Recurrent insular low-grade gliomas: factors guiding the decision to reoperate

Abstract

OBJECTIVE Reoperation has been established as an effective therapeutic strategy in recurrent diffuse low-grade gliomas (LGGs). Insular gliomas represent a specific surgical challenge because of the surrounding vascular and functional structures. The aim of this study was to investigate the main clinicoradiological factors guiding the decision to reoperate on recurrent insular LGGs (ILGGs). METHODS In this retrospective consecutive series, the authors screened all patients operated on for an ILGG in their institution who further presented with a tumor regrowth without the development of contrast enhancement. They compared patients who were subsequently offered a reoperation under awake mapping at recurrence or who underwent reoperation after adjuvant treatment had reduced the volume of the initial tumor recurrence (with a proven pathological diagnosis of LGG after the second surgery) to patients who were not selected for a reoperation. The first group (reoperated group; n = 20) included all recurrent ILGG patients who underwent second resection, and the second group (nonreoperated group; n = 60) included patients who did not undergo reoperation but 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), residual tumor volume (9.5 ± 7.1 mL [range 0–30 mL] vs 6.3 ± 7.3 mL [range 0–30 mL], p = 0.02) at first surgery and left temporopolar infiltration at the time of tumor recurrence (Liebermeister statistical analysis, 4293 voxels survived false discovery rate correction with p < 0.05; maximal z-statistic = 6.50). Infiltration of the anterior perforated substance at tumor recurrence was significantly anticorrelated to reoperation (179 voxels survived false discovery rate correction with p < 0.05; minimal z-statistic = −4.33). The mean EOR was 83.7% at reoperation with a 90% survival rate at last follow-up (9.3 ± 3.8 years), low postsurgical morbidity (Karnofsky Performance Status score ≥ 80 in 95% of patients), a high rate of postoperative professional resumption (95%), and seizure control in 57.1% of patients. CONCLUSIONS In selected patients with recurrent ILGG without radiographic evidence of malignant transformation, reoperation with intraoperative awake mapping is associated with favorable oncological outcomes and a low postsurgical morbidity. A greater EOR and a lower residual tumor volume at first surgery were significantly associated with reoperation. Patients who benefited from a second surgery typically had a recurrent pattern within cortical areas (such as the temporopolar 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.

Brain Plasticity Profiling as a Key Support to Therapeutic Decision-Making in Low-Grade Glioma Oncological Strategies

“…Therefore, neuroplasticity markers should be assessed longitudinally, with repetitive appreciations of WM infiltration, velocity of expansion, and serial neuropsychological examinations. Patients with high plastic potential and whose tumor volume can still be reduced under the 10 mL threshold should benefit from reoperation (see an example in Figure 2A), given the excellent neurological and neuropsychological tolerance of iterative awake-guided resections [89,90] and the longterm benefits in terms of overall survival [90][91][92][93][94][95], even when the tumor invades crossroads and challenging anatomical regions such as the insula [96]. Further, some authors have demonstrated that functional-based surgery remains applicable for a third operation, years after the initial diagnosis, with excellent functional outcomes and a median overall survival reaching 17.8 years [97] (here illustrated in Figure 2C).…”

Nuancing the Limitations of Axonal Plasticity in World Health Organization Grade II Gliomas: White Matter Tracts Compensation Is Driven by Cortical Remodeling

“…8,40,59 This reasoning can be applied for GIIG relapse after a first surgery: Reoperation may be decided according to the connectomal constraints, ie, with a lower chance improve EOR if the recurrent glioma migrates along the WM tracts (Figure 3). 60,61…”