RESUMO
AIM: The aim of the study was to assess the contribution of 111In-pentetreotide single-photon emission computed tomography/computed tomography (SPECT/CT) imaging to conventional somatostatin receptor scintigraphy (SRS) in terms of lesion characterization and localization in the detection of neuroendocrine tumours (NETs). MATERIALS AND METHODS: A total of 107 patients with suspected or confirmed NET underwent SRS and SPECT/CT after the injection of 148-222 MBq of 111In-pentetreotide. SRS and SPECT/CT images were interpreted independently. Each site of abnormal tracer uptake was recorded according to the anatomical localization, and as being consistent or not with NET. The findings were confirmed with pathological and/or clinical/imaging follow-up data. RESULTS: A final diagnosis of NET was achieved in 49/107 patients (45.8%). No evidence of NET was found in the rest. SPECT/CT resulted in a significant reduction of indeterminate cases [14/107 (13.1%) vs. 1/107 (0.9%); P<0.001] and correctly reclassified one patient as negative for NET and another as positive for NET. SPECT/CT had 87.8% sensitivity and 96.6% specificity on a patient-based analysis, statistically higher than SRS (P<0.001). A total of 160 foci were detected (108 NETs and 52 physiological/benign tumours). SRS correctly classified 105/160 foci (65.6%) and remained inaccurate for 55 lesions. These 55 included 31 indeterminate lesions, 12 lesions detected only by SPECT/CT and 12 false-positive lesions. The number of foci correctly classified on the SPECT/CT images was 151/160 (94.4%), whereas two remained indeterminate and seven were false-positive findings. CONCLUSION: SPECT/CT provides incremental diagnostic value over SRS, mainly because of a precise anatomical localization that helps discriminate between tumour lesions and physiological uptake. SPECT/CT may detect unsuspected lesions in a small proportion of patients.
Assuntos
Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/metabolismo , Receptores de Somatostatina/metabolismo , Somatostatina/análogos & derivados , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Tumores Neuroendócrinos/diagnóstico por imagem , Adulto JovemRESUMO
A patient with primary hyperparathyroidism underwent radio-guided surgery by means of a γ-probe and a hand-held γ-camera. Before surgery, a parathyroid double-phase planar scintigraphy and an early SPECT/CT with 99mTc-MIBI were performed and suggested an ectopic parathyroid adenoma with early washout. The hand-held γ-camera was very useful for the localization of a parathyroid adenoma, which could not be found with the probe probably due to its faint uptake and to a high blood pool activity because it was localized next to the great vessels. Besides, it demonstrated the complete extirpation of the parathyroid tissue.
Assuntos
Adenoma/cirurgia , Câmaras gama , Neoplasias das Paratireoides/cirurgia , Cirurgia Assistida por Computador/métodos , Tomografia Computadorizada de Emissão de Fóton Único/instrumentação , Tomografia Computadorizada por Raios X , Adenoma/diagnóstico por imagem , Feminino , Humanos , Pessoa de Meia-Idade , Imagem Multimodal , Neoplasias das Paratireoides/diagnóstico por imagem , Compostos Radiofarmacêuticos , Cirurgia Assistida por Computador/instrumentação , Tecnécio Tc 99m SestamibiRESUMO
We present a 19-year-old woman with a neuroendocrine tumor of the appendix diagnosed during an acute appendicitis. An 111In-pentetreotide scan was performed to establish the extension of the disease. Scintigraphy showed an abnormal focal uptake in the right side of the pelvis. The SPECT/CT images demonstrated a round-shaped mass in the right ovary. Pathology revealed a benign cystic mature teratoma. In our case, hybrid imaging combining SPECT and CT contributed to localize the unusual 111In-pentetreotide accumulation within the anatomical context.
