Chair, Department of Dermatology, Dartmouth Health, and Professor of Dermatology, Geisel School of Medicine, Dartmouth University

M. Shane Chapman, MD, MBA

Going Deeper With Photodynamic Therapy for BCC, With M. Shane Chapman, MD, MBA

Photodynamic therapy (PDT) has emerged as a non-surgical option for treating precancerous lesions and superficial basal cell carcinoma (BCC), offering patients another option in addition to excision with strong clearance rates and favorable cosmetic outcomes. While its use in the United States (US) is relatively new, international experience—particularly in Europe and South America—has long demonstrated its utility in clinical practice. These regions, where surgical resources may be more limited, have relied on PDT for years, generating a wealth of data on efficacy, technique, and patient outcomes.

That global experience is now informing U.S.-based research and clinical decision-making. One recent study conducted evaluated red light PDT with 10% 5-aminolevulinic acid (ALA) gel, which was approved by the US Food and Drug Administration (FDA) in 2016, in a randomized, double-blind, vehicle-controlled, pivotal phase 3 study across 21 centers in the U.S.

The study found that, in 145 participants, those receiving 10% ALA gel had a 75.9% histological clearance rate and an 83.4% clinical clearance rate compared with 19.0% and 21.4%. respectively, in those receiving vehicle (both 

spoke with study investigator M. Shane Chapman, MD, MBA, Chair, Department of Dermatology, Dartmouth Health, and Professor of Dermatology, Geisel School of Medicine, Dartmouth University, to learn more about questions that remain with PDT's use and further research trying to optimize it for skin cancer.

Chapman discussed the wide variation that clinicians currently employ with PDT usage, including in incubation time, light source selection, and treatment cycles. Other questions remain around the optimal activation schedule, whether red light, blue light, or combinations are most effective, and how PDT can be paired with other topical or systemic therapies. He stressed that his team is looking into measuring aminolevulinic acid (ALA) uptake in tissue that may eventually personalize treatment intervals, while collaborations with biomedical engineers are further refining light delivery and depth of penetration. 

"I'm glad this study got done, and I'm glad we're finding out these different ways to use PDT and using it for superficial BCC, but I think we're very early in the course of PDT, and I think there's a whole lot more to do with it," Chapman said.

Ameluz FDA Approval History. Ameluz. Webpage. 

https://www.drugs.com/history/ameluz.html

Schlesinger T, Chapman MShane, Tu JH, et al. Red light photodynamic therapy with 10% aminolevulinic acid gel showed efficacy for treatment of superficial basal cell carcinoma in a randomized, vehicle controlled, double-blind, multicenter phase III study. 

 Published online August 2025. doi: 10.1016/j.jaad.2025.08.031

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Chapman discussed further research to be done with PDT for basal cell carcinoma.

Advantages of Photodynamic Therapy with 10% ALA Gel in Basal Cell Carcinoma, With M. Shane Chapman, MD, MBA

Basal cell carcinoma (BCC) remains the most common form of skin cancer worldwide, and while surgical excision continues to be the standard treatment, non-surgical alternatives are gaining traction. Photodynamic therapy (PDT), a 2-step process combining a topical photosensitizer with light activation, has been used for years in actinic keratosis and is now increasingly explored for superficial BCC. The approach offers a non-invasive option with favorable cosmetic outcomes and has recently expanded its role in the United States (US). following US Food and Drug Administration (FDA) approval of a 10% aminolevulinic acid (ALA) gel formulation designed to improve tissue penetration and reduce incubation times in 2016.

A recent phase 3 study of 145 participants with ≥1 naïve superficial BCC found that those receiving 10% ALA gel had a 75.9% histological clearance rate and an 83.4% clinical clearance rate compared with 19.0% and 21.4%. respectively, in those receiving vehicle (both 

 <.0001). Baseline size of the main target lesions (MTLs) slightly affected clearance rates, which decreased with increasing size (clinical clearance: 90.7% at £81 mm

; histological clearance: 86.0% at £81 mm

). After the first PDT cycle, 83 MTLs (57.2%) treated with 10% ALA gel and 6 MTLs (14.3%) treated with vehicle reached clinical clearance. Investigators excised and confirmed histological clearance in 64 MTLs (44.1%) treated with 10% ALA gel and in 1 MTL (2.4%) treated with vehicle.

After the last PDT cycle, 82.1% of participants treated with 10% ALA gel and 21.4% of those treated with vehicle achieved complete clinical clearance (

 <.0001). Complete clinical and histological clearance was observed in 64.1% of the 10% ALA gel group versus 4.8% in the vehicle group (

 <.0001). Esthetic outcomes were rated very good or good in 89.3% of 10% ALA gel–treated lesions versus 58.0% of vehicle-treated lesions. Participant satisfaction was high in both groups, with very good or good esthetic outcomes reported for 88.1% of lesions in the 10% ALA gel group and 74.0% in the vehicle group; most would choose treatment again (95.0% vs 100.0%).

 spoke with study investigator M. Shane Chapman, MD, MBA, Chair, Department of Dermatology, Dartmouth Health, and Professor of Dermatology, Geisel School of Medicine, Dartmouth University, to learn more about the use of PDT with 10% ALA gel for superficial BCC and the latest data.

Chapman shared that the availability of 10% ALA gel in the US brings the practice more in line with Europe and South America, where PDT has long been used to treat skin cancers in addition to precancerous lesions. Its role continues to expand not only as a treatment but also as a preventive measure in patients with significant photodamage or recurrent tumors. Chapman highlighted how the therapy can be tailored to patient needs, serving both as a standalone option for superficial BCC and as part of a broader strategy in ongoing skin cancer management.

"I think, with very superficial, not complex, not deep, tumors, PDT is a way to go. In the central face where the anatomy is a little bit more complex, it probably wouldn't be a first line treatment for me or for many patients. That's still a surgical preference of mine, probably the patients as well. But for other locations, the arms, legs, back, other other areas that are less anatomically complex, some people are going to choose to use PDT to treat the skin cancer over some of the other options, including over over surgery," Chapman said.

Ameluz FDA Approval History. Ameluz. Webpage. https://www.drugs.com/history/ameluz.html

Chapman discussed the latest findings from a phase 3 study assessing PDT with 10% ALA in people with BCC.

M. Shane Chapman, MD, MBA

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