Cognitive function after concurrent temozolomide-based chemoradiation therapy in low-grade gliomas

Purpose: We sought to evaluate the effects of concurrent temozolomide-based chemoradiation therapy on neurocognitive function in patients with low-grade glioma (LGG). Materials/methods: We included adult patients with LGG who were treated postoperatively with radiotherapy (RT) with concurrent and adjuvant temozolomide (TMZ). Patients were evaluated with comprehensive psychometric tests at baseline (prior to RT + TMZ) and at various time intervals following RT + TMZ. Baseline cognitive performance was analyzed by sex, age, education history, history of seizures, IDH mutation status, and 1p/19q codeletion status. Changes in neurocognitive performance were evaluated over time. Results: Thirty-seven LGG patients (mean age 43.6, 59.5% male) had baseline neurocognitive evaluation. Patients with an age > 40 years old at diagnosis and those with an education > 16 years demonstrated superior baseline verbal memory as assessed by HVLT. No other cognitive domains showed differences when stratified by the variables mentioned above. A total of 22 LGG patients had baseline and post RT + TMZ neurocognitive evaluation. Overall, patients showed no statistical difference between group mean test scores prior to and following RT + TMZ on all psychometric measures (with the exception of HVLT Discrimination). Conclusion: Cognitive function remained stable following RT + TMZ in LGG patients evaluated prospectively up to 2 years. The anticipated analysis of RTOG 0424 will provide valuable neurocognitive outcomes specifically for high risk LGG patients treated with RT + TMZ.