RT Therapy for Brain Tumors May Negatively Impact Processing Speed

CancerNetwork® spoke with Mailhot, a radiation oncologist at the University of Florida College of Medicine, about surprising findings he came across when conducting a retrospective analysis of scholastic performance on pediatric patients who had undergone Study findings were presented at the 2024 American Society of Radiation Oncology (ASTRO) Annual Meeting.

Mailhot began by expressing his surprise at the feasibility of the research his team had undertaken, particularly when linking scholastic and medical data. He explains that this was accomplished through a meeting between the legal counsels of the Florida Department of Education legal and the University of Florida, College of Medicine, to develop the ability for patients to consent to have their educational data used.

He further expressed shock at the statistical significance of the relatively small sample of 50 treated patients, indicating a warrant for further research. He additionally expressed surprise at the high proportion of treated patients eligible for free or reduced lunch, an indicator for socioeconomic status.

Mailhot concluded by stating that processing speed and working memory were most impacted by radiation therapy. He expressed that, for the findings related to processing speed in particular, they were validating the observed outcomes associated with patients who had not undergone neuropsychological testing.

The retrospective study analyzed the scholastic achievement in patients under 21 with primary brain tumors (n = 50) treated at the University of Florida College of Medicine vs 150 control students available through the Florida Department of Education from 2007-2021. The primary end point of the study was Achievement Level for English language arts and mathematics from a score of 1-5 with 5 reflecting the highest achievement.

Results from the study found that the odds of a treated patient receiving a passing math score was 67% lower post treatment and was 47% lower than the odds of a control patient receiving a passing math score. Additionally, the interaction term between time and treatment was significant for mathematics (P = .052).

Transcript:

I think there were a couple [surprising] aspects of [the research]. The first was, honestly, the feasibility of doing this type of data linkage, of being able to have this individual survivor to demonstrate we could connect school data to medical data. I think everyone, if they are listening to this, is familiar with HIPAA, which is federally mandated to protect our medical data, but actually passed legislatively before that, something called FERPA, which people might not be as familiar with, which protects individual educational data.

To achieve this, the Florida Department of Education legal counsel actually had to meet with the University of Florida, College of Medicine legal counsel to develop a consent because, to their knowledge, this had not been linked before. Being able to conceive that was an important point. The fact that we saw statistically significant results for a cohort of 50 treated patients and then 200 total patients, given those small numbers, was surprising, but definitely exciting work in the sense that if we are picking up a signal here, it is something that we should pursue.

Looking at the demographics of our 50 children about 50% of them were eligible for free or reduced lunch, which, off the bat, had we not investigated that, I would not have expected, necessarily. In terms of the actual findings themselves, when we do look at the different ways in brain processing that children who receive brain radiation can be affected, 2 of them are processing speed and working memory.

Processing speed has to do with the ability to do math in your head, like ‘30+5+12”, or simply, if you are doing a bill and adding it up together. The fact that that has been established–– and what we are seeing are impacts on math performance and state testing–– there is a certain kind of biologic rationale, or in a certain sense, it is validating with what we understand with those neuropsychological outcomes, and what we are seeing play out in the small cohort regarding math performance.

Reference

Mailhot Vega R. Establishing the association between OAR dose and post-therapy scholastic performance in pediatric brain tumor survivors. Presented at: ASTRO 2024 Annual Meeting. September 29-October 2, 2024. Washington, DC. Abstract 172