[Recurrent carcinoid tumor and 18F-DOPA PET]. / Récidive d'une tumeur carcinoïde et TEP à la (18)F-DOPA.

We report the case of a carcinoid tumor with suspicion of recurrence on biology. Scintigraphic explorations of the whole body had a major role in diagnostic of this recurrence. OctreoScan((R)) showed an abdominal uptake corresponding to a mesenteric lymph node. PET with (18)F-DOPA also showed a liver uptake corresponding to liver metastases.

[Adrenal incidentaloma and nuclear medicine examination]. / Différentes explorations d'un incidentalome surrénalien en médecine nucléaire.

In the setting of adrenal incidentaloma, nuclear medicine evaluation is only indicated after biological and imaging work-up has been completed. MIBG scintigraphy is helpful to characterize pheochromocytomas. In lesions without MIBG uptake, 18F FDG or 18F DOPA PET can be considered to characterize chromaffin cell tumours. To characterize lesions of the adrenal cortex, iodocholesterol scintigraphy is performed to confirm the origin of the adenoma and the benign or malignant nature of the lesion since benign adenomas show tracer uptake and malignant lesions show no tracer uptake. 18F FDG PET only characterizes the lesion as benign or malignant.

Exploration and management of adrenal incidentalomas. French Society of Endocrinology Consensus.

The French Society of Endocrinology convened a multidisciplinary panel of endocrinologists, radiologists, nuclear physicians and surgeons to address the appropriate evaluation and treatment of adrenal incidentalomas. The panel conducted a systematic review of medical literature on the following issues: epidemiology, natural history, radiological and scintigraphic evaluation, endocrine assessment, surgical management and appropriate follow-up. The following text reports the recommendations of experts on behalf of the French Society of Endocrinology. The authors emphasize the paucity of published scientific data that hampers evidence-based medicine recommendations. The crucial points of the French consensus are: the usefulness of CT-scanning evaluation of adrenal incidentalomas, the systematic screening for pheochromocytoma, the usefulness of the 1mg overnight dexamethasone test to screen for latent hypercortisolism, the difficulty to interpret mild biological abnormalities of the HPA axis, the consensus to remove surgically most of tumours greater than 4cm, the necessity to follow clinically glucorticoid tissular targets in the follow-up of non operated benign adrenocortical incidentalomas.

Comparison of seven serum thyroglobulin assays in the follow-up of papillary and follicular thyroid cancer patients.

BACKGROUND: Serum thyroglobulin (Tg) is the marker of differentiated thyroid cancer after initial treatment and TSH stimulation increases its sensitivity for the diagnosis of recurrent disease. AIM: The goal of the study is to compare the diagnostic values of seven methods for serum Tg measurement for detecting recurrent disease both during L-T4 treatment and after TSH stimulation. METHODS: Thyroid cancer patients who had no evidence of persistent disease after initial treatment (total thyroidectomy and radioiodine ablation) were studied at 3 months on L-T4 treatment (Tg1) and then at 9-12 months after withdrawal or recombinant human TSH stimulation (Tg2). Sera with anti-Tg antibodies or with an abnormal recovery test result were excluded from Tg analysis with the corresponding assay. The results of serum Tg determination were compared to the clinical status of the patient at the end of follow-up. RESULTS: Thirty recurrences were detected among 944 patients. A control 131I total body scan had a low sensitivity, a low specificity, and a low clinical impact. Assuming a common cutoff for all Tg assays at 0.9 ng/ml, sensitivity ranged from 19-40% and 68-76% and specificity ranged from 92-97% and 81-91% for Tg 1 and Tg2, respectively. Using assays with a functional sensitivity at 0.2-0.3 ng/ml, sensitivity was 54-63% and specificity was 89% for Tg1. Using the two methods with a lowest functional sensitivity at 0.02 and 0.11 ng/ml resulted in a higher sensitivity for Tg1 (81% and 78%), but at the expense of a loss of specificity (42% and 63%); finally, for these two methods, using an optimized functional sensitivity according to receiver operating characteristic curves at 0.22 and 0.27 ng/ml resulted in a sensitivity at 65% and specificity at 85-87% for Tg1. CONCLUSION: Using an assay with a lower functional sensitivity may give an earlier indication of the presence of Tg in the serum on L-T4 treatment and may be used to study the trend in serum Tg without performing any TSH stimulation. Serum Tg determination obtained after TSH stimulation still permits a more reliable assessment of cure and patient's reassurance.

Association of peripheral multifocal choroiditis with sarcoidosis: a study of thirty-seven patients.

