Treatment response on CT scan in patients with brain metastases treated with irradiation.

To evaluate the role of CT scans in the assessment of response to therapeutic irradiation of brain metastases, CT findings of 64 patients were reviewed retrospectively. Enhanced tumor on CT scans disappeared in 21 patients, who survived significantly longer than those whose CT scans showed less than 50% regression (p less than 0.01). Ring contrast enhancement (ring CE) of the tumor on pre-RT CT scan did not seem to affect the patient's prognosis for survival. Tumors with ring-CE on pre- and post-RT CT scans, however, did not regress as much as those without ring-CE. Patients without ring-CE on pre- and post-RT CT scans tended to survive longer than those with ring-CE. This study suggests that tumor regression and the CE pattern on pre- and post-RT CT scans would be useful prognostic indicators for patients with brain metastases.