Management of intramuscular melanoma metastases to the psoas.

We detail a case of a woman in her 40s with isolated melanoma skeletal muscle metastasis (MSMM) to the right psoas muscle. This patient underwent R0 surgical resection through a novel pelvic approach. She received subsequent adjuvant immunotherapy with Braftovi/Mektov along with adjuvant radiation. She is currently disease free at 9 months post surgery. Here, we describe our novel surgical approach including description of the tumour pathology. We explain our multidisciplinary management of MSMM consisting of a multidisciplinary surgical approach by surgical oncology, gynecological oncology and urology as well as multidisciplinary medical management by oncology, radiation oncology and pathology. Finally, we discuss best current options for therapeutic management.

Are trunk muscle sizes different between acute lumbar spondylolysis and nonspecific low back pain?

INTRODUCTION: Morphological differences in the trunk muscles between adolescent athletes with lumbar spondylolysis (LS) and nonspecific low back pain (NSLBP) have not been fully elucidated. This study aimed to investigate the differences in physiological cross-sectional areas (CSA) of the trunk muscles between athletes with acute LS and those with acute NSLBP. METHODS: Magnetic resonance images of 48 patients aged 13-14 years diagnosed with acute LS or NSLBP were retrospectively evaluated. The CSA of the paraspinal, psoas major, and rectus abdominis muscles at the L4-5 intervertebral disc level were measured. RESULTS: CSA of the left and right paraspinal muscles in the acute LS group were significantly larger than those in the acute NSLBP group (left: mean difference, 276.0 mm2; 95% confidence interval [CI], 68.5-483.6 mm2; P = 0.01; right: mean difference, 228.8 mm2; 95% CI, 7.6-450.1 mm2; P = 0.04). The ratio between the left paraspinal muscles and left psoas major in the acute LS group was significantly larger than that in the acute NSLBP group (mean difference, 0.2; 95% CI, 0.0-0.4; P = 0.03). CONCLUSIONS: Trunk muscle size may differ between adolescent athletes with acute LS and those with NSLBP. Future research involving healthy controls is required to better understand the morphological characteristics of these injuries.

The relationship between the psoas major muscle morphology characteristics with disability index and pain in patients with chronic nonspecific low back pain.

BACKGROUND: Chronic nonspecific low back pain (CNLBP) is a common disorder in people of active ages and significantly affects their quality of life. Different structures in the lumbar area can cause LBP. The lumbar muscle disorders, including the psoas major (PM) muscles, have an essential role in LBP. Magnetic Resonance Imaging (MRI) has been introduced as a safe and useful instrument for investigating the morphological properties of skeletal muscle. In general, PM morphology changes may be one reason for the pain and disability experienced in CNLBP patients. Thus, this study aimed to assess the relationship among the PM's Cross-sectional area (CSA), medial-lateral (ML), and anterior-posterior (AP) diameters, with disability index and pain score in patients with CNLBP. METHOD: One hundred twenty patients with CNLBP (60 men and 60 women) participated in this cross-sectional study. Axial MRIs were obtained from L3/L4 and L4/L5 disc levels. Then, patients filled out Rolland Morris Disability Questionnaires, demographic data forms, and the Numeric Pain Rating Scale (NPRS). Image J software was used to analyze the images. Using Linear Regression and the Pearson test, the correlation between muscle CSA and diameters, as well as data obtained from questionnaires and NPRS, was analyzed. RESULTS: Results from the statistical analysis showed no statistically significant relationship among morphological characteristics of the psoas major muscle in L3/L4 and L4/L5 disc levels with disability index and pain score (p < 0.05). CONCLUSIONS: There is no significant relationship between the PM morphological characteristics and disability index and pain score. Therefore, muscle CSA and diameters are insufficient to determine the cause of CNLBP.

Comparison of different 2D muscle indexes measured at the level of the 3rd lumbar vertebra in survival prediction in patients with renal cell carcinoma.

