Clinico-pathological factors associated with radioiodine refractory differentiated thyroid carcinoma status.

PURPOSE: Risk factors for developing radioiodine refractory thyroid cancer (RAIR-TC) have rarely been analyzed. The purpose of the present study was to find clinical and pathological features associated with the occurrence of RAIR-disease in differentiated thyroid cancers (DTC) and to establish an effective predictive risk score. METHODS: All cases of RAIR-DTC treated in our center from 1990 to 2020 were retrospectively reviewed. Each case was matched randomly with at least four RAI-avid DTC control patients based on histological and clinical criteria. Conditional logistic regression was used to examine the association between RAIR-disease and variables with univariate and multivariate analyses. A risk score was then developed from the multivariate conditional logistic regression model to predict the risk of refractory disease occurrence. The optimal cut-off value for predicting the occurrence of RAIR-TC was assessed by receiver operating characteristic (ROC) curves and Youden's statistic. RESULTS: We analyzed 159 RAIR-TC cases for a total of 759 controls and found 7 independent risk factors for predicting RAIR-TC occurrence: age at diagnosis ≥ 55, vascular invasion, synchronous cervical, pulmonary and bone metastases at initial work-up, cervical and pulmonary recurrence during follow-up. The predictive score of RAIR-disease showed a high discrimination power with a cut-off value of 8.9 out of 10 providing 86% sensitivity and 92% specificity with an area under the curve (AUC) of 0.95. CONCLUSION: Predicting the occurrence of RAIR-disease in DTC patients may allow clinicians to focus on systemic redifferentiating strategies and/or local treatments for metastatic lesions rather than pursuing with ineffective RAI-therapies.

Supraventricular cardiac conduction system exposure in breast cancer patients treated with radiotherapy and association with heart and cardiac chambers doses.

Purpose: To assess sinoatrial node (SAN) and atrioventricular node (AVN) doses for breast cancer (BC) patients treated with 3D-CRT and evaluate whether "large" cardiac structures (whole heart and four cardiac chambers) would be relevant surrogates. Material and methods: This single center study was based on 116 BCE patients (56 left-sided, 60 right-sided) treated with 3D-CRT without respiratory gating strategies and few IMN irradiations from 2009 to 2013. The heart, the left and right ventricles (LV, RV), the left and right atria (LA, RA) were contoured using multi-atlases for auto-segmentation. The SAN and the AVN were manually delineated using a specific atlas. Based on regression analysis, the coefficients of determination (R2) were estimated to evaluate whether "large" cardiac structures were relevant surrogates (R2 > 0.70) of SAN and AVN doses. Results: For left-sided BC, mean doses were: 3.60 ± 2.28 Gy for heart, 0.47 ± 0.24 Gy for SAN and 0.74 ± 0.29 Gy for AVN. For right-sided BC, mean heart dose was 0.60 ± 0.25 Gy, mean SAN dose was 1.57 ± 0.63 Gy (>85 % of patients with SAN doses > 1 Gy) and mean AVN dose was 0.51 ± 0.14 Gy. Among all "large" cardiac structures, RA appeared as the best surrogate for SAN doses (R2 > 0.80). Regarding AVN doses, the RA may also be an interesting surrogate for left-sided BC (R2 = 0.78), but none of "large" cardiac structures appeared as relevant surrogates among right-sided BC (all R2 < 0.70), except the LA for patients with IMN (R2 = 0.83). Conclusions: In BC patients treated 10 years ago with 3D-CRT, SAN and AVN exposure was moderate but could exceed 1 Gy to the SAN in many right-sided patients with no IMN-inclusion. The RA appeared as an interesting surrogate for SAN exposure. Specific conduction nodes delineation remains necessary by using modern radiotherapy techniques.

Risk of pacemaker implantation after radiotherapy for breast cancer: A study based on French nationwide health care database sample.

BACKGROUND: Among cardiac complications of breast cancer radiotherapy (BC RT), there are very limited data on arrhythmia and conduction disorders, in particular severe cases requiring permanent pacemaker implantation (PPMI). Therefore, this exploratory study aimed to evaluate the risk of PPMI for BC patients treated with RT, compared with the general population and with BC patients not treated with RT. METHODS: The study was performed on a 1/97 representative sample of the French health care database (EGB database). Adult women with a first BC treated with or without RT between 2008 and 2016 were included, followed until 2018, and de novo PPMI were identified. We compared the PPMI incidence in BC cohort relative to the general population with standardized incidence ratio (SIR) and evaluated the risk of PPMI in RT patients compared to patients without RT with a competing risk survival analysis. RESULTS: A total of 3853 BCE patients were included. Among BC patients treated with RT, 28 PPMI cases were observed compared with 13 expected cases, corresponding to a SIR of 2.18 [95% CI: 1.45-3.06]. For BC patients not treated with RT, the SIR was 1.01 [95% CI: 0.40-1.90]. Patients treated with RT showed a borderline significant higher risk of PPMI compared with those not treated with RT (subdistribution Hazard Ratio = 2.08, 95% CI 0.87-4.97, p = 0.09). CONCLUSIONS: Our exploratory findings indicate that, over the last decade in France, BC patients treated with RT appeared to be at higher risk of PPMI than general population. Further studies are needed to expand on this topic.

Occupational low-dose irradiation and cancer risk among medical radiation workers.

BACKGROUND: Medical workers are the largest group of workers occupationally exposed to low doses of ionizing radiation (IR) worldwide. AIMS: This review presents all the cohorts of medical workers exposed in the world and summarizes cancer risks associated with radiation exposure in this population. METHODS: Epidemiological studies on health professionals exposed to IR published from 1975 to 2019 were reviewed. Strength of evidence was assessed according to the modified Royal College of General Practitioners three-star system. RESULTS: Among the 16 epidemiological studies focusing on cancers from 11 cohorts among medical staff exposed to radiation, higher risks of cancer were observed for pre-1950 exposure and for medical workers who performed fluoroscopically guided interventional procedures or radionuclides procedures compared to those who did not. However, strength of evidence supporting the associations remains moderate as several methodological limits including the lack of dosimetry data, lifestyle factors and recent updates may obscure the link between medical occupational exposure and cancer occurrence. CONCLUSIONS: Excess risk of cancer is suspected for high and former exposures. The more highly exposed professions, i.e. interventional physicians and nuclear medicine workers, should be monitored carefully. Collaborative projects aiming to increase the quantity and quality of information of the studied populations would be a key point.

Dose distribution of the brain tissue associated with cognitive functions in high-grade glioma patients.

PURPOSE: The purpose of this prospective dosimetric study was to assess the dose distribution regarding the brain areas implied in cognitive functions using two approaches: volumetric modulated arc therapy (VMAT) and helical tomotherapy (HT). PATIENTS AND METHODS: Thirty-seven patients were treated using a dual-arc VMAT approach for supratentorial glioblastoma between 2016 and 2018. The total dose of 60Gy in 30 daily fractions was administered to the planning target volume (PTV). The brain structures that play an important role in cognitive physiology, such as the hippocampi, corpus callosum, cerebellum, subventricular zones (SVZ), were delineated. For each patient, a new treatment plan in HT was determined by a second medical physicist in a blindly fashion according to the same dose constraints and priorities. Statistical analyses were performed using the Wilcoxon-signed rank test. RESULTS: Conformity indexes remained similar with both techniques. The mean values were 0.96 (0.19-1.00) for VMAT and 0.98 (range, 0.84-1.00) for HT, respectively (P=0.73). Significant D50% reductions were observed with VMAT compared to HT: 14.6Gy (3.8-28.0) versus 17.4Gy (12.1-25.0) for the normal brain (P=0.014); 32.5Gy (10.3-60.0) versus 35.6Gy (17.1-58.0) for the corpus callosum (P=0.038); 8.1Gy (0.4-34.0) versus 12.8Gy (0.8-27.0) for the cerebellum (P<0.001), respectively. CONCLUSION: The VMAT approach seemed to improve the sparing of the key brain areas implied in cognitive functions without jeopardizing PTV coverage.

Patient radiation doses in paediatric interventional cardiology procedures: a review.

A large number of investigations into the radiation doses from x-ray guided interventional cardiology procedures in children have been carried out in recent years. A review was conducted of these studies, gathering data on kerma area product (P KA), fluoroscopic screening time (FT), air kerma, and estimates of effective dose and organ doses. The majority of studies focus on P KA and FT with no estimation of dose to the patient. A greater than ten-fold variation in average P KA was found between different studies, even where data were stratified by patient age or weight. Typical values of P KA were 0.6-10 Gy · cm2 (<1 year/10 kg), 1.5-30 Gy · cm2 (1-5 years), 2-40 Gy · cm2 (5-10 years), 5-100 Gy · cm2 (10-16 years) and 10-200 Gy · cm2 (>16 years). P KA was lowest for heart biopsy (0.3-10 Gy · cm2 for all ages combined) and atrial septostomy (0.4-4.0 Gy · cm2), and highest for pulmonary artery angioplasty (1.5-35 Gy · cm2) and right ventricular outflow tract dilatation (139 Gy · cm2). Most estimates of patient dose were in the form of effective dose (typically 3-15 mSv) which is of limited usefulness in individualised risk assessment. Few studies estimated organ doses. Despite advances in radiation protection, recent publications have reported surprisingly large doses, as represented by P KA and air kerma. There is little indication of a fall in these dose indicators over the last 15 years. Nor is there much suggestion of a fall in doses associated with the use of flat panel detectors, as opposed to image intensifiers. An assessment of the impact of radiation dose in the context of overall patient outcome is required.

Childhood CT scans and cancer risk: impact of predisposing factors for cancer on the risk estimates.

To investigate the role of cancer predisposing factors (PFs) on the associations between paediatric computed tomography (CT) scan exposures and subsequent risk of central nervous system (CNS) tumours and leukaemia. A cohort of children who underwent a CT scan in 2000-2010 in 23 French radiology departments was linked with the national childhood cancers registry and national vital status registry; information on PFs was retrieved through hospital discharge databases. In children without PF, hazard ratios of 1.07 (95% CI 0.99-1.10) for CNS tumours (15 cases) and 1.16 (95% CI 0.77-1.27) for leukaemia (12 cases) were estimated for each 10 mGy increment in CT x-rays organ doses. These estimates were similar to those obtained in the whole cohort. In children with PFs, no positive dose-risk association was observed, possibly related to earlier non-cancer mortality in this group. Our results suggest a modifying effect of PFs on CT-related cancer risks, but need to be confirmed by longer follow-up and other studies.

Follow-up of children exposed to ionising radiation from cardiac catheterisation: the Coccinelle study.

Cardiac catheterisation has become an essential tool in the diagnosis and treatment of children with a wide variety of congenital and acquired forms of cardiovascular disease. Despite the clear clinical benefit to the patient, radiation exposure from paediatric cardiac catheterisation procedures (CCPs) may be substantial. Given children's greater sensitivity to radiation and the longer life span during which radiation health effects can develop, an epidemiological cohort study, named Coccinelle or 'Ladybird' (French acronym for 'Cohorte sur le risque de cancer après cardiologie interventionnelle pédiatrique'), is carried out in France to evaluate the risks of leukaemia and solid cancers in this population. A total number of 8000 included children are expected. Individual CCP-related doses will be assessed for each child included in the cohort. For each CCP performed, dosimetric parameters (dose-area product, fluoroscopy time and total number of cine frames) are retrieved retrospectively. Organ doses, especially to the lung, the oesophagus and the thyroid, are calculated with PCXMC software. The cohort will be followed up through linkage with French paediatric cancer registries.

Are the studies on cancer risk from CT scans biased by indication? Elements of answer from a large-scale cohort study in France.

BACKGROUND: Recent epidemiological results suggested an increase of cancer risk after receiving computed tomography (CT) scans in childhood or adolescence. Their interpretation is questioned due to the lack of information about the reasons for examination. Our objective was to estimate the cancer risk related to childhood CT scans, and examine how cancer-predisposing factors (PFs) affect assessment of the radiation-related risk. METHODS: The cohort included 67,274 children who had a first scan before the age of 10 years from 2000 to 2010 in 23 French departments. Cumulative X-rays doses were estimated from radiology protocols. Cancer incidence was retrieved through the national registry of childhood cancers; PF from discharge diagnoses. RESULTS: During a mean follow-up of 4 years, 27 cases of tumours of the central nervous system, 25 of leukaemia and 21 of lymphoma were diagnosed; 32% of them among children with PF. Specific patterns of CT exposures were observed according to PFs. Adjustment for PF reduced the excess risk estimates related to cumulative doses from CT scans. No significant excess risk was observed in relation to CT exposures. CONCLUSIONS: This study suggests that the indication for examinations, whether suspected cancer or PF management, should be considered to avoid overestimation of the cancer risks associated with CT scans.

Local reference levels and organ doses from pediatric cardiac interventional procedures.

Interventional cardiology (IC) procedures can be responsible for relatively high radiation doses compared to conventional radiology especially for young patients. The aim of this study was to assess current exposure levels in a French reference centre of pediatric IC. Dosimetric data including dose area product (DAP), fluoroscopy time (FT) and number of cine frame (NF) were analysed taking into account patient weight. Doses to the lungs, esophagus, breast and thyroid were evaluated using anthropomorphic phantoms and thermoluminescent dosimeters. Finally, effective doses (E) were calculated using DAP and conversion factors calculated with PCXMC 2.0 software. 801 IC procedures performed between 2010 and 2011 were analysed. Large variations were observed for DAP, FT and NF values for a given procedure and a given weight group. The assessment of organ doses showed high levels of dose to the lungs and esophagus especially in new-born babies. For diagnostic procedures, E varied from 0.3 to 23 mSv with a mean value of 4.8 mSv and for therapeutic procedures, values ranged from 0.1 to 48.4 mSv with a mean value of 7.3 mSv. The highest values were recorded for angioplasty procedures (mean 13 mSv, range 0.6-48.4 mSv). The increasing use of IC in pediatric population stresses the need of setting up reference levels and keeping doses to children as low as possible.

[Role of French hospital claims databases from care units in epidemiological studies: the example of the "Cohorte Enfant Scanner" study]. / Utilisation des données du programme de médicalisation des systèmes d'information (PMSI) dans les études épidémiologiques : application à la Cohorte Enfant Scanner.

BACKGROUND: The "Cohorte Enfant Scanner", a study designed to investigate the risk of radiation-induced cancer after childhood exposure to CT (computed tomography) examinations, used clinical information contained in the "programme de médicalisation des systèmes d'information" (PMSI) database, the French hospital activities national program based upon diagnosis related groups (DRG). However, the quality and adequacy of the data for the specific needs of the study should be verified. The aim of our work was to estimate the percentage of the cohort's children identified in the PMSI database and to develop an algorithm to individualize the children with a cancer or a disease at risk of cancer from medical diagnoses provided by the DRGs database. METHODS: Of the 1519 children from the "Cohorte Enfant Scanner", who had had a CT scan in the radiology department of a university hospital in 2002, a cross linkage was performed with the DRGs database. All hospitalizations over the period 2002-2009 were taken into account. An algorithm was constructed for the items "cancer" and "disease at risk for cancer" on a sample of 150 children. The algorithm was then tested on the entire population. RESULTS: Overall, 74% of our population was identified in the DRGs database. The algorithm individualized cancer diagnoses with 91% sensitivity (95% confidence interval [95%CI]: 86%; 97%) and 98% specificity (95%CI: 97%; 99%) and 86% positive predictive value (95%CI: 80%; 93%). For the diagnosis of disease at risk for cancer, the sensitivity, specificity and positive predictive value were respectively 91% (95%CI: 84%; 98%), 94% (95%CI: 92%; 95%) and 52% (95%CI: 43%; 61%). CONCLUSION: The DRG database identified with excellent sensitivity and specificity children with diagnoses of cancer or disease at risk for cancer. Hence, potential confounding factors related to the disease of the child can be taken into account for analyses performed with the cohort.

[Diagnostic radiation exposure in children and cancer risk: current knowledge and perspectives]. / Expositions radiologiques à visée diagnostique pendant l'enfance et risque de cancer : bilan des connaissances et perspectives.

The question of the risk of cancer associated with postnatal diagnostic medical exposure involving ionizing radiation in childhood is particularly relevant at the moment given the growing use of diagnostic examinations, especially computed tomography scans, in children. Compared to adults, pediatric patients are more sensitive to radiation and have more years of life expectancy and therefore more years at risk of cancer occurrence as compared to adults. This paper provides a description of diagnostic x-ray exposure in children in France and summarizes epidemiologic studies on subsequent risk of cancer. Overall, this review, based on 12 case-control studies and 6 cohort studies, shows no significant association between exposure to medical diagnostic radiation exposure and childhood cancer risk. The methodological limitations of these studies are discussed. As the expected cancer risks are low, epidemiological studies require very large sample sizes and long periods of follow-up in addition to a good dosimetry assessment to enable quantitative risk estimation. New cohort studies of young patients who underwent CT scans are currently underway within the European EPI-CT project. In the meantime, continued efforts to reduce doses and the number of radiological examinations in children are needed, including adhering to the "as long as reasonably achievable" (Alara) principle.

Radiation exposure from CT in early childhood: a French large-scale multicentre study.

