68Ga-DOTATATE PET/CT, 99mTc-HYNIC-octreotide SPECT/CT, and whole-body MR imaging in detection of neuroendocrine tumors: a prospective trial.

UNLABELLED: There are different metabolic imaging methods, various tracers, and emerging anatomic modalities to stage neuroendocrine tumor (NET). We aimed to compare NET lesion detectability among (99m)Tc-hydrazinonicotinamide (HYNIC)-octreotide (somatostatin receptor scintigraphy [SSRS]) SPECT/CT, (68)Ga-DOTATATE PET/CT, and whole-body diffusion-weighted MR imaging (WB DWI). METHODS: Nineteen consecutive patients (34-77 y old; mean, 54.3 ± 10.4 y old; 10 men and 9 women) underwent SSRS SPECT/CT, (68)Ga-DOTATATE PET/CT, and WB DWI. Images were acquired with a maximum interval of 3 mo between them and were analyzed with masking by separate teams. Planar whole-body imaging and SPECT/CT were performed from thorax to pelvis using a double-head 16-slice SPECT/CT scanner 4 h after injection of 111-185 MBq of (99m)Tc-HYNIC-octreotide. (68)Ga-DOTATATE PET/CT was performed from head to feet using a 16-slice PET/CT scanner 45 min after injection of 185 MBq of tracer. WB DWI was performed in the coronal plane using a 1.5-T scanner and a body coil. The standard method of reference for evaluation of image performance was undertaken: consensus among investigators at the end of the study, clinical and imaging follow-up, and biopsy of suggestive lesions. RESULTS: McNemar testing was applied to evaluate the detectability of lesions using (68)Ga-DOTATATE PET/CT in comparison to SSRS SPECT/CT and WB DWI: a significant difference in detectability was noted for pancreas (P = 0.0455 and P = 0.0455, respectively), gastrointestinal tract (P = 0.0455 and P = 0.0455), and bones (P = 0.0082 and P = 0.0082). Two unknown primary lesions were identified solely by (68)Ga-DOTATATE PET/CT. (68)Ga-DOTATATE PET/CT, SSRS SPECT/CT, and WB DWI demonstrated, respectively, sensitivities of 0.96, 0.60, and 0.72; specificities of 0.97, 0.99, and 1.00; positive predictive values of 0.94, 0.96, and 1.00; negative predictive values of 0.98, 0.83, and 0.88; and accuracies of 0.97, 0.86, and 0.91. CONCLUSION: (68)Ga PET/CT seems to be more sensitive for detection of well-differentiated NET lesions, especially for bone and unknown primary lesions. NET can be staged with (68)Ga-DOTATATE PET/CT. WB DWI is an efficient new method with high accuracy and without ionizing radiation exposure. SSRS SPECT/CT should be used only when (68)Ga-DOTATATE PET/CT and WB DWI are not available.

Follicular thyroid carcinoma metastasis to the internal jugular vein demonstrated by 131I SPECT/CT.

Cervical uptake detected by 131I whole body scintigraphy (131I-WBS) may be due to thyroid remnants or loco-regional metastases. We describe a patient with follicular carcinoma submitted to total thyroidectomy. 131I-WBS showed left cervical linear uptake and focal areas of uptake in the abdomen and pelvis. SPECT/CT images demonstrated a potential thrombus in the left jugular vein (confirmed by doppler neck ultrasound and MRI) as well as bone metastases. The patient was submitted to thrombectomy and histopathology confirmed metastasis of follicular carcinoma.

Accuracy of anthropometric measurements in estimating fat mass in individuals with 21-hydroxylase deficiency.

OBJECTIVE: The use of anthropometric measurements to estimate the percentage of body fat (%BF) is easy and inexpensive. However, the accuracy of these methods in patients with 21-hydroxylase deficiency (21OHD) has not been explored. The objective of this study was to evaluate the accuracy of skinfold-based models, body mass index (BMI), and waist circumference (WC) in estimations of %BF using dual-energy X-ray absorptiometry (DXA) as the reference method in individuals with 21OHD. METHODS: Fifty-four 21OHD patients (32 women and 22 men), aged 7 to 20 y, were recruited for the study. DXA was used to determine %BF; four predictive skinfold equations, BMI, and WC were assessed for accuracy in determining %BF. RESULTS: All predictive skinfold equations were highly associated (R, range: 0.82-0.89) with DXA %BF values. In women, BMI and WC showed moderate correlations (R = 0.69 for both BMI and WC) with DXA values. In contrast, among men there was a low explanatory power for BMI (13%) and WC (4%) and high errors (BMI, 6.9%; WC, 7.4%). All predictive equations significantly underestimated %BF (range of differences, -4.1 to -8.9) compared with DXA (women, 31.3 ± 6.1; men, 24.4 ± 7.3), and large limits of agreement were observed (range, -15.3 to 1.7 and -15.5 to 4.2 for women and men, respectively). CONCLUSION: In children and adolescents with 21OHD, %BF as estimated by skinfold measurements was associated more strongly with DXA-assessed %BF than both BMI and WC. However, still, the skinfold-based assessment underestimated DXA %BF and showed moderate agreement.

