Fat-free muscle area measured by magnetic resonance imaging predicts overall survival of patients undergoing radioembolization of colorectal cancer liver metastases

Compositional and Functional MRI of Skeletal Muscle: A Review

Due to its exceptional sensitivity to soft tissues, MRI has been extensively utilized to assess anatomical muscle parameters such as muscle volume and cross-sectional area. Quantitative Magnetic Resonance Imaging (qMRI) adds to the capabilities of MRI, by providing information on muscle composition such as fat content, water content, microstructure, hypertrophy, atrophy, as well as muscle architecture. In addition to compositional changes, qMRI can also be used to assess function for example by measuring muscle quality or through characterization of muscle deformation during passive lengthening/shortening and active contractions. The overall aim of this review is to provide an updated overview of qMRI techniques that can quantitatively evaluate muscle structure and composition, provide insights into the underlying biological basis of the qMRI signal, and illustrate how qMRI biomarkers of muscle health relate to function in healthy and diseased/injured muscles. While some applications still require systematic clinical validation, qMRI is now established as a comprehensive technique, that can be used to characterize a wide variety of structural and compositional changes in healthy and diseased skeletal muscle. Taken together, multiparametric muscle MRI holds great potential in the diagnosis and monitoring of muscle conditions in research and clinical applications. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 2.

Clinical impact of myosteatosis measured by magnetic resonance imaging on long-term outcomes of hepatocellular carcinoma after radical hepatectomy

AIMS

A variety of factors have been reported to affect long-term outcomes after radical resection of hepatocellular carcinoma (HCC). However, the indicators remain controversial. The purpose of this study was to evaluate the relationship between myosteatosis of the multifidus muscle and long-term outcomes after radical surgery for HCC.

METHODS

We retrospectively analyzed clinicopathological data for 187 patients with HCC who underwent radical surgery at Tokushima University between January 2009 and December 2020 and measured the density of fat in the multifidus muscle at L3 on their preoperative magnetic resonance images (MRI). Associations of myosteatosis and clinicopathological factors with long-term outcomes were evaluated.

RESULTS

The patients were divided into a myosteatosis-negative group (n = 122) and a myosteatosis-positive group (n = 65). The cancer-specific survival rate after hepatectomy was significantly worse in the myosteatosis-positive group than in the myosteatosis-negative group (p = 0.03). Univariate analysis identified multiple tumors, stage III/IV disease, an alfa-fetoprotein level ≥ 10 ng/ml, PIVKA-II ≥ 400 AU/ml, vp(+) status, and myosteatosis to be prognostic factors for cancer-specific survival. Multivariate analysis revealed multiple tumors, an alfa-fetoprotein level ≥ 10 ng/ml, and myosteatosis to be independent prognostic factors.

CONCLUSIONS

Myosteatosis measured by MRI is a simple and useful predictor of the long-term outcome after radical surgery for HCC.

Computed tomography derived cervical fat-free muscle fraction as an imaging-based outcome marker in patients with acute ischemic stroke: a pilot study

BACKGROUND

Outcome assessment in stroke patients is essential for evidence-based stroke care planning. Computed tomography (CT) is the mainstay of diagnosis in acute stroke. This study aimed to investigate whether CT-derived cervical fat-free muscle fraction (FFMF) as a biomarker of muscle quality is associated with outcome parameters after acute ischemic stroke.

METHODS

In this retrospective study, 66 patients (mean age: 76 ± 13 years, 30 female) with acute ischemic stroke in the anterior circulation who underwent CT, including CT-angiography, and endovascular mechanical thrombectomy of the middle cerebral artery between August 2016 and January 2020 were identified. Based on densitometric thresholds, cervical paraspinal muscles covered on CT-angiography were separated into areas of fatty and lean muscle and FFMF was calculated. The study cohort was binarized based on median FFMF (cutoff value: < 71.6%) to compare clinical variables and outcome data between two groups. Unpaired t test and Mann-Whitney U test were used for statistical analysis.

RESULTS

National Institute of Health Stroke Scale (NIHSS) (12.2 ± 4.4 vs. 13.6 ± 4.5, P = 0.297) and modified Rankin scale (mRS) (4.3 ± 0.9 vs. 4.4 ± 0.9, P = 0.475) at admission, and pre-stroke mRS (1 ± 1.3 vs. 0.9 ± 1.4, P = 0.489) were similar between groups with high and low FFMF. NIHSS and mRS at discharge were significantly better in patients with high FFMF compared to patients with low FFMF (NIHSS: 4.5 ± 4.4 vs. 9.5 ± 6.7; P = 0.004 and mRS: 2.9 ± 2.1 vs.3.9 ± 1.8; P = 0.049). 90-day mRS was significantly better in patients with high FFMF compared to patients with low FFMF (3.3 ± 2.2 vs. 4.3 ± 1.9, P = 0.045).

