[History of imaging: cases under study]. / Histoire de l'imagerie: chapitres sous presse.

Techniques of body scanning and imaging each give a partial picture of the cases under study, with technical limitations connected to translation parameters, scanning frequency, etc. 3D imaging can analyze foetuses, "dedicated" imaging can detect focus of inflammation(?). Will today's techniques such as scintiscanning or scanning become obsolete within the coming decade? The protection of medical personnel and patients must be improved.

[Does thyroid scintigram still have indications in 2005?]. / La scintigraphie thyroïdienne a-t-elle encore des indications en 2005?

Since 15 years, the indications of thyroid scintigrams have been dramatically reduced. This examination appeared useless in most cases of hypothyroidism and for the evaluation of thyroid cysts or for infracentimetric nodules. For greater solid nodules, its poor sensibility and bad specificity have resulted in its replacement by echography and fine needle biopsy. Thyroid scintigram is however usefull for the non obvious etiologic diagnosis of thyrotoxicosis and in case of thyroid goiter with a low TSH and normal thyroid hormons. Whole body131 I scans remain usefull for thyroid cancer follow up, especially after therapeutic dose of radioiodine.

Prognostic factors associated with the survival of patients developing loco-regional recurrences of differentiated thyroid carcinomas.

To estimate survival of patients with loco-regional recurrences (LRRs) of differentiated thyroid carcinomas (DTCs) and to identify factors associated with survival after LRRs, we analyzed retrospective data of the 172 patients treated and followed up in our institution from 1958 to 2000 who had developed LRRs (6% of DTC patients). Ultrasound, when used, picked up 95% of the recurrences. Survival was estimated with the method of Kaplan-Meier, and associated prognostic features were studied in univariate and multivariate Cox model-based analyses. Cumulated survival rates 10 yr after LRRs were 49.1, 89.3, and 32.1% for all patients, patients aged less than 45 yr, and older patients, respectively. Multivariate analysis identified three features related to initial tumor (age >/= 45 yr, follicular histology, presence of thyroid capsular effraction), the absence of radioiodine ablation of thyroid remnants after initial surgery (10% of patients did not receive radioiodine), the presence of distant metastases before LRR diagnosis, and two features related to the LRRs (no radioiodine uptake and thyroid bed location) as significantly associated with a reduced survival. Our results underline the seriousness of LRRs of DTCs and could be used to identify patients who should benefit from a closer follow-up and especially reactive therapeutic intervention.

[Adaptation of thyroid function to excess iodine]. / Adaptation de la fonction thyroïdienne à la surcharge iodée.

NORMALLY: The production of thyroid hormones is normally stable, despite iodine supplies that may vary widely and even on sudden excess iodine. The metabolism of iodine is characterised by adapted thyroid uptake, the requirements varying on the age and physiological status of the individual (pregnancy, breastfeeding) and by insufficient supplies in several areas in France. IN THE CASE OF EXCESS: The mechanisms that permit the thyroid to adapt to a sudden or chronic excess of iodine are immature in the newborn and sometimes deficient in adults, and may lead to iodine-induced dysthyroidism. Thanks to the recent progress made in thyroid physiology, these mechanisms are now better known. PATHOLOGICAL IMPACT: Iodine-induced hyperthyroidisms in a healthy or pathological thyroid are frequent. They are predominantly related to amiodarone. Iodine-related hypothyroidism frequently appears in cases of pre-existing thyroid diseases (asymptomatic autoimmune thyroiditis, for example). They are frequent in the newborn, notably in the premature. The iodine prophylaxis organised in Poland following the Tchernobyl accident led to very few pathological consequences in adults or children.

Post-operative neck ultrasound and risk stratification in differentiated thyroid cancer patients with initial lymph node involvement.

