Youichi Otomi, Takayoshi Shinya, Hideki Otsuka, Hiroto Kasai, Tomoki Matsushita, Yukiko Takaoka, Yuka Hiroshima, Tomoyasu Matsubara, Koji Fujita, Yukiko Tomioka, Masahito Nakataki, Shusuke Numata, Yuishin Izumi and Masafumi Harada : Serial amyloid PET demonstrates marked reduction in amyloid burden following donanemab treatment: a real-world cohort study, Japanese Journal of Radiology, 2026.
(要約)
To evaluate changes in amyloid burden on serial amyloid PET before and after donanemab treatment in a real-world clinical cohort. This retrospective study included 20 consecutive patients who underwent serial amyloid PET before and after donanemab treatment. Quantitative analysis was performed using Centiloid values and tracer-specific standardized uptake value ratios (SUVr). Visual assessment was also performed to determine amyloid-positive or amyloid-negative status before and after treatment. Centiloid values significantly decreased from 52.3 ± 23.4 at baseline to - 5.6 ± 16.5 at follow-up, with a mean change of - 58.0 (p < 0.001). All patients showed a reduction in Centiloid values. In the flutemetamol group (n = 12), pons-referenced SUVr significantly decreased, while in the florbetapir group (n = 8), cerebellar-referenced SUVr also showed significant reductions (both p < 0.001). On visual assessment, 17 of 20 patients (85%) converted from amyloid-positive to amyloid-negative status after treatment. Serial amyloid PET demonstrated a substantial reduction in amyloid burden following donanemab treatment in this real-world cohort. Quantitative amyloid PET, particularly using Centiloid scaling, may be a useful tool for monitoring treatment response in clinical practice.
Manduukhai Badarchin, Youichi Otomi, Takayoshi Shinya, Hideki Otsuka, Yukiko Takaoka, Tomoki Matsushita, Tomoyasu Matsubara, Koji Fujita, Yukiko Tomioka, Masahito Nakataki, Yuishin Izumi, Shusuke Numata and Masafumi Harada : Comparative evaluation of CortexID and VIZCalc software in brain amyloid PET: a retrospective study of 116 cases, Annals of Nuclear Medicine, 40, 4, 425-433, 2025.
(要約)
Quantitative analysis of amyloid positron emission tomography (PET) is increasingly applied in clinical and research settings; however, its consistency across software platforms remains uncertain. This study aimed to compare standardized uptake value ratio (SUVr) measurements obtained from CortexID Suite and VIZCalc, to evaluate their concordance with expert visual assessment, and to assess the concordance of Centiloid values derived from VIZCalc with the visual reference. We retrospectively analyzed 116 patients who underwent 18F-flutemetamol PET at a single institution. SUVr values were calculated using both CortexID Suite and VIZCalc, while Centiloid values were derived from VIZCalc only. Visual assessments were performed by two nuclear medicine physicians. Correlations among indices were examined using Pearson's correlation. Agreement between SUVr values was assessed with Bland-Altman analysis. Agreement with the non-independent visual reference was evaluated using receiver operating characteristic (ROC) analysis, and areas under the curves (AUCs) were compared with DeLong's test. SUVr values from CortexID and VIZCalc were strongly correlated (r = 0.986, p < 0.001), with a small mean difference of + 0.0397. Both platforms showed high concordance with the non-blinded visual assessment (AUC: 0.991 for CortexID; 0.989 for VIZCalc). Centiloid values also showed high agreement with the visual reference (AUC: 0.994) and were strongly correlated with SUVr values (r = 0.975 for CortexID; r = 0.965 for VIZCalc, p < 0.001). No significant difference was observed between platforms (p = 0.84). CortexID Suite and VIZCalc demonstrated high concordance with the non-blinded visual assessment and showed consistent quantitative trends. Both platforms can be reliably applied for amyloid burden quantification, provided that software-specific characteristics are appropriately considered.