BACKGROUND: Low computed tomography (CT)-determined muscle mass, commonly determined with height-adjusted muscle indexes (MIs), predicts worse survival in several cancers and has been suggested as a prognostic assessment tool. Although several MIs measured at the level of the 3rd lumbar vertebra (L3) are commonly used, it remains unestablished how different L3-determined MIs perform in survival prognostication compared to each other. The objective of this study was to investigate the performance of different MIs for survival prognostication in renal cell carcinoma (RCC). METHODS: We retrospectively enrolled 214 consecutive patients with RCC. We determined three L3-MIs (psoas muscle index (PMI), psoas muscle index and erector spinae index (PMI+ESI), and whole skeletal muscle index (SMI)) from preoperative CT scans. Categorization of those with low and normal muscle mass was based on the Youden Index sex-specific MI cut-offs. We determined sensitivity, specificity, and accuracy metrics for predicting 1-year, 5-year, and overall survival (OS) using Cox regression models. RESULTS: Low PMI, PMI+ESI, and SMI significantly predicted decreased 1-year, 5-year, and OS in uni- and multivariate models. PMI+ESI and SMI were more accurate than PMI in males, and PMI and PMI+ESI were more accurate than SMI in females in the prediction of 1-year survival. However, there were no differences in accuracies between MIs in 5-year and OS prediction. INTERPRETATION: PMI+ESI performed well overall in short-term prognostication, but there were no differences between the MIs in long-term prognostication. We recommend the use of PMI+ESI for muscle evaluation, particularly when SMI cannot be evaluated.

Correlation between relative dose intensity of adjuvant S-1 chemotherapy and psoas muscle mass volume and survival after resection of pancreatic ductal adenocarcinoma: A retrospective study.

This study aimed to investigate the prognostic relationship between relative dose intensity (RDI) of adjuvant S-1 chemotherapy and psoas muscle mass volume (PMV) in patients with resected pancreatic ductal adenocarcinoma. We enrolled 105 patients with histologically confirmed pancreatic ductal adenocarcinoma who had undergone pancreatectomy. Adjuvant S-1 chemotherapy was administered to 72 (68.6%) of the 105 patients and not to the remaining 33 patients. Patients who received adjuvant S-1 chemotherapy were stratified into high- and low-RDI groups by the cutoff value for RDI. Five-year overall survival (OS) and relapse-free survival (RFS) rates were significantly higher in the high- than in the low-RDI group. Similarly, both the 5-year OS and RFS rates were significantly greater among patients in the high-PMV group than among patients in the low-PMV group. The RDI was an independent prognostic factor in our study patients. Furthermore, patients who received adjuvant S-1 chemotherapy were stratified into 3 groups: those with both high RDI and high-PMV, Group A; those with either high RDI or high PMV (but not both), Group B; and those with both low RDI and low-PMV, group C. There were statistically significant differences in 5-year OS and RFS between 3 patient groups (5-year overall survival: P = .023, 5-year relapse-free survival: P = .001). The area under the curve for the combination of RDI and PMV (0.674) was greater than that for RDI alone (0.645). A sufficient dosage of adjuvant S-1 chemotherapy is important in improving survival of patients with resected pancreatic ductal adenocarcinoma. A combination of RDI and PMV may predict the prognosis of patients with resected pancreatic ductal adenocarcinoma more effective than RDI alone.

Psoas mass index at the level of the third lumbar vertebra on computed tomography is a prognostic predictor for metastatic castration-sensitive prostate cancer.

BACKGROUND: Computed tomography-defined low skeletal muscle mass is associated with oncological outcomes in patients with prostate cancer. However, its association with the outcomes of hormone-treated metastatic castration-sensitive prostate cancer remains unclear. We aimed to determine the association between metastatic castration-sensitive prostate cancer and psoas muscle parameters. METHODS: We retrospectively reviewed 121 patients with N1 and/or M1 metastatic castration-sensitive prostate cancer who underwent primary androgen deprivation therapy between 2005 and 2021, either by administration of luteinizing hormone-releasing hormone agonist/antagonist or by surgical castration accompanied by bicalutamide, a first-generation antiandrogen. Before treatment administration, the psoas muscle index at the level of the third lumbar vertebra (psoas muscle area [cm2]/height2 [m2]) and the mean Hounsfield units of the psoas muscle were evaluated using non-contrast computed tomography and in relation to oncological outcomes. RESULTS: The median follow-up was 56.9 months. Furthermore, during follow-up, 82 (67.7%) and 53 (43.8%) patients progressed to castration-resistant prostate cancer and died, respectively. Multivariate analysis of castration-resistant prostate cancer-free survival and overall survival showed significant differences in the Gleason score, clinical N-stage, and psoas muscle index (median cutoff: 3.044 cm2/m2). CONCLUSIONS: Pretreatment psoas muscle index is an independent predictor of poor castration-resistant prostate cancer-free survival and overall survival in patients with N1 and/or M1 metastatic castration-sensitive prostate cancer.

