Meshkinpour et al (2005) examined the safety and effectiveness of the ThermaCool TC radiofrequency system for treatment of hypertrophic and keloid scars and assessed treatment associated collagen changes. Six subjects with hypertrophic and 4 with keloid scars were treated with the ThermaCool device: 1/3 of the scar received no treatment (control), 1/3 received one treatment and 1/3 received 2 treatments (4-week interval). Scars were graded before and then 12 and 24 weeks after treatment on symptoms, pigmentation, vascularity, pliability, and height. Biopsies were taken from 4 subjects with hypertrophic scars and evaluated with hematoxylin and eosin (H & E) staining, multi-photon microscopy, and pro-collagen I and III immunohistochemistry. No adverse treatment effects occurred. Clinical and H & E evaluation revealed no significant differences between control and treatment sites. Differences in collagen morphology were detected in some subjects. Increased collagen production (type III > type I) was observed, appeared to peak between 6 and 10 weeks post-treatment and had not returned to baseline even after 12 weeks. The authors concluded that use of the thermage radiofrequency device on hypertrophic scars resulted in collagen fibril morphology and production changes. ThermaCool alone did not achieve clinical hypertrophic scar or keloid improvement. They noted that the collagen effects of this device should be studied further to optimize its therapeutic potential for all indications.