Preliminary Studies on the Effect of Time-Dose Patterns in the Treatment of Keloids

The roentgen therapy of keloidal growths and keloidectomy scars has long been discussed in the literature, but there has been a lack of any serious effort on the part of radiotherapists to correlate the various methods of radiotherapy with the results of treatment. This deficiency, as was to be expected, has led to many therapy schemes with such inconsistent results that other methods have largely been used, while radiotherapy has been dismissed as of doubtful value. It has also led many therapeutic centers to treat this condition with inadequate amounts of radiation spread over a prolonged time. In the Radiotherapy Clinic at Bellevue Hospital (New York), we were particularly disturbed by the reported ineffectiveness of roentgen therapy, since in our experience it had proved to be (when indicated and used properly) an invaluable tool in the treatment of keloids both primarily and following surgical keloidectomy. We are at present undertaking a study of all the keloidal growths treated at our hospital for the past fifteen years, the results of which, in detailed form, will be published later. Our preliminary inspection of the data, however, revealed some interesting and apparently significant findings, which we wish to report at this time in an effort to stimulate other therapy centers to verify our results and to approach their own roentgen treatment of keloids more effectively. Since this study does not attempt to evaluate different types of radiation but merely various methods of administration, we have included only those cases treated with a similar modality (100 kvp, 1.0 to 2.0 mm. Al h.v.l.). Factors such as age, race, and location are not considered important for this brief report. Nor shall we make any distinction between a true keloid and a hypertrophic scar, since we agree with Van den Brenk (1) that the degree and duration of fibroblastic overgrowth which occur before the regression phase of the keloid determine whether the keloidal growth is clinically one or the other of those types. In other words, a keloidal growth results from an overproduction and overgrowth of the apparently normal fibroblastic tissue as it grows in to occupy the site of the injury. At any time this tissue may stop and undergo involution. If this occurs within several months, the result would be called a hypertrophic scar but if there is continued growth beyond this time most clinicians would term it a keloid. Our work and that of Van den Brenk tend to support this concept. One must remember this natural history of a keloidal growth when reviewing factors influencing therapy, since in any stage natural regression may occur with or without treatment. A failure to understand this concept has led to confusing reports in the literature. There are two ways in which radiation may be used in the overall treatment plan for keloidal growths. The first is in the treatment of an established keloid aiming for a decrease in size or control of symptoms.