CONCLUSION

Cervical FFMF obtained from routine clinical CT might be a new imaging-based muscle quality biomarker for outcome prediction in stroke patients.

Combination of Fat-Free Muscle Index and Total Spontaneous Portosystemic Shunt Area Identifies High-Risk Cirrhosis Patients

Background

Sarcopenia and spontaneous portosystemic shunts (SPSSs) are common complications of liver cirrhosis, and both are associated with higher rates of hepatic encephalopathy (HE) development in these patients. This study aimed to evaluate the simultaneous impact of skeletal muscle mass and spontaneous portosystemic shunting, measured from routine diagnostic CT on outcomes in patients with liver cirrhosis.

Methods

Retrospective analysis of patients with cirrhosis. Skeletal muscle mass [including fat-free muscle index (FFMI) as a surrogate for sarcopenia] and total cross-sectional spontaneous portosystemic shunt area (TSA) were quantified from CT scans. The primary endpoint was the development of HE, while the secondary endpoint was 1-year mortality.

Results

One hundred fifty-six patients with liver cirrhosis were included. Patients with low (L-) FFMI and large (L-)TSA showed higher rates of HE development. In multivariable analysis, L-FFMI and L-TSA were independent predictors of HE development (L-FFMI HR = 2.69, CI 1.22–5.93; L-TSA, HR = 2.50, CI = 1.24–4.72) and 1-year mortality (L-FFMI, HR = 7.68, CI 1.75–33.74; L-TSA, HR = 3.05, CI 1.32–7.04). The simultaneous presence of L-FFMI and L-TSA exponentially increased the risk of HE development (HR 12.79, CI 2.93–55.86) and 1-year mortality (HR 13.66, CI 1.75–106.50). An easy sequential algorithm including FFMI and TSA identified patients with good, intermediate, and poor prognoses.

Conclusion

This study indicates synergy between low skeletal muscle mass and large TSA to predict exponentially increased risk of HE development and mortality in liver cirrhosis. Simultaneous screening for sarcopenia and TSA from routine diagnostic CT may help to improve the identification of high-risk patients using an easy-to-apply algorithm.

Clinical Trial registration

[ClinicalTrials.gov], identifier [NCT03584204].

Assessment of anterior thigh muscle size and fat infiltration using single-slice CT imaging versus automated MRI analysis in adults

OBJECTIVES

We examined the longitudinal and cross-sectional relationship between automated MRI-analysis and single-slice axial CT imaging for determining muscle size and muscle fat infiltration (MFI) of the anterior thigh.

METHODS

Twenty-two patients completing sex-hormone treatment expected to result in muscle hypertrophy (n = 12) and atrophy (n = 10) underwent MRI scans using 2-point Dixon fat/water-separated sequences and CT scans using a system operating at 120 kV and a fixed flux of 100 mA. At baseline and 12 months after, automated volumetric MRI analysis of the anterior thigh was performed bilaterally, and fat-free muscle volume and MFI were computed. In addition, cross-sectional area (CSA) and radiological attenuation (RA) (as a marker of fat infiltration) were calculated from single slice axial CT-images using threshold-assisted planimetry. Linear regression models were used to convert units.

RESULTS

There was a strong correlation between MRI-derived fat-free muscle volume and CT-derived CSA (R = 0.91), and between MRI-derived MFI and CT-derived RA (R = -0.81). The 95% limits of agreement were ±0.32 L for muscle volume and ±1.3% units for %MFI. The longitudinal change in muscle size and MFI was comparable across imaging modalities.

CONCLUSIONS

Both automated MRI and single-slice CT-imaging can be used to reliably quantify anterior thigh muscle size and MFI.

ADVANCES IN KNOWLEDGE

This is the first study examining the intermodal agreement between automated MRI analysis and CT-image assessment of muscle size and MFI in the anterior thigh muscles. Our results support that both CT- and MRI-derived measures of muscle size and MFI can be used in clinical settings.

Deep Learning-Based Body Composition Analysis Predicts Outcome in Melanoma Patients Treated with Immune Checkpoint Inhibitors

