RT Journal Article SR Electronic T1 Significance of a Single-Time-Point Somatostatin Receptor SPECT/Multiphase CT Protocol in the Diagnostic Work-up of Gastroenteropancreatic Neuroendocrine Neoplasms JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 180 OP 185 DO 10.2967/jnumed.115.161117 VO 57 IS 2 A1 Ruf, Juri A1 von Wedel, Friederike A1 Furth, Christian A1 Denecke, Timm A1 Stelter, Lars A1 Steffen, Ingo G. A1 Schütte, Kerstin A1 Arend, Jörg A1 Ulrich, Gerhard A1 Klose, Silke A1 Bornschein, Jan A1 Apostolova, Ivalya A1 Amthauer, Holger YR 2016 UL http://jnm.snmjournals.org/content/57/2/180.abstract AB This prospective study compared a 1-d SPECT/CT protocol with the commonly used 3-d protocol for somatostatin receptor scintigraphy in patients with gastroenteropancreatic neuroendocrine neoplasms. Additionally, the influence of SPECT/CT on patient management was evaluated. Methods: From October 2011 to October 2012, all gastroenteropancreatic neuroendocrine neoplasm patients undergoing restaging with somatostatin receptor scintigraphy on a modern SPECT/CT device were enrolled in this study. The protocol consisted of planar imaging at 4, 24, and 48 h; low-dose SPECT/CT at 24 and 48 h; diagnostic CT at 24 h using a triple-phase delay after administration of contrast; and diagnostic SPECT/CT at 24 h. All components of the imaging data were reassessed by 3 masked interpreters. The results were compared with a reference standard based on all clinical, imaging, and histopathology follow-up data available (follow-up range, 24–36 mo; mean, 29.9 mo). The reference standard was defined by a study-specific interdisciplinary tumor board that also reassessed treatment decisions. Results: Thirty-one patients were eligible for analysis (18 men and 13 women; mean age, 60.4 y). Ten had no imaging signs of disease and remained disease-free during follow-up. Twenty-one had persistent or recurrent disease (82 lesions: 24 in the liver, 21 in the lymph nodes, 16 in bone, 12 in the pancreas, and 9 in other locations). The respective lesion detection rates for interpreters 1, 2, and 3 were 51.9%, 49.4%, and 71.6% for low-dose SPECT/CT at 24 h; 51.9%, 55.6%, and 67.9% for low-dose SPECT/CT at 48 h; 63.0%, 70.4%, and 85.2% for diagnostic CT; and 77.8%, 84.0%, and 88.9% for diagnostic SPECT/CT. Interobserver agreement was moderate for diagnostic SPECT/CT (κ = 0.44), diagnostic CT (κ = 0.43), low-dose SPECT/CT at 48 h (κ = 0.61), and low-dose SPECT/CT at 24 h (κ = 0.55). For planar imaging, interobserver agreement was fair after 48 h (κ = 0.36) and 24 h (κ = 0.38) and moderate after 4 h (κ = 0.42). Every lesion detectable on planar imaging or low-dose SPECT/CT was also detectable on diagnostic SPECT/CT. The CT and SPECT components of diagnostic SPECT/CT strongly complemented each other, as 34 of 82 lesions (41.4%) were detected on only the CT component or only the SPECT component. Therapeutic management was influenced by the diagnostic SPECT/CT interpretation in 8 of 31 patients (25.8%). Conclusion: The highest detection rates were achieved by diagnostic SPECT/CT. Thus, a more patient-friendly 1-d protocol is feasible. Furthermore, multiphase SPECT/CT affected management in about a quarter of patients.