OBJECTIVE: Cervical ultrasound (US) scan is a key tool for detecting metastatic lymph nodes (N1) in patients with papillary thyroid cancer (PTC). N1-PTC patients are stratified as intermediate-risk and high-risk (HR) patients, according to the American Thyroid Association (ATA) and European Thyroid Association (ETA) respectively. The aim of this study was to assess the value of post-operative cervical US (POCUS) in local persistent disease (PD) diagnosis and in the reassessment of risk stratification in N1-PTC patients. DESIGN: Retrospective cohort study. METHODS: Between 1997 and 2010, 638 N1-PTC consecutive patients underwent a systematic POCUS. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of POCUS for the detection of PD were evaluated and a risk reassessment using cumulative incidence functions was carried out. RESULTS: After a median follow-up of 41.6 months, local recurrence occurred in 138 patients (21.6%), of which 121 were considered to have PD. Sensitivity, specificity, NPV, and PPV of POCUS for the detection of the 121 PD were 82.6, 87.4 95.6, and 60.6% respectively. Cumulative incidence of recurrence at 5 years was estimated at 26% in ETA HR patients, 17% in ATA intermediate-risk patients, and 35% in ATA HR patients respectively. This risk fell to 9, 8, and 11% in the above three groups when the POCUS result was normal and to <6% when it was combined with thyroglobulin results at ablation. CONCLUSION: POCUS is useful for detecting PD in N1-PTC patients and for stratifying individual recurrence risk. Its high NPV could allow clinicians to tailor follow-up recommendations to individual needs.

Scoring system for predicting recurrences in patients with papillary thyroid microcarcinoma.

CONTEXT: Papillary thyroid microcarcinomas (PMC) defined as tumors ≤10 mm in diameter (including pT1a and pT3 according to the latest pTNM classification) have good prognosis, although recurrence is possible. Clinicians are interested in using a scoring system for predicting recurrences. OBJECTIVE: To identify the prognostic factors for recurrence in patients with PMC and to develop a scoring system based on lymph node involvement, multifocality, and sex. To determine the impact of extrathyroidal invasion (ETI) and a threshold value for analyzing multifocality. METHODS: Single-center retrospective study of a cohort of 1669 patients with PMC managed from 1960 to 2007. The Kaplan-Meier survival rate and prognostic factors of events were analyzed using log-rank tests and uni- and multivariate Cox model-based analyses. A scoring system was proposed. RESULTS: Sixty-eight recurrences were observed. Initial lymph node metastases (P=0.0001), multifocality (P=0.05), and male sex (P=0.01) were significantly associated with recurrence, although there was a period effect (after 1990). PMC size was not a significant variable. Our scoring system allows us to separate patients into three risk groups according to their recurrence-free probability. For PMC Nx patients, total foci size of multifocal tumors >20 mm was significantly associated with recurrence (P<0.0001). Radioiodine (RAI) ablation was associated with better outcome only in PMC with ETI. CONCLUSION: Our scoring system classifies recurrence risk. In PMC Nx patients, multifocality is important in planning therapeutic strategies. Recurrence probability of pT3 PMC appears lower if RAI ablation is performed.

Ultrasound, elastography, and fluorodeoxyglucose positron emission tomography/computed tomography imaging in Riedel's thyroiditis: report of two cases.

BACKGROUND: Riedel's thyroiditis (RT) is a rare disease characterized by a chronic inflammatory lesion of the thyroid gland with invasion by a dense fibrosis. Publications of the imaging features of RT are scarce. To our knowledge, ultrasound elastography (USE) findings have not been previously reported. Therefore, we describe two patients with RT who were imaged with ultrasonography (US), USE, and fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT). SUMMARY: Two women were referred for a large, hard goiter with compressive symptoms (dyspnea and dysphagia); in one patient, the goiter was associated with retroperitoneal fibrosis. In both cases, RT was confirmed by surgical biopsy with pathological examination. Thyroid US imaging was performed with a US scan and a 10-13 MHz linear transducer. The hardness of the tissues was analyzed using transient USE (ShearWave, Aixplorer-SuperSonic Imagine). PET/CT scanning was performed with a Philips Gemini GXL camera (GE Medical Systems). In the first patient, US examination revealed a compressive multinodular goiter with large solid hypoechoic and poorly vascularized areas adjacent to the nodules. The predominant right nodule was hypoechoic with irregular margins. The second patient had a hypoechoic goiter with large bilateral hypoechoic areas. In both cases, an unusual feature was observed: the presence of tissue surrounding the primitive carotid artery, associated with thrombi of the internal jugular vein. Further, USE showed heterogeneity in the stiffness values of the thyroid parenchyma varying between 21 kPa and 281 kPa. FDG-PET/CT imaging showed uptake foci in the thyroid gland. In both cases, US showed a decrease in the thyroid gland volume and the disappearance of encasement of the neck vasculature in response to corticosteroid treatment. In contrast, the FDG-PET/CT features remained unchanged. CONCLUSIONS: US features, such as vascular encasement and improvement under corticosteroid treatment, seem to be specific to this rare disease. For the first time, USE documents the hardness of RT tissues. Apart from the FDG-PET/CT findings that merit further investigation, US and USE prove useful tools in the assessment of such a rare disease.