Body weight and composition in users of levonorgestrel-releasing intrauterine system.

BACKGROUND: There is little information about body weight and body composition (BC) among users of the levonorgestrel-releasing intrauterine system (LNG-IUS). The aim of this study was to evaluate body weight and BC in LNG-IUS users compared to users of the TCu380A intrauterine device (IUD). STUDY DESIGN: A prospective study was done with 76 new users of both contraceptive methods. Women were paired by age (±2 years) and body mass index (BMI, kg/m², ±2). Body weight and BC (% lean mass and % fat mass) were evaluated by a trained professional at baseline and at 1 year of contraceptive use. The BC measurements were obtained using Lunar DXA equipment. Weight and BC were evaluated in each woman at baseline and at 12 months and analyzed as the mean change within each woman. Then, the changes in weight and BC for each woman were calculated and then compared between LNG-IUS and TCu380A IUD users (paired data for each woman). The central-to-peripheral fat ratio was calculated by dividing trunk fat by the upper and lower limb fat. RESULTS: There were no significant differences at time of IUD insertion between LNG-IUS and TCu380A IUD users regarding age (mean±SD) (34.4±7.5 vs. 33.9±8.0 years), BMI (25.3±4.1 vs. 25.9±4.1) and number of pregnancies (1.9±0.2 vs. 1.7±0.2), respectively. Mean body weight gain of 2.9 kg was observed among LNG-IUS users at 12 months (p=.0012), whereas the body weight of TCu380A IUD users only increased by 1.4 kg (p=.067). There was no significant difference in body weight change between the two groups of users at 12 months. The variation in the central-to-peripheral fat ratio was the same between the two groups (-1.6% vs. -0.2%; p=.364). LNG-IUS users showed a 2.5% gain in fat mass (p=.0009) and a 1.4% loss of lean mass, whereas TCu380A IUD users showed a loss of 1.3% of fat mass (p=.159) and gain of 1.0% of lean mass (p=.120). TCu380A IUD users gained more lean mass than LNG-IUS users (p=.0270), although there was no significant difference between the two groups after 12 months of use. CONCLUSIONS: Although an increase in mean fat mass among LNG-IUS users at 12 months of use was observed, it should be noted that an increase of body weight was also observed in both groups after 1 year of insertion of the device. However, a study with a larger number of women and long-term evaluation is necessary to evaluate these body changes.

Tc-99m sestamibi thyroid imaging in patients on chronic amiodarone treatment: a comparison with Tc-99m pertechnetate imaging.

PURPOSE OF THE REPORT: To compare thyroid imaging using Tc-99m sestamibi with the standard Tc-99m pertechnetate scintigraphy in patients on chronic use of amiodarone. MATERIALS AND METHODS: A total of 23 patients on oral amiodarone for at least 4 months had thyroid scintigraphy and uptake measurement using Tc-99m pertechnetate and Tc-99m sestamibi. Thyroid function was evaluated by measuring serum concentrations of thyrotropin, free thyroxine, and free triiodothyronine, and antithyroglobulin and antithyroperoxidase antibodies. RESULTS: Ten of the 23 patients were euthyroid, 9 hypothyroid, and 4 hyperthyroid, with normal, increased, and decreased serum thyrotropin, respectively. All euthyroid patients had markedly decreased thyroid Tc-99m pertechnetate uptake and normal or slightly increased Tc-99m sestamibi uptake, except for one patient who had increased uptake of both radiotracers. One of the 4 hyperthyroid patients had Graves' disease and markedly increased thyroid uptake of both tracers. The other 3 hyperthyroid patients had normal or decreased Tc-99m pertechnetate uptake and increased Tc-99m sestamibi uptake. Differently than expected, all 9 hypothyroid patients had normal or increased uptake of both radiopharmaceuticals. CONCLUSIONS: This study suggests that Tc-99m sestamibi may be an alternative tracer for thyroid scintigraphy and uptake measurement of patients on chronic use of amiodarone. Tc-99m sestamibi seems to be better than Tc-99m pertechnetate for the scintigraphic evaluation of the thyroid of euthyroid and hyperthyroid patients.