High-dose-rate interstitial brachytherapy vs external beam radiation for the treatment of complex keloids

Postoperative external beam radiation therapy (EBRT) with superficial X-rays or electrons and high-dose-rate brachytherapy (HDR BT) are both viable options for managing keloid scars. However, complex keloid scars are especially challenging to manage. We aim to compare the benefit and challenges between interstitial HDR BT and electron EBRT in treating the complex keloids. Three patients with 7 complex keloids: 3 jaw lines, 1 postauricular, 1 posterior neck, and 2 chest walls are included in this study. All patients are treated to 6 Gy x 3 fractions with HDR BT using the flexible interstitial catheters, and electron EBRT plans were created retrospectively for dosimetric comparison. The average D₉₀ is 21.8 ± 8.3 Gy (1 SD) (121%) and 16.9 ± 1.9 Gy (1SD) (94%) in HDR and EBRT plans, respectively. The average treatment time was 7 minutes per patient (range: 6 - 8.5 minutes) for the HDR BT. Dosimetric comparison reveals that HDR plans provide superior coverage to the keloid scars than the EBRT plans. Clinical workflow is streamlined with HDR procedures. The cosmetic outcome with the interstitial HDR BT is satisfactory.