99mTc-technephyt quantitative lymphoscintigraphy for evaluating lymphodynamic conditions in patients with secondary upper-limb lymphedema after breast cancer surgery

In this paper the applicability of 99mTc-technephyt lymhposcintigraphy for evaluating lymphodynamic conditions in patients with secondary upper-limb lymphedema after breast cancer surgery is studied. The patients (20 females) with unilateral upper-limb lymphedema enrolled in the study underwent lymphoscintigraphy of both upper limbs. For scintigraphy 99mTc-technephyt was administered subcutaneously, emitted radiation signals were captured by 2 detectors of gamma-camera immediately, in 30 minutes and 2 hours after the radiopharmaceutical injection. The following lymphoscintigraphic features were estimated: radiopharmaceutical accumulation in lymphatic tissue, dermal backflow, visualization of main and collateral lymphatic vessels; clearance of 99mTc-technephyt from the site of injection and the radiopharmaceutical uptake ratio of the affected side to the unaffected side. The findings were used for examination of correlation between the features and clinical lymphedema grade. Analysis of images and mentioned above lymphoscintigraphic features allows us to make the following conclusions: the most informative quantitative and qualitative lymphscintigraphic features are in the delayed phase; the highest radiopharmaceutical uptake ratio of the affected side to the unaffected side (r=0.73) is in the delayed phase, i.e. in 2 hours after the injection. Based on the study findings one can say that 99mTc-technephyt lymphoscintigraphy can be the tool for quantitative and qualitative evaluating lymphedema conditions, categorization of the disease, selection of treatment options in the management of lymphedema and monitoring the efficacy of lymphedema treatment.