Surgical resection in medulloblastoma: a crossroads in the molecular era.

Surgical resection for medulloblastoma has been a mainstay of treatment for decades due to the need for definitive diagnosis and known benefits on treatment efficacy and survival. While many pediatric neurosurgeons and neurooncologists agree that maximal safe surgical resection should be the goal of medulloblastoma surgery, actual practical application and benefits of maximal safe resection seem to vary. Early work on extent of resection provided a relatively arbitrary 1.5 cm2 threshold to distinguish subtotal resection (STR) from near total resection (NTR) and demonstrated a survival benefit if the residual was ≤ 1.5 cm2 (NTR or gross total resection (GTR)). However, recent evidence questions the validity of this threshold, with European researchers even suggesting that STR alone should not be considered a high-risk feature during adjuvant therapy planning. The question regarding extent of resection, therefore, is undeniably controversial and has become even more complex in recent years due to the seminal work done to identify medulloblastoma subgroups based on molecular characteristics. Adjuvant treatment approaches are being tailored to these molecular subgroups, and the impact of extent of resection on survival is being reconsidered within the context of subgroups. Certainly, the goal when treating children with medulloblastoma, or any form of brain cancer, should be to cure the disease while minimizing treatment-related toxicity, including surgical injury. In this article, we discuss the role of surgical resection for treating medulloblastoma and whether it is possible to maximize both surgical resection, to potentially improve survival and adjuvant treatment efficacy, while minimizing neurological morbidity.