PDT/ Photodynamic Therapy for Sunspots

  • Best Results1-2 sessions
  • Treatment Recovery3-6 days
  • Procedure Time15-40 minutes
  • Skin SpecialistDermatologist
  • Duration of Results2-6+ years
  • AnaestheticLocal, sedation
  • Back to Work3-7 days
  • CostFree (DVA)- $$

PDT/ Photodynamic Therapy for Sunspots

PDT, also known as photodynamic therapy, is one of the best treatments for actinic keratosis. This treatment uses a chemical known as a photosensitiser & a light source. The photosensitive topical is preferentially concentrated in abnormal skin cells. Light sources include lasers, LEDs or day light. PDT has a much shorter downtime compared to Efudix or Aldara.

FactsFacts on PDT For Solar Keratosis

  • PDT is one of most effective methods to treat solar keratosis & sun damage
  • Efficacy ranges from 60 to 90+% with just one treatment
  • Laser assisted PDT has the highest efficacy 
  • Downtime is much less compared to traditional solar keratosis treatments
  • PDT can be employed to treat sunspots as well as superficial skin cancers
  • Light sources include red & blue LEDs, vascular lasers, as well as solar spectrum

What types of skin conditions are treatable with PDT?

In the context of skin cancer & skin cancer prevention, lesions that can respond to PDT include-

  1. Solar keratosis or actinic keratosis, non-pigmented, non-hyperkeratotic.
  2. Superficial basal cell cancer.
  3. Thin intraepidermal cancers including Bowen disease. 

PDT has been used on many other skin conditions including erosive pustular dermatosis, sebaceous hyperplasia, adjunctive therapy to nodular BCCs in low risk areas, recalcitrant rosacea, & acne. Further information in relevant sections on this website.

What is daylight PDT?

This uses natural sunlight to activate the ALA or mALA. This cuts down in-clinic time & pain associated with illumination. Your dermatologist will give you a guide as to how to perform this procedure. Refer to the section on daylight PDT for application instructions.

What is laser assisted PDT & is it better than normal PDT?

Laser assisted PDT has the highest clearance rates of solar keratosis. The use of fractional CO2 assisted short contact ALA *(30 minutes) with blue light activation resulted in a clearance of 89% of solar keratosis.

  • CO2 fractional laser with red light activation or daylight activation
  • Erbium fractional laser with red/blue/ daylight activation
  • Non-ablative lasers such as Fraxel, 1927, 1940, 1440, 1550 with ALA

*3-month follow-up

**Short contact PDT is thought to be mediated with intracellular mechanisms, possibly mitochondrial & not via the absorption of ALA by dysplastic (abnormal) keratinocytes.

What is vascular laser PDT?

This treatment uses a vascular laser to activate porphyrins (photosensitiser). I did use this method over a decade ago to treat both sun damage & broken capillaries, followed by conventional illumination. The downside of this treatment is discomfort to the patient.

Studies have confirmed that using lasers in the wavelength of 585 to 595 nm is not as effective as illumination with daylight or a lamp (typically with lasers we deliver between 12 to 18 mj, compared to 37 mj with a lamp). Modification of this technique includes pre-treatment with vascular then daylight PDT.

Davin’s Viewpoint on PDT for actinic keratosis

I have been using this procedure for nearly two decades, initially with normal PDT, namely illumination with the Galderma red light with 37j/cm squared, time of seven & a half minutes. A decade ago I started using laser assisted PDT, namely with an erbium laser, either as a micropeel (ten microns) or moderate density fractional at around 30%, 20-50 microns deep.

Fast forward to 2022, the majority of dermatologists are now using very superficial lasers, primarily CO2 at around 6 to 10 mj in a higher density. This reduces pain, & importantly increases the efficacy of PDT. Additionally, daylight is the preferred light source to illuminate aminolevulinic acid. Laser assisted PDT has other benefits including reducing the number of pigmented solar keratosis as well as hypertrophic SKs to enhance penetration of ALA. In my practice, my most frequent laser combination is with either 1927 thulium or CO2 laser. The former is used for aggressive solar damage as I spit the intervals over 2-4 weeks. With CO2, PDT is conducted after high pass, low joule setting. Illumination is either daylight or low-level laser emitting diodes in a clinic.

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