Prognostic value of pretreatment temporal muscle thickness after curative surgery for oral cavity squamous cell carcinoma.

BACKGROUND: Sarcopenia is a poor prognostic factor in various diseases. Temporal muscle thickness (TMT) has been reported to be associated with sarcopenia. We investigated the prognostic value of TMT in patients with oral squamous cell carcinoma. METHODS: This study included 61 patients with oral squamous cell carcinoma. Two board-certified otolaryngologists measured TMT based on pre-treatment CT. The following sex-specific TMT cut-off values were used in accordance with previous reports: ≤ 6.3 mm in men, and ≤ 5.2 mm in women. We classified patients into normal TMT group and low TMT group according to the cutoff values. The correlation between the TMT measurements of the two readers was tested using the interclass correlation coefficient (ICC). Cox regression models were used to verify the association between TMT and prognostic factors. RESULTS: The low TMT group had a significantly lower BMI than the normal TMT group. Patients with low TMT at baseline had a significantly higher risk of death than those with normal TMT (hazard ratio 4.51; 95% confidence interval [CI] 1.49-13.61; p = 0.0076). There were no significant differences in disease-specific survival between the two groups. The correlation between the two evaluators' TMT measurements was excellent (ICC 0.988, 95% CI 0.981-0.933). CONCLUSIONS: Sex-specific TMT was associated with overall survival in patients with oral squamous cell carcinoma. TMT is easy to assess and its measurement is consistent between evaluators.

The relationship between temporal muscle thickness and disease activity in Cushing's disease.

OBJECTIVE: This study aimed to investigate the relationship between hypercortisolism and temporal muscle thickness (TMT) in Cushing's disease (CD). METHODS: A retrospective review of medical records was conducted for patients with CD who presented to our clinic between 2012 and 2022. Biochemical data and TMT measurements from sella imaging were evaluated during diagnosis and the first postoperative year. RESULTS: A total of 44 patients were included in the study, with an average age of 43.9 years, of which 38 were female. The mean TMT at the time of diagnosis was 19.07 ± 1.71 mm, with no significant difference between males and females (p = 0.097), and no correlation between the TMT and age at diagnosis (p = 0.497). There was an inverse relationship between TMT and serum cortisol levels, 24-h UFC, and midnight salivary cortisol at the time of diagnosis of CD (p < 0.05, for all). One year after surgery, TMT significantly increased in all patients compared to baseline (p < 0.001). Furthermore, patients who achieved postoperative remission had significantly higher TMT values compared to those who did not achieve remission (p = 0.043). Among the patients who achieved remission, those who achieved remission through surgery had significantly higher TMT compared to those who could not reach remission with surgery and patients who started medical treatment and achieved biochemical remission (p = 0.01). Patients with severe myopathy and sarcopenia had significantly lower TMT values than the others (p < 0.001). CONCLUSION: Temporal muscle thickness was found to be associated with disease activity and disease control in Cushing's disease.

Correlation of reduced temporal muscle thickness and systemic muscle loss in newly diagnosed glioblastoma patients.

PURPOSE: Reduced temporal muscle thickness (TMT) has recently been postulated as a prognostic imaging marker and an objective tool to assess patients frailty in glioblastoma. Our aim is to investigate the correlation of TMT and systemic muscle loss to confirm that TMT is an adequate surrogate marker of sarcopenia in newly diagnosed glioblastoma patients. METHODS: TMT was assessed on preoperative MR-images and skeletal muscle area (SMA) was assessed at the third lumbar vertebra on preoperative abdominal CT-scans. Previous published TMT sex-specific cut-off values were used to classify patients as 'patient at risk of sarcopenia' or 'patient with normal muscle status'. Correlation between TMT and SMA was assessed using Spearman's rank correlation coefficient. RESULTS: Sixteen percent of the 245 included patients were identified as at risk of sarcopenia. The mean SMA of glioblastoma patients at risk of sarcopenia (124.3 cm2, SD 30.8 cm2) was significantly lower than the mean SMA of patients with normal muscle status (146.3 cm2, SD 31.1 cm2, P < .001). We found a moderate association between TMT and SMA in the patients with normal muscle status (Spearman's rho 0.521, P < .001), and a strong association in the patients at risk of sarcopenia (Spearman's rho 0.678, P < .001). CONCLUSION: Our results confirm the use of TMT as a surrogate marker of total body skeletal muscle mass in glioblastoma, especially in frail patients at risk of sarcopenia. TMT can be used to identify patients with muscle loss early in the disease process, which enables the implementation of adequate intervention strategies.

