[Adjuvant treatment of keloid scars: electrons or brachytherapy?]

Evaluation of perioperative treatment of keloid scars with electron beam therapy or iridium 192 low dose rate brachytherapy.

From 1994 to 2010, 95 patients with 142 keloid scars have been treated by immediate perioperative irradiation and retrospectively reviewed in our institute: 116 scars were treated by electrontherapy and 26 by brachytherapy.

In the electrontherapy group treated locations were: earlobe (n=88, 76%), thorax (n=14, 12%), neck (n=9, 8%), limbs (n=5, 4%). The median size of lesions was 3cm (range [R]: 0.5-18cm). In 95.6% of cases, a dose of 15Gy was delivered in five fractions of 3Gy. The median follow-up was 70 months (R: 7-161 months). The 2-year and 5-year local control were respectively 69% (95% confidence interval [95% CI]: 59-76%) and 55% (95% CI: 45-64%). In the brachytherapy group treated locations were: neck (n=3, 11%), earlobe (n=8, 32%), abdomen (n=3, 11%), thorax (n=2, 8%), limbs (n=10, 38%). The median size of lesions was 6.6cm (R: 1.7-28cm). The median dose delivered at 5mm from the source was 20Gy (R: 15-20.69). The median follow-up was 113 months (R: 21-219 months). The 2-year and 5-year local control were respectively 84.6% (95% CI: 64-94%) and 73.5% (95% CI: 49-87%). So far, no radiation-induced cancer has occurred. A trend to a better local control with brachytherapy was noted (compared to electrontherapy, 2-year relapse is halved with brachytherapy) though this difference did not reach the significance (P=0.0991), probably due to the reduced number of patients in the brachytherapy group.

Brachytherapy seems to provide better local control compared to electrontherapy, and should be proposed as first line treatment. However, electrontherapy is an interesting alternative in case of difficulty to realize brachytherapy. There is probably a dose effect: according to published data, 25 to 30Gy should at least be proposed.