Prognostic value of (18)F-FDG PET/CT metabolic parameters in metastatic differentiated thyroid cancers.

PURPOSE: To evaluate the prognostic value of F-fluorodeoxyglucose positron emission tomography (FDG PET) with quantitative analysis using metabolic parameters in metastatic differentiated thyroid cancer (DTC). MATERIALS AND METHODS: The FDG-PET scans of 37 patients with metastatic DTC were studied retrospectively. The number of FDG-avid lesions, the SUVmax, the SULpeak of the lesion with the highest FDG uptake, the overall metabolic tumor volume (MTV), and the total lesion glycolysis (TLG) were measured. Curves of progression-free survival (Kaplan-Meier) and Cox univariate and multivariate analyses determined the prognostic factors for survival. RESULTS: Progression-free survival was better in patients with less than 10 FDG-avid lesions (P = 0.0089), the SUVmax less than 10 (P = 0.0026), the SULpeak less than 5 (P = 0.0004), and the TLG less than 154 (P = 0.0110).Cox analyses showed that only the result of the PET scan was predictive of survival (age, TNM stage, histology, and the I whole body radioiodine scan were not associated with prognosis). In the univariate analysis, prognostic factors for progression-free survival and overall survival were the SUVmax (P = 0.004; P = 0.018), the SULpeak (P = 0.001; P = 0.017), and the TLG (P = 0.014; P = 0.012). The number of FDG-avid lesions was significantly associated with progression-free survival (P = 0.012), but not the MTV. In the multivariate analysis, the number of FDG-avid lesions and the SULpeak were independent prognostic factors. CONCLUSIONS: FDG PET using metabolic parameters is a prognostic factor in metastatic DTC. It could improve the therapeutic management and follow-up of patients.

Impact on overall survival of radioactive iodine in low-risk differentiated thyroid cancer patients.

CONTEXT: American Thyroid Association and European Thyroid Association guidelines cannot recommend for or against radioactive iodine (RAI) ablation after surgery in low-risk differentiated thyroid cancer (DTC) patients. OBJECTIVES: The objective of the study was to assess the survival benefit of RAI for these patients. DESIGN: We identified 1298 DTC patients at low risk treated between 1975 and 2005. Logistic regressions were used to identify variables associated to RAI and to calculate the propensity score to receive RAI after surgery. We compared overall survival (OS) and disease-free survival (DFS) according to RAI with the log-rank tests and univariate and multivariate Cox analyses. Analyses stratified on propensity score were also performed. RESULTS: Median follow-up was 10.3 yr. Nine hundred eleven patients received RAI after surgery vs. 387 patients without RAI after surgery. Using univariate analysis, 10-yr OS was found to be 95.8% in patients without RAI after surgery vs. 94.6% in RAI after surgery (P = 0.006), and 10-yr DFS was found to be 93.1% vs. 88.7% (P = 0.001). All clinical factors except sex were significantly associated with RAI. Using multivariate Cox analyses, RAI was neither significantly nor independently associated with OS (P = 0.243) and DFS (P = 0.2659). After stratification on propensity score, Cox univariate analyses showed that OS did not differ according to RAI (P = 0.3524), with a hazard ratio for RAI of 0.75 (95% confidence interval 0.40-1.38). Similarly, DFS did not differ (P = 0.48) with a stratified univariate hazard ratio of 1.11 (95% confidence interval 0.73-1.70). CONCLUSION: With a long-term follow-up of 10.3 yr, we failed to prove any survival benefit of RAI after surgery in a large cohort of low-risk DTC patients.

Diabetes in acromegaly, prevalence, risk factors, and evolution: data from the French Acromegaly Registry.

OBJECTIVES: The French Acromegaly Registry records data of acromegalic patients' since 1992 in French, Belgian (Liège), and Swiss (Lausanne) centers. We studied the prevalence of diabetes in this population looking for risk factors. Patients from one of the centers (Reims) were then analyzed more thoroughly. METHODS: This study has been conducted on all the patients recorded from 1999 until 2004 (519 patients). Evolution of cohorts' was reassessed in 2009. Of the different variables recorded in the registry: age, sex, body mass index (BMI), duration of acromegaly, GH, IGF1 and prolactin levels, pituitary tumor size, hormonal deficiencies, presence, duration and treatment of diabetes, hypertension, and rheumatological disease were analyzed. RESULTS: The prevalence of diabetes in the registry was 22.3%. Diabetic patients were older and had a higher BMI. Compared with the data of the French Social Security, acromegalic patients showed a more precocious apparition of diabetes and prevalence was higher in each age group. Compared with non-diabetic acromegalic subjects, diabetic patients had a more prolonged evolution of acromegaly before diagnosis. The levels of GH and IGF1 were not significantly different between the two groups. Only hypertension was significantly more frequent in diabetic patients. CONCLUSIONS: In our population, the prevalence of diabetes was estimated to be 22.3%. The GH and IGF1 levels did not appear as predictive factors for the presence of diabetes. On the contrary, age, BMI, and hypertension were significant risk factors as in the general population of type 2 diabetics.