The relative roles of neurological examination, functional abilities, and computed tomography in the definition of treatment failure in patients with anaplastic gliomas

Forty-one patients with anaplastic gliomas undergoing postoperative treatment and evaluation underwent bimonthly evaluation of the following indices of treatment failure: neurological examination; Karnofsky functional rating; and computed tomography (CT) brain scanning. Treatment failure was declared when neurological examination or Karnofsky rating showed increased impairment or when CT scan revealed an increase in tumor sizes. Most often, all three indices simultaneously indicated treatment failure. In only 6 of 41 cases the CT scan alone was the first indication of treatment failure. During the first 6 months of follow-up, tumor enlargement on CT scan as a sole index of treatment failure occurred in only 3 of 26 cases that showed evidence of treatment failure during that time. For patients with glioblastoma, about 6% of treatment failures within 6 months are predicted to be missed by Karnofsky rating plus neurological examination, whereas CT scan alone is predicted to miss about 30%. It would seem reasonable to rely on the neurological examination and Karnofsky rating for follow-up during the first 6 months after surgery, without routine serial CT scanning during that time.