It can be difficult to determine the best dosage of radiation for each particular patient, but – say it with me – 3D printing can help! Researchers at the University of Würzburg have been using 3D printing to prototype kidney models, or kidney phantoms, of different shapes and sizes in order to assess how much radiation is needed for optimal imaging. The goal is to be able to develop patient-specific treatment, and kidneys were chosen for prototyping as they’re one of the highest-risk organs in radiation therapy and imaging.
“This research shows a way of producing inexpensive models of patient-specific organs/lesions for providing direct and patient-specific calibration constants,” said Johannes Tran-Gia, Ph.D., corresponding author on the study. “This is particularly important for imaging systems suffering from poor spatial resolution and ill-defined quantification, such as SPECT/CT.”
The 3D printed phantoms were then used to test the accuracy of quantitative imaging for internal renal dosimetry. The study determined the proper nuclide-dependent SPECT/CT calibration factors for technetium-99m (Tc-99m), lutetium-177 (Lu-177), and iodine-131 (I-131).
“In this work, FDM 3D printing was successfully used to manufacture a set of refillable, waterproof, and chemically stable phantoms,” the researchers stated. “With a maximum volumetric deviation of about 6% between the CAD model and the final 3D object—even in case of the smallest kidney (volume, ;9 mL)—the printing accuracy was sufficient for SPECT/CT calibration measurements.”
The deviation, the researchers continued, was likely caused by the fact that the single-extruder printer required that the models be printed in two separate parts with supports, then glued together, an issue that could be eliminated with a dual-extruder 3D printer. Future studies may also involve more complex organ models, as well as other organs besides kidneys.
‟Although in our study the kidneys were modeled as a relatively simple one-compartment model, the study represents an important step towards a reliable determination of absorbed doses and, therefore, an individualized patient dosimetry of other critical organs in addition to kidneys,” said Dr. Tran-Gia.
Additional authors of the research paper, entitled “Design and Fabrication of Kidney Phantoms for Internal Radiation Dosimetry Using 3D Printing Technology,” include Susanne Schlögl and Michael Lassman. You can read the full study here. Discuss in the Kidney Phantoms forum at 3DPB.com.
[Images: University of Würzburg]