3D printing ¹⁸F radioactive phantoms for PET imaging

Area of Science:

• Medical Imaging
• Radiochemistry
• 3D Printing

Background:

• Traditional molecular imaging phantoms lack anatomical realism.
• 3D-printed phantoms offer anatomical accuracy but can be limited by inactive walls, especially for small structures.
• There is a need for advanced phantoms that overcome these limitations for better scanner performance evaluation.

Purpose of the Study:

• To investigate the feasibility of creating resin-based 3D-printed phantoms incorporating Fluorine-18 (18F).
• To develop a method for producing anatomically relevant phantoms without inactive walls.
• To assess the performance and accuracy of these novel radioactive phantoms.

Main Methods:

• An emulsion of printer resin and 18F-FDG was prepared to create radioactive resin.
• Various test objects, including cylinders, spheres, and a double helix, were 3D-printed.
• Radioactive concentration uniformity, dimensional accuracy, and radioactivity leaching were evaluated.

Main Results:

• The radioactive resin emulsion was successfully created and demonstrated to be effective.
• Radioactive concentration was uniform across identical printed objects (CoV 0.7%).
• Printed objects showed high dimensional accuracy (within 4% of model dimensions), and a complex double helix was accurately rendered.

Conclusions:

• 18F-labeled resin emulsion printing is a viable method for creating accurate, complex phantoms without inactive walls.
• This technique enables the production of clinically relevant phantoms for molecular imaging.
• Limitations include single-use nature, inability to create hollow structures without an exit hole, and minor radioactivity leaching.