A feasibility study for using ABS plastic and a low-cost 3D printer for patient-specific brachytherapy mould design

Abstract

This feasibility study aims to determine if a low-cost 3D printer (BitsFromBytes 3D Touch) with ABS plastic can print custom mould structures and catheter channels defined in a brachytherapy treatment planning system (Nucletron Oncentra) for patient-specific treatment. Printer accuracy was evaluated through physical measurement, and print quality was investigated by adjusting print parameters (print speed, layer thickness, percentage infill). Catheter positioning and reproducibility were measured over repeated insertions. ABS plastic water equivalency was investigated by comparing Ir-192 HDR source dose distributions, measured with radiochromic film, in ABS plastic and in water. Structures and catheter channels were printed accurately to within 0.5 mm laterally and 1 mm in the vertical print direction. Adjusting print parameters could reduce print time, albeit with reduced print quality. 3.5 mm channel diameters allowed for easy catheter insertion. Catheter positioning was reproducible to within 0.5 mm but, because of catheter flex within the channel, was on average 1 mm offset from defined TPS positions. This offset could be accounted for by repeating the treatment planning CT scan with the printed mould positioned on the patient. Dose attenuation in ABS plastic and in water was equivalent to within the measurement limitations. While clinical uses for this particular low-cost printer and ABS plastic are limited by print size restrictions and non-certification for biocompatibility, it has been demonstrated that a low-cost 3D printer set-up can accurately create custom moulds and catheter channels potentially acceptable for clinical use.

Individualized 3D scanning and printing for non-melanoma skin cancer brachytherapy: a financial study for its integration into clinical workflow

“…One of those is the use of 3D printing technology, which is being utilized more frequently in medicine more each year [1,2,3]. In radiotherapy, 3D printing has been introduced to create boluses [4,5,6,7,8,9], phantoms for quality assurance [10,11,12,13], compensator blocks [14], proton range compensators [15], and tools for brachytherapy [16,17,18,19,20,21,22]. Skin cancer is currently one of the most common tumors [23,24].…”

Three‐dimensional‐printed vaginal applicators for electronic brachytherapy of endometrial cancers

“…33,34 Due to this shortcoming, there have been attempts to discover printing materials that can be used by a cheap desktop 3D printer to print the applicators. [35][36][37][38] One of these attempts involved printing cylindrical applicators and flat shaped applicators using acrylonitrile butadiene styrene (ABS) as printing material, and comparing their dosimetric properties to those of commercially available applicators when using HDR Ir-192 as the radiation source. 38 Nonetheless, ABS has issues with heat resistance, and thus, is difficult to sterilize.…”

Analysis of Suspension System for 3D Printed Mobile Robot

“…When properly cooled, PLA seems to have higher maximum printing speeds, lower layer heights, and sharper printed corners. Combining this with low fault on parts make it a popular plastic for general printers, hobbyists, and schools [9]. Mechanical properties of PLA and ABS are given in Table 2.…”