The prognostic importance of tumor size in malignant gliomas: a computed tomographic scan study by the Brain Tumor Cooperative Group.

Abstract

The prognostic importance of tumor size was studied in 510 patients with malignant glioma (80% with glioblastoma multiforme) in the Valid Study Group of Study 80-01 of the Brain Tumor Study Group (now the Brain Tumor Cooperative Group [BTCG]). The endpoint was length of survival from randomization, which occurred within 3 weeks of definitive surgery. Following randomization, patients were scheduled to receive radiotherapy (RT) (6,020 cGy) during a 7-week period, along with continuing courses of chemotherapy. Computed tomographic (CT) scan information was available for 124 patients preoperatively, 300 patients postoperatively (preradiation), and 218 patients 9 weeks post-RT (+/- 3 weeks). Tumor size was determined as area (length x width) on the contrast-enhanced scan and survival was compared by log rank statistics. Preoperative tumor area was unrelated to survival (P = .48), but postoperative area was significantly prognostic (P less than .0001); the smaller the residual tumor, the longer the patient liv...