Functional and oncological outcomes following more than three consecutive surgical resections for multiple relapses of initially grade 2 IDH-mutated gliomas

Background: Second and third surgeries were demonstrated as safe and efficient in recurrent diffuse low-grade glioma (LGG). Here, the feasibility of more than 3 resections is investigated.

Methods: Patients who underwent 4 or 5 operations for recurrent initially WHO grade 2 IDH-mutated gliomas were consecutively selected.

Results: Twenty-three operations were performed in five patients (all males, mean age 27.2 ± 4 years). Three patients underwent 5 surgeries and two patients underwent 4 surgeries. Twelve procedures (52%) were achieved with awake mapping, including all 4th and 5th operations but one. Repeat electrical mapping detected changes of the cortical maps between at least two awake surgeries in 4 patients. No patients experienced permanent neurological impairment (KPS score ≥ 80 in all cases). The patients returned to work after 22 surgeries among 23 (95.6%). There were 3 oligodendrogliomas and 2 astrocytomas (4 gliomas became malignant at fourth or fifth operation). Although the preoperative tumor volume significantly increased before the fourth (p = 0.026) and fifth operation (p = 0.003) compared with the first operation, there was no significant difference between the residual tumor volume after the fourth or fifth resection versus the first one. The mean delay was 10.6 ± 3.9 years before chemotherapy and 15.4 ± 3.4 years before radiotherapy (one patient never received adjuvant treatment after 21.5 years). The mean follow-up duration was 18.3 ± 3.1 years since the first surgery (2.3 ± 1.8 years since the last surgery). Three patients were still alive at last follow-up.

Conclusions: This is the first series showing that to reoperate beyond three times is feasible with a low functional risk and a long survival in multiple LGG recurrences, with the use of awake mapping in 87.5% of 4th and 5th surgeries.