Imaging study of using radiopharmaceuticals labeled with cyclotron-produced99mTc.
Cyclotron-produced99mTc (CPTc) has been recognized as an attractive and practical substitution of reactor/generator based99mTc. However, the small amount of92-98Mo in the irradiation of enriched100Mo could lead to the production of other radioactive technetium isotopes (Tc-impurities) which cannot be chemically separated. Thus, these impurities could contribute to patient dose and affect image quality. The potential radiation dose caused by these Tc-impurities produced using different targets, irradiation conditions, and corresponding to different injection times have been investigated, leading us to create dose-based limits of these parameters for producing clinically acceptable CPTc. However, image quality has been not considered. The aim of the present work is to provide a comprehensive and quantitative analysis of image quality for CPTc. The impact of Tc-impurities in CPTc on image resolution, background noise, and contrast is investigated by performing both Monte-Carlo simulations and phantom experiments. Various targets, irradiation, and acquisition conditions are employed for investigating the image-based limits of CPTc production parameters. Additionally, the relationship between patient dose and image quality of CPTc samples is studied. Only those samples which meet both dose- and image-based limits should be accepted in future clinical studies.
University of British Columbia, Vancouver, BC, Canada.
X
X
Hou
J
J
Tanguay
M
M
Vuckovic
K
K
Buckley
P
P
Schaffer
F
F
Bénard
T J
TJ
Ruth
A
A
Celler
D017357:Cyclotrons; D004340:Drug Contamination / Q000517:prevention & control; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods / Q000592:standards*; D009010:Monte Carlo Method; D015609:Organotechnetium Compounds / Q000737:chemistry*; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement; D019275:Radiopharmaceuticals / Q000737:chemistry* / Q000302:isolation & purification*; D014057:Tomography, X-Ray Computed / Q000379:methods
D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals