Continuous measurement of leakage during isolated liver perfusion with a radiotracer

Isolation and perfusion of an organ or a part of the body has been attempted to improve cancer chemotherapy results. Our study was aimed at developing a reliable method of leakage detection permitting safe clinical application of isolated liver perfusion with high dosages of cytostatics. In a pig model a method of continuous leakage monitoring was developed, which would give a fast indication of leakage using a minimum quantity of radioactive tracer. To this end we added 99mTc labelled erythrocytes (total activity: 3.7 MBq) to the isolated external circuit. Initially a scintillation phototube detector was placed upon the body above the heart (three experiments). However, this method did not meet our requirements of accuracy and reproducibility, and a measurement technique was chosen, where an arterio-venous shunt outside the body functioned as a measuring cavity. The results of 11 experiments showed that the accuracy was 98 +/- 12%, and the detection threshold was below the required sensitivity of 1% (of the perfusate volume). From this study it can be concluded that our method of leakage measurement using a minimum quantity of 99mTc is an accurate method allowing safe application of isolated liver perfusion, and is in principle able to be carried out in any isolation and perfusion technique in the clinical situation.