Skeletal muscle cutoff values for sarcopenia diagnosis using T10 to L5 measurements in a healthy US population

Psoas muscle area as a predictor of low muscle mass in Asian patients with compensated advanced chronic liver disease

PURPOSE

The relationship between the psoas muscle index (PMI) and the appendicular skeletal muscle index (ASMI) in patients with compensated advanced chronic liver disease (cACLD) is not yet understood. Our goal is to determine which level of the lumbar spine best represents the appendicular skeletal muscle.

METHODS AND MATERIALS

This retrospective study involved patients with cACLD between January 2020 and December 2021. We documented the patients' body weight, height, gait speed, handgrip strength, appendicular skeletal muscle measured by DXA, and psoas muscle area segmented on computed tomography or magnetic resonance imaging. Low muscle mass, as defined by the Asian working group for sarcopenia, is less than 7.0 kg/m2 in males and less than 5.4 kg/m2 in females. We analyzed the correlation between PMI and ASMI.

RESULTS

A total of 134 patients were enrolled in the study, with 74 being male and 60 being female. The mean age was 63.9 ± 7.7 years old. Significant associations (p < 0.001) were found between PMI of all levels and ASMI. In the analysis of Pearson's correlation coefficients, it was noted that the r value increased gradually in both males (r = 0.3197 at L2, 0.4006 at L3, 0.5769 at L4) and females (r = 0.3771 at L2, 0.4557 at L3, 0.5251 at L4). Similarly, the area under the curve (AUC) values predicting low muscle mass were as follows: for males, AUC=0.582 at L2, 0.619 at L3, 0.728 at L4; for females, AUC=0.685 at L2, 0.733 at L3, 0.744 at L4. The cut-off point for PMI in males was 4.12 at L2, 6.25 at L3, and 8.48 at L4, while in females was 2.61 at L2, 4.47 at L3, 6.07 at L4.

CONCLUSION

The Psoas muscle index can be used to assess the muscle mass status in patients with cACLD. Among the various levels that can be used, we recommend using the fourth inferior endplate of the lumbar spine, as it shows the highest correlation. Additionally, we suggest using a PMI cut-off point of 8.48 cm2/m2 for males and 6.07 cm2/m2 for females as a predictor of low muscle mass in Asian.

Integrated impact of multiple body composition parameters on overall survival in gastrointestinal or genitourinary cancers: A descriptive cohort study

BACKGROUND

This study aimed to evaluate if combining low muscle mass with additional body composition abnormalities, such as myosteatosis or adiposity, could improve survival prediction accuracy in a large cohort of gastrointestinal and genitourinary malignancies.

METHODS

In total, 2015 patients with surgically-treated gastrointestinal or genitourinary cancer were retrospectively analyzed. Skeletal muscle index, skeletal muscle radiodensity, and visceral/subcutaneous adipose tissue index were determined. The primary outcome was overall survival determined by hospital records. Multivariate Cox hazard models were used to identify independent predictors for poor survival. C-statistics were assessed to quantify the prognostic capability of the models with or without incorporating body composition parameters.

RESULTS

Survival curves were significantly demarcated by all 4 measures. Skeletal muscle radiodensity was associated with non-cancer-related deaths but not with cancer-specific survival. The survival outcome of patients with low skeletal muscle index was poor (5-year OS; 65.2%), especially when present in combination with low skeletal muscle radiodensity (5-year overall survival; 50.2%). All examined body composition parameters were independent predictors of lower overall survival. The model for predicting overall survival without incorporating body composition parameters had a c-index of 0.68 but increased to 0.71 with the inclusion of low skeletal muscle index and 0.72 when incorporating both low skeletal muscle index and low skeletal muscle radiodensity/visceral adipose tissue index/subcutaneous adipose tissue index.

CONCLUSION

Patients exhibiting both low skeletal muscle index and other body composition abnormalities, particularly low skeletal muscle radiodensity, had poorer overall survival. Models incorporating multiple body composition prove valuable for mortality prediction in oncology settings.

Analysis of the current status of computed tomography diagnosis of sarcopenia

Sarcopenia is a clinical syndrome characterized by the reduction of skeletal muscle mass and strength, leading to adverse events such as falls, fractures, frailty, disability, and increased mortality. Compared to previous diagnostic techniques such as dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), and body composition analysis, computed tomography (CT) offers significant advantages. Opportunistic CT imaging, enhanced by artificial intelligence (AI) software, provides a superior diagnostic tool for sarcopenia. AI software can automatically segment muscle groups on opportunistic CT images from different populations, enabling the efficient calculation of body composition parameters and more accurate and rapid diagnosis of sarcopenia. Early intervention may significantly reduce adverse clinical outcomes associated with sarcopenia. This study aims to evaluate the advantages of using CT images compared to traditional diagnostic techniques and to assess the value of skeletal muscle parameters at different spinal levels on opportunistic CT images for diagnosing sarcopenia.

Prognostic value of 18F-FDG PET radiomics and sarcopenia in patients with oral squamous cell carcinoma

BACKGROUND

Oral cancer is one of the most common malignancies in the head and neck region. Approximately 90% of oral cancers are oral squamous cell carcinomas (OSCC). 18F-FDG PET/CT has been used in OSCC patients for its high value in detecting metastatic lymph nodes and distant metastases. PET radiomics and sarcopenia can be measured on the PET and CT components of 18F-FDG PET/CT.

PURPOSE

This study aimed to investigate the prognostic value of radiomics and sarcopenia measured on the PET and CT components of pre-operation 18F-FDG PET/CT in OSCC.

METHODS

A total of 116 patients eventually enrolled in our study were randomly divided into two cohorts: training cohort (n = 58) and validation cohort (n = 58). The Cox model combined with the least absolute shrinkage and selection operator (LASSO) algorithm was applied to construct the radiomics score (Rad_score). The third lumber skeletal muscle index (L3 SMI) was calculated to identify sarcopenia. Univariate and multivariate Cox regression analyses were performed to identify the independent prognostic factors. Based on the clinical factors, the clinical model was constructed, and the combined model was developed through the combination of the clinical model and Rad_score. C index, time-dependent C-index curves, receiver operating characteristic (ROC) curve, calibration curves, and decision curve analysis were used to evaluate the performance of prediction models.

RESULTS

Three radiomics features constitute the Rad_score for overall survival (OS) and progression-free survival (PFS), respectively. Multivariate Cox regression analysis revealed that Rad_score was an independent prognostic factor, whereas sarcopenia was not. The combined models showed satisfactory performance in both the training cohort (C-index: OS:0.836, PFS:0.776) and the validation cohort (C-index: OS:0.744, PFS:0.712). The combined models were visualized as nomograms. Nomogram scores can realize the risk stratification of OSCC patients. Lower nomogram score is significantly related to the poorer OS (training cohort: p < 0.0001, validation cohort: p < 0.0001, overall cohort: p < 0.0001) and PFS (training cohort: p < 0.0001, validation cohort: p = 0.00017, overall cohort: p < 0.0001).

CONCLUSIONS

Rad_score, but not sarcopenia, was an independent prognostic factor for patients with OSCC. The nomograms had a satisfactory performance, which might be helpful for OSCC patients and clinicians in personalized prognostic prediction and treatment decision-making.

Skeletal muscle estimation: A review of techniques and their applications

Quantifying skeletal muscle size is necessary to identify those at risk for conditions that increase frailty, morbidity, and mortality, as well as decrease quality of life. Although muscle strength, muscle quality, and physical performance have been suggested as important assessments in the screening, prevention, and management of sarcopenic and cachexic individuals, skeletal muscle size is still a critical objective marker. Several techniques exist for estimating skeletal muscle size; however, each technique presents with unique characteristics regarding simplicity/complexity, cost, radiation dose, accessibility, and portability that are important factors for assessors to consider before applying these modalities in practice. This narrative review presents a discussion centred on the theory and applications of current non-invasive techniques for estimating skeletal muscle size in diverse populations. Common instruments for skeletal muscle assessment include imaging techniques such as computed tomography, magnetic resonance imaging, peripheral quantitative computed tomography, dual-energy X-ray absorptiometry, and Brightness-mode ultrasound, and non-imaging techniques like bioelectrical impedance analysis and anthropometry. Skeletal muscle size can be acquired from these methods using whole-body and/or regional assessments, as well as prediction equations. Notable concerns when conducting assessments include the absence of standardised image acquisition/processing protocols and the variation in cut-off thresholds used to define low skeletal muscle size by clinicians and researchers, which could affect the accuracy and prevalence of diagnoses. Given the importance of evaluating skeletal muscle size, it is imperative practitioners are informed of each technique and their respective strengths and weaknesses.

Diagnostic and prognostic value of parameters of erector spinae in patients with uremic sarcopenia

AIM

This study aimed to investigate whether computed tomography (CT)-measured erector spinae parameters (ESPs) have diagnostic, severity assessment, and prognostic predictive value in uremic sarcopenia (US).

MATERIALS AND METHODS

A total of 202 uremic patients were enrolled and divided into two groups: a control group and a sarcopenia group. Sarcopenia was classified into two types: severe and nonsevere. The area, volume, and density of the erector spinae (ES) were measured using chest CT images, and the relevant ESP, including the erector spinae index (ESI), total erector spinae volume (TESV), erector spinae density (ESD), and erector spinae gauge (ESG) were calculated. The occurrence of adverse events was followed-up for 36 months. The diagnostic value and severity of US were determined using the receiver operating characteristic (ROC) curve. Survival curves diagnosed using CT were plotted and compared with the curve drawn using the gold standard. Cox regression analysis was used to identify independent risk factors associated with survival in US.

RESULTS

With an area under the curve (AUC) of 0.840 and 0.739, the combined ESP has diagnostic value and the ability to assess the severity of US. There was no significant difference in the survival curve between the combined ESP for the diagnosis of US and the gold standard (P > 0.05). ESI is a standalone predictor of survival in patients with US.

CONCLUSION

ESP measured by CT has diagnostic values for US and its severity, as well as being a predictive value for the prognosis of US.

Objective comparison of commonly used computed tomography body composition analysis software

OBJECTIVES

Sarcopenia is defined as an age-related, involuntary loss of skeletal muscle mass and strength. This condition is increasingly gaining clinical attention, as it has proved a predictor of complications and unfavorable outcomes in several diseases. For analysis of body composition on computed tomography images, several different software packages are used. Extensive research is being conducted globally to establish general cutoff values for different patient groups by combining the results of different studies with meta-analysis. Therefore, it is important that the measurements are independent of the software used. However, clinical software comparisons suggest there are differences between analysis packages, which would complicate establishment of cutoff values. For this study, we compared the eight most used analysis software programs in an objective manner, using a phantom image, to assess if their results can be readily compared.