OBJECTIVE: To assess the clinical spectrum of peripheral multifocal choroiditis (PMC) and its association with sarcoidosis. METHODS: Thirty-seven patients examined between November 1997 and November 2001 who met all diagnostic criteria for PMC were included in this retrospective study. Patients were assessed for the following signs of sarcoidosis: typical changes on chest radiography or computed tomography; predominantly CD4 lymphocytosis in bronchoalveolar lavage fluid; elevated serum angiotensin-converting enzyme levels; elevated gallium uptake; and noncaseating granuloma on biopsy. RESULTS: Most of the patients were female (30 of 37; 81%) and white (30 of 37; 81%). Mean +/- SD age at onset was 57.5 +/- 18.7 years. Seven (19%) of the 37 patients had biopsy-proven sarcoidosis and 18 patients (49%) with presumed sarcoidosis met at least 2 of the above-mentioned criteria for sarcoidosis but had normal biopsy results. Twelve patients (32%) had an indeterminate diagnosis. Patients with presumed sarcoidosis did not differ from those with proven sarcoidosis as regards the above-mentioned criteria, except for noncaseating granuloma, implying that more than two-thirds of patients (predominantly whites) had underlying sarcoidosis. Most patients with positive gallium scintigraphy had increased mediastinal uptake, as described in sarcoidosis. Patients with underlying sarcoidosis had more severe visual impairment due to cystoid macular edema (CME). Weekly methotrexate (0.3 mg/kg) seemed to control CME. CONCLUSION: White patients with PMC should be considered to have sarcoidosis. The identification of sarcoidosis in patients with severe ocular disease can help with therapeutic choices.

Somatostatin receptors 2 and 5 are the major somatostatin receptors in insulinomas: an in vivo and in vitro study.

Somatostatin (SRIF) receptors (sst) are present on normal pancreatic endocrine beta-cells. However, the use of SRIF analogs in the scintigraphic imaging of insulinomas and in the medical management of these tumors seems to be restricted to a subgroup of patients. The aim of this study was to determine the prevalence of sst expression in vitro and characterize sst subtype binding in insulinomas and its correlation with in vivo sst receptor scintigraphy (SRS). In vitro studies were performed on 27 insulinomas from 25 patients: 22 with benign and three with malignant tumors. Semiquantitative RT-PCR of sst mRNAs was performed for 20 of these insulinomas. Sst2 and sst5 were expressed in 70%, sst1 in 50%, and sst3 and sst4 subtypes only in 15-20% of the tumors. (125)I-Tyr(0)DTrp(8)SRIF(14) binding was assessed by quantitative autoradiography in 18 insulinomas, and competition experiments were performed with SRIF(14) and L797-591, L779-976, L796-778, L803-087, L817-818, selective agonists of the five sst subtypes, and BIM23244, a selective agonist of sst2 and sst5. Significant specific binding was observed in 72% of the insulinomas. Displacement experiments with ligands of higher affinity for each of the sst receptors revealed significant binding with the sst2 and sst5 ligands in 72%, sst3 in 44%, sst1 in 44%, and sst4 in 28% of cases. All insulinomas displaying sst2 binding were also sst5 sensitive. However, the ratio of sst5/sst2 displacement was variable and only equal to that for SRIF(14) in experiments with the sst2/sst5 agonist BIM23244. SRS was performed 10 times in nine patients; it detected 60% of the tumors, including metastases of a malignant insulinoma. All the tumors detected by SRS displayed high levels of (125)I-Tyr(0)DTrp(8)SRIF(14) binding. The mechanisms underlying the loss of expression of sst2/sst5 in a third of insulinomas remains to be determined, but this loss of expression may be involved in beta-cell dysfunction.

[Positron emission tomography in clinical oncology]. / Tomographie par émission de positons en oncologie clinique.

A NEW FORM OF MEDICAL IMAGING: Positron emission tomography (PET) is used for the non-invasive in vivo visualisation of biochemical cell processes. It reveals the metabolic characteristics of neoplastic lesions and hence their identification by compensating the lack of lesion specificity of radiological techniques. VARIOUS INDICATIONS: Using the current oncology marker, 18F-fluorodeoxyglucose (FDG), excellent results with PET have been established at all stages of neoplasia, notably for the diagnosis of initial malignancy and the identification of residual lesions and early detection of relapses. Moreover, the fact that the whole of the body can be explored makes PET the tool of choice in the control of the extension and operability of cancers. With the close correlation between imaging and the metabolism of the lesions, PET is the earliest and most precise for assessing the effects of treatment. LIMITS AND PERSPECTIVES: The existence of benign inflammatory FDG binding should lead to the development of markers of other metabolisms directly linked to cell proliferation. The lack of anatomical reference points characteristic of PET does not permit the precise localisation of the lesions detected and could be corrected by combining, in a single apparatus, the PET camera and an X scan, the anatomical resolution of which is irreplaceable. This type of equipment represents the development of a new branch of medical imaging, oncological imaging.

