High resolution ultrasound imaging: value in treatment of basocellular carcinoma by cryosurgery

OBJECTIVE: We conducted a prospective evaluation of the contribution of high-resolution ultrasound imaging prior to cryosurgery for basocellular carcinoma and in search for recurrence. PATIENTS AND METHODS: All patients seen between 1992 and 1994 at the skin tumor clinic and treated by cryosurgery were included. Ultrasound imaging using 20 MHz prototype 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, often with rare areas of highly dense echoes. The tumor limits described by ultrasound imaging were larger than the clinical limits in 32% of the cases. In 8 of the 16 cases of recurrent tumors, the ultrasound examination revealed the recurrence first. In the other 8 cases, clinical manifestations were confirmed by ultrasonography. In our series, recurrence 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 that high-resolution ultrasound imaging of basocellular carcinomas prior to cryosurgery: 1) visualizes tumor limits allowing adapted cryosurgery, 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 skin tumors and could be a particularly useful tool for "blind" cryosurgery destruction of skin tumors.