  Immunotherapy is an effective precision medicine treatment for several
cancers. Imaging signatures of the underlying genome (radiogenomics) in
glioblastoma patients may serve as preoperative biomarkers of the tumor-host
immune apparatus. Validated biomarkers would have the potential to stratify
patients during immunotherapy clinical trials, and if trials are beneficial,
facilitate personalized neo-adjuvant treatment. The increased use of whole
genome sequencing data, and the advances in bioinformatics and machine learning
make such developments plausible. We performed a systematic review to determine
the extent of development and validation of immune-related radiogenomic
biomarkers for glioblastoma. A systematic review was performed following PRISMA
guidelines using the PubMed, Medline, and Embase databases. Qualitative
analysis was performed by incorporating the QUADAS 2 tool and CLAIM checklist.
PROSPERO registered CRD42022340968. Extracted data were insufficiently
homogenous to perform a meta-analysis. Results Nine studies, all retrospective,
were included. Biomarkers extracted from magnetic resonance imaging volumes of
interest included apparent diffusion coefficient values, relative cerebral
blood volume values, and image-derived features. These biomarkers correlated
with genomic markers from tumor cells or immune cells or with patient survival.
The majority of studies had a high risk of bias and applicability concerns
regarding the index test performed. Radiogenomic immune biomarkers have the
potential to provide early treatment options to patients with glioblastoma.
Targeted immunotherapy, stratified by these biomarkers, has the potential to
allow individualized neo-adjuvant precision treatment options in clinical
trials. However, there are no prospective studies validating these biomarkers,
and interpretation is limited due to study bias with little evidence of
generalizability.