METHODS

Eight software packages (sliceOmatic, OsiriX, ImageJ/Fiji, Mimics, CoreSlicer, SarcoMeas, 3D Slicer, and Aquarius iNtuition) were objectively evaluated, by performing measurements in a standardized synthetic image, containing fixed muscle and fat compartments with homogeneous radiodensities. For all programs, the measured areas and radiodensities of the regions of interest were assessed.

RESULTS

For sliceOmatic, OsiriX, ImageJ/Fiji, Mimics, CoreSlicer, SarcoMeas, and 3D Slicer, identical results were found, all reporting correct values for muscle and fat areas as well as correct radiodensity values, whereas values reported by Aquarius iNtuition deviated ≤ 5% for area measurements and had slight variation in radiodensity measurements.

CONCLUSIONS

Seven of eight software packages (sliceOmatic, OsiriX, ImageJ/Fiji, Mimics, CoreSlicer, SarcoMeas, and 3D Slicer) perform identically, so their results can be readily compared and combined when assessing body composition in computed tomography images. Area measurements acquired with Aquarius iNtuition may differ slightly (≤ 5%) from the other packages.

Radiographic Thigh Muscle Measurements Are a Reliable Predictor of Psoas Area and Sarcopenia

BACKGROUND

Sarcopenia is associated with falls, fractures, postoperative complications such as periprosthetic joint infections and dislocations, and early mortality. Although cross-sectional imaging is currently used to diagnose sarcopenia, inexpensive and widely available screening tests are needed. The goal of this study was to investigate whether measurements of thigh muscles made on radiographs can predict psoas muscle area and the presence of sarcopenia as determined on computed tomography (CT) scans.

METHODS

A retrospective radiographic review was performed to measure thigh muscle area in the coronal and sagittal planes using the differential in soft-tissue attenuation. Psoas muscle area on CT at L3 and L4 served as the gold standard for the diagnosis of sarcopenia. The correlation between thigh muscle and psoas muscle areas was determined, and multivariable models were developed to identify predictors of psoas muscle area and sarcopenia.

RESULTS

Four hundred and fourteen patients (252 male, 162 female) were identified. Seventy-six (18.4%) of the patients had an L4 psoas muscle area below the sex-specific cutoff value for sarcopenia. Patients with sarcopenia on abdominal CT had significantly smaller thigh muscle measurements on all radiographic views. The mean and standard deviation of the thigh muscle measurements were determined for the entire cohort and for patients with sarcopenia, as well as for adults aged 18 to 40 years without sarcopenia to provide normative reference values. The intraclass correlation coefficients were >0.8 for all radiographic measurements. The anteroposterior-view measurement of thigh muscle width and lateral-view measurement of quadriceps height were identified as independent predictors of both psoas muscle area and sarcopenia.

CONCLUSIONS

Measurements of thigh muscle size made on radiographs can predict both psoas muscle area and sarcopenia. These measurements are a reliable and readily available screening tool to aid in the diagnosis and treatment of sarcopenia in the orthopaedic population.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

AI-based fully automatic image analysis: Optimal abdominal and thoracic segmentation volumes for estimating total muscle volume on computed tomography scans

Objectives

Evaluation of sarcopenia from computed tomography (CT) is often based on measuring skeletal muscle area on a single transverse slice. Automatic segmentation of muscle volume has a lower variance and may be a better proxy for the total muscle volume than single-slice areas. The aim of the study was to determine which abdominal and thoracic anatomical volumes were best at predicting the total muscle volume.

Methods

A cloud-based artificial intelligence tool (recomia.org) was used to segment all skeletal muscle of the torso of 994 patients who had performed whole-torso CT 2008-2020 for various clinical indications. Linear regression models for several anatomical volumes and single-slice areas were compared with regard to predicting the total torso muscle volume.

Results

The muscle volume from the tip of the coccyx and 25 cm cranially was the best of the abdominal volumes and was significantly better than the L3 slice muscle area (R2 0.935 vs 0.830, P < 0.0001). For thoracic volumes, the muscle volume between the top of the sternum to the lower bound of the Th12 vertebra showed the best correlation with the total volume, significantly better than the Th12 slice muscle area (R2 0.892 vs 0.775, P < 0.0001). Adjusting for body height improved the correlation slightly for all measurements but did not significantly change the ordering.

Conclusions

We identified muscle volumes that can be reliably segmented by automated image analysis which is superior to single slice areas in predicting total muscle volume.

Sarcopenia Identification Using Alternative Vertebral Landmarks in Individuals with Lung Cancer

Background

(1)Sarcopenia, or low skeletal mass index (SMI), contributes to higher lung cancer mortality. The SMI at third lumbar vertebrae (L3) is the reference standard for body composition analysis. However, there is a need to explore the validity of alternative landmarks in this population. We compared the agreement of sarcopenia identification at the first lumbar (L1) and second lumbar (L2) to L3 in non-Hispanic Black (NHB) and White (NHW) individuals with lung cancer.

Methods

(2)This retrospective, cross-sectional study included 214 NHB and NHW adults with lung cancer. CT scans were analyzed to calculate the SMI at L1, L2, and L3. T-tests, chi-square, Pearson's correlation, Cohen's kappa, sensitivity, and specificity analysis were used.

Results

(3)Subjects presented with a mean age of 68.4 ± 9.9 years and BMI of 26.3 ± 6.0 kg/m2. Sarcopenia prevalence varied from 19.6% at L1 to 39.7% at L3. Cohen's kappa coefficient was 0.46 for L1 and 0.64 for L2, indicating weak and moderate agreement for the identification of sarcopenia compared to L3.

Conclusions

(4)Sarcopenia prevalence varied greatly depending on the vertebral landmark used for assessment. Using L2 or L1 alone resulted in a 16.8% and 23.8% misclassification of sarcopenia in this cohort of individuals with lung cancer.

Using maximum plasma concentration (Cmax) to personalize taxane treatment and reduce toxicity

Taxanes are a widely used class of anticancer agents that play a vital role in the treatment of a variety of cancers. However, toxicity remains a major concern of using taxane drugs as some toxicities are highly prevalent, they can not only adversely affect patient prognosis but also compromise the overall treatment plan. Among all kinds of factors that associated with taxane toxicity, taxane exposure has been extensively studied, with different pharmacokinetic (PK) parameters being used as toxicity predictors. Compared to other widely used predictors such as the area under the drug plasma concentration curve versus time (AUC) and time above threshold plasma drug concentration, maximum plasma concentration (Cmax) is easier to collect and shows promise for use in clinical practice. In this article, we review the previous research on using Cmax to predict taxane treatment outcomes. While Cmax and toxicity have been extensively studied, research on the relationship between Cmax and efficacy is lacking. Most of the articles find a positive relationship between Cmax and toxicity but several articles have contradictory findings. Future clinical trials are needed to validate the relationship between Cmax and treatment outcome and determine whether Cmax can serve as a useful surrogate endpoint of taxane treatment efficacy.

Normative values of skeletal muscle mass, strength and performance in the Indian population

BACKGROUND AND OBJECTIVES

Skeletal muscle is characterized by its mass, strength and performance. These normative values are pivotal in defining sarcopenia. Sarcopenia is associated with poor outcome of numerous medical and surgical conditions. This study aimed to establish normative benchmarks for skeletal muscle mass, strength and performance within the context of the Asian (Indian) population.

METHODS

Our investigation utilized the computed tomography (CT) skeletal muscle index (SMI), handgrip strength (HGS), gait velocity and chair-stand test to construct reference values for muscle characteristics in the Indian population.

RESULTS

The SMI analysis incorporated 1485 cases of acute abdomen (54.7%) males). The calculated SMI (kg/m2) was 38.50 (35.05-42.30) in males and 36.30 (32.20-41.20) in females (p = 0.510). The study also involved 3083 healthy individuals (67.6% males) evaluated for muscle strength and performance between August 2017 and August 2018. Notably, HGS (kg force) was recorded at 34.95 (26.50-43.30) in males and 25.50 (18.60-31.20) in females (p < 0.001). Gait velocity (metres/second) exhibited values of 1.25 (1.04-1.56) in males and 1.24 (1.03-1.56) in females (p = 0.851). Additionally, chair-stand test (seconds) results were 10.00 (9.00-13.00) in males and 12.00 (10.00-14.00) in females (p < 0.001).

CONCLUSIONS

The investigation determined that males had greater muscle strength and performance than females. But gender wise, there was no significant difference in muscle mass. Interestingly, our population's muscle parameters were consistently lower compared to western literature benchmarks. These normative values will help to define sarcopenia parameters in our population, which have prognostic value in multiple ailments.

Opportunistic screening for long-term muscle wasting in critically ill patients: insights from an acute pancreatitis cohort

OBJECTIVES

To assess the feasibility of long-term muscle monitoring, we implemented an AI-guided segmentation approach on clinically indicated Computed Tomography (CT) examinations conducted throughout the hospitalization period of patients admitted to the intensive care unit (ICU) with acute pancreatitis (AP). In addition, we aimed to investigate the potential of muscle monitoring for early detection of patients at nutritional risk and those experiencing adverse outcomes. This cohort served as a model for potential integration into clinical practice.

MATERIALS

Retrospective cohort study including 100 patients suffering from AP that underwent a minimum of three CT scans during hospitalization, totaling 749 assessments. Sequential segmentation of psoas muscle area (PMA) was performed and was relative muscle loss per day for the entire monitoring period, as well as for the interval between each consecutive scan was calculated. Subgroup and outcome analyses were performed including ANOVA. Discriminatory power of muscle decay rates was evaluated using ROC analysis.

RESULTS

Monitoring PMA decay revealed significant long-term losses of 48.20% throughout the hospitalization period, with an average daily decline of 0.98%. Loss rates diverged significantly between survival groups, with 1.34% PMA decay per day among non-survivors vs. 0.74% in survivors. Overweight patients exhibited significantly higher total PMA losses (52.53 vs. 42.91%; p = 0.02) and average PMA loss per day (of 1.13 vs. 0.80%; p = 0.039). The first and the maximum decay rate, in average available after 6.16 and 17.03 days after ICU admission, showed convincing discriminatory power for survival in ROC analysis (AUC 0.607 and 0.718). Both thresholds for maximum loss (at 3.23% decay per day) and for the initial loss rate (at 1.98% per day) proved to be significant predictors of mortality.

