Background: A previously published study used a radio frequency (RF) focused field device (Vanquish, BTL Industries Ltd., Framingham, MA) to reduce porcine abdominal fat. The purpose of this case study was to reproduce the veterinary study on human subjects. The primary objective was measurement of apoptotic index before and after treatment with the RF device. As a second outcome demonstrating selective heating and safety, superficial skin temperature and temperature 1 and 2 cm into the subcutaneous tissue were measured.
Methods and measurements: Two healthy female subjects underwent abdominal skin and fat biopsies at baseline and after one treatment with a similar focused field high frequency RF device capable of 200 watts for 45 minutes. Biopsies were performed 1 hour post-treatment and were analyzed using the TUNEL method. Infrared imaging of the skin surface temperature was measured in both subjects. Thermocouple measurements at 1 and 2 cm were performed during the treatment cycle on a single subject.
Results: Histologic apoptotic index (pre and 1 hour post) showed an average increase of 487% (6.5 to 31.7). Thermal imaging demonstrated an average surface temperature of 31.6C° pre-treatment and 39.2°C post-treatment. The 1 cm depth thermocouple showed an initial temperature of 40C° and reached a maximum of 45°C 15 minutes into the treatment. It remained stable at 45°C for the remaining 30 minutes treatment time. No adverse events were noted.
Conclusion: RF treatment induces an increase in apoptotic index in adipocytes 1 hour post-RF treatment. This is accompanied by a peak temperature of 45°C in the fat layer. Skin surface temperatures remain substantially lower than fat temperatures.