32. Keloids - The GEC-ESTRO Handbook of Brachyterapy

Keloids

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THE GEC ESTRO HANDBOOK OF BRACHYTHERAPY | Part II Clinical Practice Version 1 - 11/04/2025

13. ADVERSE EVENTS

in their series. They used surface brachytherapy with the Leipzig applicator and customised moulages. Bhattacharya et al. [24] reported a recurrence rate of 6%, they used superficial double layer moulds and electron beam radiotherapy. Scalfani [25] compared corticosteroids and radiation therapy: the recurrence rate was 33% for surgery + steroid injection, and 12.5% for surgery and radiation therapy. For external irradiation following excision, the control rates are between 73 - 93 % reported by Kovalic (113 keloids) [4], 93% by Durosinmi (454 keloids) [9] to 97.6% by Borok (393 keloids) [8] In an extensive retrospective overview of the literature Kal et al. [10, 11] reported a recurrence rate of < 10% if a minimum dose of 30 Gy BED10 (corresponding to 25 Gy EQD210) was applied. In an extensive overview of reported series in the literature, van Leeuwen et al found that the time interval between surgery and external beam irradiation was better if administered within 7 hours (16.8 %) instead of longer duration 7-24 (28.4 %) or over 24 hours (21.5%.) [6]. However, no differences were noted for HDR BT cases; 10.7 % (< 7h) versus 10 % (7-24 h). In case of LDR brachytherapy the numbers are: 22.3% (< 7h) versus 19.4% (7-24h).

Side effects that can occur are infections. Postoperative bleeding should be avoided, since they influence recurrence and bad cosmetic outcome rate For the figures of cosmesis see table 32.1. Other reported side effects are hyperpigmentation, hypopigmentation, and overstretched scars. Cancer induction estimated risk in adults is estimated about1/50000, but not yet well reported in the published studies.

14. KEY MESSAGES

• Postoperative brachytherapy prevents keloid recurrences • Recurrences and large keloids are the main indications for postoperative brachytherapy • The clinical target volume (CTV) includes the scar and 5mm of the affected skin. • The reference isodose should be least at 5 mm from the scar • A minimum EQD2 10 of 20 Gy-25 Gy is recommended