Computed tomography‐defined low skeletal muscle index and density in cancer patients: observations from a systematic review

Abstract

Background Computed tomography (CT) analysis of body composition has garnered interest as a potential prognostic tool in those with cancer. A range of pre‐defined thresholds currently exist within the literature to define low skeletal muscle mass and density. The aim of the present systematic review was to assess the prevalence of low skeletal muscle index (SMI) and density (SMD) within the literature, across a range of common solid tumours. Methods A systematic search of PubMed was carried out to identify studies reporting CT analysis of SMI and SMD in patients with colorectal, oesophageal, gastric, hepatobiliary, pancreatic, breast, and lung cancer. The type of cancer, whether curative or non‐curative disease, the anthropomorphic parameter studied, threshold used to define low SMI and SMD, and the prevalence of these anthropomorphic measurements within the population were recorded. Results Of the 160 studies included, 156 reported an assessment of SMI and 35 reported assessment of SMD. The median prevalence of low SMI was 43% (30.1–57.1) and low SMD 49.4% (31.7–58.5) across the entire cohort. There was little variation in the prevalence of low SMI and SMD when studies were divided into curative and non‐curative cohorts—40.7% (27.5–51.3) vs. 48.4% (30.9–60.1) and 37.8% (32.2–52.2) vs. 55.3% (38.5–64.7) respectively. When divided into colorectal, oesophageal, gastric, hepatobiliary, pancreatic, breast and lung cancers, similar prevalence of low SMI (46.0% %, 49.8%, 35.7%, 41.1%, 32.3%, 34%, and 49.5%) and low SMD were also observed (52.1%, 54.3%, 71.2%, 56.8%, 55.3%, and 52.6%). This was maintained when studies were stratified into cohorts by threshold used—low SMI (Martin 48.9%, Prado 49.9%, and Others 36.0%) and low SMD (Martin 52.4% and Others 48.6%). Conclusions Low SMI and SMD are endemic across a range of cancer types and disease stage, challenging pre‐existing dogma of the determinants of prevalence.

Prediction of abdominal CT body composition parameters by thoracic measurements as a new approach to detect sarcopenia in a COVID-19 cohort

“…CT body composition parameters at L3 have been found to be of predictive value in many entities including COVID-19 9 , 10 , 14 . However, most COVID-19 patients only receive chest X-rays or thoracic CT scans and while there are reviews with hundreds of studies on abdominal CT body composition measurements 15 , 16 experience on thoracic CT body composition parameters is less profound, with especially few studies on thoracic CT body composition assessment in COVID-19 5 , 6 , 17 . Furthermore, no consensus exists on which thoracic muscle groups to employ and proposed thoracic cut-off values to assess sarcopenia vary 18 – 21 .…”

The combination of computed tomography‐derived muscle mass and muscle density and relationship with clinicopathological characteristics and survival in patients undergoing potentially curative surgery for colorectal cancer

“…4,5 Skeletal muscle mass is most often calculated from the cumulative volume of the intra-abdominal musculature on a CT image slice, generally at the level of the third lumbar vertebra, normalized by the square of the patient's height in metres (skeletal muscle index, SMI), analogous to that of BMI. 6 Indeed, CT-derived muscle mass measurements have been shown to be consistent with measurements of other modalities, 7 specifically bioelectrical impedance analysis 8 and dual-energy X-ray absorptiometry. 9 Skeletal muscle density (SMD) on the other hand is an assessment of muscle quality, with striated skeletal muscle, free from fat infiltration, having a greater density on CT analysis compared against that with fat deposition.…”

“…As such, the present observations are in keeping with those of a recent review by our group, of 160 studies of CT-derived SMI and SMD that found poor muscle status was endemic in patients with cancer, suggesting that tumour stage was not a major determinant of sarcopenia. 6 Furthermore, in the review we also hypothesized that the prognostic value of sarcopenia may reflect its measure of the nutritional and functional reserve of the cancer patient and that it is imperative that such body composition measurements be used in conjunction with potential confounding factors such as systemic inflammation. 6 Hacker and co-workers reported similar observations in a recent longitudinal study of patients with advanced gastric and oesophagogastric junctional cancer.…”

Diagnostic and prognostic value of psoas muscle thickness and area in patients with liver cirrhosis and sarcopenia

“…Раніше було доведено, що площа поперечного зрізу скелетних м'язів на рівні L3 тісно корелює з загальною масою скелетних м'язів [25] та, на відміну від м'язів кінцівок, не залежить від фізичної активності [7]. Індекс скелетних м'язів (Skeletal Muscle Index, SMI), що являє собою скориговану до зросту площу поперечного зрізу скелетних м'язів на рівні L3, є найбільш дослідженим показником м'язової маси у пацієнтів з онкопатологією, термінальними захворюваннями печінки та показав свою вагому прогностичну цінність [19,20,22,24]. Альтернативним місцем оцінки загальної м'язової маси є поперековий м'яз, який легко ідентифікується на КТ та може бути точно окреслений.…”