Mediastinal lymphoscintigraphy in ovarian cancer using intraperitoneal autologous technetium-99m-labelled erythrocytes.

99Tcm-labelled autologous erythrocytes (approximately 2.0 ml and 2.0 mCi) were administered intraperitoneally (IP) to 15 patients with ovarian cancer. Anterior abdominal images were then collected for up to six hours to evaluate both the dynamics of intraperitoneal tracer distribution and the potential for visualizing internal mammary lymph nodes as correlated with the presence of diaphragmatic tumour. Results indicated that dispersion of red cells closely resembled that seen during IP contrast studies; the distribution patterns were heterogeneous, remained constant with time, and were intimately related to bowel peristalsis. Visualization of internal mammary lymph nodes indicated patency of diaphragmatic lymphatics; non-visualized nodes correlated with the presence of diaphragmatic tumour. The test had a sensitivity of 0.80 and a specificity of 0.90 for defining disease. Results of this study suggest use of 99Tcm-red blood cells as a diagnostic test for diaphragmatic involvement by ovarian cancer and as a method for monitoring the effects of therapy.