Quantitative comparison of prone and supine myocardial SPECT MIBI images.

The myocardial count distribution and the stress/rest ratio distribution were compared between prone and supine Tc-99m MIBI myocardial SPECT acquisitions. Ninety-nine male patients with a low stress supine inferior wall count underwent stress and rest acquisitions in the supine and prone positions successively. For each study, values depicting the inferior, anterior, septal, and lateral wall counts were extracted from a medioventricular normalized circumferential profile and underwent a statistical analysis (Student's paired t-test). On prone imaging, when compared to supine imaging, counts showed a highly significant mean relative increase of 11% +/- 1% in the inferior wall and of 7% +/- 1% in the septum. Conversely, these counts showed a significant mean relative decrease of 4% +/- 1% in the anterior wall and of 3% +/- 1% in the lateral wall. Moreover, the inferior wall stress/rest ratio showed a highly significant mean relative increase (6% +/- 2%). The prone position is probably preferable for interpreting the inferior wall and septum, where relative counts are enhanced, as with TI-201, and because the inferior stress-rest discrepancies are reduced in that position. But the anterior and lateral wall information is impaired in the prone position. The authors suggest, in case of a low stress supine inferior count, the combination of both positions, which is feasible with Tc-99m MIBI, in order to prevent a misleading interpretation.

Visualization of myocardial infarction six hours after injection of 111 In-antimyosin antibodies using an image subtraction technique.

111 In-antimyosin antibodies are capable of visualizing acute myocardial infarction (MI). Because of slow blood clearance, images are usually recorded 24 or 48 h postinjection. This pilot study was aimed at validating a blood pool subtraction technique, which makes it possible to visualize MI 6 h postinjection. Twenty-five patients with proven MI (16 anterior, 9 inferior) were imaged 10 minutes, 6 and 24 h after an injection of 110 MBq 111 In-labelled antimyosin antibodies, with a mean delay of two weeks after infarction. Three planar views were obtained each time. Using software which performs geometric registration, grey level normalization and subtraction of images, the blood pool image (obtained 10 minutes postinjection) was subtracted from the 6 hour image. The resulting image was the blood pool corrected 6 h image. The 24 h images and the blood pool corrected 6 h images were interpreted blindly and the number of correct, incorrect and indeterminate MI localizations were tabulated. The number of correct localizations was 19/25 for the standard 24 h images and 22/25 for the blood pool corrected 6 h images. With this blood pool subtraction method it was possible to visualize MI 6 h postinjection. Theoretically, this method could be applied six hours after myocardial infarction.

Shape preserving three-dimensional display of myocardial scintigraphic data.

A three-dimensional display has been developed which is specifically suited to the visualization of myocardial single photon emission tomographic (SPET) data. A set of radial maxima voxels, representative of the whole left ventricle uptake and shape is first extracted by cylindrical and spherical sampling of the short axis slices. A three-dimensional representation of these voxels is then obtained, with hues depicting the uptake amount and shades (i.e. intensity and saturation) depicting the shape. This technique is suitable for 201Tl and 99TCm-hexakis-2-methoxyisobutyl isonitrile (99TCm-sestamibi) myocardial images. It is proposed as an aid to interpreting myocardial SPET as it enables the physician to distinguish simultaneously the actual shape, the extent and the severity of perfusion defects on a single frame.

[Role of adrenocortical scintigraphy in the exploration of incidentally discovered tumors]. / Place de la scintigraphie corticosurrénalienne dans l'exploration des incidentalomes.

