ABSTRACT
To assess the role of scintigraphy with 111In-DTPA-D-Phe-octreotide (111In-octreotide) in the diagnosis of pituitary adenomas and in the evaluation of post-surgical recurrent or residual tumours, we performed scintigraphy with 111In-DTPA-D-Phe-octreotide (SRS) in 35 patients: 14 patients with confirmed pituitary tumours and 15 with confirmed recurrent tumours. Clinical, biochemical and histological analyses, conventional images (CT/MRI), and follow-up assessments during a period of 1 year to 4 years were recorded in all patients. In the present study, scintigraphy with 111In-octreotide showed positive uptake in 10 out of 14 patients with confirmed pituitary tumour and in 13 out of 15 patients with confirmed recurrent tumour, with an overall sensitivity of 79%. SRS showed better results in growth hormone (GH)- and prolactin (PRL)-secreting tumours (7/8 patients correctly identified) than in other adenomas (3/9). SRS detected recurrence of adenocorticotrophic hormone (ACTH)-secreting tumours (4/5 patients correctly identified) and non-secreting tumours (5/7 patients correctly identified). 111In-octreotide scintigraphy, in combination with other imaging modalities, is useful in the diagnosis and follow-up of pituitary tumours. It allows scar tissue to be differentiated from tumour recurrence after surgical treatment and ensures better selection of patients who will benefit from medical treatment with somatostatin analogues.
Subject(s)
Adenoma/diagnostic imaging , Neoplasm Recurrence, Local/diagnostic imaging , Pentetic Acid/analogs & derivatives , Pituitary Neoplasms/diagnostic imaging , Radiopharmaceuticals , Receptors, Somatostatin , Adenoma/metabolism , Adenoma/therapy , Adolescent , Adult , Aged , Child , Female , Follow-Up Studies , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Neoplasm, Residual , Pituitary Neoplasms/metabolism , Pituitary Neoplasms/therapy , Postoperative Care , Prospective Studies , Radionuclide Imaging , Tomography, X-Ray Computed/methodsABSTRACT
Objetivo: Valorar la utilidad de los estudios con 99mTc-DMSA pre y postcaptopril (imagen gammagráfica y función renal unilateral) para identificar el origen vasculorrenal o renal de la enfermedad en pacientes hipertensos con alta sospecha clínica de hipertensión vasculorrenal. Pacientes y Métodos: Se han estudiado 27 pacientes hipertensos (12 varones, 15 mujeres) de edades comprendidas entre 23 y 65 años (edad media 49 años, DE: 9,46) con alta sospecha clínica de hipertensión vasculorrenal, a los que se les realizó protocolo general analítico, ecográfico y radiológico incluyendo arteriografía renal que se utilizó como gold standard. A todos se les practicaron dos estudios gammagráficos con 99mTc-DMSA, uno basal y otro una hora después de la administración de 50 mg de captopril, con una semana de intervalo entre ambos. Los estudios gammagráficos se obtuvieron a las 4 horas de la administración de 3 mCi (111MBq) de 99mTc-DMSA, obteniéndose imágenes en anterior y posterior, y evaluándose los resultados cualitativamente y cuantitativamente mediante el cálculo de la función renal unilateral porcentual. Se consideraron positivos para hipertensión vasculorrenal los estudios con disminución de 5 puntos porcentuales de la función renal unilateral porcentual o la aparición de un defecto nuevo no existente en el estudio basal. Los resultados gammagráficos fueron comparados con el estudio arteriográfico para determinar la sensibilidad y valores predictivos. Resultados: El estudio arteriográfico demostró la existencia de un 18,5 por ciento de pacientes con estenosis de la arteria renal angiográficamente significativa ( > 50 por ciento de la luz).Los estudios gammagráficos pre y postcaptopril con 99mTcDMSA mostraron una sensibilidad del 60 por ciento, especificidad del 91 por ciento, valor predictivo positivo del 60 por ciento y valor predictivo negativo del 91 por ciento. Se identificaron 3 pacientes con defectos de captación segmentarios compatibles con cicatrices pielonefríticas crónicas. Conclusiones: Los estudios con 99mTc-DMSA basal y tras captopril presentan una alta especificidad y son útiles en pacientes con alta sospecha clínica de hipertensión vasculorrenal, identificando adecuadamente un alto porcentaje de pacientes con estenosis arterial renal significativa. La capacidad del DMSA para identificar la presencia o ausencia de anomalías renales, sobre todo cicatrices pielonefríticas, aporta un valor añadido a los estudios de renograma tras IECAs con otros trazadores pudiendo identificar causas renales de hipertensión diferentes a la estenosis de la arteria renal (AU)
Subject(s)
Middle Aged , Adult , Aged , Male , Female , Humans , Radiopharmaceuticals , Renal Artery Obstruction , Pyelonephritis , Renal Artery , Angiotensin-Converting Enzyme Inhibitors , Angiography , Chronic Disease , Captopril , Cicatrix , Diagnosis, Differential , Hypertension, Renovascular , False Positive Reactions , Predictive Value of Tests , Technetium Tc 99m Dimercaptosuccinic Acid , Kidney Function TestsABSTRACT
