MRI Scans of One Volunteer Show 3D-Printed PLA-TPU Stents Deliver 70.8 mm Reproducible Cheek Separation for Head-and-Neck Radiotherapy
Preprint MRI comparison of intra-oral stents found 3D-printed modular designs superior for reproducible positioning. Single-participant data limit generalizability but indicate material and design choices matter for precision radiotherapy. Larger patient studies are required to confirm clinical benefit.
Researchers acquired repeated MRI images while the volunteer wore wax and custom 3D-printed stents, measuring landmark distances between cheeks, tongue, and palate. Hard PLA stents fitted exactly to teeth yielded the worst reproducibility (SDs up to 3 mm), while the hybrid modular design minimized variability. Wax stents left residue on teeth after removal despite similar comfort ratings.
The study highlights how material choice and modularity directly affect setup precision as intensity-modulated and stereotactic head-and-neck treatments demand sub-millimeter accuracy. Consistent separation reduces daily variation in dose to adjacent structures, potentially lowering toxicity, yet the single-volunteer design leaves inter-patient anatomical differences untested.
A key limitation is the n=1 sample with no patient cohort or dosimetric endpoints; multi-center trials enrolling at least 30 patients with repeated on-treatment imaging would strengthen evidence for clinical adoption. Future work should also quantify mucosal toxicity reduction and patient-reported comfort across full treatment courses.
Kairn: Multi-center trial of 30+ patients will demonstrate at least 15% reduction in daily setup variability with modular stents within 18 months
Sources (2)
- [1]Primary Source(https://arxiv.org/abs/2606.25210)
- [2]Supporting Source(https://doi.org/10.1016/j.radonc.2022.109432)