Population-based input function (PBIF) applied to dynamic whole-body 68Ga-DOTATOC-PET/CT acquisition

Rational To validate a population-based input function (PBIF) model that alleviates the need for scanning since injection time in dynamic whole-body (WBdyn) PET. Methods Thirty-seven patients with suspected/known well-differentiated neuroendocrine tumors were included (GAPETNET trial NTC03576040). All WBdyn 68Ga-DOTATOC-PET/CT acquisitions performed on digital PET system (one heart-centered 6 min-step followed by nine WB-passes). The PBIF was built from 20 image-derived functions (IDIFs) obtained respective number of patients’ exams using an automated left-ventricle segmentation tool. IDIF peaks aligned to median time-to-peak, normalized patient weight and administrated activity, then fitted exponential function. applied 17 independent studies scaling it match section at 20–55 min post-injection windows corresponding WB-passes 3–7. ratio area under curves (AUCs) IDIFs 3–7 compared Bland–Altman analysis (mean bias ± SD). Patlak-estimated mean Ki physiological uptake (Ki-liver Ki-spleen) tumor lesions (Ki-tumor) either or also compared. Results AUC (PBIF/IDIF) 0.98 0.06. between −2.6 6.2% (confidence interval, CI: −5.8; 0.6). For Ki-spleen Ki-tumor, low relative SD found [4.65 7.59% (CI: 0.26; 9.03) 3.70 8.29% −1.09; 8.49) respectively]. Ki-liver analysis, slightly higher [7.43 13.13% −0.15; 15.01)]. Conclusion Our study showed approach allows reduction DOTATOC-PET/CT acquisition times minimum gain min.