AIM: Value the utility of studies with 99mTc-DMSA with captopril (scintigraphy imaging and unilateral renal function) in identifying renovascular disease or renal disease in hypertension patients with high probability of renovascular hypertension. METHODS: We studied 27 hypertension patients (12 males, 15 females) mean age 49 years, SD: 9.46, with high probability of renovascular disease. General analysis and radiology was made to all of them including renal arteriography as gold standard. Two renal scintigraphies with 99mTc-DMSA were made to all of them, baseline study and one hour after administration of 50 mg of captopril, a week between both studies. Renal scintigraphy (anterior and posterior images) was obtained 4 hours after the administration of 111 MBq (3 mCi) of 99mTc-DMSA and results were evaluated quantitatively and qualitatively calculating unilateral renal function. We considered positive for renovascular hypertension studies with decrease of more than five percentual points in unilateral renal function or a new defect absent in baseline study. Scintigraphic results were compared with arteriography to determine sensitivity, specificity and predictive values. RESULTS: Arteriography demonstrated significant renal artery stenosis in 18.5% of patients. Renal scintigraphy with captopril using 99mTc-DMSA demonstrated sensitivity of 60%, specificity of 91%, positive predictive value of 60% and negative predictive value of 91%. We identified 3 patients with segmental defects of uptake consistent with chronic pyelonephritis scarring. CONCLUSIONS: Studies with 99mTc-DMSA using captopril present high specificity and are useful in patients with high probability for renovascular hypertension, identifying high number of patients with significant renal artery stenosis. The utility of DMSA in identify renal abnormalities, as specially pyelonephritis scarring, add value to renal studies with captopril using others tracers. DMSA could identify renal etiologies of renovascular hypertension different to renal artery stenosis.
Subject(s)
Angiotensin-Converting Enzyme Inhibitors/pharmacology , Captopril/pharmacology , Hypertension, Renovascular/diagnostic imaging , Radiopharmaceuticals , Renal Artery Obstruction/diagnostic imaging , Technetium Tc 99m Dimercaptosuccinic Acid , Adult , Aged , Angiography , Angiotensin-Converting Enzyme Inhibitors/administration & dosage , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Captopril/administration & dosage , Captopril/therapeutic use , Chronic Disease , Cicatrix , Diagnosis, Differential , False Positive Reactions , Female , Humans , Hypertension, Renovascular/drug therapy , Hypertension, Renovascular/etiology , Kidney Function Tests , Male , Middle Aged , Predictive Value of Tests , Pyelonephritis/complications , Pyelonephritis/diagnostic imaging , Pyelonephritis/pathology , Radionuclide Imaging , Renal Artery/diagnostic imaging , Renal Artery Obstruction/complicationsABSTRACT
Three cases of intracranial 201Tl uptake, reported as positive tumour activity in patients with a final diagnosis of abscess, are described. 201Tl has been proposed as a useful oncotropic radiotracer in the diagnosis of brain tumour activity. These cases suggest a note of caution in the interpretation of 201Tl brain images in the differential diagnosis of an intracranial expanding mass.
Subject(s)
Brain Abscess/diagnostic imaging , Brain Neoplasms/diagnostic imaging , Tomography, Emission-Computed, Single-Photon , Aged , Diagnosis, Differential , False Positive Reactions , Glioma/diagnostic imaging , Humans , Male , Middle Aged , Thallium RadioisotopesABSTRACT
The recommended method for controlling the radiochemical purity (RCP) of 99Tcm-labelled tetrofosmin is thin-layer chromatography (TLC) with silica gel as the stationary phase and acetone:dichloromethane (35:65, v/v) as the mobile phase. However, this test is time-consuming and uses a toxic substance. We propose an alternative method to control RCP, based on a solid-phase extraction method (SPE) using a Sep Pak C18 cartridge. We used both methods to analyse 35 samples and to determine the percentages of colloid, radiopharmaceutical and free 99Tcm-pertechnetate. Normal labelling processes were modified to obtain a wide range of values. The range of RCP values obtained was 63.4-96.5% (median = 93.8%) by the standard TLC method and 70.1-96.4% (median = 94.1%) by the SPE method. A significant difference was observed only for the percentage of free 99Tcm-pertechnetate (P < 0.05). The agreement between the two methods, using 90% RCP as the limit, gave a kappa index = +1 (P < 0.001), indicating total agreement between them. The proposed method is useful to control RCP because it yields results that are in good agreement with those of the standard method, and because it is safer and less time-consuming.
