Quantitative Lymphoscintigraphy SPECT/CT Parameters in the Assessment of Upper Extremity Lymphedema.

Purpose: Lymphedema is a chronic disorder of the lymphatic system. This study evaluated quantitative lymphoscintigraphy SPECT/CT parameters for assessing lymphatic function in patients with unilateral upper extremity lymphedema and examined their relationship with clinical outcomes.

Patients and methods: Twenty-two patients with unilateral upper extremity lymphedema underwent quantitative lymphoscintigraphy SPECT/CT. Maximum lymphatic activity (MLA) and total lymphatic accumulation (TLA) were measured in both the affected and the unaffected limbs. Limb circumference measurements were obtained at baseline and 1-month follow-up to calculate the relative volume increase (%RVI) and reduction of %RVI (%RRVI). Differences in SPECT/CT-derived parameters between the affected and the unaffected limbs were analyzed, and their correlations with clinical outcomes were evaluated.

Results: MLA ( P =0.0289) and TLA ( P <0.001) were significantly lower in the affected limbs compared with the unaffected limbs. MLA (ρ=0.58, P =0.011), MLA ratio (ρ=0.6, P =0.0077), and TLA ratio (ρ=0.59, P =0.0091) in the affected limbs showed significant positive correlations with %RRVI. Patients with improved lymphedema exhibited significantly higher MLA ( P =0.016), MLA ratio ( P =0.003), and TLA ratio ( P =0.003) in the affected limb compared with those with persistent lymphedema.

Conclusions: Quantitative lymphoscintigraphy SPECT/CT parameters showed significant differences between the affected and the unaffected limbs and demonstrated a meaningful association with treatment response. These parameters may facilitate early detection of lymphatic dysfunction and prediction of therapeutic outcomes, potentially contributing to improved clinical management.