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Information on precision errors and the least significant change (LSC) of dual energy X-ray absorptiometry (DXA)-derived body composition estimates is scarce, particularly for the appendicular lean mass (ALM) and appendicular lean mass index (ALMI). Overnight fasting is recommended for body composition measurements but has not been well tolerated by some elderly patients. This study aimed to establish precision errors and LSC values of body composition estimates in all regions-including visceral adipose tissue (VAT) and ALM-and the ALMI to assess the effect of a small meal on body composition and to estimate the changes it incurred.Our institutional review board approved the study protocol. Altogether, 36 non-obese men aged ≥60 years, having given written informed consent, underwent body composition assessment after fasting overnight except for water. They underwent DXA scans three times, each time with repositioning (to simulate the clinical setting), the last after consuming a standardized meal (210-250 g and 200 cc of water).Precision errors and LSC values of DXA-derived body composition estimates in these elderly men tended to be higher than those in reports on younger subjects. Coefficients of variation (CVs (%)) of total bone mass (Tb.BMC) and total lean mass (Tb.LM) were1%, whereas those of total fat mass (Tb.FM) and total %fat mass (Tb.%FM) were2%, with LSCs of 45.8 g, 706.52 g, 731.4 g, and 1.15%, respectively. The CVs (LSC) of VAT, ALM, and ALMI were 8.9% (150.65 g), 0.93% (501 g), and 0.94% (0.19), respectively. After meal consumption, the mean changes in Tb.FM, Tb.BMC, and Tb.LM were -100, -8.2, and 440 g, respectively.Effects of a small meal on most parameters were trivial, including those for VAT, ALM, and ALMI, where changes were not statistically significant. None exceeded the LSC of ALM and ALMI, suggesting that a small meal is allowable before these measurements.

Background I-meta-iodo-benzylguanidine (I-mIBG) therapy has been used in treatment of for advanced neuroblastoma for many years with promising results. There are several studies regarding predictors and outcomes of I-mIBG therapies in relapsed/refractory neuroblastoma patients. Objective To identify the predictors and outcomes of I-mIBG treatment in relapsed/refractory neuroblastoma. Methods This study was a retrospective review of 22 patients with high risk stage IV relapsed/refractory neuroblastoma who received at least one cycle of I-mIBG therapy. Patient' characteristics, hematologic toxicity, scintigraphic semi-quantitative scoring, and overall survival were recorded. Factors predicting survival were analyzed. Results Twenty-two patients (50% male) with mean age of 3.7 years (4.8 months to 8.3 years) received I-mIBG therapies at an average of 3.8 and mean dose of 136 mCi (5032 MBq) per treatment. Most common acute hematologic toxicity was thrombocytopenia. Overall 5-year survival rate was 37% (95% confidence interval: 16.3-58.0) and median survival time was 2.8 year (95% confidence interval: 1.38-6.34). Patients with rising Curie score of ≥25% upon the second therapy were major determinants of overall survival with poorer response to treatment. At least three treatments of I-mIBG were needed to identify some degrees of survival prolongation (crude hazard ratio: P-value = 0.003). Age, sex, metastatic status, and baseline Curie scoring system were good predictors associated with survival. Seven patients (32%) demonstrated objective responses. Conclusion Despite multimodality therapy, high risk neuroblastoma had a propensity of treatment failure in terms of relapsed or refractory, with some objective responses after I-mIBG treatments. The declined or non-rising Curie score upon second post-treatment total body scan was an important predictor of survival and aided a decision whether or not to proceed with bone marrow transplantation.

