Value of continuous leakage monitoring with radioactive iodine-131-labeled human serum albumin during hyperthermic isolated limb perfusion with tumor necrosis factor-alpha and melphalan

Background: The aim of this study was to analyze the value of continuous leakage monitoring with radioactive iodine-131-labeled human serum albumin (RISA) in patients treated with hyperthermic isolated limb perfusion with tumor necrosis factor-alpha (TNFalpha) and melphalan. Methods: Forty-eight patients with melanoma (n = 14) or soft tissue sarcoma (n = 34) of an extremity underwent 51 perfusions. Perfusion was performed at the iliac level in 22 cases, at the popliteal level in 16 cases, at the femoral level in 7 cases, and at the axillary level in 6 cases. Leakage rates and perfusion circuit and systemic levels of TNFalpha, interleukin-6, and C-reactive protein were determined, as were systemic hematological and metabolic profiles and tumor response. Results: The mean isotopically measured leakage was 2.9%. Systemic leakage was less than or equal to2% in 28 perfusions and >2% in 23 perfusions. The correlation between the maximal monitored leakage and maximal systemic TNFalpha levels was .7114. The area under the curve for TNFalpha in the perfusion circuit, indicating the exposure of the perfused limb to TNFalpha, was 18.7% lower in the >2% leakage group. No significant differences in tumor response were found between groups. The area under the curve for systemic TNFalpha, indicating the exposure of the patient to TNFalpha, was 18.1 times higher in the >2% leakage group, resulting in a significant decrease in leukocyte and platelet count, hyperbilirubinemia. hypocholesterolemia, and proteinemia. No beneficial effect of the systemically leaked TNF and melphalan was seen on the occurrence of distant metastasis during follow-up. There was a significant difference between perfusions, performed at the iliac and femoral levels compared with leakage values at the popliteal level. Conclusions: A good correlation between RISA leakage measurement and TNFalpha exposure during and after hyperthermic isolated limb perfusion with TNFalpha and melphalan was demonstrated. RISA leakage measurement serves as a good guide for the effectiveness of isolation during perfusion. If leakage exceeds the 2% limit during perfusion, less exposure of the tumor-bearing limb to TNFalpha, increased exposure of the patient systemic circulation to TNFalpha, and more systemic side effects can be expected.