From Pre- and Intraoperative Functional Mapping to Postoperative Adjuvant Treatment – Individualized Glioma Treatment Reveals Optimal Oncological Results in the Elderly

Introduction: While maximum extent of resection should be achieved during glioma resection, patients’ functionality must be preserved. Afterwards, postoperative adjuvant treatment is adjusted depending on integrated diagnosis. However, it might be necessary to modify standard treatment strategies for an optimal oncological therapy in the elderly.

Methods: We subdivided our prospective cohort of 175 patients above 64 years with eloquent gliomas (WHO CNS °II: 1.7%, °III: 5.7%, °IV: 92.6%) into four age-based groups (group 1: 65-69 years, 64 cases [36.6%]; 2: 70-74 years, 48 cases [27.4%]; 3: 75-79 years, 43 cases [24.6]; 4: >79 years, 20 cases [11.4%]). All patients underwent preoperative noninvasive mapping, intraoperative neuromonitoring in 141 cases (80.6%), using direct cortical and/or subcortical motor mapping in 69 (39.4%) and 51 (29.1%) cases, and awake language mapping in 12 cases (6.9%).

Results: Without significant differences, gross total and subtotal resection could be achieved in 65.1% and 27.4%. Stereotactic biopsy was performed in 7.4% of cases. Postoperatively, we found transient and permanent functional deficits in 12.6% and 10.9% of cases without significant differences. Although the preoperative Karnofsky Performance Scale (KPS) significantly differed (1: median 80 [range 50-100], 2: 80 [50-100], 3: 70 [40-100], 4: 70 [60-100]; p=0.04), the postoperative KPS did not differ between the subgroups (1: 80 [30-100], 2: 70 [40-100], 3: 70 [40-100], 4: 80 [70-90]). We did not find significant differences for duration of hospitalization, discharge destination, and postoperative board decision. With a long-term follow-up above 3 months of 49.7%, patients had a progression-free survival of 5 (1-47) months and an overall survival of 7 (0-38) months.

Conclusion : The interdisciplinary treatment of older glioma patients seems to be less age-dependent but must be adjusted based on the functional status. Function-guided surgical resections could be performed as usual, while the necessity of modifying postoperative treatment should be discussed individually.