Background: Continuous measurement of perfusate leakage into the systemic circulation is of the utmost importance and can be performed with the help of radioactive tracers. The purpose of this study was to assess changes in the perfusion leakage rate between two periods: 1977-1990 and 1991-2000, and to determine the factors responsible for these changes.
Methods: During the 1991-2000 period, 119 patients underwent HILP mainly for locally recurrent melanoma or locally advanced soft tissue sarcoma. HILP was performed with melphalan (33%) or in combination with TNFalpha (65%). There were 67 iliacal, 12 femoral, 25 popliteal, and 15 axillary perfusions performed. Leakage into the systemic circulation was monitored continuously with the help of 131I-albumin and a stationary scintillation detector placed above the heart.
Results: The median maximum leakage was 2.7% (range 0%-21%) which is significantly less than the previous period (1977-1990) where leakage of 8% (range 0%-30%) was reported (P < .05). A statistical difference in leakage was detected among perfusion locations where the iliac and femoral vessels showed more leakage than the axillary and popliteal vessels (P < .05). Furthermore, there appeared to be significantly less leakage when TNFalpha was used than when melphalan was the sole drug (P < .05).
Conclusions: Nowadays leakage from isolated perfusions into the systemic circulation is further minimized compared with the days when melphalan was the sole drug used. Increased awareness about TNFalpha leakage, continuous external monitoring with 131I-albumin as the main isotope, flow rate regulation in the perfusion circuit, and regulation of the patient's systemic blood pressure have all been major contributors to this improvement.