Peripheral nerve stimulation for psoas muscle pain.

The psoas muscle is the largest muscle in the lower lumbar spine and is innervated by the ipsilateral lumbar spinal nerve roots (L2-L4). Here, we present a 44-year-old female with left hip pain in the posterolateral aspect of the left hip radiating to the ipsilateral hamstring, and psoas atrophy (based on imaging). She is now reported to have over 50% improvement in pain scores after underdoing temporary peripheral nerve stimulation of the psoas muscle as well as significant improvement in muscle atrophy based on an electromyography (EMG) study. This case study is the first to report documented improvement in muscle atrophy based on EMG after peripheral nerve stimulation of the targeted area.

In this case study, peripheral nerve stimulation (PNS) was used for a patient suffering from pain and decreased size of the psoas muscle. The psoas muscle is responsible for walking, running and getting up from a seated position and is the largest muscle in the lower back. This study showed that peripheral nerve stimulation was effective not only for the relief of muscle pain but also for recovery of the size of the affected muscle.

Linear Muscle Segmentation for Metastatic Renal Cell Carcinoma: Changes in Clinic-Friendly Estimation Predict Survival Following Cytoreductive Nephrectomy.

INTRODUCTION: Baseline sarcopenia and postoperative changes in muscle mass are independently associated with overall survival (OS) in patients with metastatic renal cell carcinoma (mRCC) undergoing cytoreductive nephrectomy (CN). Here we examine the relationships between preoperative (baseline), postoperative changes in muscle quantity, and survival outcomes following CN as determined by linear segmentation, a clinic-friendly tool that rapidly estimates muscle mass. MATERIALS AND METHODS: Our nephrectomy database was reviewed for patients with metastatic disease who underwent CN for RCC. Linear segmentation of the bilateral psoas/paraspinal muscles was completed for baseline imaging within 60 days of surgery and imaging 30 to 365 days postoperatively. Kruskal-Wallis for numerical and Fisher's exact test for categorical variables were used to test for differences between groups according to percent change in linear muscle index (LMI, cm2/m2). Multivariable Cox proportional hazards models evaluated associations between LMI percent change and cancer-specific (CSM) and all-cause mortality (ACM). Kaplan Meier curves estimated cancer-specific (CSS) and overall survival (OS). RESULTS: From 2004-2020, 205 patients were included of whom 52 demonstrated stable LMI (25.4%; LMI change < 5% [0Δ]), 60 increase (29.3%; LMI +5% [+Δ]), and 92 decrease (44.9%; LMI -5% [-Δ]). Median time from baseline imaging to surgery was 18 days, and time from surgery to postoperative imaging was 133 days. Median CSS and OS were highest among patients with 0Δ LMI (CSS: 133.6 [0Δ] vs. 61.9 [+Δ] vs. 37.4 [-Δ] months; P = .0018 || OS: 67.2 [0Δ] vs. 54.8 [+Δ] vs. 29.5 [-Δ] months; P = .0007). Stable LMI was a protective factor for CSM (HR 0.48; P = .024) and ACM (HR 0.59; P = .040) on multivariable analysis. DISCUSSION: Change in muscle mass after CN, as measured by the linear muscle segmentation technique, is independently associated with OS and CSS in patients following CN. Of note, lack of change was associated with longer survival.

Removal of schwannoma from the psoas muscle with intraoperative neurophysiological monitoring: A case report.

