Establishing Standardized Uptake Value Threshold for Urologic Malignancies With New Analytic Software Based on Extended Single-Photon Emission Computed Tomography-Processed Bone Scintigraphy Images

Accurate reference thresholds are critical for reliable interpretation and quantification in nuclear medicine imaging. In recent years, single-photon emission computed tomography (SPECT)/CT systems capable of standardized uptake value (SUV) analysis have become commercially available; however, most SPECT/CT systems lack the capability to perform SUV analysis. The GI-BONE system (AZE Co., Ltd., Tokyo, Japan) is a new vendor-free software that incorporates a tool for calculating the becquerel calibration factor (BCF), which converts SPECT images from a count-based scale to a radioactivity concentration scale comparable to that of PET. This study aimed to first describe a way for defining optimal SUV threshold specific to GI-BONE analysis using extended SPECT (xSPECT), which is characterized by its capability to facilitate more precise diagnosis and evaluation through enhanced analytical refinement to conventional SPECT imaging. This approach can guide clinicians in formulating their own disease system-specific thresholds, an indispensable step in adapting GI-BONE as a newly applicable and reliable mode of xSPECT verification technology.