[++Scintimammography: a new imaging technique for diagnosis and follow-up of breast cancer]. / Apport de la mammoscintigraphie 99m Tc MiBi dans le diagnostic et le suivi des cancers du sein.

99m Tc MiBi has emerged as a new imaging technique for primary breast carcinomas. The aim of this study was to analyze the diagnostic performance and the additional information provided by scintimammography (SMN). Two hundred and forty consecutive women referred to surgery for abnormalities breast or suspicious breast cancer were scanned before surgery. Sensitivity and specificity were respectively 92% and 53%. PPV: 77.5% and PVN: 79.3%. All false negative scans occurred in cancers 1 cm. SMN detected multiple foci of uptake in the same breast in 13%, that were all confirmed to be multifocal disease and histology. Controlateral focal uptake was also detected; at this time 5/27 are confirmed to be bilateral breast neoplasms; 22 patients are in follow-up. SMN is reliable in the diagnosis of breast cancer and also with difficult cases of mammography. Moreover, SMN provides additional qualitative information in 19.6% of breast carcinomas, such as chest wall infiltration, multifocal or bilateral breast cancer.

[Autonomous thyroid adenoma. Value of thallium scintigraphy and pathology]. / Adénome thyroïdien autonome. Apport de la scintigraphie au thallium et de l'histologie.

Clinical, biological, scintigraphic (99mTc, 123I, 201Tl) and histological data were reviewed in 90 patients operated for autonomous adenomas (hot nodules). Analysis of the data gave the following results: 74.4% of the nodules were solitary and 25.6% occurred in a multinodular goiter (MNG). Hyperthyroidism (FT3-, FT4-, TSH < 0.1) was present in 44% of solitary nodules and in 15% of MNG. 16.6% of patients were euthyroid, and 22.2% had a TSH < 0.1 and normal free hormones. The 201 Tl scintigraphy, performed instead of the administration of exogenous TSH, showed and uptake of Tl in the remainder of the thyroid. Four types of 201Tl uptake were observed in the pathological lobe: type 1: homogeneous uptake: type 2: heterogeneous uptake and hyperfixation in the nodule; type 3: faint uptake and hypofixation in the nodule; type 4: faint and very heterogeneous uptake. Histological analysis of the nodules showed 32.2% of follicular adenomas, 25.6% of MNG and 42.2% of colloid nodules. Among these lesions, 70% showed histological signs of hypermetabolism (resorption vesicles ...). Multivariate analysis of these data clearly demonstrates the need to redefine the clinical, biological, scintigraphic and histological concepts of autonomous adenomas. On the other hand, 91.6% of follicular adenomas show a type 2 Thallium uptake (22/24). On basis of these results, we prefer to operate these patients rather than to treat them by 131I or by percutaneous injection of ethanol.

[Contribution of TRH test and anti-TPO antibody assay in the screening of infraclinical hypothyroidism]. / Apport du test à la TRH et du dosage des anticorps anti-TPO dans le dépistage de l'hypothyroïdie subclinique.

The upper limit of normal TSH levels, determined with a second generation kit (RIA-Gnost TSH, Behring) was set at 2.8 microU/ml. These TSH levels define pituitary reactivity in euthyroid subjects. The upper limit for TSH 20 minutes after injection of TRH was set at 23 microU/ml. The diagnosis of infraclinal hypothyroidism should be made in patients with a normal hormone level, normal baseline TSH and a positive response to TRH defined as a TSH above the upper limit 20 minutes after injection. A large percentage of these patients were positive for anti-TPO antibodies, emphasizing the risk of developing patent hypothyroidism. Clinicians should be aware of the need to lower the upper limit for baseline TSH, often set a 4 or even 6 microU/ml. A level of 2.8 to 4 microU/ml is recommended as the upper limit. Within this interval, the TRH test should always be performed since 50% of the TSH values obtained under in such patients are abnormal.

[Can benign and malignant thyroid nodules be differentiated with thallium 201?]. / Le thallium 201 permet-il de différencier le nodule thyroïdien bénin du nodule malin?

