A 3D Monte Carlo Method for Estimation of Patient-specific Internal Organs Absorbed Dose for (99m)Tc-hynic-Tyr(3)-octreotide Imaging
Overview
Authors
Affiliations
Single-photon emission computed tomography (SPECT)-based tracers are easily available and more widely used than positron emission tomography (PET)-based tracers, and SPECT imaging still remains the most prevalent nuclear medicine imaging modality worldwide. The aim of this study is to implement an image-based Monte Carlo method for patient-specific three-dimensional (3D) absorbed dose calculation in patients after injection of (99m)Tc-hydrazinonicotinamide (hynic)-Tyr(3)-octreotide as a SPECT radiotracer. (99m)Tc patient-specific S values and the absorbed doses were calculated with GATE code for each source-target organ pair in four patients who were imaged for suspected neuroendocrine tumors. Each patient underwent multiple whole-body planar scans as well as SPECT imaging over a period of 1-24 h after intravenous injection of (99m)hynic-Tyr(3)-octreotide. The patient-specific S values calculated by GATE Monte Carlo code and the corresponding S values obtained by MIRDOSE program differed within 4.3% on an average for self-irradiation, and differed within 69.6% on an average for cross-irradiation. However, the agreement between total organ doses calculated by GATE code and MIRDOSE program for all patients was reasonably well (percentage difference was about 4.6% on an average). Normal and tumor absorbed doses calculated with GATE were slightly higher than those calculated with MIRDOSE program. The average ratio of GATE absorbed doses to MIRDOSE was 1.07 ± 0.11 (ranging from 0.94 to 1.36). According to the results, it is proposed that when cross-organ irradiation is dominant, a comprehensive approach such as GATE Monte Carlo dosimetry be used since it provides more reliable dosimetric results.
Monte Carlo methods for medical imaging research.
Lee H Biomed Eng Lett. 2024; 14(6):1195-1205.
PMID: 39465109 PMC: 11502642. DOI: 10.1007/s13534-024-00423-x.
Asl R, Sabbaghi R, Ahangari H, Hejazi P, Foroutan M Indian J Nucl Med. 2021; 36(3):273-281.
PMID: 34658551 PMC: 8481846. DOI: 10.4103/ijnm.ijnm_6_21.
Neira S, Guiu-Souto J, Diaz-Botana P, Pais P, Fernandez C, Pubul V Med Phys. 2020; 47(9):4574-4588.
PMID: 32569389 PMC: 7586975. DOI: 10.1002/mp.14344.
K E, R A, F K, N A, A B, Gh A J Biomed Phys Eng. 2019; 9(3):285-294.
PMID: 31341874 PMC: 6613160. DOI: 10.31661/jbpe.v0i0.984.
Deformable torso phantoms of Chinese adults for personalized anatomy modelling.
Wang H, Sun X, Wu T, Li C, Chen Z, Liao M J Anat. 2018; 233(1):121-134.
PMID: 29663370 PMC: 5987821. DOI: 10.1111/joa.12815.