LAUSR

Despite current best treatment options, a glioblastoma almost inevitably recurs after primary treatment. However, in the absence of clear evidence, current guidelines on recurrent glioblastoma are not well defined. Re-resection is one of the possible treatment modalities, though it can be challenging to identify those patients who will benefit. Therefore, treatment decisions are made based on multidisciplinary discussions. This study aimed to investigate the current practice variation between neuro-oncology specialists. In this nationwide study among Dutch neuro-oncology specialists, we surveyed possible practice variation. Via an online survey, four anonymized recurrent glioblastoma cases were presented to neurosurgeons, neuro-oncologists, medical oncologists, and radiation oncologists in the Netherlands using a standardised questionnaire on whether and why they would recommend a re-resection or not. The results were used to provide a qualitative analysis of the current practice in the Netherlands. The survey was filled out by 56 respondents, of which 15 (27%) neurosurgeons, 26 (46%) neuro-oncologists, 2 (4%) medical oncologists, and 13 (23%) radiation oncologists. In two of the four cases, there appeared to be clinical equipoise. Overall, neurosurgeons tended to recommend re-resection more frequently compared to the other specialists. Neurosurgeons and radiation oncologists showed opposite recommendations in two cases. This study showed that re-resection of recurrent glioblastoma is subject to practice variation both between and within neuro-oncology specialties. In the absence of unambiguous guidelines, we observed a relationship between preferred practice and specialty. Reduction of this practice variation is of importance; to achieve this, adequate prospective studies are essential.