To determine the utility of adrenocortical scintigraphy with I131-6 beta-iodomethyl-19-nor-cholesterol (NP59) in incidentally discovered adrenal masses, we studied 12 patients with a unilateral adrenal mass and without other primary tumors or signs of pheochromocytoma or hyperfunctioning adenoma. Ten patients had an adenoma (size: 12 to 35 mm), the diagnosis was made by surgery or by no change in size on repeated CT scans. The NP59 scintigraphy showed an increased uptake on the side of the tumor in 8 cases with a decreased uptake of contra-lateral gland in 7 cases. Hormonal investigations of glucocorticoid function suggested supranormal or fluctuant cortisol secretion in 5 cases as assessed by moderately elevated urinary free cortisol or by incomplete dexamethasone suppression test. These abnormalities disappeared after surgery. Two patients had normal bilateral uptake of NP59, the sizes of the tumors were 12 and 20 mm. Two patients had an extra-adrenal tumor. The NP59 scintigraphy showed a moderately decreased uptake on the side of the hematoma of one patient and a compression of the normal adrenal by ganglioneuroma of the other patient. Our results and those of other authors suggest that positive NP59 scintigraphy could confirm the cortical nature of an incidentally discovered adrenal mass, probably an adenoma that must be followed up morphologically and functionally. No uptake by a tumor greater than 2 cm suggests a primary malignancy or extra-adrenal origin which must be diagnosed by invasive methods.

Treatment of malignant pheochromocytoma with [131I]metaiodobenzylguanidine: a French multicenter study.

Six Medical Centers in France were involved in a prospective study evaluating the efficacy of [131I]metaiodobenzylguanidine (131I-MIBG) in the treatment of malignant pheochromocytoma. Fifteen patients aged from 28 to 75 years bearing tumor sites demonstrating a good MIBG uptake were included in this study. Catecholamines were elevated in 13/14 cases, VMA in 9/14 and metanephrines in 13/14. Two to 11 therapeutic activities of 131I-MIBG were administered, with a mean number of therapeutic doses per patient of 4 and a mean single activity of 4.7 GBq (range 2.9 to 9.25 GBq). Seven patients were alive, and seven patients died 6 to 29 months after their first MIBG administration (mean follow-up of 36 months); 1 patient was lost to follow-up. Two patients had a partial tumor response only, 4 had a hormonal response only, and 3 had both a partial tumor response and a hormonal response (complete in 2 cases). Six patients did not respond to the treatment, 4 of them died. Of the 9 responding patients, 4 relapsed, 3 of whom died subsequently. Haematological toxicity was always transient and mild, except in 1 case.

Results of [131I]metaiodobenzylguanidine therapy administered to three patients with malignant pheochromocytoma.

Three patients with malignant pheochromocytoma were treated with [131I]metaiodobenzylguanidine (131I-MIBG). In two patients with widespread metastatic disease, the effect of treatment was palliative and of short duration. In the third case, with only residual tumor and no metastases, the treatment was effective after 22 GBq of 131I-MIBG.

Use of m-[131I]iodobenzylguanidine in the treatment of malignant pheochromocytoma.

The efficacy and safety of m-[131I]iodobenzylguanidine ([131I]MIBG) were assessed in 15 patients with malignant pheochromocytomas in a nonrandomized, single arm trial, in which patients were treated with [131I]MIBG (SA, 740 megabequerel/mg) every 3 months. Seven of these patients had bone and soft tissue metastases, 4 had only soft metastases, and 4 had only bone metastases. The follow-up period ranged from 6-54 months; the number of doses ranged from 2-11, with 2.9 (78.4 mCi) to 9.25 gigabequerel (GBq) (250 mCi)/administration and a cumulative activity from 11.1-85.90 GBq (300-2322 mCi). The absorbed cumulative dose in tumors ranged from 12-155 Gy. A beneficial effect of the treatment was observed in 9 patients (60%). No complete remission of the disease was observed. Seven patients died during the study, among whom 4 never responded to the treatment. Seven had hormonal responses (4 complete and 3 partial), with a duration ranging from 5-48 months. Among these patients, 4 relapsed, and 3 died within 3 months. Five patients had partial tumoral responses mainly located in soft tissues and for a duration ranging from 29-54 months. All patients with a hormonal response had objective improvement in clinical status and blood pressure. There was no clear-cut relationship between the cumulative dose and the responses. The main side-effect observed in 1 patient with widespread bone metastases after three doses (12.9 GBq) was a pancytopenia, which resolved after treatment was discontinued. This study suggests that repeated [131I]MIBG treatment could be effective in patients with advanced malignant pheochromocytoma.

