Temporal muscle thickness: a new prognostic marker in glioblastoma patients Julia Furtner, MD, PhD, MBA, Associate Professor Department of Biomedical Imaging and Image-guided Therapy (Division of Neuroradiology and Musculoskeletal Radiology), Medical University of Vienna, Austria
Univ.-Prof. Dr. Matthias Preusser, Head - Division of Oncology Department of Medicine I, Medical University of Vienna, Austria
I
n the area of personalized therapeutic planning, stratification of glioblastoma patients based on various prognostic factors is essential either for routine patient management decision-making or clinical trial participation. Whereas most of these parameters such as histopathological and molecular characteristics, age, tumor size and localization are objectively assessable, the physical condition of the patient is based mainly on the subjective evaluation of the attending physician. Thus, the use of objective parameters to measure physical performance, such as skeletal muscle mass estimation, has recently become more common.
Methods estimating skeletal muscle mass The reduction of skeletal muscle mass and function is defined as “sarcopenia” and was firstly described by Baumgartner et al. assigned to aging. Moreover, secondarilyinduced sarcopenia in various disease entities, such as chronic inflammatory diseases or cancer, has been recognized in the last few years to be an objective parameter indicating a poor prognosis due to patient frailty. Methods such as dual X-ray absorptiometry, bioelectrical impedance analysis, or the area of lumbar skeletal muscles surveyed by computed tomography or magnetic resonance imaging (MRI) studies of the abdomen are established to estimate the skeletal muscle mass. However, in glioblastoma 18
Brain Tumour
Dr Julia Furtner
Dr Matthias Preusser
patients, radiological examinations of the abdomen are generally not routinely available. In recently published studies the thickness of the temporal muscle, a muscle used for biting on each side of the head, has been shown to have a high association with the area of lumbar skeletal muscles, representing an estimation of the skeletal muscle mass, as well as with the grip strength of a person’s dominant hand, indicating a measure of the muscle function and the nutrition status of patients. Thus, the temporal muscle thickness has been proposed to be a potential marker by which to identify patients at risk for sarcopenia. This is particularly advantageous for patients with neurological or neurooncological diseases, as the thickness of the temporalis muscle can be directly
determined on the basis of routine MRI examinations of the brain without prolonging the scanning duration and it helps to avoid additional examinations or a possible increase of the radiation dose for patients, leading to reduced health care costs.
Temporal muscle thickness as a prognostic marker The temporal muscle has previously been proven to have the ability to predict outcome in various disease entities. In trauma patients or children with nonsyndromic craniosynostosis (the premature closure or fusion of the open areas between the skull plates in an infant’s skull, the cause of which is unknown) it was associated with hospital-based clinical outcome markers, such as ventilator days or the
