Using functional near-infrared spectroscopy to study neurocognitive function in adult survivors of childhood acute lymphoblastic leukemia, an exploratory study

Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy. Due to the drastic increase in survivor rate over the last 50 years, long-lasting treatment effects on moods and neurocognitive function have become a current issue. Most studies relating to the effects of treatment in ALL survivors investigate patients in their adolescence. This pilot study aims to identify measurements for evaluating late effects of childhood ALL survivors in relation to neurocognitive and mood problems in adulthood. ALL survivors who received neurotoxic treatment with high-dose methotrexate and cranial radiotherapy (n = 10) and ALL survivors only treated with high-dose methotrexate (n = 10), plus age and sex match controls (n = 20), were recruited into the study. The study protocol involved questionnaires, neurocognitive tests and optical brain imaging with functional near-infrared spectroscopy (fNIRS) over the frontal and parietal cortex. The fNIRS results indicate a reduced involvement of the parietal cortex during conflict processing for ALL survivors compared to controls. The study protocol shows promising results for identifying subgroups that suffer from neurocognitive and mood problems. However, since this is a discovery driven pilot study, the results need to be confirmed in a larger study. There is always a possibility that when larger sample sizes are considered, even within the same geographical settings, the results and conclusions may not align with the findings shown here. As our results indicate increased challenges among female ALL survivors, especially pathological fatigue, anxiety and information processing, it is important that future investigations explore the interplay between the risk of hormonal interaction with chemotherapy during development, in addition to occupational and social pressure during adulthood.