[Iodine 131 uptake by a bronchogenic cyst in a patient with differentiated carcinoma of the thyroid gland]. / Fixation à l'iode 131 d'un kyste bronchogénique chez une patiente ayant un carcinome différencié thyroïdien.

BACKGROUND: After thyroidectomy for differentiated thyroid carcinoma, extracervical uptake of iodine 131 is suggestive of metastasic dissemination. False positives can however occur. CASE REPORT: Differentiated thyroid carcinoma was found in a female patient with a non-functional nodule. Two years after subtotal thyroidectomy and an ablative dose of iodine 131, the whole body scan showed abdominal mediastinal uptake with low serum thyroglobulin level. Considering the possibility of tumor recurrence or lymph node metastasis, the mass was excised. The histology diagnosis was mediastinal bronchogenic cyst. DISCUSSION: To date, iodine uptake in a bronchogenic cyst has not been reported among other false-positives previously described. The pathophysiology of this iodine 131 uptake in a bronchogenic cyst is still unknown: the presence of NIS symporter or a protein which can organify iodine in the mucus cells of the cyst remains to be proven.

[Ovarian endometriosis cyst with iodine 131 uptake : first case of false positive in the follow up for differentiated thyroid carcinoma]. / Kyste endométriosique ovarien fixant l'iode 131 : premier cas de faux positif dans le suivi d'un cancer différencié de la thyroïde.

A whole body scan is performed after a radioiodine treatment in patients with differentiated thyroid carcinoma. This scan is useful coupled with thyroglobulin level for the patient's management. When unusual uptake is found, investigations have to be done to eliminate thyroid metastasis. A 28-year old woman underwent a total thyroidectomy for micro papillary carcinoma. Two years and a half after, ultrasonography of the neck showed a small lymph node in homolateral side of carcinoma. It was decided to begin treatment with iodine 131. The post-therapeutic scan showed an abnormal pelvic uptake. IRM found no osseous abnormality but an ovarian lesion. After surgery, histological diagnosis was an endometriosis cyst without thyroid or tumoral cells. Abdominal ou pelvic iodine false positive are rare. Ovarian cysts may be the cause of false positive radioiodine uptake. Endometriosis cyst was not previously described and the mecanism of iodine uptake is not clear.

[Imaging of adrenal glands]. / Imagerie des glandes surrénales.

The technical choice in imaging the adrenal gland will depend on several factors discussed in the review. CT and MRI are achieving increasingly high accuracy in the investigation of patients suspected to present adrenal pathology. Scintigraphy evaluates functional patterns of both adrenal cortex and medulla, depending on the radiopharmaceutical that is used. Non invasive characterization of adrenal lesions is very important in cases of incidental discovery of adrenal masses. This review concentrates on new techniques for evaluating the incidentally discovered adrenal masses and differentiating between adrenal adenomas and metastases.

[Peroperative detection probes. Evaluation and perspectives in endocrinology]. / Sonde de détection per-opératoire. Bilan et perspectives en endocrinologie.

The principal primary endocrine tumors may be visualized scintigraphically by injection of highly specific radiopharmaceuticals. When surgery is indicated, the surgeon may be assisted in difficult cases by a probe detecting the radioactivity concentrated in tumoral tissue. A radiopharmaceutical consists of a vector molecule labeled with a radioactive isotope. Only radioactive emissions with a certain half life and energy are suitable for intraoperative detection; this limits the number of usable radionuclides. In practice, one uses iodine 123 (123I), iodine 125 (125I), and iodine 131 (131I) labeled metaiodobenzylguanidine mIBG or indium 111 (111In) labeled pentetreotide (Octreoscan) or bi-specific anti CEA antibody. During intra-operative detection, the probe is closely positioned to the tumor-tissue which is surrounded by radioactive background activity due to the non-specific binding in adjacent organs. In order to work with probes that are easily handled, and sensitive at the same time, one can opt for technology which uses either diodes or scintillating crystals. These probes can be used at room temperature and their choice depends upon the energy to be detected. Interesting results begin to be published concerning pheocyromocytomas, differentiated thyroid carcinomas, gastro-entero-pancreatic tumors and medullary thyroid carcinoma, especially for reintervention when conventional imaging modalities fail to localize tumors.

Somatostatin receptor imaging: a preliminary experience in forty-nine patients.