CONCLUSIONS

The innovative AI-based PMA segmentation method proved robust and effortless, enabling the first comprehensive assessment of muscle wasting in a large cohort of intensive care pancreatitis patients. Findings revealed significant muscle wasting (48.20% on average), particularly notable in overweight individuals. Higher rates of initial and maximum muscle loss, detectable early, correlated strongly with survival. Integrating this tool into routine clinical practice will enable continuous muscle status tracking and early identification of those at risk for unfavorable outcomes.

Relationship between paraspinal muscle properties and bone mineral density based on QCT in patients with lumbar disc herniation

OBJECTIVE

Increasing research suggests that paraspinal muscle fat infiltration may be a potential biological marker for the assessment of osteoporosis. Our aim was to investigate the relationship between lumbar paraspinal muscle properties on MRI and volumetric bone mineral density (vBMD) based on QCT in patients with lumbar disc herniation (LDH).

METHODS

A total of 383 patients (aged 24-76 years, 193 females) with clinically and radiologically diagnosed LDH were enrolled in this retrospective study. The muscle cross-sectional area (CSA) and the proton density fat fraction (PDFF) were measured for the multifidus (MF), erector spinae (ES) and psoas major (PS) at the central level of L3/4, L4/5 and L5/S1 on lumbar MRI. QCT was used to measure the vBMD of two vertebral bodies at L1 and L2 levels. Patients were divided into three groups based on their vBMD values: normal bone density group (> 120 mg/cm3), osteopenia group (80 to 120 mg/cm3) and osteoporosis group (< 80 mg/cm3). The differences in paraspinal muscle properties among three vBMD groups were tested by one-way ANOVA with post hoc analysis. The relationships between paraspinal muscle properties and vBMD were analyzed using Pearson correlation coefficients. Furthermore, the association between vBMD and paraspinal muscle properties was further evaluated using multiple linear regression analysis, with age and sex also included as predictors.

RESULTS

Among the 383 LDH patients, 191 had normal bone density, 129 had osteopenia and 63 had osteoporosis. In LDH patients, compared to normal and osteopenia group, paraspinal muscle PDFF was significantly greater in osteoporosis group, while paraspinal muscle CSA was lower (p < 0.001). After adjusting for age and sex, it was found that MF PDFF and PS CSA were found to be independent factors influencing vBMD (p < 0.05).

CONCLUSION

In patients with LDH, paraspinal muscle properties measured by IDEAL-IQ sequence and lumbar MR scan were found to be related to vBMD. There was a correlation between the degree of paraspinal muscle PDFF and decreasing vBMD, as well as a decrease paraspinal muscle CSA with decreasing vBMD. These findings suggest that clinical management should consider offering tailored treatment options for patients with LDH based on these associations.

Visceral obesity and sarcopenia as predictors of efficacy and hematological toxicity in patients with metastatic breast cancer treated with CDK 4/6 inhibitors

PURPOSE

We aimed to investigate whether visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and skeletal muscle area (SMA) index are predictive for efficacy and hematological toxicity in ER + HER2-metastatic breast cancer (BC) patients who received CDK 4/6 inhibitors.

METHODS

This retrospective cohort study analyzed 52 patients who were treated with CDK 4/6 inhibitors between January 2018 and February 2021. The values of VAT, SAT, SMA indices and hematological parameters were noted before the start, at the third and sixth months of this treatment. The skeletal muscle area (SMA) and adipose tissue measurements were calculated at the level of the third lumbar vertebra. A SMA-index value of <40 cm2/m2 was accepted as the threshold value for sarcopenia.

RESULTS

Patients with sarcopenia had a worse progression-free survival (PFS) compared to patients without sarcopenia (19.6 vs. 9.0 months, p = 0.005). Patients with a high-VAT-index had a better PFS (20.4 vs. 9.3 months, p = 0.033). Only the baseline low-SMA- index (HR: 3.89; 95% CI: 1.35-11.25, p = 0.012) and baseline low-VAT-index (HR: 2.15; 95% CI: 1.02-4.53, p = 0.042) had significantly related to poor PFS in univariate analyses. The low-SMA-index was the only independent factor associated with poor PFS (HR: 3.99; 95% CI: 1.38-11.54, p = 0.011). No relationship was observed between body composition parameters and grade 3-4 hematological toxicity.

CONCLUSION

The present study supported the significance of sarcopenia and low visceral adipose tissue as potential early indicators of poor PFS in patients treated with CDK 4/6 inhibitors.

Georg Schmorl Prize of the German Spine Society (DWG) 2023: the influence of sarcopenia and paraspinal muscle composition on patient-reported outcomes: a prospective investigation of lumbar spinal fusion patients with 12-month follow-up

PURPOSE

This study aimed to investigate the impact of sarcopenia and lumbar paraspinal muscle composition (PMC) on patient-reported outcomes (PROs) after lumbar fusion surgery with 12-month follow-up (12 M-FU).

METHODS

A prospective investigation of patients undergoing elective lumbar fusion was conducted. Preoperative MRI-based evaluation of the cross-sectional area (CSA), the functional CSA (fCSA), and the fat infiltration(FI) of the posterior paraspinal muscles (PPM) and the psoas muscle at level L3 was performed. Sarcopenia was defined by the psoas muscle index (PMI) at L3 (CSAPsoas [cm2]/(patients' height [m])2). PROs included Oswestry Disability Index (ODI), 12-item Short Form Healthy Survey with Physical (PCS-12) and Mental Component Scores (MCS-12) and Numerical Rating Scale back and leg (NRS-L) pain before surgery and 12 months postoperatively. Univariate and multivariable regression determined associations among sarcopenia, PMC and PROs.

RESULTS

135 patients (52.6% female, 62.1 years, BMI 29.1 kg/m2) were analyzed. The univariate analysis demonstrated that a higher FI (PPM) was associated with worse ODI outcomes at 12 M-FU in males. Sarcopenia (PMI) and higher FI (PPM) were associated with worse ODI and MCS-12 at 12 M-FU in females. Sarcopenia and higher FI of the PPM are associated with worse PCS-12 and more leg pain in females. In the multivariable analysis, a higher preoperative FI of the PPM (β = 0.442; p = 0.012) and lower FI of the psoas (β = -0.439; p = 0.029) were associated with a worse ODI at 12 M-FU after adjusting for covariates.

CONCLUSIONS

Preoperative FI of the psoas and the PPM are associated with worse ODI outcomes one year after lumbar fusion. Sarcopenia is associated with worse ODI, PCS-12 and NRS-L in females, but not males. Considering sex differences, PMI and FI of the PPM might be used to counsel patients on their expectations for health-related quality of life after lumbar fusion.

Body composition assessment by artificial intelligence can be a predictive tool for short-term postoperative complications in Hartmann's reversals

BACKGROUND

Hartmann's reversal, a complex elective surgery, reverses and closes the colostomy in individuals who previously underwent a Hartmann's procedure due to colonic pathology like cancer or diverticulitis. It demands careful planning and patient optimisation to help reduce postoperative complications. Preoperative evaluation of body composition has been useful in identifying patients at high risk of short-term postoperative outcomes following colorectal cancer surgery. We sought to explore the use of our in-house derived Artificial Intelligence (AI) algorithm to measure body composition within patients undergoing Hartmann's reversal procedure in the prediction of short-term postoperative complications.

METHODS

A retrospective study of all patients who underwent Hartmann's reversal within a single tertiary referral centre (Western) in Melbourne, Australia and who had a preoperative Computerised Tomography (CT) scan performed. Body composition was measured using our previously validated AI algorithm for body segmentation developed by the Department of Surgery, Western Precinct, University of Melbourne. Sarcopenia in our study was defined as a skeletal muscle index (SMI), calculated as Skeletal Muscle Area (SMA) /height2 < 38.5 cm2/m2 in women and < 52.4 cm2/m2 in men.

RESULTS

Between 2010 and 2020, 47 patients (mean age 63.1 ± 12.3 years; male, n = 28 (59.6%) underwent body composition analysis. Twenty-one patients (44.7%) were sarcopenic, and 12 (25.5%) had evidence of sarcopenic obesity. The most common postoperative complication was surgical site infection (SSI) (n = 8, 17%). Sarcopenia (n = 7, 87.5%, p = 0.02) and sarcopenic obesity (n = 5, 62.5%, p = 0.02) were significantly associated with SSIs. The risks of developing an SSI were 8.7 times greater when sarcopenia was present.

CONCLUSION

Sarcopenia and sarcopenic obesity were related to postoperative complications following Hartmann's reversal. Body composition measured by a validated AI algorithm may be a beneficial tool for predicting short-term surgical outcomes for these patients.

Prediction of hematologic toxicity in luminal type breast cancer patients receiving neoadjuvant chemotherapy using CT L1 level skeletal muscle index

This study aims to explore the correlation between the CT-L1 and L3 body composition parameters and analyze the relationship between L1 body composition and hematologic toxicity in luminal-type breast cancer patients undergoing neoadjuvant chemotherapy. Data from 140 luminal-type breast cancer patients who underwent surgical treatment after neoadjuvant chemotherapy were analyzed retrospectively. Spearman analysis was used to assess the correlation between CT-L1 and CT-L3 body composition parameters pre-neoadjuvant chemotherapy. Additionally, univariate and multivariate logistic regression analyses were performed to identify factors influencing hematologic toxicity. CT-L1 body composition parameters were positively correlated with CT-L3 body composition parameters in 34 patients. Severe hematological toxicity occurred in 46 cases among the patient cohort. A skeletal muscle index (SMI) of < 32.91 cm2/m2, initial tumor size ≥ 3.335 cm, and a glucose-to-neutrophil ratio (GLR) ≥ 2.88 were identified as independent risk factors for severe hematologic toxicity during neoadjuvant chemotherapy in luminal-type breast cancer patients. The sample size in this study is small, and the predictive capacity of GLR in hematologic toxicity requires further research for comprehensive validation. CT-L1 analysis represents a viable alternative to CT-L3 analysis for body composition assessment. Patients with a low skeletal muscle index were more prone to experiencing severe hematologic toxicity during neoadjuvant chemotherapy.

