RESUMEN
AIM: Imaging with radiolabelled vascular endothelial growth factor (VEGF) has been developed for the localisation and diagnosis of a variety of human solid tumors including gastrointestinal tumors. METHODS: In this study we investigated the biodistribution, safety and absorbed dose of iodine-123 radiolabelled VEGF(165) ((123)I-VEGF(165)) in 9 patients with pancreatic carcinoma. Following intravenous administration of (123)I-VEGF(165) (189+/-17 MBq; <130 pmole (<5 microg) VEGF(165) per patient), sequential images were recorded during the initial 30 min PI. Serial whole-body images were acquired in anterior and posterior views at various time points. All patients underwent single-photon emission tomography (SPET) imaging. Dosimetry calculations were performed on the basis of gamma camera data. Estimates of radiation absorbed dose were calculated using the MIRDOSE 3 program. RESULTS: The highest absorbed organ doses were found to be thyroid (0.058+/-0.004 mGy/MBq), spleen (0.046+/- 0.017 mGy/MBq), urinary bladder (0.04+/-0.02 mGy/MBq), lungs (0.034+/-0.009 mGy/MBq) and kidneys (0.033+/-0.005 mGy/MBq). The effective dose was estimated to be 0.017+/-0.002 mSv/MBq. A majority of primary pancreatic tumors and their metastases were visualized by (123)I-VEGF(165) scan. CONCLUSION: In vitro binding results confirmed specific binding of (123)I-VEGF(165) to pancreatic tumor cells and tissues. (123)I-VEGF(165) shows favorable dosimetry and is a safe radiopharmaceutical that may be of potential value for the imaging of VEGF receptor status in vivo.
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Adenocarcinoma/diagnóstico por imagen , Adenocarcinoma/metabolismo , Neoplasias Pancreáticas/diagnóstico por imagen , Neoplasias Pancreáticas/metabolismo , Receptores de Factores de Crecimiento Endotelial Vascular/metabolismo , Factor A de Crecimiento Endotelial Vascular/farmacocinética , Anciano , Anciano de 80 o más Años , Carga Corporal (Radioterapia) , Línea Celular Tumoral , Femenino , Humanos , Radioisótopos de Yodo/efectos adversos , Radioisótopos de Yodo/farmacocinética , Masculino , Tasa de Depuración Metabólica , Persona de Mediana Edad , Especificidad de Órganos , Unión Proteica , Dosis de Radiación , Radiometría/métodos , Cintigrafía , Radiofármacos/efectos adversos , Radiofármacos/farmacocinética , Efectividad Biológica Relativa , Distribución Tisular , Factor A de Crecimiento Endotelial Vascular/efectos adversosRESUMEN
AIM: The clinical value of combined XCT/SPECT technology in a single device in patients undergoing (123)I-MIBG scintigraphy was analyzed. METHODS: 31 patients (19 men, 12 women; mean age 55 years, range: 31-79 years) demonstrating focal accumulation in planar (123)I-MIBG scan were further investigated with a double headed gamma camera with an X-ray tomograph mounted on the same gantry (GE Medical Systems, Millennium VG with Hawkeye, Milwaukee, USA) for anatomical definition of the focal (123)I-MIBG uptake. The patients were referred to (123)I-MIBG scintigraphy because of biochemically (81%) and/or clinically (19%) suspected pheochromocytoma. RESULTS: In 23 out of 31 patients (74%) the fused images demonstrated physiological accumulation (i. e. intestinal, renal) of (123)I-MIBG. In two patients (6%) suspected adrenal MIBG-accumulation was caused by inhomogeneous liver uptake. In two patients (6%) focal abdominal accumulation was correctly localised in the adrenal glands. Furthermore, the differentiation of bone metastasis from a local recurrence for phaeochromocytoma was accurately possible for two patients (6%). Adrenal lesions mimicking liver foci were correctly localised in the remaining two patients (6%). CONCLUSION: Our study demonstrates the clinical value of XCT/SPECT in a single device in patients demonstrating focal (123)I-MIBG uptake in planar scintigraphy. The combined XCT/SPECT technology provides a higher diagnostic accuracy.
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Radiofármacos , Tecnecio Tc 99m Sestamibi , Tomografía Computarizada de Emisión de Fotón Único , Tomografía Computarizada por Rayos X , Neoplasias de las Glándulas Suprarrenales/diagnóstico por imagen , Adulto , Anciano , Reacciones Falso Positivas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Feocromocitoma/diagnóstico por imagen , Reproducibilidad de los ResultadosRESUMEN
AIM: Although parathyroid scintigraphy using (99m) Tc-sestamibi is considered the best preoperative localization method for hyperfunctioning parathyroid tissue it lacks the anatomical details required for successful, minimal invasive surgery of ectopic parathyroid lesions. This study presents the role of combined SPECT/X-ray-CT imaging in a single device for localization of mediastinal parathyroid glands. METHODS: (99m) Tc-sestamibi SPECT/X-ray-CT was performed by gamma camera-mounted anatomical X-ray tomography (GMAXT; GE Medical systems, Millenium VG with Hawkeye) in four patients with ectopic parathyroid glands (two patients with primary, two with persistent secondary hyperparathyroidism). The device contains an X-ray tube and a set of detectors that rotate around the patient combined with a gamma camera. For comparison with GMAXT addition-ally high resolution computed tomography images of the neck and mediastinum were performed. RESULTS: Correct preoperative localization was achieved. The parathyroid glands were located in the anterior mediastinum. High resolution computed tomography could not provide further details. Three patients were operated by a minimal invasive open and one patient by a transsternal approach because of concomitant aortic valve replacement. CONCLUSION: (99m)Tc-sestamibi/X-ray-CT fusion imaging in a single device can accurately localise ectopic or supernumerary mediastinal parathyroid tumours in primary and secondary hyperparathyroidism. Morbidity,radiation exposure, time, and costs are reduced by avoiding multiple diagnostic examinations and minimal invasive parathyroid surgery becomes possible.
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Coristoma/diagnóstico por imagen , Hiperparatiroidismo Secundario/diagnóstico por imagen , Enfermedades del Mediastino/diagnóstico por imagen , Glándulas Paratiroides/diagnóstico por imagen , Neoplasias de las Paratiroides/diagnóstico por imagen , Radiofármacos , Tecnecio Tc 99m Sestamibi , Tomografía Computarizada de Emisión de Fotón Único , Coristoma/cirugía , Humanos , Enfermedades del Mediastino/cirugía , Procedimientos Quirúrgicos Mínimamente Invasivos , Glándulas Paratiroides/cirugía , Radiofármacos/farmacocinética , Tecnecio Tc 99m Sestamibi/farmacocinética , Tomografía Computarizada por Rayos XRESUMEN
BACKGROUND: Recent studies have shown that vascular endothelial growth factor (VEGF) receptor is overexpressed in vascular endothelial cells of various human tumours as well as in human tumour cells. The aim of this study was to evaluate the usefulness of scanning with VEGF(165) labeled with (123)I for tumor localisation in patients with gastrointestinal tumours. PATIENTS AND METHODS: Human recombinant VEGF(165) was radiolabelled with (123)I by electrophilic radioiodination using the chloramine T method. [(123)I]VEGF(165) was administered intravenously [mean dose 184 +/- 18 MBq (=130 pmol; =5 micro g) per patient] to 18 patients with gastrointestinal tumours. Dynamic acquisition was initiated immediately after administration and carried out until 30 min post-injection. Whole body images were done in anterior and posterior views at various time points. All patients underwent single-photon emission tomography imaging 1.5 h post-injection. Scanning with [(123)I]VEGF(165) was compared with computed tomography and magnetic resonance imaging. RESULTS: Intravenous injection of [(123)I]VEGF(165) did not cause any side-effects. Binding of [(123)I]VEGF(165 )to primary tumours and metastases was visible shortly after injection. In patients with pancreatic adenocarcinomas, primary tumours were visualised in seven of nine, lymph node metastases in three of four, liver metastases in three of six and lung metastases in one of three. Cholangiocarcinomas were visualised by imaging in one of two patients. Hepatocellular carcinomas were visible by imaging in two of four patients. [(123)I]VEGF(165) scans were weakly positive in one patient with abdominal schwannoma and in one patient with peritoneal carcinosis. CONCLUSIONS: These results indicate that scanning with [(123)I]VEGF(165) can visualise gastrointestinal tumours and metastases expressing receptors for VEGF(165). [(123)I]VEGF(165) receptor scintigraphy may be useful for visualisation of tumour angiogenesis.