Single-dose electron beam irradiation in treatment and prevention of keloids and hypertrophic scars.

Low megavolt electron beam irradiation was used on 354 sites in 199 patients at the Lahey Clinic either for palliation of symptomatic hypertrophic scars or as post-operative irradiation in an attempt to prevent formation or recurrence of hypertrophic scars. Electron energies used ranged from 1.5 to 3.5 MeV. The median age of the 59 male patients was 22 years and of the 140 female patients, 35 years. All patients had at least one follow-up visit, and the median follow-up was 35 months. Of the 294 sites treated for the first time, 272 (93%) were irradiated with a single fraction with a skin dose ranging from 2 to 20 Gy. Of the 85 sites in 63 patients without excision of symptomatic hypertrophic scars, single-dose electron beam irradiation was of clinically significant value in only 41 sites (48%). No patients have been treated without surgical excision since 1973. Because of a history of formation of hypertrophic scars elsewhere in the body, 13 patients with 19 incisions were treated prophylactically after operation for other diseases. All sites were irradiated with single doses ranging from 8 to 20 Gy, and hypertrophic scars did not subsequently develop in any patient. Altogether, 119 patients with 174 sites were irradiated after surgical excision of hypertrophic scars to prevent recurrence; 168 sites (97%) received single-fraction irradiation, and 161 received a dose of 8 Gy or greater, up to 15 Gy. No statistically significant differences were observed in complete success rates, ranging from 82 to 90% with doses of 9 Gy or greater.(ABSTRACT TRUNCATED AT 250 WORDS)