The detection of occult metastases with imaging studies

Abstract

The detection of occult metastases from radionuclide and roentgenographic imaging studies is not optimum. Tables l-5 contrast the incidence of metastases in bone, lung, liver and brain with that found at post-mortem examination. The postmortem incidence of metastasis gives a guide to the highest estimate of possible metastasis at the time of diagnosis. 3.6,9.10.11,1-18.20.21,2&27 Cancer of the liver, esophagus, stomach and pancreas are excluded from this analysis because patients with these cancers survive less than 1 year, despite treatment. The apparent futility of our standard imaging studies to demonstrate occult metastatic disease at diagnosis was shown in a series of operable patients with cancer of the lung who died of intercurrent disease. Postmortem examination showed an unsuspected high incidence of metastatic disease despite an extensive pre-operative investigation.14 Thus far we have been concerned with the problem of underdiagnosing occult metastatic disease. There are also problems with overdiagnosing metastatic disease. Liver scanning is quite nonspecific. Findings that increase the possibility of detecting metastatic disease on liver scans are hepatomegaly, more than two abnormal liver function tests, and focal rather than diffuse abnormality on the liver scan. Hepatic arteriography adds little to the evaiuation of metastatic liver disease. Some conditions which produce abnormal liver scans can mimic metastatic disease, i.e., cirrhosis, benign tumors, large kidneys, supradiaphragmatic abscess and gallbladder fossa variationS.~.z.lz