Prehabilitation in Adults Undergoing Cancer Surgery: A Comprehensive Review on Rationale, Methodology, and Measures of Effectiveness

Cancer surgery places a significant burden on a patients' functional status and quality of life. In addition, cancer surgery is fraught with postoperative complications, themselves influenced by a patient's functional status. Prehabilitation is a unimodal or multimodal strategy that aims to increase a patient's functional capacity to reduce postoperative complications and improve postoperative recovery and quality of life. In most cases, it involves exercise, nutrition, and anxiety-reducing interventions. The impact of prehabilitation has been explored in several types of cancer surgery, most commonly colorectal and thoracic. Overall, the existing evidence suggests prehabilitation improves physiological outcomes (e.g., lean body mass, maximal oxygen consumption) as well as clinical outcomes (e.g., postoperative complications, quality of life). Notably, the benefit of prehabilitation is additional to that of enhanced recovery after surgery (ERAS) programs. While safe, prehabilitation programs require multidisciplinary coordination preoperatively. Despite the existence of numerous systematic reviews and meta-analyses, the certainty of evidence demonstrating the efficacy and safety of prehabilitation is low to moderate, principally due to significant methodological heterogeneity and small sample sizes. There is a need for more large-scale multicenter randomized controlled trials to draw strong clinical recommendations.

Malnutrition and pectoralis muscle index in medical intensive care unit patients: A matched cohort study

BACKGROUND

Muscle assessment is an important component of nutrition assessment. The Global Leadership Initiative on Malnutrition (GLIM) consortium recently underscored the need for more objective muscle assessment methods in clinical settings. Various assessment techniques are available; however, many have limitations in clinical populations. Computed tomography (CT) scans, obtained for diagnostic reasons, could serve multiple purposes, including muscle measurement for nutrition assessment. Although CT scans of the chest are commonly performed clinically, there is little research surrounding the utility of pectoralis muscle measurements in nutrition assessment. The primary aim was to determine whether CT-derived measures of pectoralis major cross-sectional area (PMA) and quality (defined as mean pectoralis major Hounsfield units [PMHU]) could be used to identify malnutrition in patients who are mechanically ventilated in an intensive care unit (ICU). A secondary aim was to evaluate the relationship between these measures and clinical outcomes in this population.

METHODS

A retrospective analysis was conducted on 33 pairs of age- and sex-matched adult patients who are being mechanically ventilated in the ICU. Patients were grouped by nutrition status. Analyses were performed to determine differences in PMA and mean PMHU between groups. Associations between muscle and clinical outcomes were also investigated.

RESULTS

Compared with nonmalnourished controls, malnourished patients had a significantly lower PMA (P = 0.001) and pectoralis major (PM) index (PMA/height in m2; P = 0.001). No associations were drawn between PM measures and clinical outcomes.

CONCLUSION

These findings regarding CT PM measures lay the groundwork for actualizing the GLIM call to action to validate quantitative, objective muscle assessment methods in clinical settings.

Quantifying the severity of sarcopenia in patients with cancer of the head and neck

BACKGROUND & AIMS

Existing skeletal muscle index (SMI) thresholds for sarcopenia are inconsistent, and do not reflect severity of depletion. In this study we aimed to define criterion values for moderate and severe skeletal muscle depletion based on the risk of mortality in a population of patients with head and neck cancer (HNC). Additionally, we aimed to identify clinical and demographic predictors of skeletal muscle depletion, evaluate the survival impact of skeletal muscle depletion in patients with minimal nutritional risk or good performance status, and finally, benchmarking SMI values of patients with HNC against healthy young adults.

METHODS

Population cohort of 1231 consecutive patients and external validation cohorts with HNC had lumbar SMI measured by cross-sectional imaging. Optimal stratification determined sex-specific thresholds for 2-levels of SMI depletion (Class I and II) based on overall survival (OS). Adjusted multivariable regression analyses (tumor site, stage, performance status, age, sex, dietary intake, weight loss) determined relationships between 2-levels of SMI depletion and OS.

RESULTS

Mean SMI (cm2/m2) was 51.7 ± 9.9 (males) and 39.8 ± 7.1 (females). The overall and sex-specific population demonstrated an increased risk of mortality associated with decreasing SMI. Sex-specific SMI (cm2/m2) depletion thresholds for 2-levels of muscle depletion determined by optimal stratification for males and females, respectively (male: 45.2-37.5, and <37.5; female: 40.9-34.2, and <34.2). In the overall population, Normal SMI, Class I and II SMI depletion occurred in 65.0%, 24.0%, and 11.0%, respectively. Median OS was: Normal SMI (114 months, 95% CI, 97.1-130.8); Class I SMI Depletion (42 months, 95% CI, 28.5-55.4), and Class II SMI Depletion (15 months, 95% CI, 9.8-20.1). Adjusted multivariable analysis compared with Normal SMI (reference), Class I SMI Depletion (HR, 1.49; 95% CI, 1.18-1.88; P < .001), Class II SMI Depletion (HR, 1.91; 95% CI, 1.42-2.58; P < .001).

CONCLUSIONS

Moderate and severe SMI depletion demonstrate discrimination in OS in patients with HNC. Moderate and severe SMI depletion is prevalent in patients with minimal nutrition risk and good performance status. Benchmarking SMI values against healthy young adults exemplifies the magnitude of SMI depletion in patients with HNC and may be a useful method in standardizing SMI assessment.

CT-derived body composition: Differential association with disease, age and inflammation in a retrospective cohort study

BACKGROUND

Low skeletal muscle mass and density, as assessed by CT-body composition (CT-BC), are recognised to have prognostic value in non-cancer and cancer patients. The aim of the present study was to compare CT-BC parameters between non-cancer (abdominal aortic aneurysm, AAA) and cancer (colorectal cancer, CRC) patients.

METHODS

Two retrospective multicentre cohorts were compared. Thresholds of visceral fat area (VFA, Doyle), skeletal fat index (SFI, Ebadi), skeletal muscle index (SMI, Martin), and skeletal muscle density (SMD, Martin) were applied to these cohorts and compared. The systemic inflammatory response (SIR) was measured by the systemic inflammatory grade (SIG).

RESULTS

1695 patients were included; 759 patients with AAA and 936 patients with CRC. Low SMD (33% vs. 66%, p <0.001) was more prevalent in the CRC cohort. Low SMI prevalence was similar in both cohorts (51% vs. 51%, p = 0.80). Compared with the AAA cohort, the CRC cohort had a higher prevalence of raised SIG (p <0.001). Increasing age (OR 1.54, 95% CI 1.38-1.72, p < 0.001) and elevated SIG (OR 1.23, 95% CI 1.09-1.40, p = 0.001) were independently associated with increased odds of low SMI. Increasing age (OR 1.90, 95% CI 1.66-2.17, p < 0.001) CRC diagnosis (OR 5.89, 95% CI 4.55-7.62, p < 0.001), ASA > 2 (OR 1.37, 95% CI 1.08-1.73, p = 0.01), and elevated SIG (OR 1.19, 95% CI 1.03-1.37, p = 0.02) were independently associated with increased odds of low SMD.

CONCLUSIONS

Increasing age and systemic inflammation appear to be important determinants of loss of skeletal muscle mass and quality irrespective of disease.

Association between the Static and Dynamic Lung Function and CT-Derived Thoracic Skeletal Muscle Measurements-A Retrospective Analysis of a 12-Month Observational Follow-Up Pilot Study

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) with low skeletal muscle mass and severe airway obstruction have higher mortality risks. However, the relationship between dynamic/static lung function (LF) and thoracic skeletal muscle measurements (SMM) remains unclear. This study explored patient characteristics (weight, BMI, exacerbations, dynamic/static LF, sex differences in LF and SMM, and the link between LF and SMM changes.

METHODS

A retrospective analysis of a 12-month prospective follow-up study patients with stable COPD undergoing standardized treatment, covering mild to severe stages, was conducted. The baseline and follow-up assessments included computed tomography and body plethysmography.

RESULTS

This study included 35 patients (17 females and 18 males). This study revealed that females had more stable LF but tended to have greater declines in SMM areas and indices than males (-5.4% vs. -1.9%, respectively), despite the fact that females were younger and had higher LF and less exacerbation than males. A multivariate linear regression showed a negative association between the inspiratory capacity/total lung capacity ratio (IC/TLC) and muscle fat area.

CONCLUSIONS

The findings suggest distinct LF and BC progression patterns between male and female patients with COPD. A low IC/TLC ratio may predict increased muscle fat. Further studies are necessary to understand these relationships better.

Cardiovascular Imaging-Derived Skeletal Muscle Mass Correlates With Fitness and Survival in Patients With Univentricular Circulation

Aims This study aims to retrospectively quantify skeletal muscle mass from cardiovascular imaging studies in total cavopulmonary connection (TCPC) patients and to correlate calculated muscle mass with clinical outcomes. Materials and methods Ninety-one TCPC patients at a mean age of 24.0 ±5.5 years (37 women; 40.7%) who underwent chest computed tomography (CT) or cardiac magnetic resonance imaging (MRI) as part of their follow-up were identified in a single-center database. The cross-sectional skeletal muscle index (SMI) at the Th4 and Th12 levels was calculated from CT images, and the dorsal skeletal muscle area (SMA) at the Th12 level was measured from an MRI. Results Calculated SMI at Th12 level was 38.0 (34.5; 42.0) cm2.m-2 or 89.6 (81.9; 101.6) % of predicted values. The median follow-up from CT was 5.9 (3.1; 8.5) years, and the composite endpoint (death N=5, heart transplant N=6) was reached in a total of 11 (26.8%) patients. Patients with SMI (Th12) less than 90% of predicted values had a hazard ratio of 5.8 (95% CI: 1.2; 28.3) (p=0.03) for endpoint achievement. In the MRI group, dorsal SMA at the Th12 level was 27.6 ±5.1 cm2 in men and 20.0 ±5.8 cm2 in women. Correlations were found between SMA/kg and peak oxygen uptake (VO2 peak) (r=0.48, p=0.0005) and fat-free mass (r=0.63, p<0.0001), respectively. Conclusions A low SMI at the Th12 level was associated with a higher risk of death or cardiac transplantation. Evaluation of skeletal muscle mass using cardiovascular imaging methods allows rapid identification of individuals at risk of sarcopenia.

Clinical, functional, and opportunistic CT metrics of sarcopenia at the point of imaging care: analysis of all-cause mortality

PURPOSE

This study examines clinical, functional, and CT metrics of sarcopenia and all-cause mortality in older adults undergoing outpatient imaging.

METHODS

The study included outpatients ≥ 65 years of age undergoing CT or PET/CT at a tertiary care institution. Assessments included screening questionnaires for sarcopenia (SARC-F) and frailty (FRAIL scale), and measurements of grip strength and usual gait speed (6 m course). Skeletal muscle area (SMA), index (SMI, area/height2) and density (SMD) were measured on CT at T12 and L3. A modified SMI was also examined (SMI-m, area/height). Mortality risk was studied with Cox proportional hazard analysis.

