Background: Surgery-related loss of muscle quantity negatively affects postoperative outcomes. However, changes of muscle quality have not been fully investigated. A perioperative intervention targeting identified risk factors could improve postoperative outcome. This study investigated risk factors for surgery-related loss of muscle quantity and quality and outcomes after liver resection for colorectal liver metastasis (CRLM). Methods: Data of patients diagnosed with CRLM who underwent liver resection between 2006 and 2016 were analysed. Muscle quantity (psoas muscle index [PMI]), and muscle quality, (average muscle radiation attenuation [AMA] of the psoas), were measured using computed tomography. Changes in PMI and AMA of psoas after surgery were assessed. Results: A total of 128 patients were analysed; 67 (52%) had surgery-related loss of muscle quantity and 83 (65%) muscle quality loss. Chronic obstructive pulmonary disease (COPD) (P = 0.045) and diabetes (P = 0.003) were risk factors for surgery-related loss of muscle quantity. A higher age (P = 0.002), open resection (P = 0.003) and longer operation time (P = 0.033) were associated with muscle quality loss. Overall survival was lower in patients with both muscle quantity and quality loss compared to other categories (P = 0.049). The rate of postoperative complications was significantly higher in the group with surgery-related loss of muscle quality. Conclusions: Risk factors for surgery-related muscle loss were identified. Overall survival was lowest in patients with both muscle quantity and quality loss. Complication rate was higher in patients with surgery-related loss of muscle quality.

Skeletal muscle loss is often observed in intensive care patients. However, little is known about postoperative muscle loss, its associated risk factors, and its long-term consequences. The aim of this prospective observational study is to identify the incidence of and risk factors for surgery-related muscle loss (SRML) after major abdominal surgery, and to study the impact of SRML on fatigue and survival. Patients undergoing major abdominal cancer surgery were included in the MUSCLE POWER STUDY. Muscle thickness was measured by ultrasound in three muscles bilaterally (biceps brachii, rectus femoris, and vastus intermedius). SRML was defined as a decline of 10 per cent or more in diameter in at least one arm and leg muscle within 1 week postoperatively. Postoperative physical activity and nutritional intake were assessed using motility devices and nutritional diaries. Fatigue was measured with questionnaires and 1-year survival was assessed with Cox regression analysis. A total of 173 patients (55 per cent male; mean (s.d.) age 64.3 (11.9) years) were included, 68 of whom patients (39 per cent) showed SRML. Preoperative weight loss and postoperative nutritional intake were statistically significantly associated with SRML in multivariable logistic regression analysis (P < 0.050). The combination of insufficient postoperative physical activity and nutritional intake had an odds ratio of 4.00 (95 per cent c.i. 1.03 to 15.47) of developing SRML (P = 0.045). No association with fatigue was observed. SRML was associated with decreased 1-year survival (hazard ratio 4.54, 95 per cent c.i. 1.42 to 14.58; P = 0.011). SRML occurred in 39 per cent of patients after major abdominal cancer surgery, and was associated with a decreased 1-year survival.

Signal intensity of reinnervated muscle returns to its normal level, while signal intensity of denervated muscle remains high for at least 12 months after nerve transection. PurposeTo prospectively assess the short inversion time inversion-recovery (STIR) magnetic resonance (MR) signal intensity changes of denervated and reinnervated skeletal muscle over time in clinical patients.Materials and MethodsThis study was approved by the institutional review board, and informed consent was obtained from all patients. Twenty-three patients with complete traumatic transection of the median or ulnar nerve in the forearm were prospectively followed for 12 months after surgical nerve repair. STIR MR images of selected intrinsic hand muscles were obtained 1, 3, 6, 9, and 12 months after nerve repair, and signal intensities of denervated and reinnervated muscles were measured semiquantitatively. After 12 months, hand function was assessed. Signal intensity ratios were correlated to functional outcome with analysis of variance.ResultsOf the 23 patients, 10 had good function recovery, while 13 had poor recovery. For the group with good function recovery, mean signal intensity ratios of 1.267...

Generalized loss of muscle mass is associated with increased morbidity and mortality in patients with cancer. The gold standard to measure muscle mass is by using computed tomography (CT). However, the aim of this prospective observational cohort study was to determine whether point-of-care ultrasound (POCUS) could be an easy-to-use, bedside measurement alternative to evaluate muscle status. Patients scheduled for major abdominal cancer surgery with a recent preoperative CT scan available were included. POCUS was used to measure the muscle thickness of mm. biceps brachii, mm. recti femoris, and mm. vasti intermedius 1 day prior to surgery. The total skeletal muscle index (SMI) was derived from patients’ abdominal CT scan at the third lumbar level. Muscle force of the upper and lower extremities was measured using a handheld dynamometer. A total of 165 patients were included (55% male; 65 ± 12 years). All POCUS measurements of muscle thickness had a statistically significant correlation with CT-derived SMI (r ≥ 0.48; p < 0.001). The strongest correlation between POCUS muscle measurements and SMI was observed when all POCUS muscle groups were added together (r = 0.73; p < 0.001). Muscle strength had a stronger correlation with POCUS-measured muscle thickness than with CT-derived SMI. To conclude, this study indicated a strong correlation between combined muscle thickness measurements performed by POCUS- and CT-derived SMI and measurements of muscle strength. These results suggest that handheld ultrasound is a valid tool for the assessment of skeletal muscle status.

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Background: Approximately 26% of esophageal cancer (EC) patients do not respond to neoadjuvant chemoradiotherapy (nCRT), emphasizing the need for pre-treatment selection. The aim of this study was to predict non-response using a radiomic model on baseline ¹⁸F-FDG PET. Methods: Retrospectively, 143 ¹⁸F-FDG PET radiomic features were extracted from 199 EC patients (T1N1-3M0/T2–4aN0-3M0) treated between 2009 and 2019. Non-response (n = 57; 29%) was defined as Mandard Tumor Regression Grade 4–5 (n = 44; 22%) or interval progression (n = 13; 7%). Randomly, 139 patients (70%) were allocated to explore all combinations of 24 feature selection strategies and 6 classification methods towards the cross-validated average precision (AP). The predictive value of the best-performing model, i.e AP and area under the ROC curve analysis (AUC), was evaluated on an independent test subset of 60 patients (30%). Results: The best performing model had an AP (mean ± SD) of 0.47 ± 0.06 on the training subset, achieved by a support vector machine classifier trained on five principal components of relevant clinical and radiomic features. The model was externally validated with an AP of 0.66 and an AUC of 0.67. Conclusion: In the present study, the best-performing model on pre-treatment ¹⁸F-FDG PET radiomics and clinical features had a small clinical benefit to identify non-responders to nCRT in EC.