Previous studies suggest an impact of body composition on outcome in melanoma patients. We aimed to determine the prognostic value of CT-based body composition assessment in patients receiving immune checkpoint inhibitor therapy for treatment of metastatic disease using a deep learning approach. One hundred seven patients with staging CT examinations prior to initiation of checkpoint inhibition between January 2013 and August 2019 were retrospectively evaluated. Using an automated deep learning-based body composition analysis pipeline, parameters for estimation of skeletal muscle mass (skeletal muscle index, SMI) and adipose tissue compartments (visceral adipose tissue index, VAI; subcutaneous adipose tissue index, SAI) were derived from staging CT. The cohort was binarized according to gender-specific median cut-off values. Patients below the median were defined as having low SMI, VAI, or SAI, respectively. The impact on outcome was assessed using the Kaplan-Meier method with log-rank tests. A multivariable logistic regression model was built to test the impact of body composition parameters on 3-year mortality. Patients with low SMI displayed significantly increased 1-year (25% versus 9%, p = 0.035), 2-year (32% versus 13%, p = 0.017), and 3-year mortality (38% versus 19%, p = 0.016). No significant differences with regard to adipose tissue compartments were observed (3-year mortality: VAI, p = 0.448; SAI, p = 0.731). On multivariable analysis, low SMI (hazard ratio (HR), 2.245; 95% confidence interval (CI), 1.005-5.017; p = 0.049), neutrophil-to-lymphocyte ratio (HR, 1.170; 95% CI, 1.076-1.273; p < 0.001), and Karnofsky index (HR, 0.965; 95% CI, 0.945-0.985; p = 0.001) remained as significant predictors of 3-year mortality. Lowered skeletal muscle index as an indicator of sarcopenia was associated with worse outcome in patients with metastatic melanoma receiving immune checkpoint inhibitor therapy.

Association between single-slice and whole heart measurements of epicardial and pericardial fat in cardiac MRI

BACKGROUND

Epicardial (ECF) and pericardial fat (PCF) are important prognostic markers for various cardiac diseases. However, volumetry of the fat compartments is time-consuming.

PURPOSE

To investigate whether total volume of ECF and PCF can be estimated by axial single-slice measurements and in a four-chamber view.

MATERIAL AND METHODS

A total of 113 individuals (79 patients and 34 healthy) were included in this retrospective magnetic resonance imaging (MRI) study. The total volume of ECF and PCF was determined using a 3D-Dixon sequence. Additionally, the area of ECF and PCF was obtained in single axial layers at five anatomical landmarks (left coronary artery, right coronary artery, right pulmonary artery, mitral valve, coronary sinus) of the Dixon sequence and in a four-chamber view of a standard cine sequence. Pearson's correlation coefficient was calculated between the total volume and each single-slice measurement.

RESULTS

Axial single-slice measurements of ECF and PCF correlated strongly with the total fat volumes at all landmarks (ECF: r  =  0.85-0.94, P < 0.001; PCF: r  =  0.89-0.94, P < 0.001). The best correlation was found at the level of the left coronary artery for ECF and PCF (r  =  0.94, P < 0.001). Correlation between single-slice measurement in the four-chamber view and the total ECF and PCF volume was lower (r  =  0.75 and r  =  0.8, respectively, P < 0.001).

CONCLUSION

Single-slice measurements allow an estimation of ECF and PCF volume. This time-efficient analysis allows studies of larger patient cohorts and the opportunistic determination of ECF/PCF from routine examinations.

End-to-end automated body composition analyses with integrated quality control for opportunistic assessment of sarcopenia in CT

OBJECTIVES

To develop a pipeline for automated body composition analysis and skeletal muscle assessment with integrated quality control for large-scale application in opportunistic imaging.

METHODS

First, a convolutional neural network for extraction of a single slice at the L3/L4 lumbar level was developed on CT scans of 240 patients applying the nnU-Net framework. Second, a 2D competitive dense fully convolutional U-Net for segmentation of visceral and subcutaneous adipose tissue (VAT, SAT), skeletal muscle (SM), and subsequent determination of fatty muscle fraction (FMF) was developed on single CT slices of 1143 patients. For both steps, automated quality control was integrated by a logistic regression model classifying the presence of L3/L4 and a linear regression model predicting the segmentation quality in terms of Dice score. To evaluate the performance of the entire pipeline end-to-end, body composition metrics, and FMF were compared to manual analyses including 364 patients from two centers.

RESULTS

Excellent results were observed for slice extraction (z-deviation = 2.46 ± 6.20 mm) and segmentation (Dice score for SM = 0.95 ± 0.04, VAT = 0.98 ± 0.02, SAT = 0.97 ± 0.04) on the dual-center test set excluding cases with artifacts due to metallic implants. No data were excluded for end-to-end performance analyses. With a restrictive setting of the integrated segmentation quality control, 39 of 364 patients were excluded containing 8 cases with metallic implants. This setting ensured a high agreement between manual and fully automated analyses with mean relative area deviations of ΔSM = 3.3 ± 4.1%, ΔVAT = 3.0 ± 4.7%, ΔSAT = 2.7 ± 4.3%, and ΔFMF = 4.3 ± 4.4%.

CONCLUSIONS

This study presents an end-to-end automated deep learning pipeline for large-scale opportunistic assessment of body composition metrics and sarcopenia biomarkers in clinical routine.

KEY POINTS

• Body composition metrics and skeletal muscle quality can be opportunistically determined from routine abdominal CT scans. • A pipeline consisting of two convolutional neural networks allows an end-to-end automated analysis. • Machine-learning-based quality control ensures high agreement between manual and automatic analysis.

