Ouvrard E, Mestier L, Boursier C, Lachachi B, Sahakian N, Chevalier E, Mikail N, Carullo J, Bando-Delaunay A, Walter T, Malouf GG, Addeo P, Poncet G, Sebag F, Lebtahi R, Goichot B, Taïeb D, and Imperiale A
Our objective was to compare the respective value of 68 Ga-DOTATOC and 18 F-DOPA PET/CT for initial staging or presurgical work-up of patients with small-intestine neuroendocrine tumors (SiNETs). Methods: This was a retrospective, multicenter, noninterventional investigation involving 53 non-surgically treated SiNET patients who underwent both 68 Ga-DOTATOC and 18 F-DOPA PET/CT within a 6-mo interval without surgical intervention or therapeutic change between the 2 PET/CT studies. Percentage detection rate was calculated according to per-region and per-lesion analyses. Sensitivity for primary tumor detection was assessed in 37 surgically treated patients, taking surgical results (76 SiNETs) as the diagnostic gold standard. Results: 68 Ga-DOTATOC PET/CT and 18 F-DOPA PET/CT individually identified at least 1 primary SiNET in 92% (34/37) of the patients. Intestinal tumor multifocality was confirmed by histology in 8 patients. 68 Ga-DOTATOC and 18 F-DOPA PET/CT were concordantly positive for tumor multifocality in 5 patients, discordantly positive in 2 patients, and concordantly negative in 1 patient. The detection rate for subdiaphragmatic nodal metastases on per-region-based analysis was 91% and 98% for 68 Ga-DOTATOC and 18 F-DOPA PET/CT, respectively ( P = 0.18). 18 F-DOPA PET/CT detected a higher number of abnormal subdiaphragmatic nodes ( P = 0.009). Regarding mesenteric nodes only, 18 F-DOPA PET/CT detected more positive regions ( P = 0.005) and nodal lesions ( P = 0.003) than 68 Ga-DOTATOC PET/CT, including nodes at the origin of mesenteric vessels. For detection of distant metastases, 68 Ga-DOTATOC and 18 F-DOPA PET/CT performed equally well on a per-region-based analysis. As compared with 68 Ga-DOTATOC, 18 F-DOPA PET/CT detected more hepatic ( P < 0.001), peritoneal ( P < 0.001), and lung metastases ( P < 0.001). Conclusion: 18 F-DOPA PET/CT detected more lesions than 68 Ga-DOTATOC PET/CT in the studied patients. The respective roles of the two should be discussed in terms of disease staging and treatment selection., (© 2022 by the Society of Nuclear Medicine and Molecular Imaging.)