Discordant effect of body mass index on bone mineral density and speed of sound

BACKGROUND: Increased BMI may affect the determination of bone mineral density (BMD) by dual X-ray absorptiometry (DXA) and speed of sound (SOS) measured across bones. Preliminary data suggest that axial SOS is less affected by soft tissue. The purpose of this study is to evaluate the effect of body mass index (BMI) on BMD and SOS measured along bones. METHODS: We compared axial BMD determined by DXA with SOS along the phalanx, radius and tibia in 22 overweight (BMI > 27 kg/m(2)), and 11 lean (BMI = 21 kg/m(2)) postmenopausal women. Serum bone specific alkaline phosphatase and urinary deoxypyridinoline excretion determined bone turnover. RESULTS: Mean femoral neck – but not lumbar spine BMD was higher in the overweight – as compared with the lean group (0.70 ± 0.82, -0.99 ± 0.52, P < 0.00001). Femoral neck BMD in the overweight – but not in the lean group highly correlated with BMI (R = 0.68. P < 0.0001). Mean SOS at all measurement sites was similar in both groups and did not correlate with BMI. Bone turnover was similar in the two study groups. CONCLUSIONS: The high BMI of postmenopausal women may result in spuriously high BMD. SOS measured along bones may be a more appropriate means for evaluating bones of overweight women

被服に対する意識及び行動とそれに影響する要因

博士（学術）神戸大

Assessment of the Stratos, a New Pencil-Beam Bone Densitometer: Dosimetry, Precision, and Cross Calibration

The goal of this study was to assess a new pencil-beam densitometer, the Stratos (Diagnostic Medical Systems, Pérols, France). Evaluation of the dosimetry and precision were done together with an in vivo cross-calibration study performed with the fan beam densitometer Discovery A (Hologic, Bedford, MA). The results indicated that the Stratos performed bone mineral density (BMD) measurements with a good precision, low radiation dose, and good agreement with the Discovery A. The air dose, measured by an ionization chamber, was 40\textgreekmGy. The effective dose was assessed using an anthropomorphic phantom and thermoluminescent detectors resulting in 1.96 and 0.31\textgreekmSv for a lumbar spine and proximal femur scan, respectively. The average scattered dose rate at a distance of 1m from the device was 1.06 and 1.21\textgreekmSv.h -1 in the lumbar spine and left proximal femur scan mode, respectively. For the precision evaluation, 30 patients underwent 2 lumbar spine and 2 proximal femur scans with repositioning after each scan. The percentage root-mean-square coefficient of variation was 1.22%, 1.38%, 2.11%, and 0.86% for the lumbar spine (L1-L4), lumbar spine (L2-L4), femoral neck, and total hip, respectively. The cross-calibration studies were done on 57 patients (60±9yr). Lumbar spine, left neck, and left total hip mean BMD were 3.10% lower and 11.94% and 8.83% higher, respectively, with the Stratos compared with the Discovery A. Cross-calibration equations were calculated with a correlation coefficient of 98% (p\textless0.01) for the lumbar spine (L2-L4), 94% (p\textless0.01) for the left neck, and 92% (p\textless0.01) for the left total hip. After standardizing the Stratos measures using the cross-calibration equations, LIN's concordance correlation coefficient was 0.98, 0.93, and 0.92 for the lumbar spine (L2-L4), left neck, and total hip, respectively. © 2011 The International Society for Clinical Densitometry

Faut-il rééduquer les coronariens au seuil ventilatoire ? [Is it necessary to rehabilitate coronary artery disease patients based on ventilatory threshold?]

To compare the efficiency of two programs of exercise-based rehabilitation that are different for heart rate (HR) training in patients with coronary artery disease: heart rate (HR) according to Karvonen formula (HR training =70% (max HR -rest HR) +rest HR) or HR recorded at the gas exchange ventilatory threshold (VT). TYPE: Controlled randomised clinical trial. Cardiovascular rehabilitation unit. Twenty-four male patients (54 +/-9.5 years old) with coronary artery disease were allocated at random to one of the two groups: KHR group (n =13) according to Karvonen formula (n =11), and VTHR group according to VT determined by exertion test (n =13). The exercised-based program was similar for all the patients, differing only in HR training (five daily sessions a week for four weeks). Assessment tests were performed at D1 and D28 and included: - an exercise test with measure of HR and double product (HR x blood pressure) at rest, submaximal and maximal intensity, with measure of oxygen consumption and gas exchanges at rest and at maximum exercise; - specific functional tests based on daily life activities; - dyspnea assessment at maximal intensity; - quality of life measurement by SF36. It was taken notice of the drugs taken by the patients, specially betablockers. At inclusion, the two groups were not different for parametric (age, body mass index) and non parametric values (medical or surgical treatment, comorbidity). Even though HR training was significantly different (p &lt;10(-6)), at the end of the program there was a significant increase of power and oxygen consumption at VT (+42.6%, p &lt;10(-6); +18.6%, p &lt;10(-5)) and at maximal intensity (+18.7 %, p &lt;10(-6); 14.2 %, p &lt;10(-5)), but differences between the two groups were not significant; double product was significantly lower at rest (-13.9 %, p &lt;10(-5)) and at submaximal exertion (-10.6 %, p &lt; 10(-3)). Yet, the two groups differed in HR, and HR increased in VTHR group and decreased in KHR, the difference being significant at VT (p =0.05), at submaximal (p =0.037) and maximal exercise (p = 0.05). Dyspnea at maximal intensity was higher in VTHR but SF36 values were not different. These results confirm the efficiency of cardiac training program according to Karvonen formula as to ventilatory threshold. However, there is a negative chronotropic effect of cardiac training according to Karvonen formula with a higher intensity, which corresponds to a less cardiac work for a same activity