RESULTS

The study included 416 patients; mean age 73.8 years [sd 6.2]; mean follow-up 2.9 years (sd 1.34). Abnormal grip, SARC-F, and FRAIL scale assessments were associated with higher mortality risk (HR [95%CI] = 2.0 [1.4-2.9], 1.6 [1.1-2.3], 2.0 [1.4-2.8]). Adjusting for age, higher L3-SMA, T12-SMA, T12-SMI and T12-SMI-m were associated with lower mortality risk (HR [95%CI] = 0.80 [0.65-0.90], 0.76 [0.64-0.90], 0.84 [0.70-1.00], and 0.80 [0.67-0.90], respectively). T12-SMD and L3-SMD were not predictive of mortality. After adjusting for abnormal grip strength and FRAIL scale assessments, T12-SMA and T12-SMI-m remained predictive of mortality risk (HR [95%CI] = 0.83 [0.70-1.00] and 0.80 [0.67-0.97], respectively).

CONCLUSION

CT areal metrics were weaker predictors of all-cause mortality than clinical and functional metrics of sarcopenia in our older patient cohort; a CT density metric (SMD) was not predictive. Of areal CT metrics, SMI (area/height2) appeared to be less effective than non-normalized SMA or SMA normalized by height1.

Muscle Reference Values From Thoracic and Abdominal CT for Sarcopenia Assessment: The Framingham Heart Study

BACKGROUND

Loss of muscle mass is a known feature of sarcopenia and predicts poor clinical outcomes. Although muscle metrics can be derived from routine computed tomography (CT) images, sex-specific reference values at multiple vertebral levels over a wide age range are lacking.

OBJECTIVE

The aim of this study was to provide reference values for skeletal muscle mass and attenuation on thoracic and abdominal CT scans in the community-based Framingham Heart Study cohort to aid in the identification of sarcopenia.

MATERIALS AND METHODS

This secondary analysis of a prospective trial describes muscle metrics by age and sex for participants from the Framingham Heart Study without prior history of cancer who underwent at least 1 CT scan between 2002 and 2011. Using 2 previously validated machine learning algorithms followed by human quality assurance, skeletal muscle was analyzed on a single axial CT image per level at the 5th, 8th, 10th thoracic, and 3rd lumbar vertebral body (T5, T8, T10, L3). Cross-sectional muscle area (cm 2 ), mean skeletal muscle radioattenuation (SMRA, in Hounsfield units), skeletal muscle index (SMI, in cm 2 /m 2 ), and skeletal muscle gauge (SMRA·SMI) were calculated. Measurements were summarized by age group (<45, 45-54, 55-64, 65-74, ≥75 years), sex, and vertebral level. Models enabling the calculation of age-, sex-, and vertebral-level-specific reference values were created and embedded into an open access online Web application.

RESULTS

The cohort consisted of 3804 participants (1917 [50.4%] males; mean age, 55.6 ± 11.8 years; range, 33-92 years) and 7162 CT scans. Muscle metrics qualitatively decreased with increasing age and female sex.

CONCLUSIONS

This study established age- and sex-specific reference values for CT-based muscle metrics at thoracic and lumbar vertebral levels. These values may be used in future research investigating the role of muscle mass and attenuation in health and disease, and to identify sarcopenia.

Opportunistic Muscle Evaluation During Chest CT Is Associated With Vertebral Compression Fractures in Old Adults: A Longitudinal Study

BACKGROUND

Sarcopenia and bone loss are both common in older individuals. However, the association between sarcopenia and bone fractures has not been evaluated longitudinally. In this study, we evaluated the association between computed tomography (CT)-based erector spinae muscle area and attenuation and vertebral compression fracture (VCF) in elderly individuals in a longitudinal study.

METHODS

This study recruited individuals 50 years of age and older, who did not have VCF and underwent CT imaging for lung cancer screening during January 2016 to December 2019. Participants were followed up annually until January 2021. Muscle CT value and muscle area of the erector spinae were determined for muscle assessment. Genant score was used to define new-onset VCF. Cox proportional hazards models were used to assess the association between muscle area/attenuation and VCF.

RESULTS

Of the 7 906 included participants, 72 developed new VCF over a median follow-up of 2 years. Large area of the erector spinae (adjusted hazard ratio [HR] = 0.2, 95% confidence interval [CI]: 0.1-0.7) and high bone attenuation (adjusted HR = 0.2, 95% CI: 0.1-0.5) were independently associated with VCF. High muscle attenuation was associated with severe VCF (adjusted HR = 0.46, 95% CI: 0.24-0.86). The addition of muscle area improved the area under the curve of bone attenuation from 0.79 (95% CI: 0.74-0.86) to 0.86 (95% CI: 0.82-0.91; p = .001).

CONCLUSIONS

CT-based muscle area/attenuation of the erector spinae was associated with VCF in elderly individuals, independently of bone attenuation. The addition of muscle area improved the performance of bone attenuation in predicting VCF.

Body Composition, Coronary Microvascular Dysfunction, and Future Risk of Cardiovascular Events Including Heart Failure

BACKGROUND

Body mass index (BMI) is a controversial marker of cardiovascular prognosis, especially in women. Coronary microvascular dysfunction (CMD) is prevalent in obese patients and a better discriminator of risk than BMI, but its association with body composition is unknown.

OBJECTIVES

The authors used a deep learning model for body composition analysis to investigate the relationship between CMD, skeletal muscle (SM), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT), and their contribution to adverse outcomes in patients referred for evaluation of coronary artery disease.

METHODS

Consecutive patients (n = 400) with normal perfusion and preserved left ventricular ejection fraction on cardiac stress positron emission tomography were followed (median, 6.0 years) for major adverse events, including death and hospitalization for myocardial infarction or heart failure. Coronary flow reserve (CFR) was quantified as stress/rest myocardial blood flow from positron emission tomography. SM, SAT, and VAT cross-sectional areas were extracted from abdominal computed tomography at the third lumbar vertebra using a validated automated algorithm.

RESULTS

Median age was 63, 71% were female, 50% non-White, and 50% obese. Compared with the nonobese, patients with obesity (BMI: 30.0-68.4 kg/m2) had higher SAT, VAT, and SM, and lower CFR (all P < 0.001). In adjusted analyses, decreased SM but not increased SAT or VAT was significantly associated with CMD (CFR <2; OR: 1.38; 95% CI: 1.08-1.75 per -10 cm2/m2 SM index; P < 0.01). Both lower CFR and SM, but not higher SAT or VAT, were independently associated with adverse events (HR: 1.83; 95% CI: 1.25-2.68 per -1 U CFR and HR: 1.53; 95% CI: 1.20-1.96 per -10 cm2/m2 SM index, respectively; P < 0.002 for both), especially heart failure hospitalization (HR: 2.36; 95% CI: 1.31-4.24 per -1 U CFR and HR: 1.87; 95% CI: 1.30-2.69 per -10 cm2/m2 SM index; P < 0.004 for both). There was a significant interaction between CFR and SM (adjusted P = 0.026), such that patients with CMD and sarcopenia demonstrated the highest rate of adverse events, especially among young, female, and obese patients (all P < 0.005).

CONCLUSIONS

In a predominantly female cohort of patients without flow-limiting coronary artery disease, deficient muscularity, not excess adiposity, was independently associated with CMD and future adverse outcomes, especially heart failure. In patients with suspected ischemia and no obstructive coronary artery disease, characterization of lean body mass and coronary microvascular function may help to distinguish obese phenotypes at risk for cardiovascular events.

Society for Surgery of the Alimentary Tract State-of-the-Art Session 2022: Frailty in Surgery

Given the exponentially aging population and rising life expectancy in the United States, surgeons are facing a challenging frail population who may require surgery but may not qualify based on their general fitness. There is an urgent need for greater awareness of the importance of frailty measurement and the implementation of universal assessment of frail patients into clinical practice. Pairing risk stratification with stringent protocols for prehabilitation and minimally invasive surgery and appropriate enhanced recovery protocols could optimize and condition frail patients before, during, and immediately after surgery to mitigate postoperative complications and consequences on patient function and quality of life. In this paper, highlights from the 2022 Society for Surgery of the Alimentary Tract State-of-the-Art Session on frailty in surgery are presented. This work aims to improve the understanding of the impact of frailty on patients and the methods used to augment the outcomes for frail patients during their surgical experience.

Tumor-Derived Sarcopenia Factors Are Diverse in Different Tumor Types: A Pan-Cancer Analysis

Cancer-associated muscle wasting is a widespread syndrome in people with cancer and is characterized by weight loss and muscle atrophy, leading to increased morbidity and mortality. However, the tumor-derived factors that affect the development of muscle wasting and the mechanism by which they act remain unknown. To address this knowledge gap, we aimed to delineate differences in tumor molecular characteristics (especially secretion characteristics) between patients with and without sarcopenia across 10 tumor types from The Cancer Genome Atlas (TCGA). We integrated radiological characteristics from CT scans of TCGA cancer patients, which allowed us to calculate skeletal muscle area (SMA) to confirm sarcopenia. We combined TCGA and GTEx (The Genotype-Tissue Expression) data to analyze upregulated secretory genes in 10 tumor types compared with normal tissues. Upregulated secretory genes in the tumor microenvironment and their relation to SMA were analyzed to identify potential muscle wasting biomarkers (560 samples). Meanwhile, their predictive values for patient survival was validated in 3530 samples in 10 tumor types. A total of 560 participants with transcriptomic data and SMA were included. Among those, 136 participants (24.28%) were defined as having sarcopenia based on SMA. Enrichment analysis for upregulated secretory genes in cancers revealed that pathways associated with muscle wasting were strongly enriched in tumor types with a higher prevalence of sarcopenia. A series of SMA-associated secretory protein-coding genes were identified in cancers, which showed distinct gene expression profiles according to tumor type, and could be used to predict prognosis in cancers (p value ≤ 0.002). Unfortunately, those genes were different and rarely overlapped across tumor types. Tumor secretome characteristics were closely related to sarcopenia. Highly expressed secretory mediators in the tumor microenvironment were associated with SMA and could affect the overall survival of cancer patients, which may provide a valuable starting point for the further understanding of the molecular basis of muscle wasting in cancers. More importantly, tumor-derived pro-sarcopenic factors differ across tumor types and genders, which implies that mechanisms of cancer-associated muscle wasting are complex and diverse across tumors, and may require individualized treatment approaches.

