PDT combines a light-sensitive medication applied to the skin with a medical light source. After the medication has had time to absorb, red light activates it to treat the selected area. PDT is not simply a red-light facial: the medication and the light work together as a medical treatment.
At our clinic, PDT uses red light and is delivered by our trained nursing team under a clinician-directed treatment plan. The number and timing of sessions depend on the condition being treated and the response.
Why treat actinic keratoses?
An AK is more than a cosmetic rough patch. It is a precancerous change that deserves medical assessment. Treating actinic keratoses (AKs) is a preventive treatment: the goal is to remove or reduce these changes and decrease their risk of progressing to squamous cell carcinoma (SCC), a type of skin cancer.
Not every AK will become a skin cancer, and treatment cannot guarantee that skin cancer will not develop. Sun protection, follow-up, and ongoing skin checks remain important. This preventive purpose applies to treating AKs; Bowen’s disease and superficial basal cell carcinoma are already forms of skin cancer and need their own treatment decisions.
Which conditions can be treated?
Actinic keratoses
Actinic keratoses are precancerous changes, not the same diagnosis as an established skin cancer. When several occur within an area of sun-damaged skin, field therapy can address visible lesions and less obvious changes within the treatment area. Your clinician will decide whether field therapy, treatment of individual spots, or a combination is appropriate.
Bowen’s disease — squamous cell carcinoma in situ
Bowen’s disease is an early form of squamous cell carcinoma confined to the outer layer of the skin. Selected cases may be considered for 5-FU or PDT after assessment and confirmation of the diagnosis. These treatments are used off-label for Bowen’s disease in Canada; your clinician will explain the reasons for recommending them and discuss alternatives. Not every lesion is suitable for non-surgical treatment.
Superficial basal cell carcinoma
Superficial basal cell carcinoma is a type of skin cancer that grows close to the skin’s surface. Some carefully selected lesions may be suitable for a prescription cream or PDT. Suitability depends on the confirmed cancer type, location, size, and other risk factors. Surgery or another treatment may be more appropriate.
Important: These conditions are not interchangeable. Treating a field of actinic keratoses is different from treating a diagnosed skin cancer. Your clinician will identify which approach is appropriate and arrange follow-up to assess the response.
Microneedling-assisted photodynamic therapy
In selected cases, your clinician may recommend microneedling as an additional preparation step before PDT. It creates very small channels in the skin and is intended to help the light-sensitive medication enter the treatment area.
Microneedling is not required for every patient. Its potential benefits and suitability depend on the treatment protocol, and findings from one PDT protocol do not necessarily apply to another. Your clinician will explain why it is being considered, any additional discomfort or risks, and the alternatives.
See how microneedling may be used as a preparation step before PDT, why it may be considered for selected patients, and what to expect from the procedure.
Preparing for treatment
Tell us about your medications, allergies, pregnancy or breastfeeding, light sensitivity, and any history of cold sores. Include blood-thinning medication in your medication list. Your team will give you preparation instructions specific to your treatment. Do not stop prescribed medication unless the prescribing clinician advises you to do so.
Treatment and recovery
Stinging, burning, or pain can occur during light activation. Redness, swelling, peeling, and crusting may follow. Your care team will discuss comfort measures and explain the light-protection precautions and skin care required afterward.
Follow the prescribed cream schedule or attend your planned PDT appointments. Both approaches can cause a temporary inflammatory reaction. Plan around work, social commitments, and sun exposure, and follow your care team’s skin-care instructions. After PDT, follow the specific instructions for avoiding sunlight and other bright light; sunscreen alone does not replace these precautions.
A stronger reaction does not, by itself, prove that treatment has been more successful. Contact the clinic for severe or worsening pain, signs of infection, unexpected symptoms, or a reaction you are unsure how to manage. Your treatment instructions will explain when to seek urgent advice.
Follow-up
A follow-up assessment checks how your skin has responded and whether further treatment is needed. Individual AKs can clear, but new or persistent lesions still require attention. Even after successful field therapy, you remain at risk of developing squamous cell carcinoma. Ongoing sun protection and skin checks remain important after treatment.
5-FU or PDT: how do you choose?
Both can be considered for the preventive treatment of actinic keratoses, but they work differently and involve different treatment experiences. With 5-FU, you apply topical chemotherapy at home over a prescribed course. With PDT, light-sensitive medication application and light activation take place in the clinic. Both can cause visible inflammation and require recovery time.
The choice depends on your diagnosis, the treatment area, previous treatment, medical history, and your ability to follow the treatment and aftercare instructions. Appointment commitments, discomfort, and cost also matter.
We will discuss the advantages and limitations of each suitable option so you can make an informed decision with your clinician. Neither treatment is the best choice for every patient or every lesion.
What will treatment cost?
Costs depend on the treatment recommended and the area being treated. We will discuss costs before treatment so you can make an informed decision. Contact the clinic if you would like to understand the assessment process or ask about fees.
Frequently asked questions
Will field therapy replace surgery?
Not always. Field therapy is commonly considered for an area of actinic keratoses. A diagnosed skin cancer needs its own treatment decision, and surgery may be the more appropriate option. These treatments are not a substitute for assessment of a suspicious lesion.
Is treatment painful?
Prescription creams can cause soreness and inflammation during the course. PDT can cause stinging, burning, or pain during light activation, followed by tenderness and visible inflammation. We will discuss the expected experience and suitable comfort measures before treatment.
How long will my skin take to heal?
Recovery depends on the treatment, area, and individual response. With 5-FU, healing can continue for several weeks after application stops. After PDT, visible reactions often settle over one to two weeks, although some last longer. Your clinician will advise you on the likely course for your treatment; these are not guaranteed timelines.
Discuss your options
At Kelowna Private Skin Cancer Clinic, we will discuss whether topical 5-FU chemotherapy, red-light PDT field therapy, or another approach is appropriate for you. You will understand the reasons for treatment, what recovery involves, and why ongoing skin checks still matter.