Clinical implementation of PLANET® Dose for dosimetric assessment after [177Lu]Lu-DOTA-TATE: comparison with Dosimetry Toolkit® and OLINDA/EXM® V1.0

International audienceBackground The aim of this study was to compare a commercial dosimetry workstation (PLANET® Dose) and the dosimetry approach (GE Dosimetry Toolkit® and OLINDA/EXM® V1.0) currently used in our department for quantification of the absorbed dose (AD) to organs at risk after peptide receptor radionuclide therapy with [ 177 Lu]Lu-DOTA-TATE. Methods An evaluation on phantom was performed to determine the SPECT calibration factor variations over time and to compare the Time Integrated Activity Coefficients (TIACs) obtained with the two approaches. Then, dosimetry was carried out with the two tools in 21 patients with neuroendocrine tumours after the first and second injection of 7.2 ± 0.2 GBq of [ 177 Lu]Lu-DOTA-TATE (40 dosimetry analyses with each software). SPECT/CT images were acquired at 4 h, 24 h, 72 h and 192 h post-injection and were reconstructed using the Xeleris software (General Electric). The liver, spleen and kidneys masses and TIACs were determined using Dosimetry Toolkit® (DTK) and PLANET® Dose. The ADs were calculated using OLINDA/EXM® V1.0 and the Local Deposition Method (LDM) or Dose voxel-Kernel convolution (DK) on PLANET® Dose. Results With the phantom, the 3D calibration factors showed a slight variation (0.8% and 3.3%) over time, and TIACs of 225.19 h and 217.52 h were obtained with DTK and PLANET® Dose, respectively. In patients, the root mean square deviation value was 8.9% for the organ masses, 8.1% for the TIACs, and 9.1% and 7.8% for the ADs calculated with LDM and DK, respectively. The Lin’s concordance correlation coefficient was 0.99 and the Bland–Altman plot analysis estimated that the AD value difference between methods ranged from − 0.75 to 0.49 Gy, from − 0.20 to 0.64 Gy, and from − 0.43 to 1.03 Gy for 95% of the 40 liver, kidneys and spleen dosimetry analyses. The dosimetry method had a minor influence on AD differences compared with the image registration and organ segmentation steps. Conclusions The ADs to organs at risk obtained with the new workstation PLANET® Dose are concordant with those calculated with the currently used software and in agreement with the literature. These results validate the use of PLANET® Dose in clinical routine for patient dosimetry after targeted radiotherapy with [ 177 Lu]Lu-DOTA-TATE

Radioimmunotherapy of small solid tumours using monoclonal antibodies labelled with Auger electrons emitters

Introduction: The efficiency of 125I in killing tumour cells was compared in vitro and in vivo according to whether the emitter was localised at cell surface or within cytoplasm. Materials and methods: In in vitro experiments, the A-431 and SK-OV-3 carcinoma cell lines expressing the HER1/CEA and HER2/CEA receptors, respectively, were incubated for 2 days with either internalising (anti-HER1 or anti-HER2, respectively) or non-internalising (anti-CEA) 125I-labelled monoclonal antibodies (mAbs). Uptake of radioactivity per cell was measured and used for determining the mean nucleus irradiation dose according to the MIRD cellular approach. Relationship between clonogenic survival and the mean nucleus irradiation dose was next investigated using a linear mixed regression model. In vivo efficiency of 125I-labelled mAbs was also assessed in radioimmunotherapy of small solid tumours. Swiss nude mice bearing intraperitoneal A-431-xenografted tumours (<2mm) were then intravenously injected with 2 x 1mCi of either internalising or non-internalising 125I-mAbs. Tumour growth was followed by the bioluminescence technique. Uptake of radioactivity per organ was determined through a biodistribution assay and Monte carlo-calculated S-factors previously published for voxel-based mouse model were then used for dose assesment. Results: In vitro, we showed that toxicity of non-internalising mAbs was either greater or similar to the one observed with internalising mAbs suggesting the involvement of the cell membrane in radiation response to Auger electrons. In vivo, we confirmed the efficiency of 125I-labelled mAbs in the therapy of small solid tumours. Median survival time (MST) was about 19 days in non-treated mice. It was not statistically increased when the unlabelled non-internalising mAb was used (MST = 24 days). By contrast, unlabelled internalising mAb was shown to significantly increase survival (MST = 76 days, p<0.001). Labelling non-internalising mAb with 125I was accompanied by a significant increase in survival (MST = 67 days, p = 0.004) while it had no effect on efficiency of internalising mAb (MST = 77 days, p = 0.80). Irradiation doses delivered to organs and tumors were also assessed. Conclusion: This study demonstrates in vitro and in vivo the efficiency of non-internalising 125I-mAbs in radioimmunotherapy of small solid tumours. It indicates that the cell membrane is a sensitive target to Auger electrons