We report our experience with the 111In-pentetreotide scanning of 47 adult patients presenting with neuroendocrine tumors (n = 38) or malignant pheochromocytomas or related tumors (n = 9), and 2 children with metastatic neuroblastomas. A dynamic study was performed after i.v. administration of 50-190 MBq of 111In-pentetreotide followed by a whole body scan at 1.5-4 hours and at 24 hours. Where indicated, tomoscintigraphy or a dual isotope bone, liver or kidney scan was performed in order to improve the anatomical definition. Lesions were visualized in the earliest phases of the examination but contrast was enhanced on delayed images due to an improved signal to background ratio. In 9/49 patients, octreotide scan (OS) detected unknown tumors sites. On the other hand, the lesion uptake of 111In-pentetreotide varied, and not all the sites shown by other imaging modalities were visualised, probably due to differences in membrane receptor expression. In conclusion, OS can be useful in the diagnosis, follow-up and therapeutic management of neuro-endocrine tumors. Further investigations are required to assess the role of OS in other pathologies. Short title: Somatostatin receptor imaging.

Plasma levels of aldosterone versus aldosterone precursors: a way to estimate the malignancy of asymptomatic and nonsecretory adrenal tumors: a French Retrospective Multicentric Study.

The aim of this study was to find out whether the dysfunction of aldosterone pathway, previously proposed as a marker of secretory adrenal carcinoma, is also found in nonsecretory adrenal carcinomas, which pose even more difficult diagnostic problems even for patients with hypertension accompanied or not by hypokalemia. The exploration consisted of using the same method (RIA preceded by a chromatographic step) to determine the plasma levels of the following steroids in the mineral corticosteroid pathway: deoxycorticosterone (DOC), 18-hydroxydeoxycorticosterone (18-OHDOC), corticosterone (B), 18 hydroxycorticosterone (18 OH B), and aldosterone. The subjects included 16 adults, each presenting with an endocrinologically asymptomatic adrenal mass associated for some patients with hypokalemia and hypertension (8 with adrenal carcinoma, 2 with adrenal metastasis from other forms of cancer, and 6 adenomas). These results show that even in nonsecretory adrenal carcinoma, there is a dysfunction of the aldosterone pathway, which can be evaluated from the ratio between aldosterone and the substrate of 11 beta hydroxylase (DOC) and its derivative (18-OH DOC). This study suggests that exploration of mineralocorticosteroid pathway can be used as a hormonal marker of adrenal carcinoma for both secretory and non-secretory malignant masses.

Radiolabeled somatostatin analog scintigraphy in differentiated thyroid carcinoma.

UNLABELLED: After intravenous administration of a radiolabeled somatostatin analog (octreotide), an image of the thyroid gland is frequently observed; few data are available, however, on somatostatin receptors in epithelial thyroid cells assessed in vitro and on images of differentiated thyroid carcinoma (DTC) with pentetreotide scintigraphy. METHODS: In four patients with metastatic thyroid carcinoma, whole-body scintigraphy was performed 4 to 48 hr after injection of 110 MBq of 111In-pentetreotide. The results were compared to data obtained with other imaging modalities, including scintigraphy performed after administration of a therapeutic dose of 131I. RESULTS: There were positive foci in distant metastases on 111In-pentetreotide scintigraphy. Pentetreotide scintigraphy was positive in two patients with an "insular" form of DTC, one of whom had a positive (faintly) 131I scan. Of the other two patients with papillary DTC without radioiodine uptake, only one exhibited a certain degree of pentetreotide scintigraphy positivity in distant metastases. CONCLUSION: These results show promise for exploration of insular thyroid carcinoma and suggest that these carcinomas may possess functional differentiation features, including somatostatin receptors.

Cushing's syndrome in medullary thyroid carcinoma.

Ectopic ACTH secretion is a rare cause of hypercortisolism. Induced metabolic disturbances are often serious, and the management of such patients may be difficult. We report here our experience with four medullary thyroid carcinoma (MTC) patients with distant metastases in whom an ectopic ACTH syndrome occurred. The clinical presentation was significant by the severity and the rapidity of the hypercortisolism. Diagnosis and follow-up were realized by measurements of plasma cortisol, urinary free cortisol, urinary 17-hydroxycorticosteroid, plasma ACTH, plasma LPH, serum calcitonin and carcino-embryonic antigen. Initial treatment with adrenalytic medical therapy failed to control the disease. Only bilateral adrenalectomy cured the excessive cortisol production, and for a long time despite tumor progression. In conclusion, bilateral adrenalectomy should be considered in MTC patients with Cushing's syndrome even at the stage of distant spread. In fact, with regard to the slow growth rate of most MTC's, they may survive for years.