[The value of tumor volumetry as opposed to bidimensional determination of tumor size during follow-up of hepatic metastases from colorectal carcinoma]

36 patients with liver metastases due to colorectal carcinoma under treatment with arterial perfusion chemotherapy of the liver with 5-fluoro-2-desoxyuridine (FUDR) via a subcutaneous pump were investigated by axial liver CT at 6-monthly intervals. In all examinations a dynamic CT scan with intravenous bolus injection of contrast medium was carried out following a native scan. Changes in tumour size were documented by means of 1. volumetry and 2. bidimensional measurement according to WHO criteria. Since we were not able to assess small newly developing lesions within the liver using the volumetric classification, the WHO-classification showed much higher sensitivity in cases of progressive disease. In addition, volumetric determination of tumour size by means of region-of-interest technique proved to be rather impracticable in clinical routine compared to bidimensional measurement.