Extended liver venous deprivation before major hepatectomy induces marked and very rapid increase in future liver remnant function.

The aim of this study was to assess the safety and efficacy of extended liver venous deprivation (eLVD), i.e. combination of right portal vein embolisation and right (accessory right) and middle hepatic vein embolisation before major hepatectomy for future remnant liver (FRL) functional increase. eLVD was performed in non-cirrhotic patients referred for major hepatectomy in a context of small FRL (baseline FRL &lt;25% of the total liver volume or FRL function &lt;2.69%/min/m javax.xml.bind.JAXBElement@3c7ada5a ). All patients underwent javax.xml.bind.JAXBElement@33a16b03 Tc-mebrofenin hepatobiliary scintigraphy (HBS) and computed tomographic evaluations. Ten consecutive patients underwent eLVD before surgery for liver metastases (n = 8), Klatskin tumour (n = 1) and gallbladder carcinoma (n = 1). FRL function increased by 64.3% (range = 28.1-107.5%) at day 21. In patients with serial measurements, maximum FRL function was at day 7 (+65.7 ± 16%). The FRL volume increased by +53.4% at 7 days (+25 ± 8 cc/day). Thirty-one days (range = 22-45 days) after eLVD, 9/10 patients were resected. No post-hepatectomy liver failure was reported. Two grade II and one grade III complications (Dindo-Clavien classification) occurred. No patient died with-in 90 days following surgery. eLVD is safe and provides a marked and very rapid increase in liver function, unprecedented for an interventional radiology procedure. • eLVD is safe • eLVD provides a marked and very rapid increase in liver function • After eLVD, the FRL-F increased by 64.3% (28.1-107.5%) at day 21 • After eLVD, the maximum FRL-F was obtained at day 7 (+65.7 ± 16%) • After eLVD, the FRL volume increased by +53.4% at 7 days (+25 ± 8 cc/day)

Bone density reduction in various measurement sites in men and women with osteoporotic fractures of spine and hip: the European quantitation of osteoporosis study.

We have measured bone mineral density (BMD) using dual X-ray absorptiometry (DXA) of the spine and hip, spinal quantitative computed tomography (QCTspi), and peripheral radial quantitative computed tomography (pQCTrad) in 334 spine and 51 hip fracture patients. The standardized hip and spine BMD for each patient was calculated and compared with the combined reference ranges published previously, each densitometer having been cross-calibrated with the prototype European Spine Phantom (ESPp) or the European Forearm Phantom (EFP). Male and female fracture cases had similar BMD values after adjusting for body size, where appropriate. This suggests that the relationship between bone density (mass per unit volume) and fracture risk is similar between men and women. However, compared with age-matched controls, mean decreases in BMD ranged from 0.78 SD units (women with hip fracture, DXAspi) to 2.57 SD units (men with spine fractures, QCTspi). The proportion of spine and hip fracture patients falling below the cutoff for osteoporosis (T-score &lt;-2.5 SD) proposed by the World Health Organization (WHO) study group varied according to different BMD measurement procedures (range 18-94%). This finding suggests that the WHO definition requires different thresholds when used with non-DXA BMD measurement techniques. Receiver operator characteristic (ROC) analysis was used to compare measurement techniques for their ability to discriminate between cases and controls. Among DXA sites, the proximal femur was preferred when evaluating generalized bone loss, particularly in elderly people. An additional spinal BMD measurement may add clinical value if spine fracture risk assessment has a high priority. Both axial and peripheral QCT techniques performed comparably to DXA in spinal osteoporosis, so investigators and clinicians may use any of the three technologies with similar degrees of confidence for the diagnosis of generalized or site-specific bone loss providing straightforward clinical guidelines are followed