Novel Use of 3D Printing for Pre-Operative Dose Estimation in the First Case of Gammatile Spine Implantation
Recommended Citation
Huang-Vredevoogd JY, Doemer AJ, Siddiqui M, Shah M, Al Asadi A, DiCarlo AL, Scarpace L, Robin A, Lee IY, Moceri Kohrman AG, Thind KS. Novel Use of 3D Printing for Pre-Operative Dose Estimation in the First Case of Gammatile Spine Implantation. Med Phys 2025; 52(10):475.
Document Type
Conference Proceeding
Publication Date
9-30-2025
Publication Title
Med Phys
Keywords
cesium 131, bone tumor, clinical article, computer assisted tomography, conference abstract, controlled study, CPAP device, dose calculation, dosimetry, dura mater, excision, external beam radiotherapy, human, implantation, maximum permissible dose, MRI scanner, nuclear magnetic resonance imaging, organs at risk, printer, radiotherapy, re-irradiation, rectosigmoid adenocarcinoma, sacrum, simulation, software, spine, spine implant, three dimensional printing
Abstract
Purpose: For a patient who had two previous courses of external beam therapy for rectosigmoid adenocarcinoma and presented with painful, recurrent disease in the sacrum, this study describes the first use of Cs-131 LDR GammaTile therapy outside of the brain and demonstrates a novel use of 3D printing for pre-operative dose estimation. Methods: A personalized 3D-printed model of the patient's spine was created using segmented MRI data, differentiating uninvolved bone, tumor, and dura, with a Stratasys J5 MediJet® Printer. This model was used to simulate surgical resection and placement of dummy radioactive sources. A CT scan of the model facilitated pre-operative dose calculations, encompassing physical dose using Eclipse planning software and biologically effective dose (BED) using MIM Maestro software. The predicted dose was then compared to the post-implant dosimetry for the actual patient. Results: For the relevant organ at risk (sacral nerves), the max dose (D0.035cc) was calculated accurately within 8.0% for physical dose and within 10.0% for BED when comparing the dose estimated using our 3D-printed model and the actual delivered dose to the patient. Conclusion: 3D printing can be used pre-operatively to estimate dose to critical organs at risk for patients receiving surgical resection followed by Cs-131 LDR implantation in the spine and can be especially valuable in the context of reirradiation.
Volume
52
Issue
10
First Page
475