Imaging modalities for diagnosis and monitoring of cancer cachexia

Cachexia, a multifactorial wasting syndrome, is highly prevalent among advanced-stage cancer patients. Unlike weight loss in healthy humans, the progressive loss of body weight in cancer cachexia primarily implicates lean body mass, caused by an aberrant metabolism and systemic inflammation. This may lead to disease aggravation, poorer quality of life, and increased mortality. Timely detection is, therefore, crucial, as is the careful monitoring of cancer progression, in an effort to improve management, facilitate individual treatment and minimize disease complications. A detailed analysis of body composition and tissue changes using imaging modalities—that is, computed tomography, magnetic resonance imaging, (¹⁸F) fluoro-2-deoxy-d-glucose (¹⁸FDG) PET and dual-energy X-ray absorptiometry—shows great premise for charting the course of cachexia. Quantitative and qualitative changes to adipose tissue, organs, and muscle compartments, particularly of the trunk and extremities, could present important biomarkers for phenotyping cachexia and determining its onset in patients. In this review, we present and compare the imaging techniques that have been used in the setting of cancer cachexia. Their individual limitations, drawbacks in the face of clinical routine care, and relevance in oncology are also discussed.

Temporal Muscle Thickness is an Independent Prognostic Biomarker in Patients with Glioma: Analysis of 261 Cases

Purpose

Temporal muscle thickness (TMT) has been proposed as a novel surrogate marker for skeletal muscle mass in head and neck malignancies. This study investigated the TMT prognostic relevance with gliomas and evaluated the influence of TMT values on survival in patients with gliomas of different grades and IDH subtypes.

Methods

The patients’ TMT was measured on contrast-enhanced T1-weighted magnetic resonance images before surgical treatment. Patients were divided into two cohorts based on their median TMT values. The Kaplan–Meier curve was used to compute the overall survival (OS) of different categories and all gliomas. Univariate and multivariate Cox regression analyses were conducted to assess the association between OS and TMT, hematological markers, and other clinical factors in glioma patients. Moreover, the clinical diagnostic efficiency of single and combination biomarkers was evaluated using receiver operating characteristic curve analysis.

Results

We retrospectively analyzed 261 patients with newly diagnosed glioma between November 2016 and May 2020 at Hunan Cancer Hospital. Cox analysis indicated that higher TMT (HR 0.286, P< 0.001) and higher KPS score (HR 0.629, P= 0.012) were protective prognostic factors and IDH wildtype status (HR 2.946, P< 0.001), RDW > 12.6 (HR 1.513, P= 0.036), and NLR > 4 (HR 1.560, P= 0.042) were poor prognostic factors for gliomas. Subsequently, patients with thicker TMT were found to have significantly better overall survival (P<0.001) than patients with thinner TMT among WHO III and WHO IV grade and patients with or without IDH mutation. TMT was considered a better single biomarker than recently prevalent hematological biomarkers for predicting high-grade [0.856 (0.797–0.916)] and IDH- wild-type [0.864 (0.786–0.941)] gliomas.

Conclusion

This study suggests that TMT is a positive biomarker for clinical prognosis in gliomas and that patients with thicker TMT have greater overall survival for gliomas of different grades and IDH subtypes.

Contrast-Enhanced Computed Tomography Does Not Provide More Information about Sarcopenia than Unenhanced Computed Tomography in Patients with Pancreatic Cancer

Objective

The aim of this study was to understand whether enhanced CT can provide more information than unenhanced CT on diagnosis of sarcopenia.

Materials and Methods

We reviewed the enhanced CT data of 45 patients of pancreatic cancer. Manual tracing of the psoas muscles was used for measuring the cross-sectional muscle areas and attenuation at umbilicus level; afterwards, PMI, PMD, and Δ PMD were calculated.

Results

In the unenhanced scanning, arterial, venous, and parenchymal phases of enhanced CT, PMI values were 6.905 ± 2.170, 6.886 ± 2.195, 6.923 ± 2.239, and 6.866 ± 2.218, respectively, and the difference was not statistically significant. The PMD values at different phases were 34.311 ± 7.535, 37.487 ± 7.118, 40.689 ± 7.116, and 42.989 ± 7.745, respectively, which were gradually increased, and the difference was statistically significant. Meanwhile, the PMD of arterial phase, venous phase, and parenchyma phase showed a linear correlation with PMD of unenhanced scanning phase. 31 patients had low PMD and 14 had normal PMD during the unenhanced scanning phase. With the addition of contrast agent, ΔPMD values increased faster in the low PMD group than in the normal PMD group during the venous and parenchymal phases (7.048 ± 3.067 vs 4.893 ± 2.558; 9.581 ± 3.033 vs 6.679 ± 2.621; p < 0.05), which made the gap between PMD after contrast-enhancement vs. unenhanced scanning smaller.

