Is radiation therapy for keloids acceptable? The risk of radiation-induced carcinogenesis.
BACKGROUND
Keloids have been treated by using radiation for over a century, and it is currently suggested that keloids are best treated by a combination of surgery and postoperative radiation therapy, although randomized controlled trials testing this are still lacking. However, plastic surgeons tend to avoid radiation therapy for keloids for fear of inducing malignant tumors. Thus, the authors searched for previous reports of associations between carcinogenesis and keloid radiation therapy, and examined the evidence-based opinions of radiation oncologists regarding the acceptability of using radiation to treat keloids.


METHODS
A computerized literature search was carried out using PubMed that included citations from MEDLINE and PubMed Central between 1901 and March of 2009. The following search terms were used: "keloid(s)," "hypertrophic scar(s)," "radiation," "radiation therapy," "radiotherapy," "carcinogenesis," "carcinoma," "cancer," "complications," and "side effects." Moreover, the references for each report were also retrieved.


RESULTS
The authors located five cases of carcinogenesis (i.e., fibrosarcoma, basal cell carcinoma, thyroid carcinoma, and breast carcinoma) that were associated with radiation therapy for keloids. However, it was unclear whether an appropriate dose of radiation was used and whether sufficient protection of surrounding tissues was provided. Moreover, a questionnaire study of radiation oncologists around the world revealed that approximately 80 percent considered radiation to be acceptable for treating keloids.


CONCLUSIONS
The authors conclude that the risk of carcinogenesis attributable to keloid radiation therapy is very low when surrounding tissues, including the thyroid and mammary glands, especially in children and infants, are adequately protected, and that radiation therapy is acceptable as a keloid treatment modality.
Ogawa
Rei
R
Tokyo and Osaka, Japan; and Boston, Mass. From the Departments of Plastic, Reconstructive, and Aesthetic Surgery and Radiation Oncology, Nippon Medical School; the Division of Plastic Surgery, Brigham and Women's Hospital, Harvard Medical School; and the Departments of Plastic Surgery and Radiology, Osaka National Hospital.
Yoshitatsu
Sumiko
S
Yoshida
Ken
K
Miyashita
Tsuguhiro
T
D006801:Humans; D007627:Keloid / Q000532:radiotherapy*; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors