TY - JOUR T1 - <sup>68</sup>Ga-DOTATATE PET/CT Interobserver Agreement for Neuroendocrine Tumor Assessment: Results of a Prospective Study on 50 Patients JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 307 LP - 311 DO - 10.2967/jnumed.116.179192 VL - 58 IS - 2 AU - Wolfgang Peter Fendler AU - Martin Barrio AU - Claudio Spick AU - Martin Allen-Auerbach AU - Valentina Ambrosini AU - Matthias Benz AU - Christina Bluemel AU - Ravinder Kaur Grewal AU - Constantin Lapa AU - Matthias Miederer AU - Guillaume Nicolas AU - Tibor Schuster AU - Johannes Czernin AU - Ken Herrmann Y1 - 2017/02/01 UR - http://jnm.snmjournals.org/content/58/2/307.abstract N2 - We evaluated observer agreement for 68Ga-DOTATATE PET/CT interpretations in patients with neuroendocrine tumor (NET). Methods: 68Ga-DOTATATE PET/CT was performed on 50 patients with known or suspected NET of the small bowel (n = 19), pancreas (n = 14), lung (n = 4), or other location (n = 13). The images were reviewed by 7 observers, who used a standardized interpretation approach. The observers were classified as having a low level of experience (&lt;500 scans or &lt;5 y experience with 68Ga-DOTATATE PET/CT; n = 4) or a high level of experience (≥500 scans or ≥5 y experience with 68Ga-DOTATATE PET/CT; n = 3). Interpretation by the primary nuclear medicine physician, who had access to all clinical and imaging data, served as the reference standard. Interobserver agreement was determined by the Cohen κ statistic and intraclass correlation coefficient (ICC) with corresponding 95% confidence interval (95%CI). Results: Interobserver agreement was substantial, and the median number of false findings was low for the overall scan result: that is, positive versus negative scan result (κ = 0.80; 95%CI, 0.74–0.86; false findings, 3), organ involvement (κ = 0.70; 95%CI, 0.64–0.76; false findings, 5), and lymph node involvement (κ = 0.71; 95%CI, 0.65–0.78; false findings, 6). Interobserver agreement was substantial to almost perfect, and the average absolute difference (Δ) from the reference observer was low for number of organ and lymph node metastases (organ: ICC, 0.84; 95%CI, 0.77–0.89; Δ = 0.45; lymph node: ICC, 0.77; 95%CI, 0.69–0.84; Δ = 0.45), tumor SUVmax (ICC, 0.99; 95%CI, 0.97–0.99; Δ = 0.44), and reference SUV (spleen: ICC, 0.81; Δ = 1.10; liver: ICC, 0.79; Δ = 0.62). Interpretations of appropriateness for peptide-receptor radionuclide therapy varied more significantly among observers (κ = 0.64; 95%CI, 0.57–0.70), and a higher frequency of false-positive recommendations for peptide-receptor radionuclide therapy occurred in observers with low experience than in those with high experience (range, 7–12 vs. 4–8). Conclusion: The interpretation of 68Ga-DOTATATE PET/CT images for NET staging is consistent among observers with low and high levels of experience. However, image-based recommendations for or against peptide-receptor radionuclide therapy require experience and training. ER -