Role of ionizing irradiation for 393 keloids

This is the authors' abstract. We don't add key points for this paper.

Between 1928 and 1986, 393 keloid sites on 250 patients were presented. Three hundred seventy-five sites received superficial quality therapeutic irradiation. Etiologies were determined. The majority were excised prior to irradiation, and in these, histologic confirmation was obtained. Recurrence rate after irradiation was low, 9/375 (2.4%). When 7 of 9 recurrences are eliminated for post-irradiation ear lobe repiercing, true recurrence is only 2/375 (0.53%). Cosmetic result was considered excellent without recurrence in 92%; favorably improved with hypertrophic scar, nodule or altered pigment in 5.6%; and marginally improved with smaller, less symptomatic keloid in 2.4%. Significant complications were limited to persistent pigment disturbance in only 1 patient, and pre-irradiation hemorrhage in 1 patient (unrelated to radiotherapy). There was no wound dehiscence nor failure to heal irradiated incision site. Transient hyperpigmentation occurred in 91/375 (24%). Recurrence after irradiation was too rare to associate with etiology, specific technical factors, keloid configuration or velocity of initiating the post-operative radiotherapy. An unexpected finding was that 22/250 (9%) were Caucasian subjects. Our null (0%) carcinogenicity rate to date and the one-half of one percent true recurrence rate supports continued use of post-operative irradiation to prevent keloid formation in this group of documented troublesome keloid formers. Configuration subtypes are proposed, post-operative irradiation protocol is listed, and mechanism of action is explained in accordance with the dynamic pathophysiology of keloid.