RESUMEN
The follow-up of Differentiated Thyroid Cancer conventionally includes serum thyroglobulin and periodic Whole Body Scans. The uptake of 131-I in normal and pathological tissues different from metastatic thyroid cancer sites is a cause of false-positive scans. Among them, mediastinal uptake caused by thymic hyperplasia can be observed. The aim of the present study was to review a series of 573 patients with differentiated thyroid cancer treated with 131-I after surgery between 1992 and 2003 looking above all for those with mediastinal images resembling thymus. This evaluation is presented together with some hypotheses on the relationships between thymus and thyroid. Moreover, some considerations are made on the differential diagnosis between thymus and mediastinal tumour thyroid residues.
Asunto(s)
Radioisótopos de Yodo/uso terapéutico , Mediastino/diagnóstico por imagen , Radiofármacos/uso terapéutico , Timo/diagnóstico por imagen , Neoplasias de la Tiroides/radioterapia , Adenocarcinoma/radioterapia , Adenocarcinoma/cirugía , Adenocarcinoma Folicular/radioterapia , Adenocarcinoma Folicular/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Papilar/radioterapia , Carcinoma Papilar/cirugía , Reacciones Falso Positivas , Femenino , Humanos , Hiperplasia , Masculino , Persona de Mediana Edad , Cintigrafía , Radioterapia Adyuvante , Estudios Retrospectivos , Timo/patología , Neoplasias de la Tiroides/cirugía , Recuento Corporal TotalRESUMEN
BACKGROUND AND PURPOSE: Acetazolamide is commonly used with single-photon CT to assess the cerebrovascular reserve in patients with internal carotid artery stenosis or occlusion. In this study we wanted to evaluate the effects of adenosine, a well-known vasodilatatory compound with a short biological half-life, on brain circulation in humans and compare the results with those of acetazolamide. METHODS: Acetazolamide (1 g) and adenosine (140 micrograms/kg per minute) were injected intravenously on different days in 6 normal subjects and 6 patients: 4 with unilateral stenosis, 1 with bilateral stenosis, and 1 with complete occlusion of the internal carotid artery. Changes in regional cerebral blood flow relative to that of the cerebellum (cortico/cerebellar ratios) from resting conditions were evaluated by 99mTc-hexamethylpropyleneamine oxime and single-photon emission CT. RESULTS: The measured blood flow ratios increased significantly in the normal group 20 minutes after acetazolamide injection in several cortical and subcortical regions, as well as at the 4th minute of a 6-minute adenosine infusion. Regional cerebral blood flow ratio values were higher after adenosine than after acetazolamide in both cortical (frontal and parietal) and subcortical (thalamus and basal ganglia) regions. In 4 of the 6 patients the side-to-side asymmetry increased from the basal resting condition after the injection of acetazolamide and even more so after the injection of adenosine. CONCLUSIONS: Adenosine infusion causes vasodilation of cerebral arteries and can be used for the investigation of cerebrovascular perfusion capacity in patients with carotid occlusive disease. One advantage in the use of adenosine over acetazolamide is the possibility of interrupting the test with reversal of clinical symptoms or patient discomfort within a few minutes.
Asunto(s)
Acetazolamida/farmacología , Adenosina/farmacología , Arteriopatías Oclusivas/diagnóstico por imagen , Arteriopatías Oclusivas/fisiopatología , Estenosis Carotídea/diagnóstico por imagen , Estenosis Carotídea/fisiopatología , Circulación Cerebrovascular/efectos de los fármacos , Tomografía Computarizada de Emisión de Fotón Único , Acetazolamida/administración & dosificación , Acetazolamida/efectos adversos , Adenosina/administración & dosificación , Adenosina/efectos adversos , Anciano , Ganglios Basales/irrigación sanguínea , Arteria Carótida Interna/diagnóstico por imagen , Arteria Carótida Interna/fisiopatología , Cerebelo/irrigación sanguínea , Arterias Cerebrales/efectos de los fármacos , Corteza Cerebral/irrigación sanguínea , Femenino , Lóbulo Frontal/irrigación sanguínea , Humanos , Inyecciones Intravenosas , Masculino , Persona de Mediana Edad , Compuestos de Organotecnecio , Oximas , Lóbulo Parietal/irrigación sanguínea , Exametazima de Tecnecio Tc 99m , Tálamo/irrigación sanguínea , VasodilataciónRESUMEN
The effect of L-acetyl carnitine (L-AC) on cerebral blood flow (CBF) was evaluated in 20 patients with chronic cerebrovascular disease, who suffered an ischaemic stroke at least 6 months before the study. All patients performed a CT scan and were investigated with xenon-133 by brain dedicated single photon emission computed tomography (SPECT, Tomomatic 32, Medimatic Inc., Copenhagen). A single high dose (1.5 g) of L-acetyl carnitine was intravenously administered to 10 patients, while sodium acetate as placebo was injected to 10 other subjects. Cerebral blood flow (ml/min x 100 g) was evaluated before and 45 min after the injection. No changes were observed after placebo injection (43 +/- 12 ml/min x 100 g versus 43 +/- 10 ml/min x 100 g). CBF increased (from 42 +/- 9 ml/min x 100 g to 46 +/- 9, P less than 0.05) in both ipsilateral and contralateral hemisphere, the ischaemic area, but not in the stroke corresponding zone. It was concluded that L-acetyl carnitine at the i.v. dosage of 1.5 g acutely enhanced CBF in patients with chronic cerebral infarct.
Asunto(s)
Acetilcarnitina/farmacología , Infarto Cerebral/fisiopatología , Circulación Cerebrovascular/efectos de los fármacos , Acetilcarnitina/efectos adversos , Anciano , Trastornos Cerebrovasculares/fisiopatología , Enfermedad Crónica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tomografía Computarizada de Emisión de Fotón Único , XenónRESUMEN
Comparison of a water-soluble (27-487) with a water-insoluble (VP-16-213) podophyllotoxin derivative in seven murine neoplasms revealed slight therapeutic superiortiy of VP-16-213 but also slightly greater toxicity when compared with 27-487. A strikingly good response of the Taper liver tumor to both compounds was observed, providing further incentive to the use of podophyllotoxin derivatives in human hepatomas.