Temporal muscle thickness as an independent prognostic marker in glioblastoma patients-a systematic review and meta-analysis.

Glioblastoma is the most common primary malignant brain tumor in the adult population. It causes the patient to incur a great deal of malady. Even with the advances in management and the Stupp protocol in place, the prognosis remains grim. There are various parameters to evaluate patients' performance status and frailty pre-operatively, but these are mostly subjective and thus suffer from inter-observer variability. Assessment of sarcopenia serves as an objective parameter to assess the patient's performance status pre-operatively. Temporalis muscle thickness serves as a surrogate to assess sarcopenia in patients with glioblastoma. We conducted a literature review and meta-analysis to determine the prognostic implications of temporalis muscle thickness in 3283 patients with primary glioblastoma. The pooled overall survival hazard's ratio of thick versus thin TMT was 0.54. The pooled progression-free survival hazard's ratio of thick versus thin TMT was 0.38. Thus, the main finding of this study is that thicker temporal muscle is associated with better OS and PFS as compared to thinner temporal muscle. We thus conclude that TMT is a viable surrogate for predicting sarcopenia and survival in primary glioblastoma. TMT measurement is extremely easy and can be incorporated as a part of the routine neurosurgical workflow in these patients. Survival prediction will help inform treatment decisions in glioblastoma patients having poor prognosis, at the initial diagnosis itself.

The association of BMI and sarcopenia with survival in patients with glioblastoma multiforme.

Background: The association between obesity and sarcopenia (via temporal muscle thickness) with overall survival (OS) has been evaluated in several glioblastoma multiforme studies, however, the data are inconclusive. Methods: The authors conducted meta-analyses via the generic inverse-variance method with a random-effects model. Results: In the pooled analysis of five studies, including 973 patients, patients with lower temporal muscle thickness had significantly decreased OS (HR: 1.62, 95% CI: 1.16-2.28, p = 0.005). The pooled analysis of five studies, including 2131 patients, demonstrated decreased OS in patients with lower BMI compared with patients with obesity (HR: 1.45, 95% CI: 1.12-1.88, p = 0.005). Conclusion: Readily available body composition parameters could be used for prognosis prediction and to aid in treatment decisions in patients with glioblastoma multiforme.

Temporal Muscle Thickness and Sarcopenia Components in Healthy Adults, Validated through Allgeun Diagnostic Tool.

Sarcopenia, characterized by progressive muscle loss and functional decline, poses significant risks, including falls, impaired daily activities, and increased mortality. We developed Allgeun, a novel device that measures handgrip strength, muscle mass, and physical performance. This study aimed to investigate whether temporal muscle thickness (TMT) could be used as a sarcopenia marker and to evaluate the usability of Allgeun. This prospective study enrolled 28 participants without medical or neurological disorders. They underwent three-dimensional T1-weighted imaging using a 3 Tesla magnetic resonance imaging scanner. TMT was measured based on T1-weighted images by a board-certified neuroradiologist. Allgeun was used to measure the following three key components of sarcopenia: muscle strength (handgrip strength), muscle mass (calf and thigh circumference), and physical performance (five times the chair stand test). Correlation analysis was conducted between TMT and the results of the handgrip strength, calf and thigh circumferences, and chair stand tests. There were moderate positive correlations between TMT and calf circumference (r = 0.413, p = 0.029), thigh circumference (r = 0.486, p = 0.008), and handgrip strength (r = 0.444, p = 0.018). However, no significant correlation was observed between TMT and physical performance (r = -0.000, p = 0.998). Our findings underscore TMT's potential as an indicator of sarcopenia, particularly regarding muscle mass and strength. Additionally, we demonstrated that the new device, Allgeun, is useful for screening and diagnosing the severity of sarcopenia.