High permanent plasma adrenaline levels: a marker of adrenal medullary disease in medullary thyroid carcinoma.

Increases in urinary, plasma and tumour adrenaline have been previously observed in MEN II patients with phaeochromocytoma. However, the sensitivity of adrenaline for early detection of adrenal medullary disease has not been accurately evaluated. Twenty-five patients with medullary thyroid carcinoma (MTC) histologically confirmed but without clinical or biological evidence of phaeochromocytoma have been studied. Medullary adrenal status was evaluated by adrenal CT-scan. MIBG scintigraphy, determination of urinary VMA, metanephrines and total catecholamine levels, measurement of nyctohemeral plasma adrenaline or noradrenaline concentrations (every 2 h during 24 h) and clonidine suppression test. Four of the 25 patients had evidence of adrenal medullary disease in view of the coexistence of CT-scan, MIBG scintigraphy and plasma adrenaline abnormalities. Moderate adrenal enlargement (unilateral, n = 3; bilateral, n = 1) was observed on scans together with a high adrenal MIBG uptake (bilateral, n = 4). Among the urinary parameters studied, a minor MN increase was observed in only one of the four patients. Plasma adrenaline levels were significantly (P less than 0.01) different from those of the other 21 patients (mean + SD 115 + 110 pmol/l). This plasma adrenaline increase is reproducible and not suppressed by clonidine. Unilateral adrenalectomy performed in one patient confirmed a phaeochromocytoma and induced normalization of plasma adrenaline levels. In contrast, the plasma noradrenaline levels of the four patients were not statistically different from those of the other 21 patients. These data suggest that persistent high plasma adrenaline levels may be selectively increased in MTC patients together with a moderate adrenal CT-scan enlargement and a high adrenal MIBG uptake, despite a normal urinary excretion of total catecholamines and catecholamines metabolites.(ABSTRACT TRUNCATED AT 250 WORDS)

[Treatment of hyperthyroidism by radioactive iodine. Development of methods and difficulties in the surveillance]. / Traitement des hyperthyroïdies par l'iode radioactif. Evolution des méthodes et difficultés de la surveillance.

The experience of treatment of hyperthyroidism with radioactive iodine in the Nuclear Medicine department of the J. Godinot Institute, Rheims, from 1967 till 1987, is described. One thousand one hundred and fifty patients (723 with diffuse and 427 with nodular hyperthyroidism) received a total of 1,565 doses. The dosage calculation method was considerably simplified, enabling a patient to be treated in 24 hours. Thyroid gland mass evaluation, initially based on the scintigraphic projection area, is now performed by ultrasonography. The mean total radioactivity administered is 370 +/- 320 MBq per patient. All patients are seen on the 8th post-treatment week for clinical examination and hormone control. Seven out of 10 patients are cured with a single dose. Long-term follow-up, based on a computer file, is effected by means of an annual letter sent to the patient and to his family doctor, but in spite of sustained efforts 36 per cent of the patients are lost sight of. The diagnosis of iodine 131-induced hypothyroidism is based on plasma levels of TSH which, since 1984, are measured by the ultrasensitive method. The overall incidence of hypothyroidism is 6.6 per cent in the first year and 3 per cent thereafter. Despite a simplified procedure, the results obtained by the authors are similar to those found in the literature, and the cost-efficiency ratio is excellent.

[Thallium-technetium scintigraphy for presurgical localization of parathyroid adenomas and hyperplasia]. / La scintigraphie au thallium-technétium pour la localisation pré-opératoire des adénomes et hyperplasies parathyroïdiennes.

