Innovations in Photodynamic Therapy for Skin Cancer Treatment

According to a recent narrative review published in Dermatology and Therapy, photodynamic therapy (PDT) using topical photosensitizers may offer improved therapeutic outcomes with reduced toxicity for patients with skin conditions such as actinic keratosis (AK), cutaneous squamous cell carcinoma (cSCC), basal cell carcinoma (BCC), and field cancerization.

Researchers aimed to explore the latest developments and ongoing research in the use of topical photosensitizers and modified light delivery regimens to improve therapeutic outcomes with less toxicity in patients with AK, cSCC, BCC, and field cancerization.

PDT using 5-aminolevulinic acid and derivatives as a photosensitizer is currently approved in the United States for AK treatment but has also been used off-label for nonmelanoma skin cancers. Although PDT offers improved cosmesis and patient satisfaction, pain and treatment duration are significant drawbacks. The review suggests alternative illumination approaches, including intense pulsed light and pulsed dye lasers, along with mechanical skin pretreatment or warming to increase photosensitizer absorption and improve therapeutic efficacy. Additionally, combining multiple treatments and reducing pre-incubation time between photosensitizer application and illumination can significantly reduce pain scores without affecting treatment efficacy. Daylight PDT is another promising innovation that can improve tolerability and convenience.

“Various forms of PDT are being used successfully for treatment of BCC, cSCC, and field cancerization, as well as individual AKs. Clearance rates higher than 90% have been reported in patients with multiple mild to moderate AKs and BCC. Improvements in terms of illumination technologies and photosensitizer application and delivery have been investigated and demonstrated to have potential for success,” concluded study authors. “Further studies are warranted to determine how protocols may be optimized to improve efficacy and duration of lesion clearance, as well as patient experience, thereby potentially improving long-term adherence for a chronic condition, especially among high-risk individuals,” they added.

Reference
Farberg AS, Marson JW, Soleymani T. Advances in photodynamic therapy for the treatment of actinic keratosis and nonmelanoma skin cancer: a narrative review. Dermatol Ther (Heidelb). 2023;13(3):689-716. doi:10.1007/s13555-023-00888-1.