Temporal Muscle Thickness Compared to Functional Scales as a Prognostic Parameter in Patients with Brain Metastases.

Metastases are the most frequent intracranial malignant tumors in adults. While Karnofsky Performance Status (KPS) and Clinical Frailty Scale (CFS) are known to have significant impact on overall survival (OS), temporal muscle thickness (TMT) has been postulated to be a promising new parameter to estimate prognosis. Patients who received a resection of one to three brain metastases in our institution were included. Temporal muscle thickness was measured in preoperative MRI scans according to a standardized protocol. In 199 patients, the mean TMT was 7.5 mm (95CI 7.3-7.7) and the mean OS during follow-up was 31.3 months (95CI 24.2-38.3). There was no significant correlation of TMT and preoperative or follow-up CFS and KPS. While CFS and KPS did significantly correlate with OS (p < 0.001 for each), no correlation was demonstrated for TMT. CFS showed a superior prognostic value compared to KPS. TMT failed to show a significant impact on OS or patient performance, whereas the clinical scales (KPS and CFS) demonstrate a good correlation with OS. Due to its superiority over KPS, we strongly recommend the use of CFS to estimate OS in patients with brain metastases.

The predictive value of temporal muscle thickness measured by ultrasonography for detecting moderate to severe malnutrition in chronic hemodialysis patients.

INTRODUCTION AND AIM: To determine the predictive value of temporal muscle thickness (TMT) measured by ultrasonography in the diagnosing of moderate to severe malnutrition in chronic hemodialysis (CHD) patients. MATERIALS AND METHODS: Adult patients (> 18 years) who had been on CHD for at least 3 months were included in this cross-sectional study. Patients with infection or inflammatory disease, malignancy, malabsorption syndrome, history of surgery within the last 3 months excluded. Demographic, anthropometric, laboratory parameters, and Malnutrition Inflammation Score (MIS) test results recorded. RESULTS: A total of 60 chronic hemodialysis (CHD) patients (median age: 66 years, 46.7% female) and 30 healthy individuals (median age: 59.5 years, 55% female) were examined. While there were no significant difference between the dry weight (70 vs 71 kg) and body mass index (BMI) (25.8 vs 26 kg/m2) of the CHD patients and healthy control group, we found that triceps skinfold thickness (TST) (16 vs 19 mm) and left and right TMT (9.6 vs 10.7 and 9.8 vs 10.9 mm) values were significantly lower in the CHD patients (p < 0.001). CHD patients were divided into two groups according to their MIS values as mild (MIS < 6) and moderate/severe malnutrition (MIS ≥ 6). Patients with moderate/severe malnutrition were older, predominantly female and with longer HD vintage. Left (8.8 vs 11 mm) and right TMT (9.1 vs 11.2 mm) values were lower in moderate/severe malnutrition group. In the correlation analysis, a negative correlation was found between TMT and age and MIS, and a positive correlation determined with dry weight, BMI, TST and serum uric acid. In the ROC curve analysis, we found that the optimal cut-off value of left and right TMT for predicting moderate/severe malnutrition were 10.05 and 10.45 mm, respectively. Multivariate regression analysis showed that HD vintage, URR, and TMT values were independently associated with moderate/severe malnutrition. CONCLUSION: TMT value measured by ultrasonography in CHD patients can be used as a reliable, easily accessible and non-invasive diagnostic method for predicting moderate/severe malnutrition.

Temporal Muscle Thickness Correlates with Sarcopenia in Parkinson's Disease.

