ESTRO 2024 - Abstract Book

S841

Clinical - CNS

ESTRO 2024

Keywords: RE-IRRADIATION, HIGH-GRADE GLIOMAS, PROTON THERAPY

1365

Poster Discussion

Evaluating dose parameters for cognitive decline post-radiosurgery measured by App-based assessment

Sreenija Yarlagadda 1 , Alonso F La Rosa de los Rios 1 , D Jay J Wieczorek 1,2 , Yazmin Odia 3 , Tugce Kutuk 1 , Thailin Companioni Reyes 1 , Miguel A Ramirez Menendez 1 , Ranjini Tolakanahalli 1,2 , Yongsook C Lee 1,2 , Matthew D Hall 1,2 , Robert Press 1,2 , Alonso Gutierrez 1,2 , Michael W McDermott 4 , Minesh P Mehta 1,2 , Rupesh Kotecha 1,2 1 Miami Cancer Institute, Baptist Health South Florida, Radiation Oncology, Miami, USA. 2 Herbert Wertheim College of Medicine, Florida International University, Radiation Oncology, Miami, USA. 3 Miami Cancer Institute, Baptist Health South Florida, Neuro-Oncology, Miami, USA. 4 Miami Neuroscience Institute, Baptist Health South Florida, Neurosurgery, Miami, USA

Purpose/Objective:

Neurocognitive function assessment traditionally requires extensive pen and paper-based assessments, and is resource-intensive, precluding incorporation into routine daily clinical activities. As a pragmatic alternative, we initiated a prospective study (NCT05504681) of a novel, multi-dimensional app-based assessment of neurocognitive assessment incorporated into daily clinic flow. For this study, we characterized the effect of hippocampal dosimetric variables on neurocognitive outcomes for patients who received single-fraction stereotactic radiosurgery (SRS), without whole-brain radiotherapy for brain metastasis and were assessed using this approach.

Material/Methods:

Patients who underwent SRS between December 2021 and July 2023 were enrolled in-house study; those with brain metastasis treated with single fraction SRS who completed baseline and at least one follow-up assessment were deemed evaluable. Each assessment included tests of learning and memory domains (verbal recall, verbal revision, and verbal recognition), attention and speed of processing domains (symbols matching), verbal fluency (words that start with), fine motor speed (numbers ordering), and executive function (numbers and letters ordering). Neurocognitive decline (ND) was defined as a decrease of ≥2 and ≥3 standard errors of mean (SE) in each test compared to patient’s own baseline value. Mean dose, maximum dose to 100% of the volume (D100), maximum dose to 40% of the volume (D40), and maximum point dose (D0.03cc) for the unilateral (U/L) and bilateral (B/L) hippocampi were recorded. Logistic regression was used to test the impact of these dosimetric variables on ND.

Results:

Forty-eight patients treated with single fraction SRS met the inclusion criteria. Median age was 60 years (Range [R]: 47-87 years), median KPS was 90 (R: 70-100), and the majority were female (56%). Lung cancer was the most