What is photodynamic therapy (PDT)?

Photodynamic therapy (PDT) uses light sources combined with a light-sensitive drug to destroy cancer cells. PDT is particularly useful in areas where the skin cancer develops directly over bone, such as on the shins and hands. It is also useful for superficial basal cell carcinomas (BCCs).

Having photodynamic therapy (PDT) for skin cancer

Before treatment, the doctor or nurse may remove any scabs from the area. Then they will put a cream containing the light-sensitive drug onto the area. They will usually cover this with a dressing. You will wait for around 3 hours before having the light treatment. This allows the cream to soak into the layers of the skin.

Next, the doctor or nurse will clean the area. They will shine a special light directly onto your skin. The light treatment usually lasts between 8 and 45 minutes, depending on the light source they use. Some people may find they get a stinging or burning feeling in the treatment area. Tell your doctor or nurse if you are uncomfortable. They can give you something to help.

After this, they will put a dressing over the area to cover it and protect it from light. Keep the dressing on for up to 36 hours after your treatment. Your doctor or nurse will give you instructions about this before you leave hospital.

After the treatment

After having PDT, a crust usually forms over the treated area. This crust will fall off naturally after a few weeks, leaving the healed, new skin underneath.

Usually, only one treatment of PDT is needed. But occasionally you may need 2 or 3 treatments if the skin cancer is thick. Your doctor or nurse will explain how you will have the treatment and how many you may need.

We have more information about photodynamic therapy (PDT).

About our information

  • References

    Below is a sample of the sources used in our skin cancer information. If you would like more information about the sources we use, please contact us at cancerinformationteam@macmillan.org.uk

    Motley et al. British Association of Dermatologists. Management of the patient with primary cutaneous squamous cell carcinoma. 2009.

    National Institute for Health and Care Excellence (NICE). NG12: Suspected cancer: recognition and referral. 2015 (updated 2017).

    National Institute for Health and Care Excellence (NICE). NG134: Sunlight Exposure: Benefits and Risks. 2016.

    National Institute for Health and Care Excellence (NICE). PH32: Skin Cancer Prevention. 2011 (updated 2016).

    Scottish Intercollegiate Guidelines Network (SIGN) 140. Management of primary cutaneous squamous cell carcinoma. 2014.

    Telfar N et al. Guidelines for the management of basal cell carcinoma. British Journal of Haematology. 2008.


  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Professor James Larkin, Consultant Medical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

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