A feasibility study of using a 3D-printed tumor model scintillator to verify the energy absorbed to a tumor

• Main Authors: Tae Hoon Kim, Sangmin Lee, Dong Geon Kim, Jae Young Jeong, Hye Jeong Yang, Thomas Schaarschmidt, Sang Hyoun Choi, Gyu-Seok Cho, Yong Kyun Kim, Hyun-Tai Chung
• Format: Article
• Language: English
• Published: Elsevier 2021-09-01
• Series: Nuclear Engineering and Technology
• Subjects: 3D-printed tumor model; Plastic scintillator; Absorbed energy; Volumetric dosimetry; Treatment planning system; Monte Carlo simulation
• Online Access: http://www.sciencedirect.com/science/article/pii/S1738573321001777

The authors developed a volumetric dosimetry detector system using in-house 3D-printable plastic scintillator resins. Three tumor model scintillators (TMSs) were developed using magnetic resonance images of a tumor. The detector system consisted of a TMS, an optical fiber, a photomultiplier tube, and an electrometer. The background signal, including the Cherenkov lights generated in the optical fiber, was subtracted from the output signal. The system showed 2.1% instability when the TMS was reassembled. The system efficiencies in collecting lights for a given absorbed energy were determined by calibration at a secondary standard dosimetry laboratory (kSSDL) or by calibration using Monte Carlo simulations (ksim). The TMSs were irradiated in a Gamma Knife® Icon™ (Elekta AB, Stockholm, Sweden) following a treatment plan. The energies absorbed to the TMSs were measured and compared with a calculated value. While the measured energy determined with kSSDL was (5.84 ± 3.56) % lower than the calculated value, the energy with ksim was (2.00 ± 0.76) % higher. Although the TMS detector system worked reasonably well in measuring the absorbed energy to a tumor, further improvements in the calibration procedure and system stability are needed for the system to be accepted as a quality assurance tool.