title: Evaluation of pulmonary nodules and lung cancer with one-inch crystal gamma coincidence positron emission tomography/CT versus dedicated positron emission tomography/CT.
abstract: Dedicated positron emission tomography (PET)/CT scanners using BGO and related detectors (d-PET) have become standard imaging instruments in many malignancies. Hybrid gamma camera systems using NaI detectors in coincidence mode (g-PET) have been compared to d-PET but reported usefulness has been variable when gamma cameras with half-inch to three-fourth-inch thick crystals have been used without CT. Our aim was to compare g-PET with a 1-in.-thick crystal and inbuilt CT for lesion localization and attenuation correction (g-PET/CT) and d-PET/CT in patients presenting with potential and confirmed lung malignancies. One hour after (18)F-fluorodeoxyglucose (FDG), patients underwent BGO d-PET/CT from jaw to proximal thigh. This was followed by one to two bed position g-PET/CT 194 +/- 27 min after FDG. Each study pair was independently analysed with concurrent CT. d-PET/CT was interpreted by a radiologist experienced in both PET and CT, and g-PET/CT by consensus reading of an experienced PET physician and an experienced CT radiologist. A TNM score was assigned and studies were then unblinded and compared. Fifty-seven patients underwent 58 scan pairs over 2 years. Eighty-nine per cent concordance was shown between g-PET/CT and d-PET/CT for the assessment of intrapulmonary lesions, with 100% concordance for intrapulmonary lesions >10 mm (36 of 36). Eighty-eight per cent (51 of 58) concordance was shown between g-PET/CT and d-PET/CT for TNM staging. Coincidence imaging using an optimized dual-head 1-in.-thick crystal gamma camera with inbuilt CT compares reasonably well with dedicated PET/CT for evaluation of indeterminate pulmonary lesions and staging of pulmonary malignancies and may be of some value when d-PET/CT is not readily available.
authors.affiliation: The Centre for Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Moodie
authors.forename: M H
authors.initials: MH
authors.lastname: Cherk
authors.forename: E
authors.initials: E
authors.lastname: Lau
authors.forename: A
authors.initials: A
authors.lastname: Turlakow
authors.forename: S
authors.initials: S
authors.lastname: Skinner
authors.forename: R J
authors.initials: RJ
authors.lastname: Hicks
authors.forename: M J
authors.initials: MJ
authors.lastname: Kelly
authors.forename: V
authors.initials: V
authors.lastname: Kalff
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D015902:Gamma Cameras; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000175:diagnosis*; D013382:Subtraction Technique / Q000295:instrumentation*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*