Superficial Radiotherapy (SRT)

 Superficial Radiotherapy (SRT)

What is Superficial Radiotherapy?

Superficial Radiotherapy often referred to, as Superficial X-Ray Therapy or Kilovoltage (kV) Radiotherapy is the use of low energy X-ray’s to treat cancer and other conditions that occur either on or close to the skin surface.

Superficial radiotherapy is widely available throughout the UK, a recent survey of radiotherapy centres in the UK (96% responded) found that 73% of UK centres have at least on kV treatment unit, with 58 installed across the UK. [1]


What type of diagnosis is it used for?

Superficial Radiotherapy can be used to treat a broad range of clinical conditions; it is most widely used for the treatment of non-melanoma skin cancers such as Basal Cell Carcinoma (BCC) or Squamous Cell Carcinoma (SCC). However, Superficial radiotherapy can also be used to effectively treat dermatological conditions, benign (non-cancerous) conditions, other malignant conditions (cancerous) and be used for palliative care. Some examples of the conditions that can be effectively treated are described below:

Dermatological Conditions

  • Keloid scars (typically treated within 24 hours post surgery)
  • Psoriasis

Non-Melanoma Skin Cancer

  • Bowen Disease
  • Basal Cell Carcinoma
  • Squamous Cell Carcinoma

Benign (non-cancerous) conditions

  • Dupuytren contracture
  • Ledderhose Disease
  • Gynaecomastia
  • Peyronies Disease
  • Inflammatory disorders
  • Degenerative disorders
  • Hypertrophic disorders

Malignant (cancerous) conditions

  • Mycosis Fungoides
  • Kaposi sarcoma
  • Merkel Cell tumours
  • Cutaneous T cell lymphoma

By utilising a higher energy range, often referred to as Orthovoltage or deep X-rays, palliative conditions can also be treated such as:

  • Bone metastases (rib pain)
  • Soft tissue secondary lesions
  • Mesothelioma chest drain sites


What are the benefits?

Superficial Radiotherapy has many benefits, including the preservation of anatomy and avoidance of surgery, which is particularly useful in elderly patients or those on anticoagulants, who may not be suitable for general anaesthetic. [2]


Common Side Effects

The side effects of Superficial radiotherapy are dependent on several factors including diagnosis, the prescribed dose and number of treatments.

A common side effect of superficial radiotherapy for skin cancer is that the treated area may scab over (keratinise). If this happens a nurse may need to remove the scab before treatment. The cycle of the affected area healing and then scabbing over may be repeated several times during treatment and for some time after treatment is completed.


What are the alternatives?

Non-Melanoma Skin cancers may also be treated with surgery (Moh’s surgery), cryotherapy (destroying cancer cells by freezing them) or topical chemotherapy (using anti-cancer drugs to destroy cells). Some superficial conditions can also be treated using a Linear accelerator with a less penetrating energy such as electrons.



  1. Palmer A, Pearson M, Whittard P, McHugh K E, and Eaton D (2016) Current status of kilovoltage (kV) radiotherapy in the UK: installed equipment, clinical workload, physics quality control and radiation dosimetry. Br J Radiol.2016 Dec; 89(1068):20160641. Epub 2016 Oct 12.
  2. Chan S, Dhadda AS, Swindell R (2007) Single fraction radiotherapy for small superficial carcinoma of the skin. Clinical Oncology; 19 (4)








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