OBJECTIVES: The increasing use of CT scans in the paediatric population raises the question of a possible health impact of ionising radiation exposure associated with CT scans. The aim of this study was to describe the pattern of CT use in early childhood. METHODS: In 14 major French paediatric radiology departments, children undergoing at least 1 CT scan before age 5, between 2000 and 2006, were included. For each examination, absorbed organ doses were calculated. RESULTS: 43% of the 27 362 children in the cohort were aged less than 1 year during their first exposure, with 9% being aged less than 1 month. The mean number of examinations per child was 1.6 (range 1-43). The examinations included: head in 63% of the cases, chest in 21%, abdomen and pelvis in 8% and others in 8%. Brain and eye lenses received the highest cumulative doses from head examinations, with mean organ dose values of 22 mGy (maximum 1107 mGy) and 26 mGy (maximum 1392 mGy), respectively. The mean cumulative effective dose was 3.2 mSv (range 0.1-189 mSv). CONCLUSION: CT scan exposure in childhood is responsible for relatively high doses to radiosensitive organs. The rather large dose range according to the protocols used requires their optimisation. The cohort follow-up will study the risk of long-term radiation-induced cancer.

[Low doses of ionizing radiation and risk of cardiovascular disease: A review of epidemiological studies]. / Irradiations à faibles doses et risque de pathologie cardiovasculaire : revue des études épidémiologiques.

BACKGROUND: While cardiovascular risks associated with high level of ionizing radiation are well-established, long-term effects of low and medium levels of exposure, between 0 and 5 gray (Gy), on the cardiovascular system are debated. METHODS: Available literature was reviewed considering various populations, such as survivors of atomic bombs, nuclear workers, Chernobyl liquidators, radiologists and radiological technologists and patients exposed for medical reasons. RESULTS: A significant increased risk of cardiovascular diseases associated with low doses of ionizing radiation was observed in 13 studies among the 27 analyzed. The ischemic heart diseases risk was detailed in 16 studies and seven of them showed a significant increase. The cerebrovascular risk was significantly increased in five studies among the 12 considered. CONCLUSION: Some epidemiological and experimental data are clearly in favour of an increased cardiovascular risk associated with exposure to low doses. However, given the multifactorial origin of cardiovascular diseases and the lack of a clear pathophysiologic mechanism, epidemiological results have to be carefully interpreted. Further research should be conducted in this area.

Epidemiological studies of leukaemia in children and young adults around nuclear facilities: a critical review.

The existence of an increased risk of childhood leukaemia near nuclear installations is a recurrent issue. A review of the related epidemiological literature is presented here. Results for 198 nuclear sites throughout 10 countries were included in the review. In addition to local studies, 25 multi-site studies have been published for eight countries. A large variability was noticed in the quality of the data as well as in the definition of the study population and in the methods of analysis. Many studies present important limits that make the results difficult to interpret. The review confirms that some clusters of childhood leukaemia cases exist locally. However, results based on multi-site studies around nuclear installations do not indicate an increased risk globally. Many studies were launched to investigate possible origins of the observed clusters around specific sites, but up to now, none of the proposed hypotheses have explained them.

Usefulness of fine needle aspiration cytology in the diagnosis of loco-regional recurrence of differentiated thyroid carcinoma.

AIM: The aim of our study was to define the usefulness of fine needle aspiration cytology (FNAC) in the assessment of loco-regional recurrence of differentiated thyroid carcinoma (DTC). METHODS: Among 1182 consecutive patients treated and followed for DTC from 1992 to 2001, we retrospectively analysed 65 FNAC results of patients presenting a suspicion of loco-regional recurrence. Recurrences were proved at histology in 35 cases and by cervical radioiodine uptake on post-therapeutic WBS (whole body scan) in nine cases. RESULTS: Among the 44 recurrences, FNAC results were malignant, benign and unsatisfactory in 33, two and nine cases, respectively. For the diagnosis of malignancy, FNAC sensitivity was 94%, specificity 100%, positive predictive value 100% and negative predictive value 87%. In the 35 cases where divergent results between diagnostic WBS (37-111MBq (131)I) and Tg level were observed, FNAC assessed the final status in 22 cases (malignant and benign in 17 and five cases, respectively). Of the 12 non-functioning and non-secreting lesions, FNAC diagnosed malignancy in four of the five malignant cases and ruled out malignancy in all seven benign lesions. CONCLUSION: These results outline the interest of FNAC in the assessment of loco-regional recurrences of DTC, especially when classical follow-up tools such as WBS and/or Tg level are unable to detect the recurrences.

Advances in diagnostic practices affect thyroid cancer incidence in France.