BACKGROUND: Sarcopenia is characterized by a progressive loss of muscle mass, strength, and function resulting in adverse health outcomes. Current assessment strategies are bothersome and means to simplify the diagnosis are an unmet medical need in Parkinson's disease (PD). OBJECTIVE: To evaluate temporal muscle thickness (TMT) obtained on routine cranial MRI as a surrogate marker of sarcopenia in PD patients. METHODS: We correlated TMT from axial non-contrast-enhanced T1-weighted sequences of MRI close (±12 months) to an outpatient visit including sarcopenia (EWGSOP1, EWGSOP2, SARC-F), frailty (Fried's criteria, clinical frailty scale), and disease characteristics of Parkinson's patients (Hoehn and Yahr-scale, Movement Disorder Society-Unified Parkinson's Disease Rating Scale, quality of life with the Parkinson's Disease Questionnaire-8) assessments. RESULTS: Cranial MRI was available in 32 patients with a mean age of 73.56±5.14 years, mean disease duration of 11.46±5.66 years, and median Hoehn and Yahr stage of 2.5. The mean TMT was 7.49±2.76 (7.15) mm. Mean TMT was significantly associated with sarcopenia (EWGSOP2, p = 0.018; EWGSOP1, p = 0.023) and frailty status (physical phenotype; p = 0.045). Moreover, there were significant moderate to strong correlations between TMT measurement and appendicular skeletal muscle mass index (r: 0.437, p = 0.012), as well as handgrip strength (r: 0.561, p < 0.001). CONCLUSION: Reduced TMT seems to be a promising surrogate marker for sarcopenia (EWGSOP2) and muscle strength in this pilot study in PD patients.

Temporal muscle thickness has no prognostic relevance in patients with high-grade glioma compared to functional scales.

Background: GBM research is constantly assessing potential valuable prognostic biomarkers to better understand the disease and prognosticate future outcomes. Measuring temporal muscle thickness (TMT) has appeared to be a promising new surrogate marker for skeletal muscle mass and sarcopenia, which further indicates frailty and predicts overall survival (OS). The aim of this study was to determine its usefulness as a prognostic marker in patients with high-grade glioma compared to functional status scales. Methods: TMT was measured in preoperative axial T1-weighted contrast-enhanced magnetic resonance images in 277 patients who received surgical treatment of newly diagnosed WHO III and IV gliomas in our institution between 2015 and 2020. Clinical Frailty Scale (CFS) and Karnofsky Performance Scale (KPS) were assessed preoperatively and during a follow-up visit. Results: Female gender has shown significant correlation with TMT, while TMT did not correlate with preoperative and follow-up functional scores, age, WHO classification, IDH mutation, MGMT promoter methylation, EGFR and ATRX expression, or 1p/19q co-deletion. No significant prognostic value of TMT could be shown in 6, 12, and 24 months OS, while changes in CFS and KPS proved to have a significant impact. Conclusion: Only female gender, but no other clinical, histological, or molecular marker showed any interrelation with TMT. Functional scores outclass measuring TMT as a reliable prognostic factor for predicting OS in patients with high-grade glioma.

The relation of sarcopenia and disability in multiple sclerosis.

BACKGROUND: The relation of sarcopenia and disability in MS is unknown. OBJECTIVE: To investigate the relation of temporal muscle thickness (TMT) and disability. METHODS: A cohort of 132 people who presented with a clinically isolated syndrome (CIS) suggestive of MS at a mean age of 30.0 years, were prospectively followed clinically and with MRI over 30-years. TMT and expanded disability status scale (EDSS) were assessed at baseline, one- five- ten- fourteen- twenty- and thirty-year follow-up. RESULTS: At 30-years, 27 participants remained classified as having had a CIS, 34 converted to relapsing remitting MS, 26 to secondary progressive MS, and 16 had died due to MS. Using linear mixed effect models with subject nested in time, greater annualized TMT-thinning was seen in individuals who developed MS (-0.04 mm/a, 95%CI: -0.07 to -0.01, p = 0.023). In those who converted to MS, a thinner TMT was reached at 14- (p = 0.008), 20- (p = 0.002) and 30-years (p< 0.001). TMT was negatively correlated with EDSS at 20-years (R=-0.18, p = 0.032) and 30-years (R-0.244, p = 0.005). Longitudinally, TMT at earlier timepoints was not predictive for 30-year clinical outcomes. CONCLUSION: TMT thinning is accelerated in MS and correlated with disability in later disease stages, but is not predictive of future disability.

