Fabrication of malleable three-dimensional-printed customized bolus using three-dimensional scanner.

Jae Won Park,Se An Oh,Min Kyu Kang,Ji Woon Yea,Jonathan H Sherman

doi:10.1371/journal.pone.0177562

Abstract

A three-dimensional (3D)-printed customized bolus (3D bolus) can be used for radiotherapy application to irregular surfaces. However, bolus fabrication based on computed tomography (CT) scans is complicated and also delivers unwanted irradiation. Consequently, we fabricated a bolus using a 3D scanner and evaluated its efficacy. The head of an Alderson Rando phantom was scanned with a 3D scanner. The 3D surface data were exported and reconstructed with Geomagic Design X software. A 3D bolus of 5-mm thickness designed to fit onto the nose was printed with the use of rubber-like printing material, and a radiotherapy plan was developed. We successfully fabricated the customized 3D bolus, and further, a CT simulation indicated an acceptable fit of the 3D bolus to the nose. There was no air gap between the bolus and the phantom surface. The percent depth dose (PDD) curve of the phantom with the 3D bolus showed an enhanced surface dose when compared with that of the phantom without the bolus. The PDD of the 3D bolus was comparable with that of a commercial superflab bolus. The radiotherapy plan considering the 3D bolus showed improved target coverage when compared with that without the bolus. Thus, we successfully fabricated a customized 3D bolus for an irregular surface using a 3D scanner instead of a CT scanner.

Highlights

The skin-sparing effect of megavoltage-photon beams in radiotherapy forms a major benefit in the treatment of deep-seated tumours; skin-sparing reduces the target coverage of superficial tumours [1]
Our clinical experience of a 3D bolus applied to intensity-modulated radiotherapy for a patient with Kimura’s disease revealed certain problems regarding the fabrication of the 3D bolus [10]: (1) The design of a 3D bolus with the use of computed tomography (CT) scans leads to unwanted radiation exposure of the patient
Fig 2. 3D bolus fabricated with 3D scanner. (A) STL file view of the designed 3D bolus, (B) printed result obtained with malleable material, Tango Plus, and (C) CT simulation scan setup of the bolus on the Rando phantom. 3D bolus, three-dimensional-printed customized bolus; STL, STereoLithography; CT, computed tomography

Summary

Introduction

The skin-sparing effect of megavoltage-photon beams in radiotherapy forms a major benefit in the treatment of deep-seated tumours; skin-sparing reduces the target coverage of superficial tumours [1]. (4) it is difficult to minimize the air gaps between the body surface and the bolus. Our clinical experience of a 3D bolus applied to intensity-modulated radiotherapy for a patient with Kimura’s disease revealed certain problems regarding the fabrication of the 3D bolus [10]: (1) The design of a 3D bolus with the use of computed tomography (CT) scans leads to unwanted radiation exposure of the patient. In this context, here, we explore the radiotherapy application possibility of a 3D bolus made of malleable material with the aid of a 3D scanner

Methods

Results

Conclusion