Extirpation of Glioblastomas: MR and CT Follow-up of Residual Tumor and Regrowth Patterns

Purpose: To optimize the timing of CT and MR after glioblastoma resection and to define the pattern of tumor regrowth.

Subjects And Methods: Sixty-eight patients with glioblastoma were studied prospectively with CT and MR. The first postoperative scan was obtained between day 1 and day 5; follow-up scans were obtained bimonthly.

Results: Residual tumor was shown most reliably on scans obtained shortly after surgery (MR, 77%; CT, 40.5%). After the fourth day up to 3 months postoperatively, surgically induced enhancement prevented recognition of residual tumor. Seventy-five percent of patients with residual tumor shown by early postoperative MR had progressive disease during follow-up, whereas only 36% of patients without evidence of residual tumor had MR signs of progressive disease.

Conclusion: Early, enhanced, postoperative MR is the radiologic procedure of choice to determine the extent of glioblastoma resection. Gross total tumor resection as determined by early postoperative MR correlates with a prolongation of life.