Patients with gliomas are generally asked to undergo regular postoperative reviews. However, the time interval between postoperative reviews varies by grade of glioma. In general, the most important factor in determining the postoperative review interval is the grade of the glioma. Typically, the first postoperative review is 3 months after surgery. Thereafter, grade II gliomas require a postoperative review every six months, and grade III-IV gliomas require a review every three months. The rationale is simple: high-grade gliomas will recur in a shorter period of time, and both doctors and patients want to detect recurrence in time to avoid missing a second surgery or treatment.