Early diagnosis of spinal epidural metastases using out-patient computed tomographic myelography

Twenty patients with known malignancies, back pain, abnormal roentgenograms of the spine, and normal neurological examinations were evaluated by outpatient computed tomographic (CT) myelography to determine the presence and extent of epidural tumor. Spinal CT following the intrathecal administration of low doses of water soluble contrast agents provided high quality diagnostic information. Three patients experienced adverse effects from this procedure which were mild and easily managed in the outpatient setting. Epidural tumor was identified in 15 of 20 (75%) patients. Patients were followed for 9-27 months following myelography. The 14 patients with epidural tumor treated with local radiation experienced pain relief and only one of these patients developed signs or symptoms of recurrent epidural tumor in the treated site. This study documents the high incidence of epidural tumor in selected patients without neurological deficits and the excellent palliative results of non-emergent, carefully planned radiation therapy. It also demonstrates that high resolution CT myelography can be performed safely in an outpatient setting in patients at high risk for epidural tumor. Outpatient myelography facilitates the early diagnosis of epidural tumor and provides needed information on the extent of the tumor for radiation treatment planning while conserving health care resources. For these reasons, outpatient CT myelography should be considered in selected patients with cancer who are at high risk for epidural metastases.