Conclusion

The use of contrast agent has no effect on the manually measured PMI values but can change the results of PMD. This change makes the difference of PMD in different enhancement phases smaller than that in plain scan phase and furthermore increases the examination cost; therefore, it is not recommended to use enhanced CT routinely with fixed dose administration of contrast agent for patients' assessment of PMI and PMD.

Radiologic Definition of Sarcopenia in Chronic Liver Disease

Sarcopenia is prevalent in patients with chronic liver disease, and affected patients tend to have worse clinical outcomes and higher mortality. However, relevant analyses are limited by heterogeneity in the definition of sarcopenia and in the methodological approaches in assessing it. We reviewed several radiologic methods for sarcopenia in patients with chronic liver disease. Dual energy X-ray absorptiometry (DXA) can measure muscle mass, but it is difficult to evaluate muscle quality using this technique. Computed tomography, known as the gold standard for diagnosing sarcopenia, enables the objective measurement of muscle quantity and quality. The third lumbar skeletal muscle index (L3 SMI) more accurately predicted the mortality of subjects than the psoas muscle index (PMI). Few studies have evaluated the sarcopenia of chronic liver disease using ultrasonography and magnetic resonance imaging, and more studies are needed. Unification of the measurement method and cut-off value would facilitate a more systematic and universal prognosis evaluation in patients with chronic liver disease.

Radiologic Definition of Sarcopenia in Chronic Liver Disease

Sarcopenia is prevalent in patients with chronic liver disease, and affected patients tend to have worse clinical outcomes and higher mortality. However, relevant analyses are limited by heterogeneity in the definition of sarcopenia and in the methodological approaches in assessing it. We reviewed several radiologic methods for sarcopenia in patients with chronic liver disease. Dual energy X-ray absorptiometry (DXA) can measure muscle mass, but it is difficult to evaluate muscle quality using this technique. Computed tomography, known as the gold standard for diagnosing sarcopenia, enables the objective measurement of muscle quantity and quality. The third lumbar skeletal muscle index (L3 SMI) more accurately predicted the mortality of subjects than the psoas muscle index (PMI). Few studies have evaluated the sarcopenia of chronic liver disease using ultrasonography and magnetic resonance imaging, and more studies are needed. Unification of the measurement method and cut-off value would facilitate a more systematic and universal prognosis evaluation in patients with chronic liver disease.

CT fatty muscle fraction as a new parameter for muscle quality assessment predicts outcome in venovenous extracorporeal membrane oxygenation

Impaired skeletal muscle quality is a major risk factor for adverse outcomes in acute respiratory failure. However, conventional methods for skeletal muscle assessment are inapplicable in the critical care setting. This study aimed to determine the prognostic value of computed tomography (CT) fatty muscle fraction (FMF) as a biomarker of muscle quality in patients undergoing extracorporeal membrane oxygenation (ECMO). To calculate FMF, paraspinal skeletal muscle area was obtained from clinical CT and separated into areas of fatty and lean muscle based on densitometric thresholds. The cohort was binarized according to median FMF. Patients with high FMF displayed significantly increased 1-year mortality (72.7% versus 55.8%, P = 0.036) on Kaplan–Meier analysis. A multivariable logistic regression model was built to test the impact of FMF on outcome. FMF was identified as a significant predictor of 1-year mortality (hazard ratio per percent FMF, 1.017 [95% confidence interval, 1.002–1.033]; P = 0.031), independent of anthropometric characteristics, Charlson Comorbidity Index, Simplified Acute Physiology Score, Respiratory Extracorporeal Membrane Oxygenation Survival Prediction Score, and duration of ECMO support. To conclude, FMF predicted 1-year mortality independently of established clinical prognosticators in ECMO patients and may have the potential to become a new muscle quality imaging biomarker, which is available from clinical CT.

Prognostic relevance of temporal muscle thickness as a marker of sarcopenia in patients with glioblastoma at diagnosis

OBJECTIVES

Temporal muscle thickness (TMT) is a surrogate marker of sarcopenia, correlated with survival expectancy in patients suffering from brain metastases and recurrent or treated glioblastoma. We evaluated the prognostic relevance of TMT measured on brain MRIs acquired at diagnosis in patients affected by glioblastoma.

METHODS

We retrospectively enrolled 51 patients in our Institution affected by methylated MGMT promoter, IDH1-2 wild-type glioblastoma, who underwent complete surgical resection and subsequent radiotherapy with concomitant and maintenance temozolomide, from January 1, 2015, to April 30, 2017. The last clinical/radiological follow-up date was set to September 3, 2019. TMT was measured bilaterally on reformatted post-contrast 3D MPRAGE images, acquired on our 3-T scanner no more than 2 days before surgery. The median, 25th, and 75th percentile TMT values were identified and population was subdivided accordingly; afterwards, statistical analyses were performed to verify the association among overall survival (OS) and TMT, sex, age, and ECOG performance status.

