EVALUATION OF MALIGNANT GLIOMA PATIENTS DURING THE POST-IRRADIATION PERIOD

The syndrome of increased focal or generalized central nervous system (CNS) dysfunction in the early postirradiation period in patients treated with radiation therapy (RT) for malignant gliomas has not been well documented. The authors have undertaken retrospective study of 51 patients with supratentorial malignant gliomas who survived longer than 26 weeks from the time of diagnosis. All patients received irradiation and chemotherapy and were evaluated at 8-week intervals. Each evaluation consisted of a neurological examination, computerized tomography (CT) and radionuclide scans, Karnofsky rating, and an evaluation of glucocorticoid levels needed to maintain neurological function. In all, 263 evaluable periods, consisting of 1290 individual valuable tests (parameters), were analyzed. In the first 18 weeks after RT, 26 of the 51 patients studied (51%) showed deterioration in one or more tests; 14 of the 26 (53%) did not improve. These 14 patients had a median time to tumor progression (MTP) of 31 weeks. The remaining 12 patients in this group (47%) improved and had an MTP of 73 weeks. Of the 51 patients, 25 (49%) showed deterioration significant enough to presume tumor progression (two of the following three tests were unequivocally worse: neurological examination, CT scan, and radionuclide scan), seven improved with no change in therapy and had an MTP of 66 weeks, while the other 18 had an MTP of 32 weeks. Excluding the Karnofsky rating, any individual test that showed worsening during the first 18-week period had a 33% probability of significant improvement at a subsequent evaluation period. After 18 weeks the probability of the test improving was only 4%. The authors conclude that CNS decompensation up to 18 weeks after RT, as ascertained from clinical examination, scans, or glucocorticoid dosage, does not invariably predict tumor progression, because in 28% (7/25) of such cases there will be subsequent improvement.