Information about cause, treatment, and prevention

Radiation Treatment of Keloid Scars

Radiation administered after surgical keloid removal may help prevent recurrence.

Radiation is a controversial therapy because of potentially serious harmful side effects of ionizing radiation. Coupled with the wide range of response to its use as a monotherapy—from 10-94%--simply makes it not worth the potential long-term risks of cancer or stunted growth associated with radiation, except for treatment-resistant keloids that cannot be surgically taken out.8,16

When combined with surgery the rate of response and recurrence rates are much more acceptable. Still, radiotherapy is typically reserved as a last choice for otherwise unresponsive keloids by most doctors.3,17

Experts caution against using radiation in children unless it is unavoidable, because of the risk of stunted growth in the treatment area. If there are no other options maximum shielding should be used during the procedure as a protective measure.16

So which type is right for you?

There are two basic types of radiation methods—either internal (brachytherapy) or external electron beam irradiation. The recommended method varies, and clinical evidence suggests that results are comparable between both.27

Internal radiation is more suitable for:27

  • Large or small linear-shaped keloids
  • Keloids in curved areas (e.g., the shoulder region)

External radiation is typically used in cases where the keloid is:27

  • Large and bulky
  • Smaller than 4 cm and in a fairly flat area of the body

Sometimes keloids are so large and bulky and/or significantly irregular they are not suitable for brachytherapy—and so extensive they cannot be surgically removed either. These are treated with external radiation unless it is large but in a straight line, where two tubes can be used to fully cover the keloid. In either case the dosage level is the same.27

What Happens During Treatment

Low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy:27

  • Radioactive seeds or strands are put in a plastic tube and implanted into the keloid for primary therapy or sutured into the wound site right after the keloid is surgically removed. In HDR, the total dosage is divided into lower-dosed sessions but is still administered over hours instead of days.
  • LDR implants are left in for 2-3 days and then removed.
  • HDR implants are only left in for seconds to minutes at a time. In HDR the tubes are flexible and are removed in between sessions.
  • After therapy is complete the tubes are removed for the final time and the wound area is closed completely with stitches and covered with gauze.

External electron beam irradiation:27

  • There are two methods for external radiation—low-voltage photon X-rays or high-voltage electrons delivered by linear accelerators.
  • Administered after surgery (or by itself) in divided session doses once or twice daily up to the total treatment dose; recommended at no more than 5 Gy per session.
  • The target area is the perimeter of the keloid with a 4-5 mm margin

For both types moisturizing creams or lotions are recommended after the surgical gauze is removed.27

Other Things to Expect Before and After Treatment

For radiation treatment after surgical removal of the keloid, your doctor will work closely with radiology staff so that the radiation can be administered quickly, preferably within 24 hours of surgery. Surgery is usually done with a local anesthetic and the outline of the wound is drawn on the gauze after the surgery is completed in order to accurately administer the radiation therapy.27

Typically the skin around the treated scar site will temporarily darken at about 3-6 weeks. The skin will dry and flake around the wound site will occur but resolves within a month27

How Often Varies, but 4-6 fractions of total dose are typically given within a short time after surgery for best results.5,16
Types/Methods Used

Internal radiation:

  • LDR iridium-192 brachytherapy27
  • Strontium 90 brachytherapy21
  • HDR iridium-192 brachytherapy 16

External radiation:27

  • Low energy photon X-ray
  • High energy electrons via linear accelerator
Typical Dosage

Brachytherapy: 30-40 Gy post-surgery21

External radiation: 15-20 Gy after surgery, 25-30 Gy without surgery27

Is it Painful? None reported (other than surgical pain).17,27
Side Effects

Although there are limited reports of occurrence, radiation is linked to higher risk of developing cancer, even 15-30 years after treatment—especially at higher doses.8,16,21

Another serious complication for children is stunted growth of the area that was irradiated.8

Other possible adverse side effects include redness, rash, tingling, numbness or burning sensations.8 Both hyperpigmentation and hypopigmentation can occur, and may sometimes be permanent.21

How Does Radiation Work?

Radiation destroys existing collagen-producing cells permanently and limits the production of new ones.2,8

Evidence of Benefit

There are varying degrees of success with radiation therapy. Effectiveness is generally dependent on 3 factors:

  • Type of radiation used. As of a review published in 2011, electron beam irradiation is currently considered the most successful.21
  • Timing of treatment. An average of 72-92% of keloids resistant to other treatments or in areas more at risk of recurrence show a response when radiation is administered immediately after or within 24 hours of surgical removal of the keloid.8,21 However, there appears to be no additional benefit with administering radiation both before and after surgery.16
  • Dosage. High doses of radiation have been shown to be significantly more effective in limiting recurrence.21 Some experts suggest a dosage between 30 and 40 Gy for best results; others indicate that at a minimum the total dosage needs to be 12 Gy to avoid high risk of recurrence.3,21

In studies on high dose radiation for keloids, the treatment also reduced symptoms of itchiness, burning sensations, and redness.16

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Also referred to as high energy X-rays or Linac.
Also called interstitial irradiation.
The standardized international term for a unit of absorbed
dose of ionizing radiation.
This long-term risk is linked to skin cancer at the treatment site.
Either low voltage photons or high voltage electrons.
Minimum of 30 Gy.