RESULTS

In our cohort, the median OS was 20 months (range 3-51). Patients with a TMT ≥ 8.4 mm (median value) did not show a statistically significant increase in OS (Cox regression model: HR 1.34, 95% CI 0.68-2.63, p = 0.403). Similarly, patients with a TMT ≥ 9.85 mm (fourth quartile) did not differ in OS compared to those with TMT ≤ 7 mm (first quartile). The statistical analyses confirmed a significant association among TMT and sex (p = 0.0186), but none for age (p = 0.642) and performance status (p = 0.3982).

CONCLUSIONS

In our homogeneous cohort of patients with glioblastoma at diagnosis, TMT was not associated with prognosis, age, or ECOG performance status.

KEY POINTS

• Temporal muscle thickness (TMT) is a surrogate marker of sarcopenia and has been correlated with survival expectancy in patients suffering from brain metastases and recurrent or treated glioblastoma. • We appraised the correlation among TMT and survival, sex, age at surgery, and performance status, measured on brain MRIs of patients affected by glioblastoma at diagnosis. • TMT did not show any significant correlation with prognosis, age at surgery, or performance status, and its usefulness might be restricted only to patients with brain metastases and recurrent or treated glioblastoma.

Preoperative sarcopenia is associated with poor overall survival in pancreatic cancer patients following pancreaticoduodenectomy

OBJECTIVES

To analyze the effect of preoperative body composition on survival in patients with pancreatic cancer following pancreaticoduodenectomy (PD).

METHODS

Between October 2005 and August 2018, 116 patients (68 men, 48 women, mean age 66.2 ± 11.9 years) diagnosed with pancreatic adenocarcinoma following PD were retrospectively enrolled. The preoperative CT on vertebral level L3 was assessed for total abdominal muscle area (TAMA), visceral adipose tissue area (VAT), subcutaneous adipose tissue area (SAT), and mean skeletal muscle attenuation (SMD). The clinical data and pathological findings of tumors were collected. The impact of these factors on disease-free survival (DFS) and overall survival (OS) was evaluated by the Kaplan-Meier method and by univariable and multivariable Cox proportional hazards models.

RESULTS

The 3-year DFS and OS rates were 8% and 25%, respectively. Of 116 patients, 20 (17.2%), 3 (2.6%), and 46 (39.7%) patients were classified as having sarcopenia, sarcopenic obesity, and myosteatosis, respectively. The VAT-TAMA ratio (1.2 ± 0.7 vs 0.9 ± 0.5, p = 0.01) and the visceral to subcutaneous adipose tissue area ratio (1.3 ± 0.7 vs 0.9 ± 0.5, p = 0.04) were higher in sarcopenic patients than in the nonsarcopenic group. Preoperative sarcopenia and sarcopenic obesity were associated with shorter OS (p = 0.012 and p = 0.041, respectively), but not shorter DFS. Myosteatosis was neither associated with DFS nor OS. On multivariable analysis, sarcopenia was the only significant prognostic factor for OS (p = 0.039).

CONCLUSIONS

Preoperative sarcopenia assessed by CT is a poor prognostic factor for OS in pancreatic cancer patients after PD.

KEY POINTS

• Sarcopenia and sarcopenic obesity can be evaluated by abdominal CT on L3 level. • Patients with diabetes mellitus (DM) had lower sex-standardized subcutaneous adipose tissue area index and skeletal muscle density and higher visceral to subcutaneous adipose tissue area ratio than did those without DM. • Preoperative sarcopenia, sarcopenic obesity, and new-onset diabetes mellitus may predict poor overall survival in pancreatic cancer patients following pancreaticoduodenectomy.

Skeletal Muscle Composition Predicts Outcome in Critically Ill Patients

Supplemental Digital Content is available in the text.

Parameters of patients’ body composition have been suggested as prognostic markers in several clinical conditions including cancer and liver transplantation, but only limited data on its value in critical illness exist to date. In this study, we aimed at evaluating a potential prognostic value of the skeletal muscle mass and skeletal muscle myosteatosis of critically ill patients at admission to the ICU.

Body composition analysis using CT and MRI: intra-individual intermodal comparison of muscle mass and myosteatosis

Computed tomography (CT) and magnetic resonance imaging (MRI) can quantify muscle mass and quality. However, it is still unclear if CT and MRI derived measurements can be used interchangeable. In this prospective study, fifty consecutive participants of a cancer screening program underwent same day low-dose chest CT and MRI. Cross-sectional areas (CSA) of the paraspinal skeletal muscles were obtained. CT and MRI muscle fat infiltration (MFI) were assessed by mean radiodensity in Hounsfield units (HU) and proton density fat fraction (MRI^PDFF), respectively. CSA and MFI were highly correlated between CT and MRI (CSA: r = 0.93, P < 0.001; MFI: r = - 0.90, P < 0.001). Mean CSA was higher in CT compared to MRI (46.6cm² versus 43.0cm²; P = 0.05) without significance. Based on MRI^PDFF, a linear regression model was established to directly estimate skeletal muscle fat content from CT. Bland-Altman plots showed a difference between measurements of - 0.5 cm² to 7.6 cm² and - 4.2% to 2.4% regarding measurements of CSA and MFI, respectively. In conclusion, the provided results indicate interchangeability of CT and MRI derived imaging biomarkers of skeletal muscle quantity and quality. Comparable to MRI^PDFF, skeletal muscle fat content can be quantified from CT, which might have an impact of analyses in larger cohort studies, particularly in sarcopenia patients.

