Photodynamic Therapy

Photodynamic Therapy

Photodynamic therapy
Photodynamic therapy

What is Photodynamic Therapy?

Photodynamic therapy is a specific type of medical treatment in which a drug, known as a photosensitizer, is combined with a particular light in order to kill different cells that are sick. What happens is that this drug is initially non-toxic but it has an increased sensitivity to light. When this drug is exposed to a specific type of light, it becomes toxic but only for the cells that are diseased or malignant.

Also known as photochemotherapy, this method has been used for the treatment of a wide array of medical conditions, including different types of cancer. The therapy can also be used to kill different types of microbial cells, including viruses, fungi and bacteria. The advantages of the photodynamic therapy is that it is minimally invasive and its toxicity is only related to the affected area. The important thing to understand is that this drug is activated by a specific wavelength of light, this actually determining how far is the active substance going to travel into the body.

What does photodynamic therapy do?

Photodynamic therapy
Photodynamic therapy pictures

In order to understand what does photodynamic therapy do, you need to first understand that there are three main components to take into consideration. The first is the photosensitizer or the drug that is used for this particular type of therapy. The second is the source of light, which in combination with the drug kills the diseased cells. The third is the tissue oxygen, which comes as a direct result of the above combination. These are the three key components and you will find an explanation on how they function below.

When the drug is combined with a specific wavelength, the direct result is the chemical destruction of any diseased or malignant tissue. This can happen to a tissue that has selectively absorbed the photosensitizer, being exposed to the specific wavelength. Now, the adequacy of the wavelength is critical for the success of the therapy. Depending on the specific wavelength that has been chosen for a particular medical condition, the photosensitizer will be activated and it will lead to the appearance of tissue oxygen. These are in fact free radicals and they are the one responsible for the chemical destruction of the affected tissue.


The price of the photodynamic therapy is dependent on a number of factors, including the type of the condition that is going to be treated and how severe this medical condition actually is. Another factor to take into consideration is the country in which the treatment is made and the actual town, as the costs can vary from one town to the other and, clearly, from one specialist to the other. Generally speaking, a series of treatments of photodynamic therapy can cost somewhere between $2000 and $3500. However, you should talk to your doctor first about any additional costs because there are certain practices or clinics that do not include the price of follow-ups or post-therapy  care products into the starting comprehensive treatment package.

What to expect after photodynamic therapy?

In the initial period after you have undergone photodynamic treatment, the skin will present an increased sensitivity to light. This is because the medication that was introduced with the help of the light has yet to completely metabolize and that can take up to two days. In this period, you are recommended to avoid light as much as you possibly can and, if you have to go out, then you should protect the skin by wearing a hat, a scarf around your neck and also you should apply high protection sunscreen, perhaps one that contains zinc oxide as well.

In the majority of the patients, in the first two or three days after the surgery, redness and mild peeling can appear. However, there are cases in which the patients experience a burning sensation in the treated area for a period of twenty-four hours and the peeling and redness can extend up to two full weeks.

The response provided by the photodynamic therapy can vary from one patient to the other, even if the same condition was treated. Some patients might respond better to this treatment than others. For example, the greatest results are noticed in patients who have received this treatment for the following medical conditions: actinic keratosis, sagging skin, acne, enlarged pores or pigmented skin. Depending on the medical condition that is being treated with this particular type of therapy, it might take a couple of weeks before the first results are noticeable.


These are the most common side-effects that can appear in case of patients who have undergone photodynamic therapy, these being commonly caused by the drugs that are being used in combination with specific light:

  • Photosensitivity reactions – these reactions are triggered by light and they can be presented in the form of:
    • Extreme sensitivity to light (for the skin and the eyes) – light exposure after the treatment will cause the skin to blister, to swell and even sunburn can occur. Peeling will occur in the next period as well
  • Swelling in the treated area – the patient might have trouble breathing or swallowing, requiring emergency medical attention. For example, if the treatment is done to the esophagus, the patient might have difficulties swallowing. Lung treatments could lead to breathing problems as well
  • Other side-effects include:
    • Nausea
    • Vomiting
    • Fever
    • Dehydration
    • Headache
    • Scarring and esophagus constriction
    • Hiccups
    • Fluid around the lungs
  • Treatment performed for lung cancer is associated with the following potential side-effects:
    • Shortness of breath
    • Cough with blood
    • Fever
    • Pneumonia
    • Bronchitis
  • Allergic reactions can also appear in the form of:
    • Eczema or rash present on the skin
    • Rarely, anaphylactic shock
  • Burning or stinging sensation in the treated area
  • Swelling and redness
  • Crusting
  • Itchiness
  • Infections of the skin
  • Loss of pigmentation – this can appear in some patients and, unfortunately, when this happens, the results are permanent.


Watch this video to know how the photodynamic theraphy is done:

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