Advances in the relationship between temporal muscle thickness and prognosis of patients with glioblastoma: a narrative review.

The most dangerous variety of glioma, glioblastoma, has a high incidence and fatality rate. The prognosis for patients is still bleak despite numerous improvements in treatment approaches. We urgently need to develop clinical parameters that can evaluate patients' conditions and predict their prognosis. Various parameters are available to assess the patient's preoperative performance status and degree of frailty, but most of these parameters are subjective and therefore subject to interobserver variability. Sarcopenia can be used as an objective metric to measure a patient's physical status because studies have shown that it is linked to a bad prognosis in those with cancers. For the purpose of identifying sarcopenia, temporal muscle thickness has demonstrated to be a reliable alternative for a marker of skeletal muscle content. As a result, patients with glioblastoma may use temporal muscle thickness as a potential marker to correlate with the course and fate of their disease. This narrative review highlights and defines the viability of using temporal muscle thickness as an independent predictor of survival in glioblastoma patients, and it evaluates recent research findings on the association between temporal muscle thickness and prognosis of glioblastoma patients.

Correlation between temporal muscle thickness and grip strength in hemiplegic patients with acute stroke.

Recently, temporal muscle thickness (TMT) has been investigated as a novel surrogate marker for muscle mass and function in neurologic patients. This study aimed to assess the correlation of TMT with grip strength to establish a new parameter for predicting pre-stroke sarcopenia. A total of 358 patients who were newly diagnosed with acute ischemic stroke at our institution between November 2021 and August 2022 were enrolled. Eighty-four patients met the eligibility criteria. The mean TMT was measured within initial brain MRI using previously described methods. Pearson's correlation analyses assessed the relationship between grip strength and TMT. Multiple logistic regression analyses were performed to identify associations between TMT and other associated factors including grip strength, sarcopenia risk, body mass index, age, Charlson Comorbidity Index and Geriatric nutrition risk index. Mean TMT values indicated a strong correlation with the grip strength of the non-hemiplegic hand in both male and female patients. Multiple logistic regression analyses showed that TMT was associated with grip strength and sarcopenia risk in hemiplegic patients. Measuring TMT using cranial MR images during the initial stages of stroke could help predict a patient's pre-stroke muscle strength status. Further studies are required to apply TMT in pre-stroke sarcopenia diagnosis.

Frailty in cerebellar ischemic stroke-The significance of temporal muscle thickness.

While comprising only 2% of all ischemic strokes, cerebellar strokes are responsible for substantial morbidity and mortality due to their subtle initial presentation and the morbidity of posterior fossa swelling. Furthermore, low temporal muscle thickness (TMT) has recently been identified as a prognostic imaging parameter to assess patient frailty and outcome. We analyzed radiological and clinical data sets of 282 patients with cerebellar ischemic stroke. Our analysis showed a significant association between low TMT, reduced NIHSS and mRS at discharge (p = 0.035, p = 0.004), and reduced mRS at 12 months (p = 0.001). TMT may be used as a prognostic imaging marker and objective tool to assess outcomes in patients with cerebellar ischemic stroke.

Frailty in Traumatic Brain Injury-The Significance of Temporal Muscle Thickness.

