Head-To-Head Comparison Of F-18-Dopa Pet/Ct And Ga-68-Dotanoc Pet/Ct In Patients With Midgut Neuroendocrine Tumors

PurposeThe aim of this study was to compare retrospectively F-18-DOPA PET/CT versus Ga-68-DOTANOC PET/CT in a group of patients affected by midgut NET. Patients and MethodsPatients with histologically proven grade 1 or grade 2 midgut NET were explored after injection of 150 MBq of Ga-68-DOTANOC and 210 MBq of F-18-DOPA. The PET/CTs were analyzed visually and semiquantitatively at the patient level, regional level (7 defined regions), and lesion level (maximum of 5 lesions/organ). The criterion standard was determined on the basis of histology and imaging follow-up. ResultsThirty patients (17 males and 13 females; median age, 63.5 years [37-82 years]) were included. Both PET/CTs were negative in 3 patients and positive in 25 patients. PET/CTs were discordant in 2 patients, with F-18-DOPA positive and Ga-68-DOTANOC negative. F-18-DOPA PET/CT detected more involved regions and more metastatic lesions than Ga-68-DOTANOC PET/CT in 6 (20%) and 10 (33.3%) patients, respectively. Of the 81 confirmed affected regions, 77 (95%) were detected by F-18-DOPA PET/CT and 71 (87.7%) by Ga-68-DOTANOC PET/CT (P < 0.0001). F-18-DOPA PET/CT detected significantly more lesions (211/221) than Ga-68-DOTANOC PET/CT (195/221), corresponding to a sensitivity of 95.5% and 88.2%, respectively (P < 0.0001). Tumor-to-background ratios were more favorable in liver for F-18-DOPA than for Ga-68-DOTANOC. Interestingly, a correlation was found between F-18-DOPA SUVmax and tumor burden and especially with the number of regions involved by the disease (P = 0.019). ConclusionsF-18-DOPA PET/CT is superior to Ga-68-DOTANOC PET/CT for the detection of lesions, and when available, this tracer may be recommended as the first-line examination for an accurate staging of midgut NET.