ESTRO 2024 - Abstract Book

S971

Clinical - CNS

ESTRO 2024

Keywords: glioblastoma; long survivor;

3235

Mini-Oral

Predictors of executive function decline after brain RT: a novel NTCP analysis

Austin B Hopper 1 , Michael Connor 1 , Roshan Karunamuni 1 , Mia A Salans 2 , Soumya Unnikrishnan 1 , Kathryn R Tringale 1 , Anny Reyes 1 , Alena Stasenko 3 , Carrie McDonald 1,3 , Vitali Moiseenko 1 , Jona A Hattangadi-Gluth 1 1 UC San Diego, Radiation Medicine and Applied Sciences, La Jolla, USA. 2 University of California San Francisco, Radiation Oncology, San Francisco, USA. 3 UC San Diego, Psychiatry, La Jolla, USA

Purpose/Objective:

There is a paucity of evidence-based dose constraints for eloquent brain structures subserving cognitive domains for brain radiation planning. Both eloquent white matter (WM) and cortex are highly sensitive to radiation dose dependent injury. Executive functioning abilities including multi-tasking, planning, and cognitive flexibility are commonly affected after RT. We performed a multivariate normal tissue complication probability analysis of post-RT neurocognitive decline examining dosimetric predictors of decline in executive function.

Material/Methods:

Data were analyzed from a prospective longitudinal clinical trial. Patients (n=70) with primary brain tumors receiving fractionated RT complete a comprehensive neurocognitive evaluation and high-resolution volumetric and diffusion MRI at baseline and 6 months post-RT. Image processing using robust, validated automated segmentation parcellated individual WM tracts, cortical regions, and bilateral hippocampi. Well-validated neurocognitive tests including the Delis-Kaplan Executive Function System (DKEFS) and Wisconsin Card Sorting Test were assessed by certified neuropsychologists. Reliable change indices adjusted for practice effects (RCI-PE) were calculated for each patient between baseline and 6 months; a RCI-PE < -1 was scored as decline. Univariate logistic regression was performed with mean and max dose to structures of interest as well as clinical variables. Multivariate NTCP model building was performed using automated bootstrapped logistic regression, LASSO and random forest techniques.

Results:

On univariate analysis decline in cognitive flexibility (DKEFS Verbal Fluency) was associated with V40 Gy & V50 Gy to the left sided caudal middle frontal cortex and caudal anterior cingulate cortex, as well as underlying WM in both regions. DKEFS Color-Word Interference testing also includes inhibition/switching as well as flexibility; here decline was associated with D max , D mean and V30-50 Gy in the left sided cortex and WM of the pars opercularis, orbitalis, triangularis and rostral anterior cingulate.