SURGICAL-MANAGEMENT OF BRAIN-STEM TUMORS IN CHILDREN - RESULTS AND STATISTICAL-ANALYSIS OF 75 CASES

A study was made of 75 children treated between 1970 and 1990, with pa rtial, subtotal, or total removal of three intrinsic and 72 exophytic or surface brain-stem tumors. In all cases, the goal of surgery was to remove as much tumor as possible. Extent of removal was defined accor ding to data obtained from postoperative computerized tomography or ma gnetic resonance imaging, and was considered partial when only a small amount of tumor was removed, subtotal when a few cubic millimeters of tumor was left, and total when no residual tumor was seen on postoper ative radiological investigations. An ultrasonic aspirator was used fo r the 43 most recent operations. Among tumor removals without the aspi rator, 24 (75%) were partial, eight (25%) subtotal, and none total; wi th the use of the aspirator, the number of partial removals decreased to 44.5% while that of subtotal and total removals increased to 32% an d 23.5%, respectively. There were 69 gliomas (92%) and 47 benign tumor s (62.6%). Forty-nine patients were irradiated postoperatively, and 14 of the 23 patients whose benign tumors were removed totally or subtot ally did not undergo irradiation. This study showed that: 1) the overa ll prognosis of patients with malignant tumors was poor and was not im proved by surgery; 2) the survival rate of those with benign tumors wa s significantly (p < 0.01) lower after partial removal than after tota l or subtotal removal (52% and 94%, respectively, at 5 years); 3) comp arison of means and proportions (Student's and chi-squared tests) betw een benign and malignant tumors showed a significant difference relati ng to patient age (p < 0.03), peritumoral hypodensity (p < 0.001), and preoperative duration of symptoms (p < 0.001); 4) stepwise logistic r egression analysis confirmed that two of these three variables were re lated to malignancy: namely, patient age at surgery (p < 0.03) and pre sence of peritumoral hypodensity (p < 0.001); and 5) routine postopera tive irradiation was contraindicated after total or subtotal removal o f benign tumors.