Purpose This article aims to review and assess the post-operative management and treatment outcomes of papillary thyroid microcarcinoma (PTMC) in risk-stratified patients. Methods We retrospectively analyzed the data of PTMC patients who underwent thyroid surgery with or without radioactive iodine treatment (RAI) in a single center between January 2011 and December 2017. Demographic and clinicopathologic data were collected. Risk stratification according to the 2015 American Thyroid Association guideline was applied. Results Three hundred forty PTMC patients were included. Post-operative RAI was performed in 216/340 (63.53%) patients. In the non-RAI scenario, there were 122 low-risk and two intermediate-risk patients. In total, 261 (76.77%), 57 (16.76%), and 22 (6.47%) patients were classified as low, intermediate, and high risk, respectively. With a median follow-up time of 36 months (interquartile range: 23, 52), we found unfavorable outcomes (evidenced by imaging or out-of-range serum tumor marker levels: high thyroglobulin [Tg] or rising Tg antibody [TgAb] levels) in 8/340 (2.35%) patients, all of which received RAI. PTMC patients with unfavorable outcomes were stratified as low risk (4/261 [1.53%]), intermediate risk (1/57 [1.75%]), or high risk (3/22 [13.64%]). One death occurred in a patient with initial distant metastasis in the high-risk group. Initial high-risk stratification and initial stimulated Tg (of at least 10 ng/mL) were demonstrated as independent predictors for PTMC unfavorable outcomes (persistent or recurrent disease). Five patients with unfavorable outcomes (four with persistent disease and one with recurrent disease) had abnormal Tg or TgAb values despite unremarkable imaging findings. Moreover, 79/124 (63.71%) patients in the non-RAI scenario were only followed up with neck ultrasound. Conclusions In general, at least 98% of low-risk and intermediate-risk PTMC patients showed favorable outcomes without persistent or recurrent disease, defined by either imaging or serum tumor markers. Nevertheless, aggressive disease could occur in few PTMC patients. Decisions on post-operative management and follow-up may be guided by initial high-risk stratification and initial stimulated Tg levels (≥10 ng/mL) as independent predictors for PTMC unfavorable outcomes. Monitoring using both imaging and serum tumor markers is crucial and should be implemented for patients with PTMC.

Improper positioning is one of the factors that can lead to incorrect bone mineral density (BMD) results. This study aimed to assess the frequencies of erroneous positioning during three periods: before retraining of the technologists (BR), after retraining (AR), and at the current timepoint 8 years after retraining (C). The BMD images of the first 150 consecutive patients who underwent DXA of the lumbar spine and hip during each of the three periods were retrospectively reviewed. Patients were excluded if they had severe scoliosis, rendering proper positioning impossible. Each BMD image was assessed by an International Society of Clinical Densitometry certified clinical densitometrist who was blinded to the date of the initial examination. For the lumbar spine in the BR group, the criteria frequently not met were inclusion of both iliac crests (33.8%), straightness (30.3%), and midline positioning (20.4%); the respective frequencies were significantly reduced to 0.8%-5.6%, 2.1%-3.0%, and 0%-2.8% in the AR and C groups (p < 0.05). For the hip in the BR group, the criteria frequently not met were straightness (52.8%) and internal rotation (21.8%); the respective frequencies were significantly reduced to 0%-4.2% and 8.3%-8.4% in the AR and C groups (p < 0.05). Overall improper positioning in the BR group was 49.3% and 57.3% at the lumbar spine and the hip, respectively; the respective frequencies were reduced to 9.3% and 12.7% in the AR group, and to 2.7% and 7.3% in the C group. The least significant change values for the lumbar spine, femoral neck, and total hip also became smaller after retraining. Retraining the technologists improved patient positioning, as evidenced by the decreased frequencies of erroneous positioning and the improved least significant change values after the retraining.

Background Trabecular bone score (TBS), which has been proposed to be used in complementary with bone mineral density (BMD) to improve the assessment of fracture risk, is negatively associated with body mass index (BMI). The effect of soft tissue, which is expected to be thicker in subjects with high BMI, on TBS was studied using three scan types: Hologic with fast array mode (Hfa), Hologic with high definition mode (Hhd), and GE-Lunar iDXA. Methods A spine phantom provided by Hologic for routine quality control procedure was scanned using three scan types: Hfa, Hhd, and iDXA. The phantom was scanned with an overlying soft tissue equivalent material (bolus used in radiotherapy) of 0 (without), 1, 2.5, 3.5, 5 and 7.5 cm thick. For each setting, 30 acquisitions were performed in the same way as for the quality control procedure. TBS was calculated using TBS iNsight® software version 2.1 on the same regions of interest as those used for lumbar spine BMD. Results Mean ± SD TBS of the phantom (without overlying soft tissue) were 1.379 ± 0.018, 1.430 ± 0.009, and 1.423 ± 0.005 using Hfa, Hhd, and iDXA, respectively. A one-way repeated measures ANOVA showed that there were statistically differences in TBS due to different thicknesses of soft tissue equivalent materials for all three scan types (p

A 72-year-old woman with papillary thyroid cancer post-total thyroidectomy was referred for post-I treatment whole-body scan. Images revealed focal uptake within the gallbladder. Cholecystectomy was subsequently performed, and the pathology report showed well-differentiated adenocarcinoma. Given a history of papillary thyroid cancer, the iodine uptake was reasonably explained as metastasis; however, gallbladder metastasis was extremely infrequent. Literature described the incidental radioiodine retention in the gallbladder as false-positive findings, which can be normal variants or benign hepatobiliary conditions. Primary gallbladder malignancy could be counted for another possibility despite controversial mechanism of uptake.

