Whole-lesion assessment of volume and signal changes after sclerotherapy of extremity venous malformations

Purpose To investigate quantitative changes in MRI signal intensity (SI) and lesion volume that indicate treatment response and correlate these changes with clinical outcomes after percutaneous sclerotherapy (PS) of extremity venous malformations (VMs). Methods VMs were segmented manually on pre- and post-treatment T2-weighted MRI using 3D Slicer to assess changes in lesion volume and SI. Clinical outcomes were scored on a 7-point Likert scale according to patient perception of symptom improvement; treatment response (success or failure) was determined accordingly. Results Eighty-one patients with VMs underwent 125 PS sessions. Treatment success occurred in 77 patients (95 %). Mean (±SD) changes were –7.9 ± 24 cm3 in lesion volume and –123 ± 162 in SI (both, P <.001). Mean reduction in lesion volume was greater in the success group (–9.4 ± 24 cm3) than in the failure group (21 ± 20 cm3) (P =.006). Overall, lesion volume correlated with treatment response (ρ = –0.3, P =.004). On subgroup analysis, volume change correlated with clinical outcomes in children (ρ = –0.3, P =.03), in sodium tetradecyl sulfate–treated lesions (ρ = –0.5, P =.02), and in foot lesions (ρ = –0.6, P =.04). SI change correlated with clinical outcomes in VMs treated in 1 PS session (ρ = –0.3, P =.01) and in bleomycin-treated lesions (ρ = –0.4, P =.04). Conclusions Change in lesion volume is a reliable indicator of treatment response. Lesion volume and SI correlate with clinical outcomes in specific subgroups.