Researchers found in a retrospective study of 297 surgically excised keloids with superficial radiation therapy around the excision site that only 3% (n = 9), recurred during an average 6-month follow-up, according to a research letter published November 2018 in the online peer-reviewed journal SKIN, The Journal of Cutaneous Medicine.
Study author Brian Berman, M.D., Ph.D., says that he’s cautiously optimistic that superficial radiation could be a game-changing therapy for preventing recurrence of the scars. But a longer-term, prospective study is needed to help confirm results, according to Dr. Berman, professor emeritus, Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine.
The Problem With Keloids
Dr. Berman says the first thing he addresses with patients who come in with keloids is whether they really want their keloid removed.
“That’s the crucial question because if I can convince the patient that he or she would be satisfied with getting rid of the symptoms and signs—the itching, burning, maybe flattening of the keloid a little—there is a whole set of treatments for that,” he says. “It’s the patients that say they’ll only be satisfied if the keloid is gone that one would have to use a surgical procedure to remove the keloid. Clearly those procedures are pretty straightforward. The issue and problem is that in the literature the recurrence rate of the keloid after you remove it is in the range of 71%.”
For those patients who decide not to have keloids excised, the standard of care is to inject the scars with a corticosteroid. That, Dr. Berman says, decreases itching and burning and tends to make the keloid softer and flatter.
“Rarely will the keloid completely go away and virtually never will it look completely like normal skin. That’s why we use superficial radiation therapy after the keloidectomy, in order to reduce the high recurrence rate,” says Dr. Berman, a consultant with Sensus Healthcare, the company that makes the SRT-100 device that Dr. Berman and colleagues used in the study. The SRT-100 device is FDA approved for the treatment of keloids.
Superficial radiation appears to have a lower recurrence rate than what Dr. Berman says is the next best thing: cutting out a keloid, suturing it and injecting it with a steroid.
“In our hands, if you do that and wait a year, the recurrence rate was about 50%,” he says.
Superficial Radiation Therapy for Keloids
When Dr. Berman uses superficial radiation therapy post-keloidectomy, he tries to irradiate a 5 mm margin around the excision site — the suture line — starting the day after the excision.
“And then we irradiate for three days in a row, on post-operative days 1, 2 and 3,” he says. “We use a biologically effective dose (BED) 30. There are different ways you can achieve that, but we use three fractions of 6 Gy every day for three days in a row, postoperatively.”
Researchers report some patients experience transient hyperpigmentation at the treatment site, but it’s relatively minor because of the fractionation.
“In the literature, when you generate a single blast dose of radiation, that’s when you get greater pigmentary alteration. By extending it and fractionating, it offers a more cosmetically pleasing result,” he says.
There are relative contraindications for the use of superficial radiation therapy in general, whether it’s to treat nonmelanoma skin cancer or keloids, according to Dr. Berman.
“If there’s an implanted pacemaker in the area of the radiation, you’re not supposed to use radiation therapy in that area. The other relative contraindication would be if you’ve already treated a skin cancer or if you’ve already treated the post-keloidectomy site and there’s a recurrence of the skin cancer or of the keloid, I probably would not use radiation a second time at that specific site,” Dr. Berman says.
The good news about the retrospective study Dr. Berman and colleagues performed was the very low 3% recurrence rate. And even if the recurrence rate with superficial radiation therapy goes up to 10% or so in a longer-term study, that’s still way below the other therapeutic options, he says.
But this study was retrospective and based on a questionnaire to physicians using the SRT-100 with BED-30 dosing of three consecutive days. The follow-up ranged from 3 months to greater than 3 years, with the majority being followed for more than 6 months.
“The standard in my mind is to follow patients for a year,” Dr. Berman says. “So take that with a grain of salt. Now we are doing a longer-term retrospective study and planning a prospective study with a one-year follow-up.”