BACKGROUND: Temporal muscle thickness (TMT) on cranial CT scans has recently been identified as a prognostic imaging parameter for assessing a patient's baseline frailty. Here, we analyzed whether TMT correlates with Traumatic brain injury (TBI) severity and whether it can be used to predict outcome(s) after TBI. METHODS: We analyzed the radiological and clinical data sets of 193 patients with TBI who were admitted to our institution and correlated the radiological data with clinical outcomes after stratification for TMT. RESULTS: Our analyses showed a significant association between high TMT and increased risk for intracranial hemorrhage (p = 0.0135) but improved mRS at 6 months (p = 0.001) as compared to patients with low TMT. Congruent with such findings, a lower TMT was associated with falls and reduced outcomes at 6 months (p < 0.0001 and p < 0.0001). CONCLUSION: High TMT was robustly associated with head trauma sequelae but was also associated with good clinical outcomes in TBI patients. These findings consolidate the significance of TMT as an objective marker of frailty in TBI patients; such measurements may ultimately be leveraged as prognostic indicators.

Temporal muscle thickness as an independent prognostic imaging marker in newly diagnosed glioblastoma patients: A validation study.

Background: Previous studies have recognized temporal muscle thickness (TMT) as a prognostic marker in glioblastoma, but clinical implementation is hampered due to studies' heterogeneity and lack of established cutoff values. The aim of this study was to assess the validity of recent proposed sex-specific TMT cutoff values in a real-world population of genotyped primary glioblastoma patients. Methods: We measured TMT in preoperative MR images of 328 patients. Sex-specific TMT cutoff values were used to divide patients into "at risk of sarcopenia" or "normal muscle status". Kaplan-Meier analyses and stepwise multivariate Cox-Regression analyses were used to assess the association with overall survival (OS) and progression-free survival (PFS). The association with occurrence of complications and discontinuation of glioblastoma treatment was investigated using odds ratios (OR). Results: Patients at risk of sarcopenia had a significantly higher risk of progression and death than patients with normal muscle status, which remained significant in the multivariate analyses (OS HR = 1.437; 95%CI: 1.046-1.973; P = .025 and PFS HR = 1.453; 95%CI: 1.037-2.036; P = .030). Patients at risk of sarcopenia also had a significantly higher risk of early discontinuation of treatment (OR = 2.45; 95%CI: 1.011-5.952; P = .042) and a significantly lower chance of receiving second-line treatment (OR = 0.23; 95%CI: 0.09-0.60; P = .001). There was no association with the occurrence of complications. Conclusions: Our study confirms external validity of the use of proposed sex-specific TMT cutoff values as an independent prognostic marker in newly diagnosed glioblastoma patients. This simple, noninvasive marker could improve patient counseling and aid in treatment decision processes or trial stratification.

Significance of Temporal Muscle Thickness in Chronic Subdural Hematoma.

Background: Reduced temporal muscle thickness (TMT) was verified as an independent negative prognostic parameter for outcome in brain tumor patients. Independent thereof, chronic subdural hematoma (CSDH) is a neurosurgical condition with high recurrence rates and unreliable risk models for poor outcome. Since sarcopenia was associated with poor outcome, we investigated the possible role of TMT and the clinical course of CSDH patients. Methods: This investigation is a single-center retrospective study on patients with CSDH. We analyzed the radiological and clinical data sets of 171 patients with surgically treated CSDH at a University Hospital from 2017 to 2020. Results: Our analysis showed a significant association between low-volume TMT and increased hematoma volume (p < 0.001), poor outcome at discharge (p < 0.001), and reduced performance status at 3 months (p < 0.002). Conclusion: TMT may represent an objective prognostic parameter and assist the identification of vulnerable CSDH patients.

Temporal muscle thickness and survival in patients with amyotrophic lateral sclerosis.

