Treatment of keloids by high-dose-rate brachytherapy: A seven-year study

To analyze the results obtained in a prospective group of patients with keloid scars treated by high-dose-rate (HDR) brachytherapy with or without surgery.

One hundred and sixty-nine patients with keloid scars were treated with HDR brachytherapy between December 1991 and December 1998. One hundred and thirty-four patients were females, and 35 were males. The distribution of keloid scars was as follows: face, 77; trunk, 73; and extremities, 19. The mean length was 4.2 cm (range 2-22 cm), and the mean width 1.8 cm (range 1.0-2.8 cm). In 147 patients keloid tissues were removed before HDR brachytherapy treatment, and in 22 HDR brachytherapy was used as definitive treatment. In patients who underwent prior surgery, a flexible plastic tube was put in place during the surgical procedure. Bottoms were used to fix the plastic tubes, and the surgical wound was repaired by absorbable suture. HDR brachytherapy was administered within 30-60 min of surgery. A total dose of 12 Gy (at 1 cm from the center of the catheter) was given in four fractions of 300 cGy in 24 h (at 09.00 am, 15.00 pm, 21.00 pm, and 09.00 am next day). Treatment was optimized using standard geometric optimization. In patients who did not undergo surgery, standard brachytherapy was performed, and plastic tubes were placed through the skin to cover the whole scar. Local anesthesia was used in all procedures. In these patients a total dose of 18 Gy was given in 6 fractions of 300 cGy in one and a half days (at 9.00 am, 3.00 pm, and 9.00 pm; and at 9.00 am, 3.00 pm, and 9.00 pm next day). No further treatment was given to any patient. Patients were seen in follow-up visits every 3 months during the first year, every 6 months in the second year, and yearly thereafter. No patient was lost to follow-up. Particular attention was paid to keloid recurrence, late skin effects, and cosmetic results.

All patients completed the treatment. After a follow-up of seven years, 8 patients (4.7%) had keloid recurrences. Five of these had undergone prior surgery (local failure rate 3.4%), and 3 had received only HDR brachytherapy (local persistence rate 13.6%). Cosmetic results were considered to be good or excellent in 130/147 patients treated with prior surgery and in 17/22 patients without surgery. Skin pigmentation changes were observed in 10 patients, and telangiectasias in 12 patients. No late effects such as skin atrophy or skin fibrosis were observed during the 7 years of follow-up.

HDR brachytherapy is an effective treatment for keloid scars. It is well tolerated and does not present significant side effects. The brachytherapy results were more successful in patients who underwent previous surgical excision of keloid scar than in patients without surgery. We favor HDR brachytherapy rather than superficial X-rays or low energy electron beams in keloid scars, because HDR provides a better selective deposit of radiation in tissues and a lower degree of normal tissue irradiation. Other advantages of high-dose-rate brachytherapy over low-dose-rate brachytherapy are its low cost, the fact that it can be performed on an outpatient basis, its excellent radiation protection, and the better dose distribution obtained. From the clinical perspective, the technique provides a high local control rate without significant sequelae or complications.