HIGH-RESOLUTION ULTRASOUND IMAGING TO ASSESS SKIN TUMORS PRIOR TO CRYOSURGERY

Objective. We conducted a prospective evaluation of the contribution o f high-resolution ultrasound imaging prior to cryosurgery for basocell ular carcinoma and in search for recurrence. Patients and methods. All patients seen between 1992 and 1994 at the skin tumor clinic and trea ted by cryosurgery were included. Ultrasound imaging using a 20 MHz pr ototype was performed prior to cryosurgery and 2 months later. Results . Among 101 patients treated, 112 basocellular carcinomas were treated by cryosurgery. Ultrasound imaging provided good visualization of the tumor limits in all cases. The ultrasound aspect was anechogenic, oft en with rare areas of highly dense echoes. The tumor limits described by ultrasound imaging were larger than the clinical limits in 32% of t he cases. In 8 of the 16 cases of recurrent tumors, the ultrasound exa mination revealed the recurrence first. In the other 8 cases, clinical manifestations were confirmed by ultrasonography. In our series, recu rrence of basocellular carcinoma was statistically more frequent when the depth of the tumor was 3 mm (ultrasonographic measurement) or when the lateral limits established by ultrasound assessment were greater than the clinical evaluation. Discussion. These findings demonstrate t hat high-resolution ultrasound imaging of basocellular carcinomas prio r to cryosugery : 1) visualizes tumor limits allowing adapted cryosurg ery, 2)identifies factors with predictive value for recurrence, 3)can identify recurrences early. Ultrasound imaging of the skin is a useful non-invasive technique for pre- and post-therapeutic assessment of sk in tumors and could be a particularly useful tool for ''blind'' cryosu rgery destruction of skin tumors.