Abstract
PURPOSE: The long-term toxic effects of prophylactic cranial irradiation (PCI) on cognition in small cell lung cancer (SCLC) patients have not yet been well-established. The aim of our study was to examine the changes in neuropsychological variables and brain structure in a group of long-term SCLC survivors treated with PCI. PATIENTS AND METHODS: Eleven long-term SCLC patients, who underwent PCI at least two years before were compared to an age and education matched healthy control group. Both groups were evaluated using a neuropsychological battery and multimodal structural magnetic resonance imaging (MRI: T1-weigthed and diffusion-weighted imaging, DTI). Voxel-based morphometry (T1-VBM) and Tract-based Spatial Statistics (DTI-TBSS) were used to analyze gray matter (GM) and white matter (WM) integrity, respectively. RESULTS: Nearly half (45%, n = 5) of the SCLC patients met criteria for cognitive impairment in relation to verbal abilities, processing speed and visual memory. In addition, SCLC patients showed significant decreases of GM in subcortical regions such are the basal ganglia bilaterally (including the putamen and caudate), bilateral thalamus and right insula, together with lower WM integrity of the entire corpus callosum. CONCLUSION: This is the first study to demonstrate neuropsychological deficits together with brain-specific structural differences of both GM and WM in long-term SCLC survivors. Our results suggest that PCI therapy is associated with the development of permanent long-term cognitive and structural brain effects in a SCLC population.