[99mTc-DTPA-HSA lymphoscintigraphy in lymphedema of the lower extremities: diagnostic significance of dynamic study and muscular exercise].

The efficacy of lymphoscintigraphy was evaluated in 25 cases to clarify the diagnostic significance of dynamic study and muscular exercise in the diagnosis of lymphedema. 99mTc-diethylene triamine pentaacetic acid-human serum albumin (DTPA-HSA) was injected subcutaneously, and dynamic imaging was performed in 18 cases. Thirteen patients were asked to walk for 3 minutes. Qualitative evaluation of static images had sensitivity of 90% and specificity of 97%. Diagnostic criteria including qualitative evaluation of dynamic images were less specific (sensitivity 95%, specificity 76%). Interpretation of static images obtained at one hour after injection in the patients without muscular exercise had sensitivity of 89% and specificity of 67%, whereas sensitivity was 92% and specificity was 100% in the patients with muscular exercise. Lympho-scintigraphy was reliable in diagnosis of lymphedema. Dynamic study was limited usefulness because of some false-positive cases. Muscular exercise accelerated migration of the tracer in normal extremities, and improved positive predictive value.