Secondary hyperparathyroidism: detection with I-123-Tc-99m-Sestamibi subtraction scintigraphy versus US.

Purpose: To compare iodine-123-technetium-99m-sestamibi subtraction scintigraphy with ultrasonography (US) for detection of parathyroid abnormalities in uremic patients with secondary hyperparathyroidism.

Materials And Methods: Fourteen adult uremic patients with severe secondary hyperparathyroidism underwent subtraction scintigraphy before total or subtotal parathyroidectomy. Subtraction scintigrams were acquired with a double-energy-window technique.

Cardiac axis change between prone and supine positioning may contribute to differences in 99Tc(m)-MIBI myocardial SPET imaging.

The aims of this study were to assess the effect of prone and supine positioning on 99Tc(m)-MIBI myocardial SPET images and the contribution of cardiac axis change. We compared 227 tomograms of patients imaged in the prone position with 227 tomograms of the same patients imaged in the supine position. For each tomographic session, the axis angle of the heart was recorded using an in-house program.

[Differentiated thyroid cancers. 20 years' results of a protocol based on simple prognostic criteria].

Objectives: To study the long-term results of an aggressive management protocol based on a new-simple classification and to determine the duration for patient follow-up according to this classification.

Material And Methods: For the 509 patients with differentiated thyroid carcinoma, the classification was: group 1: cancer < 1 cm (n = 117), group 2A: cancer without extension in patients of age less than 45 years (n = 100), group 2B: cancer without extension in patients aged more than 45 (n = 94), group 3: cancer with nodal extension alone (n = 102), group 4: high risk cancer in patients having either distant metastases or local tissular extension or in whom after iodine-131 ablation, Tg level was > 3 micrograms/l off hormone therapy (n = 96). Total thyroidectomy was the rule except for group 1 and some patients of group 2A in whom the tumor was solitary, relatively small, well-differentiated, with no capsular or capillary invasion.

Primary hyperparathyroidism: higher success rate of first surgery after preoperative Tc-99m sestamibi-I-123 subtraction scanning.

Purpose: To evaluate the usefulness and cost-effectiveness of routine preoperative technetium-99m sestamibi-iodine-123 subtraction scanning in patients with parathyroid gland disease.

Materials And Methods: Tc-99m sestamibi-I-123 subtraction scanning was performed in 65 patients with primary hyperparathyroidism who were referred for evaluation before first surgery.

Results: Focal tracer uptake was detected in the mediastinum in two patients who then underwent primary sternotomy; a parathyroid adenoma, anterior to the ascending aorta, was resected in each case.

[Protection of the thyroid in children and fetuses in case of nuclear accident].

The administration of stable iodine in order to keep the thyroid gland away from radioactive iodine isotope contamination has long been regarded with caution by the health authorities, mainly because of the potential toxicity of iodine in newborns, young children and adults with thyroid pathology. Therefore, the risk of oral stable iodine given for a limited period of time must be compared to the risk of cancer due to radioactive exposure. The analysis of complications following the nuclear accidents of Marshall Islands in 1954 and Tchernobyl in 1986 has shown that newborn infants and young children, have the highest risk, the main complications being cancer (papillary carcinoma) and hypothyroidism.

[Recent progress in radionuclide imaging of parathyroid glands].

Scintigraphic imaging of parathyroid glands has been the subject of new developments. Efficiency of the technique has been improved by the use of a new agent Tc-99m sestamibi (MIBI). A meta-analysis study of the literature confirmed the superiority of this agent toward the conventional Tc/T1201.

[Primary hyperparathyroidism. Optimization of surgical results with systematic preoperative 99mTc-Sestamibi scintigraphy].

Objective: The importance of preoperative 99mTc Sestamibi (MIBI) scintigraphy in case of reoperation for persistent hyperparathyroidism is well recognized, but it use as a systematic exploration technique remains a question of debate. We conducted this study to determine whether preoperative MIBI scans performed in all cases before surgery have any real impact.

Method: Two successive series of 65 operated patients were included in the study.

Localization of N-(2-diethylaminoethyl)4-iodobenzamide in the pigmented mouse eye: a microanalytical study.

The 123I-N-(2-diethylaminoethyl)4-iodobenzamide (123I-BZA) is a new radiopharmaceutical used for the scintigraphic imaging of malignant melanomas. The mechanism for BZA uptake in melanic tissues is still unknown. Two methods of microanalysis, secondary ion mass spectrometry and electron probe X-ray microanalysis, were used to determine tissue distribution and subcellular location of unlabelled BZA in the C57BL6/J1 co mouse eye.

