Efficacy and safety of simultaneous integrated boost intensitymodulated radiotherapy combined with temozolomide for the postoperative chemotherapy treatment of multifocal high-grade glioma

Nan jiang Li-ping Xu Fei Li Pei-pei Wang Yuandong Cao ^*

• Department of Radiation Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China

Background: Multifocal manifestation of high-grade glioma is a rare disease with very unfavourable prognosis. The pathogenesis of multifocal glioma and pathophysiological differences to unifocal glioma are not fully understood. The optimal treatment of patients suffering from multifocal high-grade glioma is not defined in the current guidelines, therefore, individual case series may be helpful as guidance for clinical decision-making. Methods: Patients with multifocal high-grade glioma treated with simultaneous integrated boost intensity-modulated radiotherapy combined with temozolomide for the postoperative treatment in our institution between January 2020 and December 2023 were retrospectively analysed. Multifocality was neuroradiologically assessed and defined as at least two independent contrast-enhancing foci in the MRI T1 contrastenhanced sequence. Overall and progression-free survival were calculated from the diagnosis until death and from start of radiation therapy until diagnosis of progression of disease in MRI for all patients.Results: 42 patients with multifocal high-grade glioma were examined, of which 16 were female and 26 were male. The median age of all patients was 57 years (range 23-77 years). Median KPS was 80 (range 50-100) . Complete Resection was performed in ten cases and Partial resection in 32 cases before the start of radiation therapy. Prescription schedules were 54 Gy (1.8 Gy × 30) with a SIB of 60 Gy (2 Gy × 30). Concomitant temozolomide chemotherapy was applied in 40 cases. Median survival was 19 months (95% CI 14.1-23.8 months) and median progression free survival after initiation of RT 13 months (95% CI 9.2-16.7 months). Five patients experienced grade 3 toxicity, no patients experienced grade 4 toxicity, no treatment-related death occurred.Multifocal high-grade glioma could be treated safely and efficiently with simultaneous integrated boost intensity-modulated radiotherapy with concomitant and adjuvant TMZ chemotherapy.