Red blood cell distribution width is associated with sarcopenia risk in early-stage non-small cell lung cancer

BACKGROUND

Sarcopenia has received increasing attention in non-small cell lung cancer (NSCLC). Red blood cell distribution width (RDW) is a significant component of the complete blood count and indicates the heterogeneity of erythrocyte volume. Little information is known about RDW in relation to sarcopenia in early-stage (IA-IIIA) NSCLC. The purpose of the present study was to investigate the association between RDW and sarcopenia risk in early-stage NSCLC patients.

METHODS

This study included 378 patients with pathologically confirmed stage IA-IIIA NSCLC. Sarcopenia was defined by measuring the skeletal muscle index (SMI) at the eleventh thoracic vertebra level. The maximum Youden index on the receiver operating characteristic (ROC) curve was used to estimate the cutoff value for RDW to predict sarcopenia. Logistic regression analyses were carried out to assess the independent risk factors for sarcopenia in NSCLC.

RESULTS

The ROC curve indicated that the best cutoff point for RDW to predict sarcopenia was 12.9 (sensitivity of 43.80% and specificity of 76.76%, respectively). Moreover, there were significant differences in hemoglobin (p < 0.001), comorbidities (p = 0.001), histological type (p = 0.002), and cancer stage (p = 0.032) between the high RDW and low RDW groups. Logistic regression analyses revealed that high RDW is an independent risk factor for sarcopenia in early-stage NSCLC.

CONCLUSION

RDW is associated with sarcopenia risk in early-stage NSCLC.

Association of Sarcopenia With Toxicity-Related Discontinuation of Adjuvant Endocrine Therapy in Women With Early-Stage Hormone Receptor-Positive Breast Cancer

PURPOSE

Sarcopenia, an age-related decline in muscle mass and physical function, is associated with increased toxicity and worse outcomes in women with breast cancer (BC). Sarcopenia may contribute to toxicity-related early discontinuation of adjuvant endocrine  therapy (aET) in women with hormone receptor-positive (HR+) BC but remains poorly characterized.

METHODS AND MATERIALS

This multicenter, retrospective cohort study included consecutive women with stage 0-II HR+ BC who received breast conserving therapy (lumpectomy and radiation therapy) and aET from 2011 to 2017 with a 5-year follow-up. Skeletal muscle index (SMI, cm2/m2) was analyzed using a deep learning model on routine cross-sectional radiation simulation imaging; sarcopenia was dichotomized according to previously validated reports. The primary endpoint was toxicity-related aET discontinuation; logistic regression analysis evaluated associations between SMI/sarcopenia and aET discontinuation. Cox regression analysis evaluated associations with time to aET toxicity, ipsilateral breast tumor recurrence (IBTR), and disease-free survival (DFS).

RESULTS

A total of 305 women (median follow-up, 89 months) were included with a median age of 67 years and early-stage BC (12% stage 0, 65% stage I). A total of 60 (20%) women experienced toxicity-related aET discontinuation. Sarcopenia was associated with toxicity-related early discontinuation of aET (odds ratio, 2.18; P = .036) and shorter time to aET toxicity (hazard ratio [HR], 1.62; P = .031). SMI or sarcopenia were not independently associated with IBTR or DFS; toxicity-related aET discontinuation was associated with worse IBTR (HR, 9.47; P = .002) and worse DFS (HR, 4.53; P = .001).

CONCLUSIONS

Among women with early-stage HR+ BC who receive adjuvant radiation therapy and hormone therapy, sarcopenia is associated with toxicity-related early discontinuation of aET. Further studies should validate these findings in women who did not receive adjuvant radiation therapy. These high-risk patients may be candidates for aggressive symptom management and/or alternative treatment strategies to improve outcomes.

Factors Influencing Immunotherapy Outcomes in Cancer: Sarcopenia and Systemic Inflammation

BACKGROUND

Immunotherapy has shown promise in treating various subtypes of metastatic cancers, but many patients are frail and may have compromised immune systems, which can influence treatment outcomes. Sarcopenia, a condition characterized by loss of muscle mass and systemic inflammation, is a potential factor that may negatively impact the response to immunotherapy. However, more data must be collected on the extent of its influence. Therefore, this study aims to investigate the effects of sarcopenia, systemic inflammation, and Eastern Cooperative Oncology Group Performance Status (ECOG PS) on the response to immunotherapy.

METHODS

We enrolled 100 patients treated with immune checkpoint inhibitors between 2015 and 2021 who underwent computed tomography of the abdomen before the first immunotherapy dose. This study was conducted retrospectively. Gender-specific thresholds were used for the diagnosis of sarcopenia. C-reactive protein (CRP), erythrocyte sedimentation rate, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), albumin, and lactate dehydrogenase (LDH) were used as markers of systemic inflammation. Systemic inflammatory markers and sarcopenia were assessed using univariable and multivariable analyses for overall survival (OS) and progression-free survival (PFS).

RESULTS

Sarcopenia was found to be a significant prognostic factor associated with poor PFS (HR, 2.33; 95% confidence interval [CI], 1.45-3.74; P < 0.001). In addition, hypoalbuminemia was identified as a significant prognostic factor for predicting OS (HR, 2.10; 95% CI, 1.21-3.66; P = 0.008).

CONCLUSIONS

Closer monitoring and prevention of sarcopenia may enhance both OS and PFS. Additionally, our composite model may assist oncologists in predicting responses to immunotherapy more accurately. However, further prospective studies are needed to validate these findings.

Morphomics-informed population pharmacokinetic and physiologically-based pharmacokinetic modeling to optimize cefazolin surgical prophylaxis

INTRODUCTION

Cefazolin is the leading antibiotic used to prevent surgical site infections worldwide. Consensus guidelines recommend adjustment of the cefazolin dose above and below 120 kg without regard to body composition. Algorithms exist to repurpose radiologic data into body composition (morphomics) and inform dosing decisions in obesity.

OBJECTIVES

To compare the current standard of body weight to morphomic measurements as covariates of cefazolin pharmacokinetics and aid dose stratification of cefazolin in patients with obesity undergoing colorectal surgery.

METHODS

This prospective study measured cefazolin plasma, fat, and colon tissue concentrations in colorectal surgery patients in order to develop a morphomics-informed population pharmacokinetic (PopPK) model to guide dose adjustments. A physiologically-based pharmacokinetic (PBPK) model was also constructed to inform tissue partitioning in morbidly obese patients (n = 21, body mass index ≥35 kg/m2 with one or more co-morbid conditions).

RESULTS

Morphomics and pharmacokinetic data were available in 58 patients with a median [min, max] weight and age of 95.9 [68.5, 148.8] kg and 55 [25, 79] years, respectively. The plasma-to-subcutaneous fat partition coefficient was predicted to be 0.072 and 0.060 by the PopPK and PBPK models, respectively. The estimated creatinine clearance (eCLcr ) and body depth at the third lumbar vertebra (body depth_L3) were identified as covariates of cefazolin exposure. The probability of maintaining subcutaneous fat concentrations above 2 μg/mL for 100% of a 4-h surgical period was below 90% when eCLcr ≥105 mL/min and body depth_L3 ≥ 300 mm and less sensitive to the rate of infusion between 5 and 60 min.

CONCLUSIONS

Kidney function and morphomics were more informative than body weight as covariates of cefazolin target site exposure. Data from more diverse populations, consensus on target cefazolin exposure, and comparative studies are needed before a change in practice can be implemented.

[Increased muscle mass increases risks of intervertebral disc degeneration: a two-sample Mendelian randomization study]

OBJECTIVE

To investigate the causal relationship between sarcopenia (SP) and intervertebral disc degeneration (IVDD) using two-sample Mendelian randomization analysis.

METHODS

Genome-wide association study (GWAS) databases of SP (lean body mass, right and left hand grip strength) and IVDD were obtained. The single nucleotide polymorphisms (SNPs) strongly associated with exposure were obtained as an instrumental variable. After conservatively removing two confounders (smoking and sedentary life style), the causal relationship between SP and IVDD was assessed using Mendelian randomization analyses through the inverse variance weighting (IVW), weighted median (WM) and MR-Egger methods. The consistency and accuracy of the results were verified by MR-PRESSO, double validation, negative control, heterogeneity and diversity tests.

RESULTS

A total of 570 SNPs associated with lean muscle mass, 97 with strong right hand grip strength, and 79 with strong left hand grip strength were included in the analysis. The results showed that lean muscle mass had a significant positive correlation with IVDD (IVW: OR=1.139, 95% CI: 1.076-1.204, P=6.619e-6) and right hand grip strength had a possible positive correlation with IVDD. After reanalysis in MR-PRESSO and selection of a new IVDD database, the results remained largely consistent with the previous results.

CONCLUSION

Increased muscle mass may increase the risk of intervertebral disc degeneration.

Prevalence and prognostic value of baseline sarcopenia in hematologic malignancies: a systematic review

Background

The correlation between sarcopenia and hematological malignancy prognosis is still controversial. Design: A systematic review and meta-analysis. Objectives: To explore sarcopenia's prevalence and prognostic value in hematologic malignancies.

Data sources and methods

We searched Embase, MEDLINE, and Cochrane Library through Ovid SP using an appropriate search strategy on August 28, 2022, and updated the search results on January 9, 2023. Study quality was assessed using the Newcastle-Ottawa scale. The pooled prevalence of sarcopenia was calculated with a 95% confidence interval (CI). Relationships between sarcopenia and prognostic value were expressed as hazard ratio (HR) and 95% CI. HR means the probability of something undesirable, i.e., death or disease progression.

Results

The search identified more than 3992 studies, and 21 (3354 patients, median or mean age ranging from 36 to 78 years) were finally included. The risk of bias in the studies was low to medium. All included studies were diagnosed based on low muscle mass (LMM). Muscle mass was assessed mainly through imaging technologies, and different cut-offs were applied to determine LMM. The prevalence of sarcopenia was 44.5%, which could fluctuate by age. Subgroup analysis showed that older people had a higher sarcopenic rate than the non-elderly group. Sarcopenia resulted in an inferior prognosis [overall survival: HR 1.821, 95% CI 1.415-2.343; progression-free survival: HR 1.703, 95% CI 1.128-2.571).

Conclusion

Sarcopenia has a prevalence of over 30% in malignant hematologic patients and is associated with a poorer prognosis. Future studies with a standardized sarcopenia diagnostic criterion were needed to investigate sarcopenia's prevalence and prognostic effects in hematologic malignancies.

