Individualized 3D-Printed Tissue Retraction Devices for Head and Neck Radiotherapy

Abstract

BackgroundRadiotherapy for head and neck cancer may cause various oral sequelae, such as radiation-induced mucositis. To protect healthy tissue from irradiation, intraoral devices can be used. Current tissue retraction devices (TRDs) have to be either individually manufactured at considerable cost and time expenditure or they are limited in their variability. In this context, a 3D-printed, tooth-borne TRD might further facilitate clinical use.MethodsA novel approach for the manufacturing of TRDs is described and its clinical application is analysed retrospectively. The devices were virtually designed for fabrication by 3D-printing technology, enabling—in only a single printing design—caudal or bi-lateral tongue displacement, as well as stabilization of a tongue-out position. For a total of 10 patients undergoing radiotherapy of head and neck tumors, the devices were individually adapted after pre-fabrication. Technical and clinical feasibility was assessed along with patient adherence. Tissue spacing was calculated by volumetric analysis of tongue retraction. In one exemplary case, radiotherapy treatment plans before and after tissue displacement were generated and compared. The reproducibility of maxillomandibular relation at device re-positioning was quantified by repeated intraoral optical scanning in a voluntary participant.Results3D-printing was useful for the simplification of TRD manufacture, resulting in a total patient treatment time of less than 30 min. The devices were tolerated well by all tested patients over the entire radiation treatment period. No technical complications occurred with the devices. The TRDs caused an effective spacing of the healthy adjacent tissue, e.g., the tongue. Position changes of maxillomandibular relation were limited to a mean value of 98.1 µm ± 29.4 µm root mean square deviation between initial reference and follow-up positions.ConclusionsThe presented method allows a resource-efficient fabrication of individualized, tooth-bourne TRDs. A high reproducibility of maxillomandibular relation was found and the first clinical experiences underline the high potential of such devices for radiotherapy in the head and neck area.

Dual‐energy CT‐based stopping power prediction for dental materials in particle therapy

“…All these materials comprised elements of a high atomic number Z : cobalt‐chrome ( Z Co = 27, Z Cr = 24), composite I ( Z Ba = 56), composite II ( Z Yb = 70), glass‐ceramic ( Z Y = 39), lithium disilicate ( Z Zn = 30, Z Zr = 40), titanium ( Z Ti = 22), zirconium dioxide ( Z Zr = 40). Furthermore, we analyzed the single components of individualized 3D‐printed tissue retraction devices (TRDs) used to protect healthy tissue from irradiation in head and neck radiotherapy 32,33 . TRDs consist of a fixation part (made of silicone material) and a tongue retraction part (made of polymethyl methacrylate [PMMA]).…”

“…Furthermore, we analyzed the single components of individualized 3D-printed tissue retraction devices (TRDs) used to protect healthy tissue from irradiation in head and neck radiotherapy. 32,33 TRDs consist of a fixation part (made of silicone material) and a tongue retraction part (made of polymethyl methacrylate [PMMA]). Samples were fabricated into cylinders with a diameter of 2.8 cm and a length of 1−2 cm (depending on the fabrication abil-ities) (Figure 1).…”

A quick guide on implementing and quality assuring 3D printing in radiation oncology

“…3D printing, or additive manufacturing (AM), has become a widespread technology in medical fields with numerous applications. In radiation oncology, many studies have investigated the clinical implementation and development of 3D printed devices, validating the application of 3D printing and demonstrating superiority to conventional devices in many aspects 1–7 . A wide range of clinical applications have been reported such as patient‐specific bolus, immobilization, and shielding devices, various high‐dose‐rate (HDR) brachytherapy applicators and surgical or insertion guides, customized phantoms for quality assurance (QA) and research, and other random devices 8–11 .…”

Dosimetric impact of hollow intraoral stents for head and neck cancer radiotherapy: A phantom study

“…1,2 These stents are usually hollow to maintain the airway unobstructed and keep the mouth open during radiotherapy treatment. [3][4][5][6][7][8] Due to their special structures and component materials, though potentially uncomfortable for patients, intraoral stents provide significant dose sparing to the oral cavity.…”

“…Intraoral positioning stents are commonly applied in head and neck cancer radiotherapy to protect the healthy tissues surrounding tumors from unnecessary radiation and to minimize radiation‐induced oral mucositis 1 , 2 . These stents are usually hollow to maintain the airway unobstructed and keep the mouth open during radiotherapy treatment 3–8 . Due to their special structures and component materials, though potentially uncomfortable for patients, intraoral stents provide significant dose sparing to the oral cavity.…”