The purpose of this study was to assess the value of parathyroid Thallium 201-Technetium 99m scintigraphy in 45 patients with hyperplasia or parathyroid adenomas with or without associated thyroid abnormalities. The prevalence of parathyroid abnormalities found during examination was 42/45: 36 adenomas (35 patients) and 16 hyperplasias (7 patients). Seventeen patients (38%) had thyroid abnormalities. The sensitivity and specificity of the three image analysing methods (visual analysis, simple subtraction, sophisticated subtraction) were determined by assessing answers given by 3 observers. The population was divided into 6 groups: adenomas and hyperplasias with (group I, n = 42) or without (group II, n = 25) thyroid abnormalities, adenomas alone with (group III, n = 35) or without thyroid abnormalities (group IV, n = 22), hyperplasias alone with (group V, n = 7) or without thyroid abnormalities (group VI, n = 5). The highest overall sensitivity was obtained, whichever the group, by applying the sophisticated image subtraction technique; for any given method, the best results were observed in the group comprising adenomas alone, especially without associated thyroid abnormalities. On the other hand, in the groups comprising hyperplasias alone, sensitivity was low. This leads us to conclude that, together with ultrasonography, parathyroid scintigraphy is currently the best preoperative technique for localizing parathyroid adenomas, even in the presence of associated thyroid abnormalities. However this must be carried out in conjunction with a sophisticated image subtraction technique.

[Contributions of the measurement of TSH, T4 and thyroglobulin, of 99m Tc scintigraphy and of cervical ultrasonography to the early diagnosis of congenital hypothyroidism]. / Contribution des dosages de TSH, de T4 et de thyroglobuline, de la scintigraphie au 99m Tc et de l'échographie cervicale au diagnostic précoce de l'hypothyroïdie congénitale.

Over 10 years, extending from 1978, 200,000 newborns of the Champagne-Ardennes Region have been tested within the screening program for congenital hypothyroidism. Congenital hypothyroidism was diagnosed in 96 infants (28 boys, 68 girls): 73 thyroid dysgenesis (50 ectopic glands and 23 undetectable thyroid tissue) and 23 thyroid dyshormonogenesis (14 permanent and 9 transient defects). Our local frequency was 1/2,600, significantly higher than the French and European frequencies. There was a marked shortening of the age at diagnosis during the 10 year period (mean age: 45 days between 1978 and 1980, 18 days in 1987). The TSH measurement was found to be the most sensitive tool for the diagnosis. Scintigraphy and more recently ultrasonography were performed in order to characterize the anatomical variety. For the last year, the following protocol was used: high frequency ultrasonography at first, then 123I or 99 m Tc scintigraphy (using parallel colimator and digital acquisition) depending on whether the thyroid gland was seen on ultrasound or not. Treatment of thyroid dyshormonogenesis was withdrawn after 5 years for reassessment.

[Thyroid cancer in Champagne-Ardenne: 1967-1984. Epidemiologic findings in a regional register]. / Les cancers thyroïdiens en Champagne-Ardenne: 1967-1984. Exploitation épidémiologique d'un registre régional.

Between 1967 and 1984, 600 cases of clinically diagnosed thyroid carcinoma were collected in an area (Champagne-Ardenne) of about 1,500,000 inhabitants. During this period, the complete collection of the cases was progressively ensured by involving all the general practitioners and by creating a cooperative multidisciplinary group. The collected data were sex, age at diagnosis, histological classification and clinical extension in TNM system. We found 19 patients with previous neck irradiation. Thyroid cancer was diagnosed in association with thyrotoxicosis in 36 patients: 13 Graves disease and 23 nodular hyperthyroidism. Incidence rates were estimated on a well defined population of two districts (850,000 inhabitants) and limited to the last four years. The following results were obtained: incidence 4.3/100,000/year, age-specific incidence progressively increasing up to a value of 10/000,000/year in the course of the fifth decade. Sex-ratio was 0.26.