Supramaximal Resection for Glioblastoma: Redefining the Extent of Resection Criteria and Its Impact on Survival

Abstract

Glioblastomas (GBMs) are the most common and aggressive primary brain tumors, and despite advances in treatment, prognosis remains poor. The extent of resection has been widely recognized as a key factor affecting survival outcomes in GBM patients. The surgical principle of “maximal safe resection” has been widely applied to balance tumor removal and neurological function preservation. Historically, T1-contrast enhanced (T1CE) extent of resection has been the focus of research; however, the “supramaximal resection” concept has emerged, advocating for even greater tumor resection while maintaining neurological function. Recent studies have demonstrated potential survival benefits associated with resection beyond T1CE extent in GBMs. This review explores the developing consensus and newly established criteria for “supramaximal resection” in GBMs, with a focus on T2-extent of resection. Systematic reviews and meta-analyses on supramaximal resection are summarized, and the Response Assessment in Neuro-Oncology (RANO) resect group classification for extent of resection is introduced. The evolving understanding of the role of supramaximal resection in GBMs may lead to improved patient outcomes and more objective criteria for evaluating the extent of tumor resection.

High costs, low quality of life, reduced survival, and room for improving treatment: an analysis of burden and unmet needs in glioma

“…Maximum safe resection has been interpreted differently by different surgeons, leading to definitions of resection extent that have been handled inconsistently in clinical practice ( 88 ). A key operationalization of maximum safe resection is gross total resection, commonly understood as the complete removal of the contrast-enhancing tumor mass.…”

“…Resection beyond the CE tumor, termed “supratotal” or “supramaximal” resection, has become an active field of research in the last decade, based on the premise that removing non-contrast enhancing tumor or even tissue appearing normal on magnetic resonance imaging (MRI) would capture residual tumors ( 82 , 88 ). The currently available evidence on the benefits and outcomes associated with supramaximal resection remains mixed.…”

“…Favorable outcomes, including recurrence and survival, of supramaximal resection were also reported for low-grade gliomas ( 91 ). More broadly, reviews for low-grade gliomas and for glioblastoma suggested that supramaximal resection was effective and safe ( 88 , 92 ). Further and larger clinical studies are needed for more robust evidence.…”

Novel insights on genetics and epigenetics as clinical targets for paediatric astrocytoma

“… 56 , 57 Depending on the physiology of the tumour and the location, a range of studies have shown that SMR significantly improves PFS and OS of patients, compared to those that underwent GTR or partial resection surgery. 58 , 59 Other novel surgical procedures that improves GTR and prevents surgery‐associated complications involve using intraoperative imagining such as MRI or ultrasound for real‐time visualisation of the tumour region, fluorophores such as sodium fluorescein (SF) and 5‐aminolevulinic acid (5‐ALA), dyes that bind to proteins in the blood at the tumour site (SF fluorophore) or metabolised by cancer cells (5‐ALA fluorophore), which can be detected under ultraviolent light and the use of motor evoked action potentials in real‐time to help monitor vital regions of the brain that are involved in motor functions. These innovative procedures have shown significant improvements in GTR and survival rates in adults as compared to surgery alone.…”