RATIONALE: The incidence of a schwannoma within the psoas muscle is rare, and only a few cases have been reported. The surgical approach to removing schwannomas present in the psoas muscle is challenging because of its anatomical proximity to the lumbar plexus. PATIENT CONCERNS: A 31-year-old man experienced right lower back pain and anterolateral thigh numbness for 2 months. DIAGNOSIS: Magnetic resonance imaging of the patient's lumbar spine revealed a mass lesion, which was radiologically diagnosed as a well-demarcated schwannoma. INTERVENTIONS: The patient underwent surgery for excision of the schwannoma in the right psoas muscle at the second to fourth lumbar vertebrae levels. During surgery, intraoperative neurophysiological monitoring modalities, free-running and triggered electromyography and evoked potentials, from the target muscles were recorded. OUTCOMES: There was no neurotonic discharge corresponding to neuronal injury. Compound motor nerve action potential was detected in the triggered electromyography of muscles around the medial margin of the tumor. However, direct integration of the motor nerve was not observed in the intra-tumor region. LESSONS: We report that schwannoma removal in the psoas muscle, which is adjacent to the lumbar plexus, can be safely performed using intraoperative neurophysiological monitoring.

Psoas muscle area is associated with prognosis in elderly patients with hip fracture.

INTRODUCTION: Sarcopenia is a key predictor of prognosis in patients with hip fractures. This study utilized computed tomography (CT) scan (1) to determine the association between psoas muscle cross-sectional area (CSA) and mortality, along with other muscles, and (2) to confirm the correlation between muscle CSA and appendicular lean mass (ALM) measured using DXA in elderly patients with hip fracture. MATERIALS AND METHODS: Patients who were aged ≥ 50 years and underwent surgical treatment for hip fracture were eligible for this study. After a series of exclusion criteria, 217 female patients were included. Patient data, including clinical characteristics, such as body mass index (BMI), CSA, and ALM, were retrospectively collected. The Kaplan-Meier survival method and Cox proportional hazards regression analysis were used for the statistical analyses. The correlation between CSA/BMI and ALM was also assessed. RESULTS: Patients in the lowest quartile of psoas muscle CSA/BMI had shorter survival times than those in the other quartiles. When the Cox proportional hazards regression analysis was adjusted for multiple variables, the lowest quartile of the CSA/BMI of the psoas was a risk factor for mortality. The CSA/BMI of the psoas showed the highest correlation coefficient. The CSA/BMI ratio of the other muscles showed a moderately positive correlation with ALM. CONCLUSION: The CSA of the psoas is associated with prognosis in elderly patients with hip fractures and shows a moderately positive correlation with ALM. Hence, the CSA of psoas is useful for predicting survival and muscle mass in elderly patients with hip fractures.

Pre-operative psoas muscle index, a surrogate for sarcopenia; as a predictor of post-esophagectomy complications.

BACKGROUND: Esophagectomy is the standard of care for curative esophageal cancer. However, it is associated with significant morbidity and mortality. Esophageal cancer is known to negatively affect the nutritional status of patients and many manifest cancer sarcopenia. At present, measures of sarcopenia involve complex and often subjective measurements. We assess whether the Psoas Muscle Index (PMI); an inexpensive, simple, validated method used to diagnose sarcopenia, can be used to predict adverse outcomes in patients after curative esophagectomy. METHODS: Multi-centre, retrospective cohort between 2010-2020, involving all consecutive patients undergoing curative esophagectomy for esophageal cancer in University Malaya Medical Centre, Sungai Buloh Hospital, and Sultanah Aminah Hospital. The cut-off value differentiating low and normal PMI is defined as 443mm2/m2 in males and 326326 mm2/m2 in females. Complications were recorded using the Clavien-Dindo Scale. RESULTS: There was no statistical correlation between PMI and major post-esophagectomy complications (p-value: 0.495). However, complication profile was different, and patients with low PMIs had higher 30-day mortality (21.7%) when compared with patients with normal PMI (8.1%) (p-value: 0.048). CONCLUSIONS: Although PMI did not significantly predict post-esophagectomy complications, low PMI correlates with higher 30-day mortality, reflecting a lower tolerance for complications among these patients. PMI is a useful, inexpensive tool to identify sarcopenia and aids the patient selection process. This alerts healthcare professionals to institute intensive physiotherapy and nutritional optimization prior to esophagectomy.

Low skeletal muscle mass and high visceral adiposity are associated with recurrence of acute cholecystitis after conservative management: A propensity score-matched cohort study.