The merits of Thallium 201 radionuclide scanning of the thyroid mentioned as soon as 1976 by PALERMO have been confirmed in the 16 last studies published in the international literature. Over 1601 examinations, authors showed that any cold nodule (Tc 99 m or I 123) which preferentially fixes Thallium 201 as compared to surround thyroid tissue must be operated since some of them are thyroid cancer carriers, some others are carriers of a traditional follicular adenoma or Hurthle-cell adenoma, or a follicular adenoma associated with varied cell atypisms which make difficult the diagnosis between benign and malignant nodules. The analysis of the results published show a 91.3% sensitivity of this diagnosis test, all analysis methods being considered. In case of negative test, it allows eliminating the cancer risk by more than 97% (negative predictive value). Such an examination--as opposed to a cytology test on the isolated nodule only--is valid for any type of nodule, being isolated, multiple or a multinodular goitre where the degeneration risk is close to, or even higher than, that of isolated nodules (4, 22).

[Determination of thyroid peroxidase antibodies in common thyroid pathology. Methodological and clinical approach]. / Dosage des anticorps anti-thyroperoxydase en pathologie thyroïdienne courante. Approche méthodologique et clinique.

Thyroid peroxidase antibody levels were measured in 409 patients who came to the thyroid pathology consultation of our Institution between September, 1990, and November, 1991, and were compared with a reference population. In the first 231 patients, we compared the results obtained with two commercial kits. The correlation coefficient between both populations of results was assessed to be 0.919. Only one of the kits was selected later ("Immutest anti-TPOR", Henning, Germany) because normal and pathological values overlapped to a lesser extent. In a population of controls (reference population). 4 cases out of 82 (4.8%) had values exceeding 100 U/ml (arbitrary units), this value being regarded as the boundary of normal conditions. Out of the 409 assays made in patients examined during the thyroid pathology consultation, 137 (33.5%) had pathological values ranging from 100 to 5000 U/ml and even more. Peroxidase antibodies are mainly found in patients with primary hypothyroidism (positive in 82% of cases) and graves' hyperthyroidism (positive in 81%). We have also observed the highest levels in these two conditions. In addition, we have demonstrated a group of patients with normal thyroid conditions who were positive for peroxidase antibodies, sometimes in a family with a history of thyroid pathology. These may be at higher risks to develop hypothyroidism in the future than the general population. A TRH test in some subjects and the clinical evolution of these patients lead us to advocating TPO antibody assay for screening on the first consultation. Endocrine surveillance is advisable in case of positive results.

Correlation of 99Tcm-sestamibi SPECT with coronary angiography in general hospital practice.

One hundred and twenty-eight patients had a stress test with sestamibi injection and a coronarography within 2 months of the sestamibi study. Sestamibi studies were reconstructed using Hanning 0.65 and Wiener 1.0 filters; the latter improved the results significantly (P < 0.05). Significant correlations were found between sestamibi and coronarography: the sensitivity was 0.967 and the specificity was 0.711. Thus sestamibi is a very good compound, with excellent imaging quality, which is very sensitive for mild defects, even more sensitive than coronarography. Thorough studies of discrepancies show that they could be explained by reductions in coronary flow or myocardial reserve, even when the large epicardial vessels are disease free as occurs in various coronary involvements. A follow-up of positive patients with sestamibi and negative coronarography is absolutely necessary since this group of patients represents a 'risk' group. Moreover, sestamibi single photon emission computed tomographic accuracy is highly dependent on filter choice.

Kidney depth measured by using 99Tcm-DMSA. Comparison with CAT scan: review of 50 measurements.

Measurement of kidney depths using computed axial tomographic (CAT) scans, considered as the gold standard, has been compared in 25 patients with depth measured using an isotopic method (99Tcm-DMSA). 99Tcm-DMSA underestimates renal depth in 78% of the cases (mean underestimation: 0.78 cm). The correlation coefficient between the two methods is 0.82. As a comparison, kidney depths calculated using Tonnesen's formula are also given and related to CAT scan results. The presence of renal morphological abnormalities in 18% of the studied kidneys allowed the authors to study their potential influence on 99TcmDMSA measurements. They do not seem to be very different from those obtained in morphologically normal kidneys. The different methods for kidney depth measurement described in the literature are briefly reviewed.