Feasibility of using chest computed tomography (CT) imaging at the first lumbar vertebra (L1) level to assess skeletal muscle mass: a retrospective study

Background

Skeletal muscle mass is an essential parameter for diagnosing sarcopenia. The gold standard for assessing skeletal muscle mass is using computed tomography (CT) to measure skeletal muscle area at the third lumbar vertebra (L3) level. This study aims to investigate whether skeletal muscle mass could be evaluated at the first lumbar vertebra (L1) level using images obtained from routine chest CT scans.

Methods

Skeletal muscle index (SMI, cm2/m2) and skeletal muscle density (SMD, HU) are commonly used to measure relative muscle mass and the degree of fat infiltration. This study used CT images at the L1 level to measure the skeletal muscle area (SMA, cm2) in 815 subjects from the health examination center. Linear regression analysis was used to explore the association between L1 and L3 measurements. The receiver operating characteristic (ROC) analysis was used to assess the predictive performance of L1 SMI for sarcopenia. The sex-specific cut-off values for low skeletal muscle mass in patients under the age of 60 were determined using the following formula: "mean - 1.28 × standard deviation." A multivariate linear regression model was established.

Results

A significantly higher SMI at the L1 level was found in males than in females (43.88 ± 6.33 cm2/m2 vs 33.68 ± 5.03 cm2/m2; P < 0.001). There were strong correlations between measures at the L1 and L3 levels in both the total subject and sex-specific analyses. A negative association was found between age and L3 SMI in males (r = -0.231, P = 0.038). Both body mass index (BMI) and body surface area (BSA) were positively associated with L1 SMI in both males and females. A multivariate analysis was used to establish a prediction rule to predict SMI at the L3 level. The assessment of consistency and interchangeability between predicted and actual SMI at the L3 level yielded moderately good results. Considering the significant differences observed between male and female participants, the sex-specific cut-off values of the L1 SMI for defining low skeletal muscle mass were 36.52 cm2/m2 in males and 27.29 cm2/m2 in females.

Conclusions

Based on a population from central China, the correlated indicators obtained at the L1 level from routine chest CT scans may serve as effective surrogate markers for those at the L3 level in assessing overall skeletal muscle mass.

Sarcopenia and anthracycline cardiotoxicity in patients with cancer

BACKGROUND

Several studies have suggested that sarcopenia is associated with an increased treatment toxicity in patients with cancer. The aim of this study is to evaluate the relationship between sarcopenia and anthracycline-related cardiotoxicity.

METHODS

Patients who received anthracycline-based chemotherapy between 2014 and 2018 and had baseline abdominal CT and baseline and follow-up echocardiography after anthracycline treatment were included. European Society of Cardiology ejection fraction criteria and American Society of Echocardiography diastolic dysfunction criteria were used for definition of cardiotoxicity. Sarcopenia was defined on the basis of skeletal muscle index (SMI) and psoas muscle index (PMI) calculated on CT images at L3 and L4 vertebra levels.

RESULTS

A total of 166 patients (75 men and 91 women) were included. Sarcopenia was determined in 33 patients (19.9%) according to L3-SMI, in 17 patients (10.2%) according to L4-SMI and in 45 patients (27.1%) according to PMI. 27 patients (16.3%) developed cardiotoxicity. PMI and L3-SMI were significantly associated with an increased risk of cardiotoxicity (L3-SMI: HR=3.27, 95% CI 1.32 to 8.11, p=0.01; PMI: HR=3.71, 95% CI 1.58 to 8.73, p=0.003).

CONCLUSIONS

This is the first study demonstrating a significant association between CT-diagnosed sarcopenia and anthracycline-related cardiotoxicity. Routine CT scans performed for cancer staging may help clinicians identify high-risk patients in whom closer follow-up or cardioprotective measures should be considered.

Acute muscle wasting rate assessment and long-term mortality in critically ill trauma

BACKGROUND AND OBJECTIVES

To evaluate the relationship between acute muscle wasting rate and long-term mortality in critically ill trauma.

METHODS AND STUDY DESIGN

A single-center, retrospective study was conducted in critically ill trauma. Patients with Computed Tomography scans including the L3 vertebra within 24 hours and at 1 week after trauma were recruited. Acute muscle wasting rate was defined as the mean percent variation per day of skeletal muscle index in the first week after trauma. Multivariate logistic regression analysis and receiver operating characteristic curve analysis were performed to determine whether acute muscle wasting rate could help predict hospital malnutrition and 1-year mortality.

RESULTS

Skeletal muscle index was 49.3±10.7 cm2/m2 at baseline and decreased to 45.1±9.6 cm2/m2 (p<0.001) at 1 week and 39.8±10.8cm2/m2 (p<0.001) at 1 month after trauma. A sustained decrease of skeletal muscle index was observed from baseline up to 6 months (33.7±8.4cm2/m2, p<0.001) post trauma, and lasted for 1 year (37.7±5.6cm2/m2, p=0.004). Logistic regression analysis showed that acute muscle wasting rate was an independent risk factor for hospital malnutrition and 1-year mortality. Every 1% absolute increase of acute muscle wasting rate was associated with 1.82-fold higher odds of 1-year mortality in critically ill trauma. The area under curve of acute muscle wasting rate was 0.813 for hospital malnutrition prediction and 0.715 for 1-year mortality prediction.

CONCLUSIONS

Acute muscle wasting rate was independently associated with higher 1-year mortality and hospital malnutrition in critically ill trauma.

Sarcopenia in Patients With Rectal Adenocarcinoma: An Opportunity for Preoperative Rehabilitation

BACKGROUND

Sarcopenia, defined as low skeletal muscle mass, affects up to 60% of rectal adenocarcinoma patients receiving neoadjuvant chemoradiation (NACRT), with negative impact on patient outcomes. Identifying modifiable risk factors may decrease morbidity and mortality.

METHODS

A retrospective review of rectal cancer patients from a single academic center from 2006 to 2020 was performed. Sixty-nine patients with pre- and post-NACRT CT imaging were included. Skeletal muscle index (SMI) was calculated as total L3 skeletal muscle divided by height squared. Sarcopenia thresholds were 52.4 cm2/m2 for men and 38.5 cm2/m2 for women. Student T-test, chi-square test, multivariable regression, and multivariable Cox hazard analysis were performed.

RESULTS

62.3% of patients lost SMI from pre- to post-NACRT imaging, with a mean change of -7.8% (±19.9%). Eleven (15.9%) patients were sarcopenic at presentation, increasing to 20 (29.0%) following NACRT. Mean SMI decreased from 49.0 cm2/m2 (95% CI: 42.0 cm2/m2-56.0 cm2/m2) to 38.2 cm2/m2 (95% CI: 33.6 cm2/m2-42.9 cm2/m2) (P = .003). Pre-NACRT sarcopenia correlated with post-NACRT sarcopenia (OR 20.6, P = .002). Percent decrease in SMI was associated with a 5% increased mortality risk.

CONCLUSION

The presence of sarcopenia at diagnosis and its association with post-NACRT sarcopenia suggests an opportunity for a high-impact intervention.

The impact of muscle mass and myosteatosis on mortality in critically ill patients with Sars-Cov2-related pneumonia

BACKGROUND & AIMS

Sars-Cov-2 pneumonia can lead to severe complications, requiring invasive mechanical ventilation and admission to the intensive care unit (ICU). Low muscle quantity and quality (the latter evaluated by the amount of ectopic fat infiltration in the muscle [myosteatosis]) at ICU admission are associated with worse outcomes in critically ill patients. The purpose of the present study is to assess muscle mass and myosteatosis of paravertebral skeletal muscle, in critically ill patients with Sars-Cov2 pneumonia and its association with mortality.

METHODS

We conducted a retrospective observational study in 110 critically ill patients with severe Sars-Cov-2 pneumonia that had a high - resolution chest Computerized Tomography (HR-CT) at ICU admission. We acquired CT images at the level of the thoracic 12 (T12) vertebral body and measured skeletal muscle area (SMA), intermuscular adipose tissue (IMAT), and low attenuation muscle area (LAMA). Patients were followed until ICU mortality or discharge.

RESULTS

Patients were 59.8 ± 8.1 years old, 77% were male. Seventy-nine percent of patients were considered at nutritional risk, and 22% were obese. Average Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 17 ± 5.4, and the overall ICU mortality was 48,2% (53/110). At ICU admission, both parameters of myosteatosis were associated with higher mortality (IMAT [per 10% increase] HR: 2.01 (95% Confidence Interval [CI] 1.27 to 3.17), P = 0.003; LAMA HR [per 10% increase]: 1.53 (95% CI 1.10 to 2.13), P = 0.012).

CONCLUSION

Myosteatosis as assessed by CT scans plays a relevant role as a prognostic marker in critically ill patients with Sars-Cov2 severe pneumonia.

Validity of computed tomography defined body composition as a prognostic factor for functional outcome after kidney transplantation

BACKGROUND

The prevalence of sarcopenia is markedly higher in kidney transplant candidates than in the general population. It is a syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength, which increases the risk of adverse postoperative outcomes.

METHODS

We studied the impact of computed tomography defined preoperative sarcopenia, defined as a skeletal muscle index below age and gender specific cut-off values, on postoperative physical functional outcomes (grip strength, 4-m walking test, timed up and go, and sit to stand) at 6 months follow up.

RESULTS

A total of 107 patients transplanted between 2015 and 2019 were included in this single-centre study. Mean age was 60.3 (±13.1), and 68.2% of patients were male. Ten patients (9.4%) were identified as sarcopenic. Sarcopenic patients were younger (55.6 (±15.1) vs. 60.8 (±12.9) years), more likely to be female (60.0% vs. 28.9%), and had an increased dialysis vintage (19 [2.5-32.8] vs. 9 [0.0-21.0] months) in comparison with their non-sarcopenic counterparts. In univariate analysis, they had a significantly lower body mass index and skeletal muscle area (P ≤ 0.001). In multivariate regression analysis, skeletal muscle index was significantly associated with grip strength (β = 0.690, R2  = 0.232) and timed up and go performance (β = -0.070, R2  = 0.154).

CONCLUSIONS

We identified a significant association between sarcopenia existing pre-transplantation and poorer 6 months post-transplantation physical functioning with respect to hand grip strength and timed up and go tests in kidney transplant recipients. These results could be used to preoperatively identify patients with an increased risk of poor postoperative physical functional outcome, allowing for preoperative interventions to mitigate these risks.

