Gross total resection

What it is

Gross total resection is the removal of all of the tumor that is visible — both to the surgeon during the operation and on imaging — typically confirmed by an MRI after surgery. For many gliomas, achieving gross total resection is associated with better outcomes.

Understanding Gross total resection

"Gross total" refers to removing all visible tumor (the term "gross" meaning visible to the eye, as opposed to microscopic). After surgery, an MRI is usually done to assess how much tumor was removed and to confirm gross total resection (no visible residual tumor). For many glioma types, the more complete the removal, the better the outcomes tend to be — for example, gross total resection is associated with longer survival in glioblastoma and other gliomas, and may improve seizure control and symptoms. However, an important caveat applies to diffuse gliomas: because their cells infiltrate beyond what is visible, even a gross total resection leaves microscopic tumor behind, which is why additional treatment (radiation and/or chemotherapy) usually follows. Whether gross total resection is achievable depends on the tumor's location and its relationship to critical areas. Understanding gross total resection clarifies the removal of all visible tumor and its significance.

Why it matters

Understanding gross total resection helps patients and families see the goal of removing all visible tumor — associated with better outcomes for many gliomas — while recognizing that diffuse gliomas leave microscopic cells, so further treatment usually follows.