Photodynamic Therapy (PDT)

Skin cancer is one of the most prevalent cancers globally that can affect any body part. More than 1.5 million new cases are estimated yearly that may affect people irrespective of age, gender, and socio-economic status. Early detection of warning signs of skin cancer paves the way for an effective and prompt treatment with favorable outcomes.  

Though there are a variety of treatments for skin cancer based on the type, severity, and prevalence, photodynamic therapy is gaining traction. This therapy uses light energy and photosensitizing medications to treat certain cancers or other skin conditions. Keep scrolling to know everything about this innovative, minimally invasive therapy to be well-informed.  

What is Photodynamic Therapy? 

Photodynamic therapy (PDT), or photochemotherapy, is a modern, minimally invasive treatment that uses light and specially formulated chemicals known as photosensitizers to treat cancer and other conditions. 

Photosensitizers can kill nearby cells when they come in contact with specific wavelengths of light. The light used causes the chemicals (photosensitizers) to create oxygen that is toxic to the cells being targeted. This process of killing cells by using light and medications to produce oxygen that is poisonous to the cells is known as phototoxicity. 

When is Photodynamic Therapy Indicated?

Photodynamic therapy is indicated to treat a cascade of medical conditions. These include: 

Skin Conditions

• Psoriasis 
• Actinic keratosis
• Vitiligo  

Certain Types of Cancers

• Skin cancer 
• Lung cancer
• Esophageal cancer 
• Bladder cancer 
• Pancreatic cancer
• Bile duct cancer 
• Head and neck cancer 
• Brain cancer  

Non-cancerous Conditions

• Urinary tract infections
• Acute sinusitis
• Gastritis 
• Corneal infections
• Gum disease  

How is Photodynamic Therapy Performed?

Photodynamic therapy is an outpatient procedure (does not require hospitalization), and the sessions usually take 15 to 90 minutes based on the size of the targeted area. 

There are two types of PDT offered, and the procedure is as follows: 

Conventional PDT

• Your doctor will first give you a photosensitizer as a pill or through intravenous administration, typically applied to your skin. 
• You will be asked to go home after receiving the photosensitizer. 
• You must return to your doctor after 1 to 3 days (drug-to-light interval).
• Then, a special light will be targeted in the treatment area. Your doctor may use a lower-power red laser light, blue light, or natural sunlight. If the therapy is used to target internal organs, an endoscope may be used. 
• You may repeat photodynamic treatments as and when needed.  

Daylight PDT

• This method is often used for skin conditions.
• The photosensitizer is provided topically in a hospital setup or even at home. 
• You must then spend 2 to 3 hours outdoors to activate the medicine.
• You will be asked to use a broad-spectrum sunscreen to protect your other body parts.  

What to Expect After Photodynamic Therapy?

You can expect the following after your PDT session: 

Conventional PDT 

• The treated skin will be covered with a special medicated dressing for protection and optimal healing. 
• Avoid scratching or pricking the treated area.
• Keep the dressing covered until the recommended period
• Once advised to remove, you can do so and bathe as usual. Always gently pat the area dry.
• It usually takes 2 to 6 weeks for the area to heal completely.  

Daylight PDT 

• The medication is wiped out carefully after about 2 to 3 hours. 
• The treated skin is covered for the rest of the day to manage swelling and inflammation.
• If it is impossible to cover the area, you will be asked to stay indoors or use a high-SPF sunscreen for the rest of the day.  

What Are the Benefits of Photodynamic Therapy?

PDT offers several benefits when compared to medical treatments. These include:

• There are minimal side effects and no known long-term effects when administered by a qualified doctor 
• It is an outpatient procedure that does not require hospitalization
• The procedure can be repeated if required 
• Usually, you may not require anesthesia. Thus, there is no risk of anesthesia-related allergic reactions 
• There is minimal scarring 
• It is a less invasive procedure compared to other surgical procedures

Are There Any Side Effects of Photodynamic Therapy?

Like any other medical procedure, PDT also risks side effects. However, the side effects are mild and temporary. These include:

• Your skin and eyes may be more photosensitive to light for as long as three months 
• Mild swelling near the treated area
• Skin discoloration
• Scales, crusts, or blisters on the treated skin
• Mild itching, stinging, or burning sensation 
• Low-grade fever  

What Precautions Should Be Taken After Photodynamic Therapy?

You may be advised to make some lifestyle changes for short periods, depending on the type of photosensitizer used. These include:

• Staying indoors as much as possible 
• Avoiding direct, bright, or strong indoor lights 
• Wearing protective hat and clothing when outdoors 
• Staying away from beaches and water sports 
• Avoiding strong reading or examination lamps 
• Using a high-SPF sunscreen for added protection 

Final Thoughts

Photodynamic therapy is emerging as a popular treatment for skin conditions and many types of cancer. It is minimally invasive and offers effective semi-permanent to permanent results with minimal side effects. This therapy can be safely repeated when necessary since it does not damage healthy cells. Consult your doctor to find out if photodynamic therapy is right for you. 

FAQs

1. Is photodynamic therapy permanent?

PDT offers semi-permanent results lasting several months when treating skin conditions. When treating cancer, the therapy is as successful as chemotherapy or radiotherapy.

2. Are there any limitations for PDT?

Photodynamic therapy, or PDT, can be used to treat areas of the body where light can reach. Skin conditions and problems associated with organ linings can be easily treated through PDT, whereas large cancers are difficult to treat. 

3. When Can You See the Results of Photodynamic Therapy?

This depends on your unique health condition. All cells in your body absorb the photosensitizers, but they remain for a longer duration in abnormal cells. The agents may collect in unhealthy cells immediately or may take an hour or even days to build up in large amounts for effective results.