Neurocognitive Function Following Concurrent Radiotherapy and Temozolomide for Adult Patients With Low-Grade Glioma.

PURPOSE/OBJECTIVE(S) RTOG 0424 demonstrated that high-risk low-grade glioma (LGG) patients treated with concurrent temozolomide (TMZ) and radiotherapy (RT) followed by adjuvant TMZ (RT+TMZ) had a survival longer than that reported for historical controls. The impact of this treatment strategy on short term neurocognitive outcomes is not well established. We sought to evaluate neurocognitive measures among adult LGG patients prior to and following RT+TMZ. MATERIALS/METHODS We prospectively evaluated 22 LGG patients treated postoperatively with RT + TMZ. Neurocognitive batteries were administered pre- and post-treatment. Verbal (Hopkins Verbal Learning Test [HVLT]) and nonverbal (Brief Visuospatial Memory Test [BVMT]) learning and memory, motor functioning (Grooved Pegboard Test), and phonemic fluency (CFL) were assessed. Nonparametric paired t-test (Wilcoxon signed ranked test) was performed for paired samples, with post-treatment of within 3 months (14 pairs), and after 3 months (12 pairs) respectively. All the statistical analysis was performed with R 4.0.3. RESULTS The median age at diagnosis was 43 years (range: 23-77), and 18 (82%) were male. By molecular classification, the cohort was comprised of IDHmut-1p19q-codel, IDHmut-1p19q-noncodel, IDHmut-NOS, IDH1-R132H-negative, and unknown, in 3 (14%) patients, 3 (14%), 1 (5%), 11 (50%), and 4 (18%), respectively. Gross total resection was obtained for 3 (14%) patients, near total resection for 2 (9%), subtotal resection for 6 (27%), and biopsy for 11 (50%). Patients did not show a significant decline within 3 months of receiving RT+TMZ in nonverbal learning (BVMT total recall, P = 0.67, n = 14) or in verbal learning or memory (HVLT, P = 0.06, n = 14). Similarly, nonverbal learning and verbal learning/memory measured ≥ 3 months from completing treatment showed no significant decline (P = 0.62, n = 12; P = 0.67, n = 12, respectively). Motor function (Grooved Pegboard, both dominant and non-dominant) remained stable within 3 months post-treatment (P = 0.84, n = 14; P = 0.26, n = 14) and after 3 months (P = 0.94, n = 12; P = 0.09, n = 12). Phonemic fluency (CFL) did not show a significant decline within 3 months post-treatment (P = 0.083, n = 14) or after 3 months (P = 0.67, n = 12). CONCLUSION Adult LGG patients did not show subacute significant changes in verbal and nonverbal memory, motor function or phonemic fluency following RT+TMZ compared their pre-radiation baseline. A larger sample size and longer follow-up is necessary to identify the neurocognitive impact of this treatment approach. AUTHOR DISCLOSURE D.Y. Park: None. M.C. Tom: Research Grant; Blue Earth Diagnostics. Y. Chen: None. W. Wei: None. S. Tewari: None. M. Ahluwalia: Consultant; AbbVie, Bayer, VBI vaccines, Karyopharm, Elsevier. Stock; Mimivax, Doctible. J.S. Yu: None. S.T. Chao: Honoraria; Varian Medical Systems, Zeiss, AbbVie. Consultant; AbbVie. J.H. Suh: Consultant; Philips, Novocure. Met to discuss current indications for TTF; Novocure. Met during 1 day retreat to discuss future of radiation oncology; Philips. Scientific advisory board; Neutron Therapeutics. D. Peereboom: None. G. Stevens: None. G.H. Barnett: None. L. Angelov: None. A.M. Mohammadi: None. I. Katzan: None. T. Hogan: None. C. Kissel: None. B. Lapin: None. I. Schuermeyer: None. M.W. Parsons: None. R. Naugle: None. E.S. Murphy: None.