BACKGROUND: Recurrent acute cholecystitis (RAC) can occur after non-surgical treatment for acute cholecystitis (AC), and can be more severe in comparison to the first episode of AC. Low skeletal muscle mass or adiposity have various effects in several diseases. We aimed to clarify the relationship between RAC and body parameters. METHODS: Patients with AC who were treated at our hospital between January 2011 and March 2022 were enrolled. The psoas muscle mass and adipose tissue area at the third lumbar level were measured using computed tomography at the first episode of AC. The areas were divided by height to obtain the psoas muscle mass index (PMI) and subcutaneous/visceral adipose tissue index (SATI/VATI). According to median VATI, SATI and PMI values by sex, patients were divided into the high and low PMI groups. We performed propensity score matching to eliminate the baseline differences between the high PMI and low PMI groups and analyzed the cumulative incidence and predictors of RAC. RESULTS: The entire cohort was divided into the high PMI (n = 81) and low PMI (n = 80) groups. In the propensity score-matched cohort there were 57 patients in each group. In Kaplan-Meier analysis, the low PMI group and the high VATI group had a significantly higher cumulative incidence of RAC than their counterparts (log-rank P = 0.001 and 0.015, respectively). In a multivariate Cox regression analysis, the hazard ratios of low PMI and low VATI for RAC were 5.250 (95% confidence interval 1.083-25.450, P = 0.039) and 0.158 (95% confidence interval: 0.026-0.937, P = 0.042), respectively. CONCLUSIONS: Low skeletal muscle mass and high visceral adiposity were independent risk factors for RAC.

Myosteatosis as a novel predictor of new-onset diabetes mellitus after kidney transplantation.

OBJECTIVES: We evaluate the effect of myosteatosis on new-onset diabetes mellitus after kidney transplantation. METHODS: Consecutive patients who had renal transplant between 2006 and 2021 were reviewed, and 219 patients were finally included. Psoas muscle index was used to evaluate sarcopenia and average total psoas density (calculated by computed tomography before surgery) for myosteatosis. We used Cox proportional regression analyses in investigation of whether skeletal muscle depletion before surgery inclusive of sarcopenia and myosteatosis is a new additional predictor of new-onset diabetes mellitus. RESULTS: Median recipient age and body mass index were 45 years and 21.1 kg/m2 , respectively, and 123 patients (56%) were male. Preoperative impaired glucose tolerance was present in 58 patients (27%) and new-onset diabetes mellitus in 30 patients (14%), with median psoas muscle index of 6 cm2 /m2 and average total psoas density of 41 Hounsfield Unit. In multivariate analysis, significant risk factors were body mass index ≥25 kg/m2 (p < 0.01), impaired glucose tolerance (p < 0.01), and average total psoas density < 41.9 Hounsfield Unit (p = 0.03). New-onset diabetes mellitus had incidence rates of 3.7% without risk factors, 10% with a single risk factor, 33% with two, and 60% with three. Patients with new-onset diabetes mellitus were effectively stratified by the number of risk factors (p < 0.01). CONCLUSIONS: Myosteatosis could be a new risk factor used to predict new-onset diabetes mellitus.

[Sarcopenia in Chronic Liver Disease].

Sarcopenia is a crucial factor in assessing the nutritional status of chronic liver disease patients and predicting their prognosis and survival. The serum ammonia level is closely associated with sarcopenia regarding ammonia, a key regulator in the liver-muscle axis. In addition, various changes in energy metabolism and hormones are also involved in sarcopenia. The psoas muscle area can represent the overall skeletal muscle mass in liver disease patients. Therefore, measuring the psoas muscle area with computed tomography or magnetic resonance imaging is considered an objective and reliable method for assessing muscle mass. Providing sufficient calorie and protein intake is crucial for preventing and treating sarcopenia. In addition, engaging in appropriate exercise and addressing concurrent hormonal and metabolic changes can be helpful.

Fat infiltration of the posterior paraspinal muscles is inversely associated with the fat infiltration of the psoas muscle: a potential compensatory mechanism in the lumbar spine.

