Quantitative lymphoscintigraphy with 99mTc-technephyte in breast cancer patients with upper limb lymphedema after mastectomy and axillary lymph nodes dissection

The paper presents results of research on the potential of quantitative radionuclide lymphoscintigraphy (LS) with radioactive tracer (99mTc-technephyte) for evaluation of the upper limb lymphedema, developed in different time periods after mastectomy and axillary lymph nodes dissection in 56 breast cancer patients (females). Before LS-imaging the tracer was subcutaneously injected in the affected and normal extremities. The 99mTc-technephyte clearance rate from the injection site on the affected hand was higher than the tracer clearance rate from the site of injection on the normal hand, the difference in the rates was statistically insignificant. This difference did not depend on the lymphoma stage (the difference between clearance rates was 4-9%, difference in the amount of tracers cleared was 6-8%). It means that informative value of 99mTc-technephyte clearance is very low and cannot be used for differential diagnostics of lymphedema stage. To obtain more important information the quantitative asymmetry index (QAI) was used. It was shown that in all parts of the upper limb lymphedema (forearm, shoulder, and arm in general) there was a significant difference between QAI indices for lymphedema stages I, II and III. However, the significant variability of the QAI indices makes difficult proper interpretation of LS provided images. The obtained data show that the clinical and functional staging of the lymphedema is not identical, and also confirm the possibility of the presence of areas in the edematous extremity at different stages of lymph drainage disorder. The data also support the hypothesis that lymph drainage in the edematous extremity parts may be impaired in areas with different lymph drainage stages. Quantifying LS with QAI can be useful when choosing a treatment method, evaluating its effectiveness, and dynamic monitoring.