title: Quantitative evaluation in tumor SPECT and the effect of tumor size: fundamental study with phantom.
abstract: An experimental study with phantoms was performed in order to evaluate the effect of the tumor volume on the quantitative estimation in tumor SPECT. The ratio of mean count/pixel in the phantom to that of the background (T/N ratio) was well correlated with the size of the phantom: even when the concentration of the Tc-99m O-4 solution of globular phantoms with diameters of 29, 37 and 46 mm was constant, the greater the size of the phantom, the higher was the T/N ratio. This study showed that we should understand that the T/N ratio was certainly affected by the reduction of the tumor size itself whenever we evaluate treatment-response or assess tumor viability after treatment by reference to the T/N ratio.
authors.affiliation: Division of Nuclear Medicine, Chiba Cancer Center Hospital, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Togawa
authors.forename: N
authors.initials: N
authors.lastname: Yui
authors.forename: F
authors.initials: F
authors.lastname: Kinoshita
authors.forename: M
authors.initials: M
authors.lastname: Yanagisawa
mesh_terms: D005069:Evaluation Studies as Topic; D006801:Humans; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D019047:Phantoms, Imaging; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*