Adipose tissue radiodensity: A new prognostic biomarker in people with multiple myeloma.

OBJECTIVES: Standard prognostic markers based on individual characteristics of individuals with multiple myeloma (MM) remain scarce. Body-composition features have often been associated with survival outcomes in different cancers. However, the association of adipose tissue radiodensity with MM prognosis has not yet, to our knowledge, been explored. METHODS: Computed tomography at the third lumbar vertebra was used for body-composition analysis, including adipose tissue radiodensity, in 91 people with MM. Additionally, fludeoxyglucose F 18 (18F-FDG) positron emission tomography was used to assess adipose tissue 18F-FDG uptake. Proinflammatory cytokine and adipokine levels were measured. RESULTS: Event-free survival and overall survival were both shorter in participants with high subcutaneous adipose tissue (SAT) radiodensity. Those in the highest SAT radiodensity tertile had an independently higher risk for both overall survival (hazard ratio, 4.55; 95% confidence interval, 1.26-16.44; Ptrend = 0.036) and event-free survival (hazard ratio, 3.08; 95% confidence interval, 1.02-9.27; Ptrend = 0.035). Importantly, higher SAT radiodensity was significantly correlated with increased 18F-FDG adipose tissue uptake and proinflammatory cytokine (tumor necrosis factor and interleukin-6) levels, and with decreased leptin levels. CONCLUSIONS: SAT radiodensity may serve as a biomarker to predict host-related metabolic and proinflammatory milieu, which ultimately correlates with MM prognosis.

Visceral adipose tissue glucose uptake is linked to prognosis in multiple myeloma patients: An exploratory study.

BACKGROUND & AIMS: The use of computerized tomography to opportunistically assess body composition has highlighted abnormalities such as low muscle mass and high adiposity may be hidden conditions in cancer patients. However, the role of skeletal muscle (SM), subcutaneous (SAT) and visceral (VAT) adipose tissue glucose uptake measured by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)-CT on patient prognostication is unclear. METHODS: Patients with multiple myeloma (MM) with satisfactory image frame for assessing body composition and for semi-quantification of SM, SAT and VAT glucose uptakes were included. Plasmatic pro-inflammatory cytokine and adipokine levels were measured. RESULTS: High VAT mean standardized uptake value (SUV) at baseline was associated with shorter event-free survival (EFS) (hazard ratio [HR]: 7.89; 95% confidence interval [CI], 1.58-39.30; P = 0.012) and overall survival (OS) (HR, 15.24; 95% CI, 2.69-86.30; P = 0.002) among patients with newly diagnosed MM, even after adjustment for covariates. The highest tertile of VAT SUV was significantly correlated with worse MM-EFS (HR for the highest vs the lowest tertile 3.71; 95% CI, 1.22-10.56; Ptrend = 0.035) and mortality (HR, 4.41; 95% CI, 1.28-12.77; Ptrend = 0.019). Notably, patients with higher VAT SUV presented with lower VAT area, VAT index, higher SAT SUV, and higher number of individuals with visceral obesity (all P < 0.01). Additionally, we found a negative correlation between VAT mean SUV with leptin (R2 = 0.20, P = 0.003); no correlations were detected between VAT mean SUV and resistin, tumor necrosis factor (TNF) or interleukin (IL)-6. CONCLUSIONS: Functional VAT activity estimated by 18F-FDG PET-CT is a relevant prognostic factor in MM patients, specifically, a higher VAT SUV might be an early biomarker of cancer cachexia in these patients.

Investigation of anisotropic fishing line-based phantom as tool in quality control of diffusion tensor imaging.

This work proposes a low-cost, fishing line-based phantom for quality control of diffusion tensor imaging (DTI). The device was applied to investigate the relationship between DTI indexes (DTIi) and imaging acquisition parameters. A Dyneema® fishing line phantom was built with fiber bundles of different thicknesses. DTI acquisitions were performed in a 3T magnetic resonance imaging scanner using an 8-channel and a 32-channel head coil. For each coil, the following acquisition parameters were changed, one at a time: diffusion sensitivity factor (b value), echo time, sensitivity encoding, voxel size, number of signal averages, and number of diffusion gradient directions (NDGD). DTIi including fractional anisotropy, relative anisotropy (RA), linear anisotropy (CL), and planar anisotropy (CP) were calculated for each image; the data were analyzed using the coefficient of variation (CV) and distributions of DTIi values. The 32-channel head coil presented higher CV values for the DTIi RA, CL, and CP when voxel size was changed. Using the phantom, dependences between diffusion-related parameters (b value and NDGD) and DTIi were also observed; the majority of these were for the smaller thickness fiber bundles. The device proved to be useful for the verification of the DTI performance over time.