Micrometastasis of papillary thyroid carcinoma in a human immunodeficiency virus-infected patient: a case report and discussion.

Patients with acquired immunodeficiency syndrome (AIDS) have an increased risk of malignancies such as Kaposi's sarcoma, primary central nervous system lymphoma, non-Hodgkin's lymphoma, and cervical cancer, but the relative risk of other malignancies such as papillary thyroid carcinoma (PTC) is not well documented. The report describes the case of a 52-year-old HIV-infected Haitian male who presented with PTC. A post (131)I therapy whole body scan (WBS) showed abnormal uptake in several areas indicating the presence of a number of micro-metastases. Our case raises the question not only as to the role of HIV infection in predisposition to PTC, but also how it alters the clinical course of the tumor.

An estimate of cancers attributable to occupational exposures in France.

OBJECTIVE: To perform a quantitative estimate of the proportion of cancers attributable to occupational exposures in France in 2000. METHODS: Exposure data for established carcinogens were obtained from a 1994 survey and other sources. Relative risks for 23 exposure-cancer combinations were derived from meta-analyses and pooled analyses. RESULTS: A total of 4335 cases of cancer among men (2.7% of all cancers) and 403 cases among women (0.3% of all cancers) were attributed to occupational exposures. Asbestos, polycyclic aromatic hydrocarbons, and chromium VI were the main occupational carcinogens in men, and asbestos and involuntary smoking were the main carcinogens in women. Corresponding proportions for cancer deaths were 4.0% and 0.6% in men and women, respectively. Lung cancer represented 75% of deaths attributable to occupational exposures. CONCLUSION: Our estimates are comparable with those obtained for other countries in studies based on similar methodology.

Non-medical exposure to radioiodines and thyroid cancer.

The Chernobyl accident, which occurred 32 years after the accidental exposure of Marshall islanders, resulted in the exposure of neighbouring populations to a mixture of iodine isotopes and in an increased incidence of thyroid cancer. The highest thyroid doses were received by the youngest age groups. This review describes the existing evidence, and examines factors that may have increased the risk. It also stresses problems with contemporary thyroid measurements, and the lack of information on the sensitivity of the thyroid to short-lived iodine isotopes and iodine-131. Practical considerations for nuclear physicians, epidemiologists and thyroidologists are discussed in the light of this major accident.

Selection of patients with solitary thyroid nodules for operation.

OBJECTIVE: To improve the preoperative selection for operation of patients with solitary thyroid nodules. DESIGN: Prospective cohort study. SETTING: University hospital, France. PATIENTS: 155 consecutive patients who presented with solitary thyroid nodules and were operated on. INTERVENTIONS: Clinical examination, ultrasound examination, fine needle aspiration biopsy, followed by total thyroid lobectomy with frozen section and final histological examination. MAIN OUTCOME MEASURE: Correct prediction of thyroid carcinoma or benign adenoma. RESULTS: A logistic regression analysis indicated that absence of rim (p < 0.002), solid and hypoechoic feature (p < 0.003) and malignant or suspicious fine needle aspiration biopsy results (p < 0.0001) were significantly associated with malignancy. Selection for operation by the logistic model would save 40 of 73 patients from operation and 40 of 59 from unnecessarily radical operation. It would detect a similar number of cancers as a strategy based solely on fine needle aspiration cytology. CONCLUSIONS: A combination of the available diagnostic methods provides substantial benefit in the preoperative selection of patients with an isolated thyroid nodule.