Oriuchi N et al. (2005) A new, accurate and conventional five-point method for quantitative evaluation of ascites using plain computed tomography in cancer patients. Jpn J Clin Oncol 35: 386–390

A multidisciplinary team from Japan has recently reported a new objective method for the quantitative measurement of malignant ascites. Oriuchi and co-workers have developed an accurate, simple and reproducible procedure, which they assert will facilitate evaluation of response to therapy in patients with PERITONITIS CARCINOMATOSA.

Helical CT scans of the abdomen were performed in 12 patients with various primary tumors, and the thickness of ascites measured in five locations across three transverse planes—the bilateral subphrenic space, the bilateral paracolic space and the pre-bladder space. The average thickness was then multiplied by the area of the standard abdominal cavity (1,000 cm2) to calculate the volume of ascites in milliliters. To validate the accuracy of the procedure, the current gold-standard method of assessment—the 3D-CT volume rendering method—was also performed, and the volumes obtained using the two different techniques were compared. The correlation between the volumes was found to be consistent and statistically significant (correlation coefficient 0.956; P <0.01). The correlation was most marked in patients with an ascitic volume of ≥300 ml.

The authors conclude that the accuracy of this new procedure compares well with that of the volume rendering method, but the new technique has the advantage of requiring no specific radiological expertise, making it a simple and practical choice for the follow-up of patients with malignant ascites.