Distribution of technetium-99m-labeled multilamellar liposomes in patients with Hodgkin's disease

The distribution of 99mTc-labeled multilamellar liposomes composed of dimyristoyl phosphatidylcholine (DMPC) and dimyristoyl phosphatidylglycerol (DMPG) at a molar ratio of 7:3, administered intravenously, was studied in ten patients with Hodgkin's disease (HD). The dose of lipid was 150 mg/m2 and the mean dose of radioactivity injected per patient was 8.1 mCi (range 6.7-9.8). Whole-body imaging techniques were used, and for each organ an uptake index was calculated as the percent photographic density (PD) relative to the PD of the liver. Results were compared to those in a group of six patients with other malignancies. Increased liposome uptake in several skeletal areas was observed in one patient with HD with diffuse bone involvement and in the bone marrow of two patients with HD with bone marrow involvement. No definite liposome uptake was observed in lymph nodes involved by HD or in tumor areas of patients with other malignancies. Patients with HD had a significantly higher uptake by bone marrow (23.8% compared with 10.2% at 4 hr p = 0.02), and lungs (59.6% compared with 25.0% at 4 hr, p = 0.01) than patients with other malignancies. Among patients with HD, the uptake by bone marrow and lungs were higher in those with constitutional symptoms (bone marrow at 4 hr 31.4% compared with 16.2%, p = 0.02; lungs at 4 hr 68.8% compared with 50.4%, p = 0.19) and with liver involvement (bone marrow at 4 hr 30.8% compared with 16.8%, p = 0.03; lungs at 4 hr 73.6% compared with 45.6%, p = 0.03). These results suggest that patients with HD have a different pattern of distribution of multilamellar liposomes which may be related to a combination of nonspecific stimulation of the reticuloendothelial system and tumor uptake. It does not appear that liposomal 99mTc is capable of adequately imaging HD for clinical diagnosis.