Temporal muscle thickness (TMT) is a new potential MRI biomarker, which has shown prognostic relevance in neuro-oncology. We aim at investigating the potential prognostic value of TMT in patients with Amyotrophic Lateral Sclerosis (ALS). We retrospectively evaluated 30 ALS patients, whose clinical, Magnetic Resonance Imaging (MRI) and Electrodiagnostic testing (EDX) data were available, in comparison to age-matched 30 healthy subjects. TMT calculated on T1-weighted MR images was significantly lower in ALS patients than in healthy subjects (p < 0.001), correlating with the ALS Functional Rating Scale (FRS) (p:0.018) and compound motor action potential (CMAP) (p:0.012) in the patients group. Multivariate analysis of overall survival (OS) showed that the only parameters that remained significant were TMT (p:0.002, OR 0.45, 95%vCI: 0.28-0.75) and ALS FRS-R (p:0.023, OR: 0.80, 95%CI: 0.67-0.92). TMT seems to be a promising surrogate biomarker of survival and functional status in ALS. Our data deserve further investigations in multicenter and prospective trials.

Temporal Muscle and Stroke-A Narrative Review on Current Meaning and Clinical Applications of Temporal Muscle Thickness, Area, and Volume.

BACKGROUND: Evaluating muscle mass and function among stroke patients is important. However, evaluating muscle volume and function is not easy due to the disturbances of consciousness and paresis. Temporal muscle thickness (TMT) has been introduced as a novel surrogate marker for muscle mass, function, and nutritional status. We herein performed a narrative literature review on temporal muscle and stroke to understand the current meaning of TMT in clinical stroke practice. METHODS: The search was performed in PubMed, last updated in October 2021. Reports on temporal muscle morphomics and stroke-related diseases or clinical entities were collected. RESULTS: Four studies reported on TMT and subarachnoid hemorrhage, two studies on intracerebral hemorrhage, two studies on ischemic stroke, two studies on standard TMT values, and two studies on nutritional status. TMT was reported as a prognostic factor for several diseases, a surrogate marker for skeletal muscle mass, and an indicator of nutritional status. Computed tomography, magnetic resonance imaging, and ultrasonography were used to measure TMT. CONCLUSIONS: TMT is gradually being used as a prognostic factor for stroke or a surrogate marker for skeletal muscle mass and nutritional status. The establishment of standard methods to measure TMT and large prospective studies to further investigate the relationship between TMT and diseases are needed.

Influence of temporal muscle thickness on the outcome of radiosurgically treated patients with brain metastases from non-small cell lung cancer.

OBJECTIVE: The purpose of this study was to assess the impact of temporal muscle thickness (TMT), a surrogate marker for sarcopenia, in radiosurgically treated patients with brain metastases (BMs) from non-small cell lung cancer (NSCLC). METHODS: For 566 patients with BMs from NSCLC in the period between June 2012 and December 2019, TMT values were retrospectively measured on the planning brain magnetic resonance imaging (MRI) studies that had been obtained before their first Gamma Knife radiosurgery treatment (GKRS1). Predefined sex-specific TMT cutoff values were used to stratify the study cohort into patients at risk for sarcopenia and patients with normal muscle status. Cox regression models adjusted for other prognostic parameters were used to evaluate sarcopenia as an independent prognostic factor. RESULTS: In sarcopenia patients with a TMT below the sex-specific cutoff values, the risk of death was significantly increased (HR 1.908, 95% CI 1.550-2.349, p < 0.001). In addition, sarcopenia was revealed as an independent prognostic factor even after adjusting for age groups, sex, number of BMs, presence of extracranial metastases, NSCLC subtypes, Karnofsky Performance Status groups, recursive partitioning analysis classes, and concomitant immunotherapy or targeted therapy (HR 1.680, 95% CI 1.347-2.095, p < 0.001). However, patients at risk for sarcopenia showed no significant differences in the estimated mean time until local BM progression after GKRS1, compared to patients with normal muscle status (p = 0.639). CONCLUSIONS: TMT obtained from planning MRI studies is an independent prognostic marker in radiosurgically treated patients with BMs from NSCLC and may aid patient stratification in future clinical trials.