PURPOSE The study aim was to assess factors that impact on the outcome of radioiodine therapy in patients diagnosed with differentiated thyroid carcinoma (DTC). MATERIALS AND METHODS We performed a retrospective cohort study on 256 patients with DTC who underwent thyroidectomy and received radioiodine therapy during December 2003 to January 2012. All patients were followed up for at least 1 year. They were considered disease- free by the criteria of the revised American Thyroid Association Management Guideline for Patients with Thyroid nodules and DTC (ATA guideline 2009). RESULTS On Cox univariate analysis, factors associated with disease-free status were age

Radioimmunotherapy (RIT) with 131-rituximab is a safe and effective treatment in patients with relapsed, refractory follicular lymphoma. The authors demonstrated the first case of 131-rituximab treatment in the patient with relapsed non-Hodgkin's lymphoma (NHL) in Thailand. There was no immediate complication after treatment. Impressive treatment response occurred.

We present a 25-year-old woman who has a diagnosis of differentiated thyroid cancer, a 2.5-cm papillary carcinoma in the right lobe, and presence of minimal extrathyroid invasion. 131I ablation and/or treatment of 150 mCi was given orally 3 months after total thyroidectomy. A fetus with radioiodine uptake in the fetal thyroid was unsuspectedly detected by SPECT/CT after 131I treatment.

