Preliminary Demonstration Using Localized Skin Temperature Elevation as Observed With Thermal Imaging as an Indicator of Fat-Specific Absorption During Focused-Field Radiofrequency Therapy

July 2014 | Volume 13 | Issue 7 | Case Reports | 864 | Copyright © July 2014


Douglas J. Key MD

Key Laser Institute for Regenerative Cosmetic Medicine, Portland, OR

Abstract
BACKGROUND: This study incorporates concurrent thermal camera imaging as a means of both safely extending the length of each treatment session within skin surface temperature tolerances and to demonstrate not only the homogeneous nature of skin surface temperature heating but the distribution of that heating pattern as a reflection of localization of subcutaneous fat distribution.
METHODS: Five subjects were selected because of a desire to reduce abdomen and flank fullness. Full treatment field thermal camera imaging was captured at 15 minute intervals, specifically at 15, 30, and 45 minutes into active treatment with the purpose of monitoring skin temperature and avoiding any patterns of skin temperature excess.
RESULTS: Peak areas of heating corresponded anatomically to the patients’ areas of greatest fat excess ie, visible “pinchable” fat.
CONCLUSION: Preliminary observation of high-resolution thermal camera imaging used concurrently with focused field RF therapy show peak skin heating patterns overlying the areas of greatest fat excess.

J Drugs Dermatol. 2014;13(7):864-866.

INTRODUCTION

Recent demonstrations of effective fat reduction with the use of a focused field radiofrequency system designed for contactless deep tissue thermal energy application were based on a protocol of 4 treatments of 30 minutes each.1, 2 Results of efficacy in these studies were based on duplex ultrasound reduction in the subcutaneous fat layer and circumferential tape measure reduction. This study incorporates concurrent thermal camera imaging as a means of both safely extending the length of each treatment session within skin surface temperature tolerances and to demonstrate not only the homogeneous nature of skin surface temperature heating but the distribution of that heating pattern as a reflection of localization of subcutaneous fat distribution.
The use of thermal imaging to reflect the pattern of subcutaneous heat energy capture was recently demonstrated by this author in a different model, one of creating structural tightening of the skin with subsurface radiofrequency heating.3,4 In this author’s study, a direct linear relationship was established between skin surface temperature, as measured by thermal camera imaging, and subcutaneously measured temperature elevations, as determined by the placement of a radiofrequency thermistor probe. In this prior published study, subsurface thermistor probe placement allowed both subsurface heating and subcutaneous temperature monitoring, with observed mean and median subcutaneous temperature of 54.4°C and 55.0°C, respectively, as measured by thermal camera imaging and skin surface temperature peaks of 43.6°C and 43.8°C, respectively.
In other words, skin surface temperature monitoring can be used as an index of subcutaneous heat capture, whether by direct subsurface thermistor probe as in this author’s prior publication, or by transcutaneous delivery of energy as in this current study using contactless focused-field RF energy as an energy source.3

METHODS

The five subjects for this study were selected because of a desire to reduce both abdomen and flank fullness. The prior published protocol treatment sessions of 30 minutes duration were extended using thermal camera imaging. Taking into ac-