Excision and Radiotherapy

The charts below show the chances of developing various side effects from excision followed by radiotherapy.^2,4-9 For some side effects, we currently do not have enough data to provide a percentage.

Certain/Likely Side Effects (% = Incidence)

*Temporary skin redness (erythema): Skin redness is normal after excision and radiotherapy. The redness typically disappears 10 days to 3 weeks after radiotherapy.^4,5,7,8

Possible/Rare Side Effects

*Thinning of the skin (skin atrophy): Skin atrophy can make the skin appear “sunken-in.”

**CAUTION. Skin cancer (malignancy): Radiotherapy can potentially cause skin cancer (malignancy) at the treated location. There are several case reports of patients who developed cancer after undergoing radiotherapy for keloids, but there is no proof that the radiotherapy is what caused the cancer.² Six studies have looked specifically at the side effects of treating acne scars with excision followed by radiotherapy. None of these studies have found any cases of skin cancer during the follow-up period, which ranged from 8 months to 30 years.^4-9 However, cancer might potentially have developed in some patients after the follow-up period. Therefore, it is important to weight the benefits of excision and radiotherapy against the potential risks. Younger patients need to approach radiotherapy with particular caution.²

Studies:   

Six studies have looked at the side effects of excision followed by radiotherapy.

• Study 1:
  
  
  • Authors: Klumpar et al.⁵
  • Total # of patients: 186
  • # of female patients: 139
  • # of male patients: 47
  • Age of patients: (not reported)
  • Radiotherapy schedule and dose: Daily for 1-12 days (2-3 days for most patients), average cumulative dose 28 Gy
  • Duration of follow-up: 8 months to 17 years
  • Side effects:
    
    
    • Hyperpigmentation (skin darkening): 42%
    • Pruritus (itching): 36%
    • Erythema (redness): 24%
    • Paresthesias (tingling, numbness, or prickling sensations): 14%
    • Pain: 13%
    • Hypopigmentation (skin lightening): 3%
    • Telangiectasia (small dilated blood vessels under the skin surface): 2%
    • Burning: 2%
    • Tenderness: 1%

• Study 2:
  
  
  • Authors: Ogawa et al.⁷
  • Total # of patients: 129
  • # of female patients: 80
  • # of male patients: 49
  • Age of patients: (not reported)
  • Radiotherapy schedule and dose: Daily for 3 days, cumulative dose 15 Gy
  • Duration of follow-up: 18 months or more (average: 24 months)
  • Side effects:
    
    
    • Temporary erythema (redness): 100%
    • Temporary hyperpigmentation (skin darkening): 45.6%
    • Temporary hypopigmentation (skin lightening): 2%

• Study 3:
  
  
  • Authors: Ogawa et al.⁴
  • Total # of patients: 109
  • # of female patients: (not reported)
  • # of male patients: (not reported)
  • Age of patients: 19-62 Average: 26
  • Radiotherapy schedule and dose:
    • One of:
      • 2 fractions over 2 days, cumulative dose 10 Gy
      • 3 fractions over 3 days, cumulative dose 15 Gy
      • 4 fractions over 4 days, cumulative dose 20 Gy
  • Duration of follow-up: 18-30 months (average: 23 months)
  • Side effects:
    
    
    • Temporary erythema (redness): 100%
    • Hyperpigmentation (skin darkening): 37.2%

• Study 4:
  
  
  • Authors: Lo et al.⁸
  • Total # of patients: 119
  • # of female patients: (not reported)
  • # of male patients: (not reported)
  • Age of patients: Average: 22 for men, 35 for women
  • Radiotherapy schedule and dose: Once, dose 8-15 Gy
  • Duration of follow-up: 1 to 366 months (median: 35 months)
  • Side effects:
    
    
    • Erythema (redness): 100%
    • Telangiectasia (small dilated blood vessels under the skin surface): 0.8%

• Study 5:
  