Subcellular distribution of a new fluorinated, biocompatible, non-ionic telomeric carrier: a study in cultured B16 melanoma and rat skin fibroblasts.

Tris-hydroxymethyl-amino-methane telomers bearing a fluorinated end have recently been proposed as potential drug carriers. Using ion microscopy, we have investigated the cell uptake and subcellular distribution of a perfluorinated telomere, called F-TAC, in two cell lines, malignant murine B16 melanoma and normal rat skin fibroblasts. Single layer cell cultures on gold plates were incubated with F-TAC at different concentrations.

[Primary hyperparathyroidism. Relationships of symptoms to age, sex, calcemia, anatomical lesions and weight of the glands].

Objectives: Primary hyperparathyroidism is a polymorphic disease. We evaluated the effect of different factors on clinical expression.

Methods: Clinical expression in 259 patients who underwent surgery for primary hyperparathyroidism were analyzed as a function of patient age, sex, calcium level, anatomic lesions and weight of the diseased glands.

Primary hyperparathyroidism: is technetium 99m-Sestamibi/iodine-123 subtraction scanning the best procedure to locate enlarged glands before surgery?

Technetium99m (99mTc)-Sestamibi/123I subtraction scanning was prospectively performed in 30 patients with primary hyperparathyroidism in an attempt to locate enlarged glands before first surgery. Imaging results were compared to surgical findings; the surgeon tried to identify all parathyroid glands. Twenty-seven patients were found to have a solitary adenoma during surgery, and 3 had multiglandular parathyroid hyperplasia.

[Mediastinal parathyroid adenoma. Localization by scintigraphy with methoxy-isobutylisonitrile].

Cases of inaccessible mediastinal parthyroid adenomas are rare (1% of parathyroid tumours). Previously, when the localization had been confirmed by imaging techniques, we performed exploratory cervicotomy, followed by sternotomy after explorations had been completed. This procedure required two operations and sternotomy sometimes gave blank results.

SIMS microscopy: a tool to measure the intracellular concentration of carbon 14-labelled molecules.

Monolayer cultures of human fibroblasts were incubated for 24 h with 14C-arginine and observed by means of SIMS microscopy (ion microscopy). Carbon 14 imaging showed the intracellular distribution of labelled arginine which featured high nuclear incorporation. The local concentration of this amino acid in different cells and intracellular structures was assessed through local isotopic 14C/12C ratio measurement.

Mapping the cellular distribution of labelled molecules by SIMS microscopy.

We took advantage of one of the main possibilities of ion microscopy, ie isotopic analysis, to study the cellular distribution of molecules labelled either with carbon 14 or with stable isotopes of low natural abundance such as nitrogen 15 and deuterium. The surface of the sample is bombarded with an ion beam (O2+, Cs+ etc). Secondary ions emitted from the sample are filtered by a mass spectrometer and the distribution of the labelling isotope is recorded.

Rapid localization of carbon 14-labeled molecules in biological samples by ion mass microscopy.

We report here on the ability of secondary ion mass spectrometry (SIMS) to provide rapid imaging of the intracellular distribution of 14C-labeled molecules. The validity of this method, using mass discrimination of carbon 14 atoms, was assessed by imaging the distribution of two molecules of well-known metabolism, [14C]-thymidine and [14C]-uridine, incorporated by human fibroblasts in culture. As expected, 14C ion images showed the presence of [14C]-thymidine in the nucleus of dividing cells, whereas [14C]-uridine was present in the cytoplasm as well as the nucleus of all cells, with a large concentration in the nucleoli.

Ion microscopy: a new approach for subcellular localization of labelled molecules.

Secondary ion mass spectroscopy (SIMS) was used to obtain images representing the intracellular distribution of molecules labelled with carbon 14. Deoxyadenosine labelled with carbon 14 was added to a cultured human fibroblast cell medium, and the intracellular distribution of this molecule was studied using three different SIMS instruments: the CAMECA IMS 3F and SMI 300 ion microscopes and the UC-HRL scanning ion microprobe. Carbon 14 distribution images obtained by this method show that deoxyadenosine U-C14 is present in the cytoplasm as well as the nucleus, with a higher concentration in the nucleoli.

Microautoradiographic study of technetium-99m colloid uptake by the rat liver.

A new microautoradiographic technique was developed to study the distribution of 99mTc-labeled radiopharmaceuticals. Using a thick emulsion, it is possible to get microscopically visible tracks of internal conversion and Auger electrons. The liver uptake of microscopic particles has been thought to occur in Kupffer cells but no direct evidence has been provided for technetium colloids.