Evaluation of transport kinetics in lymphoscintigraphy: follow-up study in patients with transplanted lymphatic vessels

Abstract

To quantitate visual findings in lymphoscintigraphy with 99mTc-labeled stannous sulfur colloids, a numeric index of transport kinetics was designed by combining visual assessment of five criteria: temporal and spatial distribution of the radionuclide, appearance time of lymph nodes, and graded visualization of lymph nodes and vessels. For assessment, scores were used ranging from 0 to 9. Thus, the resulting transport index (TI) ranged from 0 (normal) to 45 (pathological). TI in healthy extremities was less than 10. Lymphoscintigraphy was performed routinely in healthy lower extremities to ensure normal drainage before transplantation. In 122 investigations of upper and lower extremities, TI was found to be very sensitive (97.4%). Specificity was 90.3%. An interobserver study in 179 investigations revealed a high correlation (r = 0.96). A total of 23 patients underwent autologous lymphatic transplantation. The average decrease of TI was 5.9: 31.1 before and 25.2 after transplantation. This decrease of TI was correlated with a marked decrease of the volumes of the extremities (from 3423 ml to 2580 ml). Changes in TI and volume were significant (p less than 0.05). This method of evaluation has proved to be very sensitive, reproducible, and able to measure the transport capacity of only two or three transplanted lymph collectors.