Correlation Between Sarcopenia and Growth Rate of the Future Liver Remnant After Portal Vein Embolization in Patients with Colorectal Liver Metastases

PURPOSE

To investigate whether sarcopenia and myosteatosis correlate with the degree of hypertrophy (DH) and kinetic growth rate (KiGR) of the future liver remnant (FLR) in patients with colorectal liver metastases undergoing portal vein embolization (PVE) in preparation for right hepatectomy.

MATERIALS AND METHODS

Forty-two patients were included. Total liver volume and FLR volume were measured before and 2-4 weeks after PVE. KiGR of the FLR was calculated. Sarcopenia was assessed using the total psoas muscle volume (PMV), the psoas muscle cross-sectional area (PMCS) and the total skeletal muscle index (L3SMI) at the level of 3rd lumbar vertebra. Degree of myosteatosis was assessed by mean muscle attenuation at L3 (L3MA). Correlations between muscle indices and DH and KiGR were assessed using simple linear regression analyses.

RESULTS

Mean DH was 8.9 ± 5.7%, and mean KiGR was 3.6 ± 2.3. Mean PMV was 55.56 ± 14.19 cm3/m3, mean PMCS was 8.76 ± 2.3 cm2/m2, mean L3SMI was 45.6 ± 9.89 cm2/m2, and mean L3MA was 27.9 ± 18.6 HU. There was a strong positive correlation between PMV and DH (R = 0.503, p = 0.001) and PMV and KiGR (R = 0.545, p < 0.001). Furthermore, there was a moderate correlation between PMCS and KiGR (R = 0.389, p = 0.014). L3SMI and L3MA were neither associated with DH (p = 0.390 and p = 0.768, respectively) nor with KiGR (p = 0.188 and p = 0.929, respectively).

CONCLUSION

We identified a positive correlation between PMV and PMCS, as markers for sarcopenia, and the KiGR of the FLR after PVE. PMV and PMCS might therefore aid to identify patients who are poor candidates for FLR augmentation using PVE alone.

Sarcopenia in juvenile localized scleroderma: new insights on deep involvement

OBJECTIVES

Juvenile localized scleroderma (JLS) is a rare chronic autoimmune disease which can also affect bones and muscles. Nevertheless, muscle loss was not previously investigated in patients with JLS. Thus, the aim of this study was to retrospectively evaluate deep involvement and assess and quantify sarcopenia in JLS patients using magnetic resonance imaging (MRI).

METHODS

Fourteen children with JLS (nine females, mean age ± SD, 7.1 ± 3.6 years) referring to our tertiary center from January 2012 to January 2018 who underwent at least one MRI examination including axial T1-weighted and short tau inversion recovery images were included. Two readers assessed in consensus superficial and deep involvement. Muscle edema, muscle fatty infiltration, and sarcopenia were independently scored (absent, moderate, or severe) and the Cohen's kappa coefficient computed. Skin perimeter, subcutaneous area, muscle area, and muscle volume were independently measured using the contralateral unaffected extremity as reference (paired Student's t test, p < 0.05). The intraclass correlation coefficient (ICC) was used to investigate the reliability of the measurements.

RESULTS

All patients showed superficial involvement with subcutaneous fat atrophy being the most common finding (13 patients). Bone marrow edema occurred in five patients. Muscle edema affected ten children (moderate in seven, severe in three; k = 0.89), muscle fatty replacement occurred in one case (severe; k = 1.00), and sarcopenia was detected in eight patients (severe in two; k = 0.78). All quantitative parameters were lower on the affected side than on the unaffected contralateral limb (p < 0.05, each) and all measurements showed a high reliability (ICC > 0.750, each).

CONCLUSION

Patients with JLS can be affected by sarcopenia and quantitative analyses allow a robust characterization of such finding.

KEY POINTS

• Deep involvement in juvenile localized scleroderma is frequently characterized by sarcopenia. • In juvenile localized scleroderma, muscle edema and sarcopenia are mostly moderate while fatty infiltration, even if rare, can be severe. • Sarcopenia can be reliably quantified in children with juvenile localized scleroderma using MRI.

Yttrium-90 radioembolization for hepatocellular carcinoma: Outcome prediction with MRI derived fat-free muscle area

PURPOSE

Sarcopenia is associated with adverse outcomes in several gastrointestinal malignancies and liver cirrhosis. We aimed to study the utility of magnetic resonance imaging (MRI) derived fat-free muscle area (FFMA) to predict clinical outcome in patients receiving yttrium-90 radioembolization (RE) for treatment of hepatocellular carcinoma (HCC).