BACKGROUND: The function of the paraspinal muscles and especially the psoas muscle in maintaining an upright posture is not fully understood. While usually considered solely as a hip flexor, the psoas muscle and its complex anatomy suggest that the muscle has other functions involved in stabilizing the lumbar spine. The aim of this study is to determine how the psoas muscle and the posterior paraspinal muscles (PPM; erector spinae and multifidus) interact with each other. METHODS: A retrospective review including patients undergoing posterior lumbar fusion surgery between 2014 and 2021 at a tertiary care center was conducted. Patients with a preoperative lumbar magnetic resonance imaging (MRI) scan performed within 12 months prior to surgery were considered eligible. Exclusion criteria included previous spinal surgery at any level, lumbar scoliosis with a Cobb Angle > 20° and patients with incompatible MRIs. MRI-based quantitative assessments of the cross-sectional area (CSA), the functional cross-sectional area (fCSA) and the fat area (FAT) at L4 was conducted. The degree of fat infiltration (FI) was further calculated. FI thresholds for FIPPM were defined according to literature and patients were divided into two groups (< or ≥ 50% FIPPM). RESULTS: One hundred ninetypatients (57.9% female) with a median age of 64.7 years and median BMI of 28.3 kg/m2 met the inclusion criteria and were analyzed. Patients with a FIPPM ≥ 50% had a significantly lower FI in the psoas muscle in both sexes. Furthermore, a significant inverse correlation was evident between FIPPM and FIPsoas for both sexes. A significant positive correlation between FATPPM and fCSAPsoas was also found for both sexes. No significant differences were found for both sexes in both FIPPM groups. CONCLUSION: As the FIPPM increases, the FIPsoas decreases. Increased FI is a surrogate marker for a decrease in muscular strength. Since the psoas and the PPM both segmentally stabilize the lumbar spine, these results may be indicative of a potential compensatory mechanism. Due to the weakened PPM, the psoas may compensate for a loss in strength in order to stabilize the spine segmentally.

Is preoperative sarcopenia associated with postoperative complications after pelvic exenteration surgery?

PURPOSE: Pelvic exenteration (PE) involves radical surgical resection of pelvic organs and is associated with considerable morbidity. Sarcopenia is recognised as a predictor of poor surgical outcomes. This study aimed to determine if preoperative sarcopenia is associated with postoperative complications after PE surgery. METHODS: This retrospective study included patients who underwent PE with an available preoperative CT scan between May 2008 and November 2022 at the Royal Adelaide Hospital and St. Andrews Hospital in South Australia. Total Psoas Area Index (TPAI) was estimated by measuring the cross-sectional area of the psoas muscles at the level of the third lumbar vertebra on abdominal CT, normalised for patient height. Sarcopenia was diagnosed based on gender-specific TPAI cut-off values. Logistic regression analyses were performed to identify risk factors for major postoperative complications with a Clavien-Dindo (CD) grade ≥ 3. RESULTS: In total, 128 patients who underwent PE were included, 90 of whom formed the non-sarcopenic group (NSG) and 38 the sarcopenic group (SG). Major postoperative complications (CD grade ≥ 3) occurred in 26 (20.3%) patients. There was no detectable association with sarcopenia and an increased risk of major postoperative complications. Preoperative hypoalbuminemia (P = 0.01) and a prolonged operative time (P = 0.002) were significantly associated with a major postoperative complication on multivariate analysis. CONCLUSION: Sarcopenia is not a predictor of major postoperative complications in patients undergoing PE surgery. Further efforts aimed specifically at optimising preoperative nutrition may be warranted.

CT-derived measures of muscle quantity and quality predict poorer outcomes from elective colorectal surgery: a UK multicentre retrospective cohort study.

PURPOSE: To assess whether preoperative radiologically defined lean muscle measures are associated with adverse clinical outcomes in patients undergoing elective surgery for colorectal cancer. METHODS: This retrospective UK-based multicentre data collection study identified patients having had colorectal cancer resection with curative intent between January 2013 to December 2016. Preoperative computed-tomography (CT) scans were used to measure psoas muscle characteristics. Clinical records provided postoperative morbidity and mortality data. RESULTS: This study included 1122 patients. The cohort was separated into a combined group (patients with both sarcopenia and myosteatosis) and others group (either sarcopenia or myosteatosis, or neither). For the combined group, anastomotic leak was predicted on univariate (OR 4.1, 95% CI 1.43-11.79; p = 0.009) and multivariate analysis (OR 4.37, 95% CI 1.41-13.53; p = 0.01). Also for the combined group, mortality (up to 5 years postoperatively) was predicted on univariate (HR 2.41, 95% CI 1.64-3.52; p < 0.001) and multivariate analysis (HR 1.93, 95% CI 1.28-2.89; p = 0.002). A strong correlation exists between freehand-drawn region of interest-derived psoas density measurement and using the ellipse tool (R2 = 81%; p < 0.001). CONCLUSION: Measures of lean muscle quality and quantity, which predict important clinical outcomes, can be quickly and easily taken from routine preoperative imaging in patients being considered for colorectal cancer surgery. As poor muscle mass and quality are again shown to predict poorer clinical outcomes, these should be proactively targeted within prehabilitation, perioperative and rehabilitation phases to minimise negative impact of these pathological states.

