There are different metabolic imaging methods, various tracers, and emerging anatomic modalities to stage neuroendocrine tumor (NET). We aimed to compare NET lesion detectability among 99m Tchydrazinonicotinamide (HYNIC)-octreotide (somatostatin receptor scintigraphy [SSRS]) SPECT/CT, 68 Ga-DOTATATE PET/CT, and whole-body diffusion-weighted MR imaging (WB DWI). Methods: Nineteen consecutive patients (34-77 y old; mean, 54.3 ± 10.4 y old; 10 men and 9 women) underwent SSRS SPECT/CT, 68 Ga-DOTATATE PET/CT, and WB DWI. Images were acquired with a maximum interval of 3 mo between them and were analyzed with masking by separate teams. Planar whole-body imaging and SPECT/CT were performed from thorax to pelvis using a double-head 16-slice SPECT/CT scanner 4 h after injection of 111-185 MBq of 99m Tc-HYNIC-octreotide. 68 Ga-DOTATATE PET/CT was performed from head to feet using a 16-slice PET/CT scanner 45 min after injection of 185 MBq of tracer. WB DWI was performed in the coronal plane using a 1.5-T scanner and a body coil. The standard method of reference for evaluation of image performance was undertaken: consensus among investigators at the end of the study, clinical and imaging follow-up, and biopsy of suggestive lesions. Results: McNemar testing was applied to evaluate the detectability of lesions using 68 Ga-DOTATATE PET/CT in comparison to SSRS SPECT/CT and WB DWI: a significant difference in detectability was noted for pancreas (P 5 0.0455 and P 5 0.0455, respectively), gastrointestinal tract (P 5 0.0455 and P 5 0.0455), and bones (P 5 0.0082 and P 5 0.0082). Two unknown primary lesions were identified solely by 68 Ga-DOTATATE PET/CT. 68 Ga-DOTATATE PET/CT, SSRS SPECT/CT, and WB DWI demonstrated, respectively, sensitivities of 0.96, 0.60, and 0.72; specificities of 0.97, 0.99, and 1.00; positive predictive values of 0.94, 0.96, and 1.00; negative predictive values of 0.98, 0.83, and 0.88; and accuracies of 0.97, 0.86, and 0.91. Conclusion: 68 Ga PET/CT seems to be more sensitive for detection of well-differentiated NET lesions, especially for bone and unknown primary lesions. NET can be staged with 68 Ga-DOTATATE PET/CT. WB DWI is an efficient new method with high accuracy and without ionizing radiation exposure. SSRS SPECT/CT should be used only when 68 Ga-DOTATATE PET/CT and WB DWI are not available.

Although 177 Lu-octreotate is an effective treatment for patients with gastroentero-

Neuroendocrine tumours are a heterogeneous group of diseases with a significant variety of diagnostic tests and treatment modalities. Guidelines were developed by North American and European groups to recommend their best management. However, local particularities and relativisms found worldwide led us to create Brazilian guidelines. Our consensus considered the best feasible strategies in an environment involving more limited resources. We believe that our recommendations may be extended to other countries with similar economic standards.

Neuroendocrine tumours (NETs) are a heterogeneous group of neoplasms whose incidence has dramatically increased in recent years. Octreotide is a somatostatin analogue used in the treatment of NETs, and its use in clinical trials has been associated with substantially increased survival. Although traditionally used for the relief of symptoms that result from release of peptides and neuroamines, there has been a growing body of evidence that suggest octreotide has antiproliferative effects. A phase III clinical study has demonstrated that the long-acting formulation (LAR), octreotide LAR, lengthens time to tumour progression in patients with well-differentiated metastatic midgut NETs, and that octreotide LAR is a treatment option for patients with metastatic midgut NETs, regardless of functional status. Furthermore, octreotide LAR has demonstrated clinical efficacy in different types of NETs. These data, along with emerging data on somatostatin analogs, may change the way doctors approach this patient population and reinforce the use of these drugs as a treatment option for patients with non-functioning tumours.