OBJECT The relative benefit of repeat surgery for recurrent glioblastoma is unclear, in part due to the very heterogeneous nature of the patient population and the effect of clinician philosophy on the duration and aggressiveness of treatment. The authors sought to investigate the role of time to last recurrence on patient outcomes following aggressive repeat surgery for recurrent glioblastoma. METHODS The authors present outcomes in 104 patients undergoing repeat surgery for focally recurrent glioblastoma with at least 95% resection and adjuvant treatment at most recent prior surgery. In addition to common variables, they provide data regarding the period of progression-free survival (PFS) following an aggressive lesionectomy for focally recurrent primary glioblastoma (T2) and the time the tumor took to recur since the previous surgery (T1). They term the ratio T1/T2 the relative aggressivity index (RAI). RESULTS The median PFS was 7.8 months, 6.0 months, and 4.8 months following the second, third, and fourth-sixth craniotomies, respectively. Importantly, there was a wide range of outcomes, with time to postoperative recurrence ranging from 1 to 24 months in this group. Analysis showed no meaningful relationship between T1 and T2, meaning that previous PFS is entirely unable to predict the PFS that another surgery will provide the patient. CONCLUSIONS Repeat surgery for glioblastoma is beneficial in many cases, however this is hard to predict preoperatively. Often, surgery can provide the patient with a good period of disease freedom, but this is variable and in general it is not possible to reliably predict who these patients are.
Keywords: GBM; GBM = glioblastoma; KPS = Karnofsky Performance Status; OS = overall survival; PFS = progression-free survival; RAI = relative aggressivity index (T1/T2 ratio); RANO = Response Assessment in Neuro-Oncology; T1 = time from previous surgery to GBM recurrence; T2 = period of progression-free survival following an aggressive lesionectomy for focally recurrent primary GBM; astrocytoma; glioblastoma; recurrence; recurrent glioma; surgery; survival.