Psoas muscle index is not representative of skeletal muscle index for evaluating cancer sarcopenia.

BACKGROUND: A common method for diagnosing sarcopenia involves estimating the muscle mass by computed tomography (CT) via measurements of the cross-sectional muscle area (CSMA) of all muscles at the third lumbar vertebra (L3) level. Recently, single-muscle measurements of the psoas major muscle at L3 have emerged as a surrogate for sarcopenia detection, but its reliability and accuracy remain to be demonstrated. METHODS: This prospective cross-sectional study involved 29 healthcare establishments and recruited patients with metastatic cancers. The correlation between skeletal muscle index (SMI = CSMA of all muscles at L3/height2 , cm2 /m2 ) and psoas muscle index (PMI = CSMA of psoas at L3/height2 , cm2 /m2 ) was determined (Pearson's r). ROC curves were prepared based on SMI data from a development population (n = 488) to estimate suitable PMI thresholds. International low SMI cut-offs according to gender were studied for males (<55cm2 /m2 ) and for females (<39 cm2 /m2 ). Youden's index (J) and Cohen's kappa (κ) were calculated to estimate the test's accuracy and reliability. PMI cut-offs were validated in a validation population (n = 243) by estimating the percentage concordance of sarcopenia diagnoses with the SMI thresholds. RESULTS: Seven hundred and sixty-six patients were analysed (mean age 65.0 ± 11.8 years, 50.1% female). Low SMI prevalence was 69.1%. Correlation between the SMI and PMI for the entire population was 0.69 (n = 731, P < 0.01). PMI cut-offs for sarcopenia were estimated in the development population at <6.6cm2 /m2 in males and at <4.8 cm2 /m2 for females. The J and κ coefficients for PMI diagnostic tests were weak. The PMI cut-offs were tested in the validation population where 33.3% of the PMI measurements were dichotomously discordant. CONCLUSIONS: A diagnostic test employing single-muscle measurements of the psoas major muscle as a surrogate for sarcopenia detection was evaluated but found to be unreliable. The CSMA of all muscles must be considered for evaluating cancer sarcopenia at L3.

Combination of psoas muscle mass index and neutrophil-to-lymphocyte ratio as a noninvasive prognostic marker in hepatocellular carcinoma patients undergoing radiofrequency ablation.

AIM: The psoas muscle index (PMI) and neutrophil-to-lymphocyte ratio (NLR) have been reported as useful noninvasive prognostic markers in patients with hepatocellular carcinoma (HCC). The usefulness of the combination of the PMI and NLR as a prognostic marker in HCC patients undergoing radiofrequency ablation (RFA) is unclear. METHODS: We retrospectively analyzed the PMI and NLR in 112 patients undergoing RFA, including 40 patients aged 75 years and older (36%). The influence of the PMI and NLR on disease-free survival and overall survival (OS) was analyzed. RESULTS: There were 66 patients with high PMI and low NLR values (58%), 36 patients with a low PMI or high NLR value (32%), and 10 patients with low PMI and high NLR values (9%). The combination of the PMI and NLR did not show a significant association with the disease-free survival rate. For patients aged ≥75 years, those with both low PMI and high NLR values showed significantly shorter OS periods (log-rank: P < 0.001). In the multivariate analysis, the combination of a low PMI value and high NLR value was significantly associated with shorter survival periods (hazard ratio: 19.72; 95% confidence interval, 4.933-78.8; P < 0.001). CONCLUSION: In this study, the combination of PMI and NLR was associated with prognosis in patients with early HCC and preserved liver function. The combination of the PMI and NLR may be a useful and noninvasive prognostic marker in HCC patients aged 75 years and older, as well as in younger patients.