OBJECTIVE: To analyse trends in diagnostic practices of thyroid diseases and to relate them to the increase in thyroid cancer incidence in France over time. DESIGN: From 1980 to 2000, a French retrospective multicentric (three endocrinology and three nuclear medicine centres) study of thyroid diseases was conducted on 20 consecutive unselected patients' records, sampled every 5 years in each centre. METHODS: Characteristics of the population and diagnosis procedures (thyroid ultrasonography (US), radionuclide scan, cytology and hormonal measurements) were described over time. Changing trends in operated patients and in cancer prevalence were analysed as well as the impact of practices on cancer incidence. RESULTS: The study included 471 patients (82% female, mean age 46.7, range 9-84 years), referred for nodular thyroid diseases (66.7%) or thyroid dysfunctions (33.3%). A significant increase in US (3 to 84.8%) and cytological practices (4.5 to 23%), and a decrease (89.4 to 49.6%) in radionuclide scan procedures were observed over time. Although the proportion of patients undergoing surgery remained constant (24.8%), the prevalence of cancer increased among operated patients from 12.5 to 37% (P=0.006). In a Cox's proportional hazard model stratified on the clinical characteristics of patients, only the cytological practice, regardless of its results, was significantly associated with the occurrence of cancer: relative risk (RR)=4.4 (95% confidence interval (CI): 1.1-16; P=0.04). CONCLUSIONS: From 1980 to 2000, a major evolution in clinical practices has led to the increase in thyroid cancer reported in France. Such changes in medical, as well as in surgical and pathological, practices must be taken into account in incidence measurement.

[Genital bleeding secondary to chemotherapy in adolescent girls]. / Métrorragies de l'adolescente au cours des chimiothérapies responsables de thrombopénies sévères.

UNLABELLED: Severe genital bleeding during adolescence can occur in the event of thrombocytopenia related to chemotherapy. Preventive hormonal treatment to induce therapeutic amenorrhea is recommended by some clinicians. Nevertheless, the adverse effects of oestroprogestative treatment, such as thromboembolic risk or hepatic toxicity, could potentialize the adverse effects of some chemotherapies. AIM OF THE STUDY: To assess retrospectively the risk of genital bleeding associated with thrombocytopenia secondary to chemotherapy in a population of adolescent girls for whom therapeutic amenorrhea was induced or not. PATIENTS AND METHODS: Among 140 girls, 12 to 18 years old, who were subjected to chemotherapy between 1991 and 1998, 24 girls presented at least one thrombocytopenic event (platelet level < 20 x 10(9) l(-1)) and were included. RESULTS: Six out of 24 adolescent girls received hormonal therapy to induce amenorrhea. Only one bleeding event was observed, in a girl who had not received preventive oestroprogestative treatment. Vital prognosis was preserved. Furthermore, spontaneous amenorrhea occurring before chemotherapy was observed in 33% of the patients and permanent secondary ovarian insufficiency in 17% of the patients. CONCLUSION: The risk of genital bleeding among adolescent population at risk of chemotherapy-induced thrombocytopenia is low. The high frequency of amenorrhea, secondary to weight loss or to chemotherapy toxicity, should raise questions as to the usefulness of preventive oestroprogestative treatment.

Survival and therapeutic modalities in patients with bone metastases of differentiated thyroid carcinomas.

Data for patients with bone metastases (BMs) of differentiated thyroid carcinoma (DTC) were retrospectively studied to identify factors associated with survival. We especially studied the impact of therapies. Among the 1977 patients followed for DTC in our department from 1958 to 1999, 109 (77 females and 32 males; age range, 20--87 yr) presented BMS: All patients except 1 underwent total thyroidectomy, followed by radioiodine therapy (> or =3.7 gigabecquerels) in 95 cases. Survival rates at 5 and 10 yr were 41% and 15%, respectively. Univariate analyses indicated that a young age at BM discovery (P < 0.005) and the discovery of BM as a revealing symptom of DTC (P < 0.05) were features significantly associated with improved survival as well as radioiodine therapy (P < 10(-4)) and BM complete surgery (P < 0.02). Using multivariate analysis, the detection of BMs as a revealing symptom of thyroid carcinoma (P < 0.0005), the absence of metastasis appearance in other organs than bones during the follow-up (P < 0.03), the cumulative dose of radioiodine therapy (P < 0.0001), and complete BM surgery in young patients (P < 0.04) appeared as independent prognostic features associated with an improved survival.