| dc.description.abstract | Background Glioblastoma (GBM) is an aggressive form of primary brain cancer, with a median survival rate of less than one year in unselected patient populations. Standard treatment for GBM includes surgery, chemotherapy, and radiation therapy (RT). In 2015, Norway implemented Cancer Patient Pathways (CPPs) to streamline the patient process for various types of cancer, aiming to provide predictability and reduce non-medical delays. While CPPs were not initially expected to impact patient outcomes, for rapidly progressing cancers like GBM, even minor delays in treatment initiation could affect prognosis. This study explores the effect of implementing CPPs on the time interval between GBM resection and the initiation of RT, as well as their potential impact on GBM patient survival. Materials and Methods This retrospective cohort study utilizes data from established databases at Oslo University Hospital's (OUH) Neurosurgical Department and Department of Oncology. The study encompasses 1,215 patients diagnosed with GBM between 2006 and 2019 who received RT, categorized into two groups: the pre-CPP group, spanning from 2006 to 2014 (n=731), and the post-CPP group, encompassing the years from 2016 to 2019 (n=397). The patients diagnosed in the year 2015 (n=86) were excluded. The patient population is stratified based on the time interval between surgery and the initiation of RT (≤4 weeks, 4.1-6 weeks, >6.1 weeks). The study employs Kaplan-Meier and Cox regression analyses to compare overall survival (OS) between these groups. Results In a cohort of 1,128 eligible patients for the CPP analysis, no significant survival difference was observed between the pre-CPP and post-CPP groups in unadjusted analysis (p=0.060). However, when adjusting for patient, tumor, and treatment factors, the post-CPP group had a significantly better outcome compared to the pre-CPP group (p<0.001). In addition, there was a significant higher fraction of patients, receiving RT within 4 weeks in the post-CPP group compared to the pre-CPP group (p<0.001). In unadjusted analysis both standard and hypofractionated RT groups had improved outcomes post-CPP implementation (p=0.017 and p<0.001, respectively), as well as older patients (p=0.001), and patients with multifocal tumors (p=0.004). Adjusted analysis of both pre- and post-CPP groups identified prognostic factors associated with better outcomes, including female gender (p=0.024), age ≤ 60 years (p<0.001), gross total resection (p<0.001), and standard RT dose (p<0.001). In the entire cohort (n=1215), including patients diagnosed with GBM in 2015, patients who started RT ≤4 weeks after surgery did not experience a survival benefit compared to those with a more delayed RT initiation at 4.1-6 weeks (p=0.641) and >6 weeks (p=0.359). Conclusion Patients with GBM had significantly improved survival after the introduction of CPPs when adjusting for patient, tumor, and treatment factors. However, the survival difference was not significant in unadjusted analysis. In addition, a significant higher proportion of patients received RT start within 4 weeks from surgery in the post-CPP group. However, the timing of RT start from surgery did not impact survival. | enm |