s 487 Discussion and Conclusions: For a correct evaluation of bone mineral density and for the reproducibility follow-up scans we need consistent patient positioning, consistent scan analysis and exclusion of artifacts. 109 Central Measurements: Bone Density and Other CROSS CALIBRATION OF BONE MINERAL DENSITY VALUES AMONG THREE DUAL ENERGY X-RAY ABSORPTIOMETRY SYSTEMS Sasithorn Amnuaywattakorn, Faculty of Graduate Studies, Mahidol University Sasivimol Promma, Ramathibodi Hospital, Mahidol University; Kanungnij Thamnirat, Nuclear Medicine Unit; Chiraporn Tocharoenchai, Faculty of Medical Technology, Mahidol University; Chanika Sritara, Ramathibodi Hospital, Mahidol University Introduction: Monitoring BMD with different DXA systems is sometimes unavoidable. The manufacturer may provide a cross-calibration equation to convert BMD from one system to another. However, ISCD recommends the use of Generalize Least Significant Change (GLSC), 95% confidence interval of precision error between the two DXA systems. Aims: To generate the GLSC values among three DXA machines (Lunar Prodigy, Hologic Discovery A and Hologic Discovery W) and to compare these values with the errors from the cross-calibration equations provided by the manufacturer. Methods: The IRB approved the study protocol. The patients sent for BMD measurement who signed a consent form underwent BMD measurement at Nuclear Medicine Unit, Faculty of Medicine Ramathibodi Hospital, Bangkok, Thailand were included. The measurement was performed on the same day with all 3 DXA machines at L1-L4 vertebrae, femoral neck, and total hip. Each measurement was performed twice with repositioning in between. The analysis was performed with the ISCD cross-calibration calculating tool. Using the manufacturer’s cross-calibration equation provided by Hologic, the predicted BMD values at each site were calculated. Results: Thirty female patients with mean s.d. of age, weight and height of 55.2 8.6 years, 59.6 8.5 kg and 152.8 6.1 cm, respectively. The GLSCs for L1-L4 vertebrae, femoral neck, and total hip were 0.020-0.088 (Table 1). Most of the measurement sites had moderate to high percentages of patients with Table 1 GLSCs for L1-L4 Vertebrae, Femoral Neck, and Total Hip Among 3 DXA Machines GLSC (g/cm) L1-L4 Femoral Neck Total Hip Hologic Discovery A vs. Lunar Prodigy 0.066 0.088 0.066 Hologic Discovery W vs. Lunar Prodigy 0.064 0.076 0.070 Hologic Discovery W vs. Hologic Discovery A 0.020 0.074 0.062 Table 2 Prediction Errors Prediction Errors 95% CI (g/cm) % Patient With Prediction Error ! GLSC Hologic Discovery A BMD Predicted From Lunar Prodigy L1-L4 -0.025 (-0.006) 96.7 Femoral neck -0.003 0.027 93.3 Total hip -0.048 (-0.025) 76.7 Hologic Discovery W BMD Predicted From Lunar Prodigy L1-L4 -0.055 (-0.035) 83.3 Femoral neck -0.002 0.024 96.7 Total hip -0.036 (-0.013) 90.0 Hologic Discovery W BMD Predicted From Hologic Discovery A L1-L4 -0.035 (-0.023) 23.3 Femoral neck -0.011 0.009 96.7 Total hip -0.001 (-0.023) 96.7 Journal of Clinical Densitometry: Assessment of Skeletal Health prediction errors less than the site-specific GLSC values (Table 2), suggesting that the predictions were reasonable. However, only 23% of the patients had their predicted L1-L4 BMD errors less than the site-specific BMD due to relatively small GLSC at this site. Conclusions: The GLSC values among three DXA machines were presented. These values were greater than the conversion errors from the manufacturer’s equations. The results suggest that, if performing a cross-calibration study is not at all possible, the conversion equations may still provide some useful information for patient monitoring. 110 Central Measurements: Bone Density and Other CROSS-CALIBRATION OF BONE MINERAL DENSITY VALUES AMONG THREE DUAL ENERGY X-RAY ABSORPTIOMETRY SYSTEMS: COMPARISON BETWEEN CENTER-DERIVED AND MANUFACTURER’S EQUATIONS Sasithorn Amnuaywattakorn, Faculty of Graduate Studies (Medical Physics), Mahidol University Suchawadee Musikarat, Ramathibodi Hospital, Mahidol University; Sasivimol Promma, Ramathibodi Hospital, Mahidol University; Chirawat Utamakul, Ramathibodi Hospital, Mahidol University; Chiraporn Tocharoenchai, Faculty of Medical Technology, Mahidol University; Chanika Sritara, Ramathibodi Hospital, Mahidol University Introduction: When the replacement of the old DXA system with a new one is unplanned as in the case of irreparable of the old system, Generalized Least Significant Change (GLSC) cannot be obtained because it requires that the duplicate or triplicate BMD measurement with the old system. BMD monitoring may have to rely on a cross-calibration equation, which is provided by the manufacturer. Aims: The aims were to derive cross-calibration equations among three DXA machines (Lunar Prodigy, Hologic Discovery A and Hologic Discovery W) and to compare the BMD prediction errors from these equations with those from the manufacturer. Methods: The study protocol was approved by the IRB. The female patients sent for BMD measurement were invited. Thirty patients who gave written informed consent underwent BMD measurements using all 3 DXA machines at L1-L4 vertebrae, femoral neck, and total hip on the same day. Each measurement was performed twice with in-between repositioning. Cross-calibration equations were derived using linear regression analysis. The predicted BMDs were calculated from both our and manufacturer’s equations and the difference between the observed and the predicted BMDs were compared using pair t-test. Results: The means SDs of the 30 female patients’ age, weight and height were 55.2 8.6 years, 59.6 8.5 kg and 152.8 6.1 cm, respectively. As shown in Table 1, the derived cross-calibration equations were fitted the BMD data relatively well (R2 0.89-1.0). Table 1. Cross-calibration equations for L1-L4 vertebrae, femoral neck, and total hip among 3 DXA machinesThe differences between the predicted and the observed BMD (Table 2) were statistically significant at L1-L4 vertebrae and total hip (p!.05), where the manufacturer’s equations tended to Table 1 Cross-Calibration Equations for L1-L4 Vertebrae, Femoral Neck, and Total Hip Among 3 DXA Machines Lunar Prodigy vs. Hologic Discovery A R L1-L4 Hologic Discovery A 5 -0.008 + (0.875 x Lunar Prodigy) 0.97 Femoral neck Hologic Discovery A 5 -0.018 + (0.848 x Lunar Prodigy) 0.89 Total hip Hologic Discovery A 5 0.043 + (0.848 x Lunar Prodigy) 0.93 Lunar Prodigy vs. Hologic Discovery W L1-L4 Hologic Discovery W 5 -0.044 + (0.881 x Lunar Prodigy) 0.97 Femoral neck Hologic Discovery W 5 -0.056 + (0.900 x Lunar Prodigy) 0.92 Total hip Hologic Discovery W 5 -0.033 + (0.945 x Lunar Prodigy) 0.94 Hologic Discovery A vs. Hologic Discovery W L1-L4 Hologic Discovery W 5 -0.029 + (1 x Hologic Discovery A) 1.00 Femoral neck Hologic Discovery W 5 0.003 + (1.003 x Hologic Discovery A) 0.93 Total hip Hologic Discovery W 5 -0.057 + (1.086 x Hologic Discovery A) 0.95