METHODS

Fifty-eight patients with unresectable HCC and pre-interventional liver MRI undergoing salvage RE were retrospectively evaluated. Using axial T2-weighted turbo spin echo sequences, FFMA was calculated by subtraction of the intramuscular adipose tissue area from the total cross-sectional area of paraspinal skeletal muscles at the superior mesenteric artery level. FFMA values lower than 3582 mm² in male and 2301 mm² in female patients were defined as low FFMA. Main outcomes were progression-free survival (PFS) and overall survival (OS). For outcome analysis, the Kaplan-Meier method with log rank test and multivariate cox regression analysis were used.

RESULTS

Mean time from pre-interventional MRI to RE was 27 ± 20 days. Median OS and PFS after RE were 250 (range: 21-1230 days) and 156 days (range: 21-674 days), respectively. Patients with low FFMA showed significantly reduced OS (197 vs. 294 days, P = 0.024) and tended to have shortened PFS (109 vs. 185 days, P = 0.068). Low FFMA (HR 2.675; P = 0.011), estimated liver tumor burden (HR 4.058; P = 0.001), and Eastern Cooperative Oncology Group (ECOG) performance status (1.763; P = 0.009) were independent predictors of OS on multivariate analysis.

CONCLUSIONS

FFMA as a measure of sarcopenia predicts OS and might represent a promising new biomarker for survival prognosis in patients undergoing RE for treatment of unresectable HCC.

Single-slice CT measurements allow for accurate assessment of sarcopenia and body composition

OBJECTIVES

To evaluate the correlation between simple planimetric measurements in axial computed tomography (CT) slices and measurements of patient body composition and anthropometric data performed with bioelectrical impedance analysis (BIA) and metric clinical assessments.

METHODS

In this prospective cross-sectional study, we analyzed data of a cohort of 62 consecutive, untreated adult patients with advanced malignant melanoma who underwent concurrent BIA assessments at their radiologic baseline staging by CT between July 2016 and October 2017. To assess muscle and adipose tissue mass, we analyzed the areas of the paraspinal muscles as well as the cross-sectional total patient area in a single CT slice at the height of the third lumbar vertebra. These measurements were subsequently correlated with anthropometric (body weight) and body composition parameters derived from BIA (muscle mass, fat mass, fat-free mass, and visceral fat mass). Linear regression models were built to allow for estimation of each parameter based on CT measurements.

RESULTS

Linear regression models allowed for accurate prediction of patient body weight (adjusted R² = 0.886), absolute muscle mass (adjusted R² = 0.866), fat-free mass (adjusted R² = 0.855), and total as well as visceral fat mass (adjusted R² = 0.887 and 0.839, respectively).

CONCLUSIONS

Our data suggest that patient body composition can accurately and quantitatively be determined by using simple measurements in a single axial CT slice. This could be useful in various medical and scientific settings, where the knowledge of the patient's anthropometric parameters is not immediately or easily available.

KEY POINTS

• Easy to perform measurements on a single CT slice highly correlate with clinically valuable parameters of body composition. • Body composition data were acquired using bioelectrical impedance analysis to correlate CT measurements with a non-imaging-based method, which is frequently lacking in previous studies. • The obtained equations facilitate a quick, opportunistic assessment of relevant parameters of body composition.

Prognostic factors in patients treated with transarterial radioembolization for unresectable and chemorefractory colorectal cancer with liver metastases

Background: Transarterial radioembolization (TARE) is used to treat unresectable colorectal cancer with liver metastases (CRCLM). This study aimed to assess survival after TARE and to identify potential prognostic factors in this patient population. Methods: Patients with unresectable and chemorefractory CRCLM treated with TARE at our institution between February 2006 and September 2015 were included in the study. Survival rate, hepatic tumor response, and potential prognostic factors were analyzed. Results: In the 43 study patients, the mean follow-up was 15.0 ± 14.2 months, with a median survival of 13.0 months and 1-, 2-, 3-, 4-, and 5-year survival rates of 52.1%, 24.9%, 21.4%, 21.4%, and 7.1%, respectively. The mean activity of yttrium-90 administered was 1.55 ± 0.28 GBq for the disease-controlled group and 1.19 ± 0.27 GBq for the progressive disease group (p= 0.031). Survival was correlated with Child-Pugh class (p< 0.001), hepatic tumor response (p= 0.001), and baseline carcinoembryonic antigen (CEA) level (p= 0.013). Conclusion: Child-Pugh class B, low degree of hepatic tumor response, and normal baseline CEA levels are prognostic factors for poorer survival after TARE in patients with unresectable and chemorefractory CRCLM. Hepatic tumor response is related to radiation activity delivered to the liver.