|dc.description.abstract||Brain metastases occur when tumour cells developed anywhere in the body spread to the brain. Radiotherapy (RT) is a treatment option for brain metastases that aims to eliminate the tumor cells within the brain, but it also causes healthy tissue damage that can lead to cognitive decline.
In order to measure the effects of different RT treatments on the patients, the quality of life (QoL) is measured to determine which one leads to the best cognitive outcome. For this purpose, tests with varying degrees of specificity, such as, neurocognitive assessment (NCA), patient reported outcome (PRO) and Karnofsky Performance Scale (KPS) aim to quantify the cognitive change of the patients before and after RT. However, the high cost of NCAs, patient dependency of PROs and unreliability of KPS highlight the need for a new approach to measure the cognitive state of patients. Such novel approach could estimate the QoL of the patients solely based on anatomical markers from MRI scans, reducing costs and patient interactions alike. In order to develop such tool, the anatomical markers related to cognitive must be identified first.
In response, we performed a systematic review to analyse existing literature on the anatomical changes captured in MRI that have been linked to cognitive decline. We searched the Pubmed database where studies that evaluated cognitive change as a result of a specific anatomical change after RT were selected. Out of 298 publications, 16 were chosen, wherein tumor morphology, lesion number and location, peritumoral edema and necrosis were identified as the most relevant anatomical markers for the estimation of the QoL of brain metastatic patients based on MRI data.
We identified multiple limitations within our review regarding inhomogeneous patient cohorts, low-quality image processing and the lack of correlation between the anatomical changes and the effect that might have in the QoL of patients. Consequently, although the studies reviewed all reached similar conclusions, further research based on larger samples with more uniform patient cohorts and advanced imaging must be conducted, to be able to definitively quantify the effect these anatomical changes have in the QoL of patients after RT.||