[Imaging of melanoma: accuracy of ultrasonography before and after contrast injection for diagnostic and early evaluation of treatments]

Abstract

INTEREST FOR DIAGNOSIS: High-frequency sonography (12-16 MHz) allows to visualize primary cutaneous melanomas. The maximal echographic thickness was measured and strongly correlated to the Breslow index (p< 10(-4)). Lesions were well defined with homogeneous hypoechoic echostructure. A study including 111 patients with a 5 years median follow-up period demonstrated that the detection of neo-vascularization by color Doppler was significantly correlated to occurrence of metastasis (p < 10(-4)). INTEREST FOR EARLY EVALUATION OF TREATMENTS: For patients with local recurrent melanomas treated by isolated limb perfusion, contrast enhanced ultrasonography allows early evaluation of therapeutic. The access to raw linear data associated to quantification software permits to estimate tumoral perfusion. Several perfusion parameters (area under the contrast tune intensity curve, maximal intensity peak, mean transit time,...) are obtained after curves modelization. A study of 40 patients with a follow-up by dynamic contrast enhanced ultrasonography at D-1, D+1, D+7 and D+30 demonstrated that means of the quantification using raw linear data was able to identify as early as D+1 patients with complete response at 3 months.