Computed tomography-determined skeletal muscle density predicts 3-year mortality in initial-dialysis patients in China

BACKGROUND

Skeletal muscle mass and quality assessed by computed tomography (CT) images of the third lumbar vertebra (L3) level have been established as risk factors for poor clinical outcomes in several illnesses, but the relevance for dialysis patients is unclear. A few studies have suggested a correlation between CT-determined skeletal muscle mass and quality at the first lumbar vertebra (L1) level and adverse outcomes. Generally, chest CT does not reach beyond L1. We aimed to determine whether opportunistic CT scan (chest CT)-determined skeletal muscle mass and quality at L1 are associated with mortality in initial-dialysis patients.

METHODS

This 3-year multicentric retrospective study included initial-dialysis patients from four centres between 2014 and 2017 in China. Unenhanced CT images of the L1 and L3 levels were obtained to assess skeletal muscle mass [by skeletal muscle index, (SMI), cm2 /m2 ] and quality [by skeletal muscle density (SMD), HU]. Skeletal muscle measures at L1 were compared with those at L3. The sex-specific optimal cutoff values of L1 SMI and L1 SMD were determined in relation to all-cause mortality. The outcomes were all-cause death and cardiac death. Cox regression models were applied to investigate the risk factors for death.

RESULTS

A total of 485 patients were enrolled, of whom 257 had both L1 and L3 images. Pearson's correlation coefficient between L1 and L3 SMI was 0.84 (P < 0.001), and that between L1 and L3 SMD was 0.90 (P < 0.001). No significant association between L1 SMI and mortality was observed (P > 0.05). Low L1 SMD (n = 280, 57.73%) was diagnosed based on the optimal cutoff value (<39.56 HU for males and <33.06 HU for females). Multivariate regression analysis revealed that the low L1 SMD group had higher risks of all-cause death (hazard ratio 1.80; 95% confidence interval 1.05-3.11, P = 0.034) and cardiac death (hazard ratio 3.74; 95% confidence interval 1.43-9.79, P = 0.007).

CONCLUSIONS

In initial-dialysis patients, there is high agreement between the L1 and L3 measures for SMI and SMD. Low SMD measured at L1, but not low SMI, is an independent predictor of both all-cause death and cardiac death.

Predictive Value of CT Biomarkers in Lung Transplantation Survival: Preliminary Investigation in a Diverse, Underserved, Urban Population

INTRODUCTION

Survival following lung transplant is low. With limited donor lung availability, predicting post-transplant survival is key. We investigated the predictive value of pre-transplant CT biomarkers on survival.

METHODS

In this single-center retrospective cohort study of adults in a diverse, underserved, urban lung transplant program (11/8/2017-5/20/2022), chest CTs were analyzed using TeraRecon to assess musculature, fat, and bone. Erector spinae and pectoralis muscle area and attenuation were analyzed. Sarcopenia thresholds were 34.3 (women) and 38.5 (men) Hounsfield Units (HU). Visceral and subcutaneous fat area and HU, and vertebral body HU were measured. Demographics and pre-transplant metrics were recorded. Survival analyses included Kaplan-Meier and Cox proportional hazard.

RESULTS

The study cohort comprised 131 patients, 50 women, mean age 60.82 (SD 10.15) years, and mean follow-up 1.78 (SD 1.23) years. Twenty-nine percent were White. Mortality was 32.1%. Kaplan-Meier curves did not follow the proportional hazard assumption for sex, so analysis was stratified. Pre-transplant EMR metrics did not predict survival. Women without sarcopenia at erector spinae or pectoralis had 100% survival (p = 0.007). Sarcopenia did not predict survival in men and muscle area did not predict survival in either sex. Men with higher visceral fat area and HU had decreased survival (p = 0.02). Higher vertebral body density predicted improved survival in men (p = 0.026) and women (p = 0.045).

CONCLUSION

Pre-transplantation CT biomarkers had predictive value in lung transplant survival and varied by sex. The absence of sarcopenia in women, lower visceral fat attenuation and area in men, and higher vertebral body density in both sexes predicted survival in our diverse, urban population.

Cancer Cachexia: New Insights and Future Directions

Cancer remains a major health problem and is associated with cachexia in up to 80% of cases, leading to decreased survival and quality of life. Cachexia involves complex metabolic disturbances in both protein and energy balance, muscle wasting phenomena, weight loss, systemic inflammation, overall decreased performance status, and tolerability to treatment. The clinical impact of cancer cachexia is very complex, with early detection of cachectic patients and identification of predictive biomarkers being two key factors for improving survival. Thus, a better understanding of the complexity of cancer cachexia phenomena and its main pathophysiological mechanism is much needed. Our review highlights the most important information about cancer cachexia, aiming to disseminate updated research findings about this highly deadly condition.

Diagnosis of Sarcopenia Using the L3 Skeletal Muscle Index Estimated From the L1 Skeletal Muscle Index on MR Images in Patients With Cirrhosis

BACKGROUND

Cirrhotic patients with sarcopenia have poor prognoses and higher mortality. The third lumbar vertebra (L3) skeletal muscle index (SMI) is widely used to assess sarcopenia. However, L3 is generally outside the scanning volume on standard liver MRI.

PURPOSE

To investigate SMIs change between slices in cirrhotic patients and the relationships between SMI at the 12th thoracic vertebra (T12), the first lumbar vertebra (L1) and the second lumbar vertebra (L2) levels and L3-SMI and assess the accuracy of the estimated L3-SMIs in diagnosing sarcopenia.

STUDY TYPE

Prospective.

SUBJECTS

A total of 155 cirrhotic patients (109 with sarcopenia, 67 male; 46 without sarcopenia, 18 male).

FIELD STRENGTH/SEQUENCE

A 3.0 T, 3D dual-echo T1-weighted gradient echo sequence (T1WI).

ASSESSMENT

Two observers analyzed T12 to L3 skeletal muscle area (SMA) in each patient based on T1W water images and calculated the SMI (SMA/height2 ). Reference standard was L3-SMI.

STATISTICAL TESTS

Intraclass correlation coefficient (ICC), Pearson correlation coefficients (r), and Bland-Altman plots. Models relating L3-SMI to the SMI at T12, L1, and L2 levels were constructed using 10-fold cross-validation. Accuracy, sensitivity, and specificity were calculated for the estimated L3-SMIs for diagnosing sarcopenia. P < 0.05 was considered statistically significant.

RESULTS

Intraobserver and interobserver ICCs were 0.998-0.999. The L3-SMA/L3-SMI were correlated with the T12 to L2 SMA/SMI (r = 0.852-0.977). T12-L2 models had mean-adjusted R2 values of 0.75-0.95. The estimated L3-SMI from T12 to L2 levels to diagnose sarcopenia had good accuracy (81.4%-95.3%), sensitivity (88.1%-97.0%), and specificity (71.4%-92.9%). The recommended L1-SMI threshold of 43.24 cm2 /m2 in males and 33.73 cm2 /m2 in females.

DATA CONCLUSION

The estimated L3-SMI from T12, L1 and L2 levels had good diagnostic accuracy in assessing sarcopenia in cirrhotic patients. Although L2 was best associated with L3-SMI, L2 is generally not included in standard liver MRI. L3-SMI estimate from L1 may therefore be most clinically applicable.

EVIDENCE LEVEL

1.

TECHNICAL EFFICACY

Stage 2.

SARC-F as a screening tool to detect computed tomography-based sarcopenia and myosteatosis among older adults with cancer

BACKGROUND

The European Working Group on Sarcopenia in Older People (EWGSOP) recommends SARC-F as a tool for identifying sarcopenia among older adults. However, the role of SARC-F among older adults with cancer remains unexplored. We aimed to evaluate the diagnostic utility of SARC-F to identify those with sarcopenia, or low muscle mass (using skeletal muscle index [SMI]), and myosteatosis (using skeletal muscle density [SMD]) from computed tomography (CT) imaging and the association of SARC-F with all-cause mortality.

METHODS

Older adults (≥60 years) presenting for initial consultation at UAB medical oncology clinic who underwent geriatric assessment were enrolled in a prospective cohort study. We identified study participants who completed SARC-F screening and had available CT imaging within 60 days of study enrollment. Using single-slice CT images at the L3 vertebral level, we computed SMI and SMD using published methods. Sarcopenia and myosteatosis were defined using published cutpoints. We calculated the sensitivity and specificity of SARC-F for detecting low muscle mass and low muscle density using published thresholds. Finally, we computed the impact of SARC-F and CT measures on overall survival using Kaplan-Meier curves and Cox regression models, after adjusting for age, sex, cancer type, and cancer stage.

RESULTS

We identified 212 older adults with a median age of 68.8 years; with 60.8% males, 76.6% whites, and pancreatic cancer (21.2%) being the most common malignancy. In the overall cohort, 30.7% had abnormal SARC-F using published cutpoints. SARC-F ≥ 4 had a sensitivity of 35% and a specificity of 76% to identify low muscle mass. SARC-F ≥ 4 had a sensitivity of 38% and a specificity of 74% to identify low muscle density. Those with SARC-F ≥ 4 and low SMI/SMD had worse survival compared to those with low SMI/SMD alone. Incorporating SARC-F improved survival prognostication beyond SMI and SMD (HR = 3.1; p < 0.001; Harrel's C from 0.73 to 0.76).

CONCLUSIONS

SARC-F as a screening tool has limited diagnostic utility for identifying older adults with low muscle mass and/or density. However, SARC-F retains prognostic value independent of CT-based muscle measures in predicting mortality among older adults with cancer.

Assessment of skeletal muscle using deep learning on low-dose CT images

The visceral fat area obtained by computed tomography (CT) at the navel level is clinically used as an indicator of visceral fat obesity in Japan. Analysis of skeletal muscle mass using CT images at the navel level may potentially support concurrent assessment of sarcopenia and sarcopenic obesity. The purpose of this study was to assess the performance of deep learning models (DLMs) for skeletal muscle mass measurement using low-dose abdominal CT. The primary dataset used in this study included 11,494 low-dose abdominal CT images at navel level acquired in 7,370 subjects for metabolic syndrome screening. The publicly available Cancer Imaging Archive (TCIA) dataset, including 5,801 abdominal CT images, was used as a complementary dataset. For abdominal CT image segmentation, we used the SegU-net DLM with different filter size and hierarchical depth. The segmentation accuracy was assessed by measuring the dice similarity coefficient (DSC), cross-sectional area (CSA) error, and Bland-Altman plots. The proposed DLM achieved a DSC of 0.992 ± 0.012, a CSA error of 0.41 ± 1.89%, and a Bland-Altman percent difference of -0.1 ± 3.8%. The proposed DLM was able to automatically segment skeletal muscle mass measurements from low-dose abdominal CT with high accuracy.