Grzegorz Zwierzchowski, Artur J. Chyrek, Wojciech Burchardt, Patrycja Stefaniak, Natalia Wiśniewska, Kinga Czereba, Julian Malicki
Abstract
Purpose: One of the main challenges in facial region brachytherapy is fixation of vendor-delivered standard applicators. Reproducibility can be maintained; however, there are frequent problems with applicator fitting to the skin surface in pleated regions. Manually prepared individual moulds require technological facilities and highly-trained staff. This article presents 3D-printed applicator preparation for a particular patient skin brachytherapy, using low-cost equipment and free software. We described applicator preparation in a step-by-step workflow. Material and methods: This study demonstrated preparation of a skin brachytherapy applicator for a challenging recurrent tumor located in the nose bridge. During first visit of patient, fiducial markers were placed to enclose treated region. Patient was computed tomography (CT)-scanned, and reconstruction of target volume and surrounding organs at risk (OARs) were performed using treatment planning system (TPS). In TPS on patient's surface, a 1-cm thick bolus was added as a body of applicator. Inside the bolus, source paths were designed, and pre-plan was prepared. Using Beben - DICOM to standard triangle language (STL) software, the body of applicator and source-paths from pre-planning was transformed into an STL file, which was used as a solid definition in 3D printing. Results: , which was higher for the realized plan (1.15% vs. 1.83%). All reported doses to OARs were lower in the realized plan. Conclusions: A low-cost 3D printer and widely available PLA filaments seem feasible to produce individual contact applicators for skin brachytherapy. Beben - DICOM to STL software and presented workflow appear to be convenient and simple tool.