Tumor carcinoide bronquial como causa de neumonías de repetición en paciente joven: papel del 111In-pentetreotida en el contexto de las pruebas de imagen / Recurrent Pneumonia Due to Bronchial Carcinoid Tumour in a Young Patient: The Role of 111In-Pentetreotide in Imaging Studies

Los tumores carcinoides bronquiales son una causa infrecuente de neumonías de repetición en pacientes jóvenes. El diagnóstico se obtiene mediante pruebas de imagen, broncoscopia y confirmación histológica, y el tratamiento es fundamentalmente quirúrgico. Mediante la presentación de 2 casos, revisamos la utilidad de la gammagrafía con 111In-DTPA-Phe-octreotide (111In-pentetreotida) en la valoración de estos pacientes antes de la cirugía, apoyando el diagnóstico de tumor neuroendocrino ante una imagen sospechosa en otras pruebas (radiografía simple, TC) y descartando enfermedad regional o a distancia. Frente al reducido valor de la PET con 18F-FDG (realizada en uno de los casos), se destaca el papel de laSPECT-TC, que mejora notablemente la localización y la caracterización de los hallazgos

Bronchial carcinoid tumours are an uncommon cause of recurrent pneumonia in young patients. Diagnosis is determined from imaging studies, bronchoscopy, and histological confirmation, and treatment is generally surgical. Two cases are reviewed in order to examine the value of 111In-DTPA-Phe-octreotide (111In-pentetreotide) scintigraphy in the pre-surgical evaluation of these patients. After a suspicious area was observed in other tests (standard X-ray, CT), a neuroendocrine tumour was diagnosed using this technique and the presence of regional or distant disease was ruled out. Comparison with the less valuable 18F-FDG PET (carried out in one of the cases) highlights the usefulness of SPECT-CT, which performs notably better in terms of the localization and characterisation of findings

Contribution of ¹¹¹In-pentetreotide SPECT/CT imaging to conventional somatostatin receptor scintigraphy in the detection of neuroendocrine tumours.

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.

Recurrent pneumonia due to bronchial carcinoid tumour in a young patient: the role of (111)in-pentetreotide in imaging studies.

Bronchial carcinoid tumours are an uncommon cause of recurrent pneumonia in young patients. Diagnosis is determined from imaging studies, bronchoscopy, and histological confirmation, and treatment is generally surgical. Two cases are reviewed in order to examine the value of (111)In-DTPA-Phe-octreotide ((111)In-pentetreotide) scintigraphy in the pre-surgical evaluation of these patients. After a suspicious area was observed in other tests (standard X-ray, CT), a neuroendocrine tumour was diagnosed using this technique and the presence of regional or distant disease was ruled out. Comparison with the less valuable (18)F-FDG PET (carried out in one of the cases) highlights the usefulness of SPECT-CT, which performs notably better in terms of the localization and characterisation of findings.

Unsuspected urinoma of an obstructed kidney detected in a bone scan in a patient with lung cancer.

A 60-year-old woman with an adenocarcinoma of the lung was referred to our department for a bone scan to assess the extension of the metastatic bone disease. The images showed several foci of radiotracer uptake in the bone consistent with malignant involvement. Besides, a considerable accumulation of tracer was shown in the right perinephric region as well as in the renal pelvis. SPECT/CT images demonstrated a superior perirenal urine leak due to rupture of the collecting system. The leakage was treated by urinary catheter decompression with complete recovery after 4 weeks.

The value of early SPECT/CT and hand-held γ-camera in radio-guided surgery: a case of a hard-to-locate parathyroid adenoma.

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.