  
  • Authors: Kovalic and Perez⁶
  • Total # of patients: 75
  • # of female patients: 65
  • # of male patients: 10
  • Age of patients: 5-79 Average: 24
  • Radiotherapy schedule and dose: 3 fractions over 3 days, cumulative dose 12 Gy
  • Duration of follow-up: 13-239 months (average: 117 months)
  • Side effects: Hyperpigmentation (skin darkening): 5%

• Study 6:
  
  
  • Authors: Enhamre and Hammar⁹
  • Total # of patients: 47
  • # of female patients: 28
  • # of male patients: 19
  • Age of patients: 7-15 (7 patients), 16-25 (30 patients), 26-73 (19 patients)
  • Radiotherapy schedule and dose: 1-3 fractions, cumulative dose 10-15 Gy
  • Duration of follow-up: 6 months to 9 years
  • Side effects:
    
    
    • Hyperpigmentation (skin darkening): 34%
    • Telangiectasia (small dilated blood vessels under the skin surface): 10.6%
    • Skin atrophy (loss of normal skin markings): 4.2%

Study 1: In a study published in 1994 in the Journal of the American Academy of Dermatology, Klumpar and colleagues treated 186 patients with keloids with excision followed by radiotherapy. The patients received radiation treatment for 1 to 12 days after surgery. Most patients received radiation treatment for 2 or 3 consecutive days at an average cumulative dose of 28 Gy. The researchers were able to locate only 83 patients for follow-up, which occurred 8 months to 17 years after treatment. Of these patients, 42% reported experiencing residual side effects. The most common side effect was hyperpigmentation (skin darkening).⁵

Study 2: In a study published in 2003 in the journal Plastic and Reconstructive Surgery, Ogawa and colleagues treated 129 patients with 147 keloids with surgical excision followed by radiotherapy. Patients received a total of 15 Gy radiation and were followed up for at least 18 months. The most common side effect was hyperpigmentation (skin darkening). Redness occurred 2-3 weeks after radiotherapy in most patients but was temporary.⁷

Study 3: In a study published in 2007 in the journal Annals of Plastic Surgery, Ogawa and colleagues treated 109 patients with keloid or hypertrophic scars with excision followed by radiotherapy. The patients received varying doses of radiation: 10 Gy over 2 days, 15 Gy over 3 days, or 20 Gy over 4 days, and were followed up for 18 months or more. Most patients developed erythema (redness) 2-3 weeks after radiotherapy, but this redness later disappeared. The side effect most commonly found was mild hyperpigmentation (skin darkening), which usually occurred 1-6 months after radiotherapy.⁴

Study 4: In a study published in 1990 in the journal Radiotherapy and Oncology, Lo and colleagues treated 119 patients with a total of 168 lesions with excision followed by radiotherapy. Each patient received between 8 and 15 Gy of radiation in a single dose. The patients were followed up at least once after treatment. The follow-up period ranged from 1 month to 366 months, with the median follow-up period being 35 months. Redness developed in almost all patients 10-14 days after radiotherapy.⁸ 

Study 5: In a study published in 1989 in the International Journal of Radiation Oncology, Biology, Physics, Kovalic and Perez looked at 75 patients with a total of 113 keloids who had been treated with excision followed by radiotherapy. The patients had received 3 doses of radiation for a total dose of 12 Gy. The researched followed the patients over an average period of 9.75 years (117 months) after treatment to observe any side effects. Four of the patients developed mild hyperpigmentation (skin darkening).⁶

Study 6: In a study published in 1983 in the journal Dermatologica, Enhamre and Hammar looked at 47 patients with a total of 62 keloids who had been treated with excision followed by radiotherapy. The patients had received 1-3 doses of radiation for a total dose of 1,000-1,500 rad, which is equivalent to 10-15 Gy. The researchers followed each patient for 6 months to 9 years after to observe side effects. The most common side effect was hyperpigmentation (skin darkening).⁹