Résumé
Reoperation has been established as an effective therapeutic strategy in recurrent diffuse low-grade gliomas. Insular gliomas represent a specific surgical challenge due to surrounding vascular and functional structures. Here, our aim was to investigate the main clinico-radiological factors guiding the decision to reoperate on recurrent insular low-grade gliomas (ILGG). Methods: in this retrospective consecutive series, we screened all patients operated on for an ILGG in our institution who further presented with a tumor regrowth without signs of malignant transformation. We compared patients who were subsequently offered a reoperation under awake mapping at recurrence (with a proven pathological diagnosis of low-grade glioma after second surgery) to patients who were not selected for a reoperation. The first group (reoperated; n=20) included all recurrent ILGG patients who underwent second resection and the second group (non-reoperated; n=60) included non-reoperated patients who underwent adjuvant oncological treatment. Results: factors significantly associated with reoperation were extent of resection (EOR) at first surgery (91.9% vs 89.7% p=0.014) and left temporo-polar infiltration at the time of tumor recurrence (Liebermeister statistical analysis, Z-statistics=6.50, FDR-corrected with q=0.05). Infiltration of the anterior perforated substance at tumor recurrence was significantly anticorrelated to reoperation (Z-statistics=-4.33). Mean EOR was 83.7% at reoperation with 90% of survivors at last follow-up (9.3 ± 3.8 years), a low postsurgical morbidity (KPS ≥ 80 in 95% of patients), a high rate of postoperative professional resumption (95%) and 56.2% of seizure control. Conclusions: in selected patients with recurrent ILGG, reoperation with intraoperative awake mapping is associated with favorable oncological outcomes, and a low postsurgical morbidity. A greater EOR at first surgery was significantly associated with reoperation. Patients who benefited from a second surgery typically had a recurrent pattern within cortical areas (such as the temporo-polar region), while other patients typically presented with a deeper infiltrative pattern within the anterior perforated substance and the surrounding white matter pathways. Such original findings may be helpful to select the optimal indications of reoperation in recurrent ILGG.