Quantitative volumetric analysis of head and neck venous and lymphatic malformations to assess response to percutaneous sclerotherapy

Background: Venous and lymphatic malformations of the head and neck can be successfully treated with percutaneous sclerotherapy. Purpose: To examine the utility of three-dimensional volumetric analysis to assess these lesions and their response to therapy. Material and Methods: Prospectively maintained procedure records were retrospectively reviewed to identify all patients with vascular malformations who underwent percutaneous sclerotherapy. Clinical data were used to classify lesions by apparent size and degree of visible physical asymmetry due to the lesions. Lesion volume was calculated using magnetic resonance images. Cohen's weighted kappa coefficients were calculated to assess both intra-and inter-rater agreement. Pearson coefficients were calculated to identify correlation between clinical and volumetric measures, both at initial diagnosis and following treatment. Results: Thirty-seven patients with head and neck venous or lymphatic malformations underwent 55 treatment sessions. Cohen's weighted kappa coefficients were 0.84 and 0.77 for intra-and inter-rater agreement, respectively. Clinical size did not significantly correlate with measured volume at diagnosis (rho=0.08, P=0.57). For lymphatic malformations, total lesion volume correlated with volume of macrocystic components (rho=0.47, P<0.01). Total volume reduction significantly correlated with clinical response grade (rho=0.46, P=0.02). For lymphatic malformations, reduction of volume of the macrocystic component significantly correlated with clinical response grade (rho=0.44, P=0.03). Conclusion: Changes in calculated volume corresponded to clinical measures of treatment response. Variability of qualitative approaches to lesion analysis may have led to the lack of correlation between initial size of a lesion based on clinical measures and calculated volume. Future research should include quantitative metrics to augment qualitative clinical results.