131I labeling of tamoxifen and biodistribution studies in rats.

Tamoxifen [TAM ([Z]-2-[4-(1,2-diphenyl-1-di-butenyl)-phenoxy]-N,N-dimethylethanamine)] has been used as an antiestrogen drug for treatment and prevention of human breast cancer. Tamoxifen was labeled with 131I using iodogen as an oxidizing agent. Mass spectroscopy of the cold standard showed that the labeling occurs in ortho position to the phenyl ether position of TAM as expected. Quality control, radiochemical yield and stability were established using the radioelectrophoresis method. The radiolabeled compound maintained its stability throughout working period of 24 h. Scintigraphic imaging was performed and tissue distribution was determined in Albino Wistar rats. According to biodistribution and imaging experiments the radiolabeled compound presented estrogen receptor (ER) specificity and it was uptaken by endometrium as well as breast tissue.

Parathyroid adenoma-related hypercalcaemia in breast cancer: a critical diagnosis in clinical oncology.

Hypercalcaemia in patients with breast cancer is generally due to osteolytic metastases or to the activity of circulating tumour-derived products. Hyperparathyroidism is one of the most frequent aetiological factors in benign hypercalcaemia, but it is usually not considered in oncology patients. We present a high-risk early breast cancer case with hypercalcaemia in the 19th postoperative month of follow-up. The patient had high serum parathyroid hormone (PTH) levels, but ultrasonography was not diagnostic, and the existence of parathyroid adenoma was established by scintigraphy. Histopathological examination revealed chief cell parathyroid adenoma. The patient is still free of cancer recurrence in the 48th month of follow-up. Hyperparathyroidism should be considered as a possible cause of hypercalcaemia in breast cancer patients, and parathyroid scintigraphy is essential in the initial evaluation of the cases with increased serum calcium and PTH concentrations.

Repeated hypoglycemia and cognitive decline. A case report.

OBJECTIVE: Diabetes mellitus has a high incidence in general population and goes by high morbidity by specific micro vascular pathology in the retina, renal glomerul and peripheral nerves. In type 1 DM, intensive therapy can prevent or delay the development of long-term complications associated with DM but hypoglycaemia especially severe hypoglycaemia defined, as a low blood glucose resulting in stupor, seizure, or unconsciousness that precludes self-treatment is a serious threat. Hypoglycaemia that may preferentially harm neurons in the medial temporal region, specifically the hippocampus, is a potential danger for the brain cognitive function which several studies failed to detect any significant effects, whereas others indicated an influence on it. A young diabetic case presented here with severe cognitive defect. Great number of severe hypoglycaemic or hyperglycaemic attacks and convulsion episodes were described in his medical history. RESULTS AND CONCLUSION: Neuroradiologic findings on CT and MRI, pointed that global cerebral atrophy that is incompatible with his age. Brain perfusion studies (SPECT, (99m)Tc-labeled HMPAO) also showed that there were severe perfusion defects at superior temporal region and less perfusion defects at gyrus cingulum in frontal region. These regions are related with memory processing. Severe cognitive defect in this patient seems to be closely related these changes and no another reason was found to explain except the repeated severe hypoglycaemic episodes.

Sublingual nitrate plus 99Tcm-tetrofosmin infusion in the detection of severely ischaemic but viable myocardium: a comparative study with stress, redistribution, reinjection and late redistribution 201Tl imaging.

To investigate the role of sublingual nitrate plus 99Tcm-tetrofosmin infusion in the detection of severely ischaemic but viable myocardium, we selected 25 patients with coronary artery disease who had at least one fixed segmental defect during conventional stress-redistribution (ST-RD) 201Tl single photon emission tomographic (SPET) imaging. Reinjection (RI) and 24 h late redistribution (LRD) imaging were also performed. Within a week of 201Tl imaging, one-day rest-stress (R-ST) 99Tcm-tetrofosmin SPET was performed with the same stress levels. The following day, 99Tcm-tetrofosmin was infused over 1 h immediately after sublingual nitrate administration and SPET images (N + Inf) were acquired. Of 100 fixed defects on R-ST 99Tcm-tetrofosmin imaging, 15 were reversible on N + Inf 99Tcm-tetrofosmin imaging. There was 91% concordance between ST-RD/RI/LRD 201Tl and R-ST/N + Inf 99Tcm-tetrofosmin imaging regarding reversibility. We conclude that N + Inf 99Tcm-tetrofosmin imaging may be clinically useful in the detection of severely ischaemic but viable myocardium.

Lung clearance of inhaled 99Tcm-erythromycin lactobionate in non-smokers and smokers.

99Tcm-labelled erythromycin lactobionate (99Tcm-EL) was used as a radioaerosol for lung ventilation imaging in humans after animal studies had shown slow clearance of 99Tcm-EL from the alveolar spaces. We performed inhalation studies in 26 volunteers: 11 non-smokers, 13 smokers (3 of whom smoked one cigarette just before inhalation of 99Tcm-EL) and 2 patients with pulmonary emboli (PE). The PE patients were imaged by both 99Tcm-EL and xenon-133 (133Xe) for comparison. The image quality with 99Tcm-EL was comparable to that with 133Xe, showing good peripheral penetration. The biological clearance half-lifes for 99Tcm-EL were 3.9 +/- 1.1 h in the non-smokers, 5.9 +/- 2.2 h in the smokers and 9.8 +/- 6.6 h in the three subjects who smoked a cigarette just before inhalation of the aerosol. 99Tcm-EL was cleared more slowly in the smokers and after smoke exposure, which could have indicated alveolar macrophage uptake. 99Tcm-EL can be used as an alternative to 99Tcm-diethylenetriamine pentaacetate (99Tcm-DTPA) in ventilation imaging, thus overcoming the problem of the fast clearance of 99Tcm-DTPA in smokers.

Somatostatin receptors in the orbits.

In-111 pentetreotide has been recommended for the detection of somatostatin receptor (SSR) positive tumors. Sites with increased numbers of activated lymphocytes may also show In-111 pentetreotide with Graves' ophthalmopathy (GO) compared to various other orbital disorders. Five patients with GO, three patients with necrotizing scleritis, and two patients with orbital pseudotumor were imaged at 4 hours, 24 hours, and 48 hours after injection of In-111 pentetreotide. Although planar images did not show considerable uptake, SPECT slices showed marked and persistent uptake in the orbits unilaterally in one patient, and bilaterally in three patients with GO. There was no significant correlation between the In-111 pentetreotide activity and the degree of opthalmopathy determined by Werner's classification. Pseudotumors also showed positive uptake. Early uptake was present in one patient with necrotizing scleritis because of Wegener's granulomatosis, and was completely diminished at 24 hours. Octreotide treatment in three patients with GO did not cause any clinical improvement. Although the presence of SSR, either on the infiltrated lymphocytes or on fibroblasts, implies that octreotide treatment for GO can be considered, the results are not encouraging. Nonspecific binding might be present when uptake patterns of orbits and persistence of activity during octreotide treatment are considered.