Brain Cancer Radio-Pathomics

Relevance

Glioblastomas (GBMs) are the most common central nervous system originating tumor, accounting for around 50% of new brain-originating cancer diagnoses. After abnormal findings on magnetic resonance imaging (MRI), surgical resection is conducted to debulk the tumor and provide tissue samples for pathological diagnosis. Gross total resection is often attempted. Patients are then typically treated with localized radiation treatment with concordant temozolomide therapy and may receive additional treatments such as anti-angiogenic agents (i.e., bevacizumab) or tumor treating fields (TTFields) therapy. Despite the therapeutic benefit of these treatments, patient prognosis is dismal, with one- and five-year survival rates of 41% and 6.6%, respectively. Critical to maximizing the efficacy of GBM treatment is accurately localizing the full extent of the tumor. Non-invasive tumor monitoring via MRI includes pre- (T1) and -post-Gd contrast (T1C) T1-weighted imaging, which is typically used to define the primary tumor mass, T2-weighted FLAIR imaging, where hyperintense areas may reflect active tumor or edema, and apparent diffusion coefficient (ADC) images calculated from diffusion weighted imaging, where areas of restricted diffusion are thought to correlate with hypercellularity. However, autopsy studies have found areas of infiltrative tumor as far as 10 cm beyond the T1C and FLAIR margins and have shown little-to-no relationship between ADC values and cellularity when using tissue collected from beyond the suspected tumor region. Therefore, there is a pressing need to develop new imaging tools to more precisely localize treatment and monitor tumor progression to improve patient prognoses.