Autostent: A Semi-Automated Approach to Designing Customized 3D-Printed Oral Radiation Stents for Patients with Head and Neck Cancer

Oral stents may reduce toxicities during radiation therapy for head and neck cancer (HNC). Although customized 3D-printed oral stents are more quickly fabricated and non-inferior (in terms of patient reported outcomes) compared to conventionally-fabricated stents, the design process is still relatively time-consuming, unstandardized, and requires experienced technicians. We hypothesized that semi-automating the 3D-printed stent design process can reduce design time and standardize the workflow. Using oral stent design principles established over decades by oral oncologists, we developed a customized computer program (Autostent) using MATLAB to semi-automate the design process. We then compared a previously described method utilizing non-automated computer-aided design with Autostent. Three users designed stents for four patients with HNC enrolled on a prospective observational study. These patients were selected based on differing dental anatomies, and each user designed stents for each patient thrice, using both the non- and semi-automated methods. The design time and stent volumes for the two methods were statistically analyzed. Semi-automation was found to significantly reduce the average design time by 23.6 minutes (51.2%, p=0.001), independent of user, dental anatomy, and trial number. Additionally, semi-automation reduced the average stent volume by 4.33 mL (12.9%, p=0.016, univariate analysis). While this was not statistically significant after accounting for the other experimental variables (p=0.40, multivariate analysis), semi-automation did reduce the variability in the stent volume across users (overall standard error of the mean reduced by 40%). Thus, the semi-automated workflow significantly reduced the design time and the variability in the stent volume across users compared to the non-automated workflow. This may lead to potential cost benefits, standardization of the device, and increased population-wide access to a device that could help reduce toxicities for HNC. ### Competing Interest Statement Authors M.M.Z. and E.J.K. have a pending patent application titled "APPARATUS AND METHODS FOR THREE-DIMENSIONAL PRINTED ORAL STENTS FOR HEAD AND NECK RADIOTHERAPY", and this technology is being licensed for commercialization. The MD Anderson Cancer Center Conflict Of Interest Committee (COI) manages all COI for E.J.K. We otherwise have no conflicts of interest to disclose. ### Funding Statement We gratefully acknowledge partial support from the Andrew Sabin Family Fellowship, the Sheikh Ahmed Center for Pancreatic Cancer Research, institutional funds from The University of Texas MD Anderson Cancer Center, equipment support by GE Healthcare and the Center of Advanced Biomedical Imaging, Project Purple, and Cancer Center Support (Core) Grant CA016672 from the National Cancer Institute to MD Anderson. Dr. Eugene Koay was also supported by the NIH (U54CA210181-01, U54CA143837, U01CA196403, 5U01CA200468-04, R01CA248917, 5R01CA218004-02, 5U01CA214263-02, 1P50CA221707-01A1, P50 CA217674). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: IRB of the University of Texas MD Anderson Cancer Center gave ethical approval for this work (protocol: 2017-0269). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Research data are not available at this time.