The Photodynamic Therapy Experience of a High Volume Laser and Dermatologic Surgery Center
November 2016 | Volume 15 | Issue 11 | Original Article | 1420 | Copyright © November 2016
David E. Orbuch BS,c Lauren Penn MD MS,b Bradley S. Bloom MD,a,b Jeremy A. Brauer MD,a,b Daniel B. Shin MS PhD,d Joshua Greenbaum,a Leonard J. Bernstein MD,a,e Elliot T.Weiss MD,a,e Robert T. Anolik MD,a,b and Roy G. Geronemus MD1,2
aLaser & Skin Surgery Center of New York, New York, NY bRonald O. Perelman Department of Dermatology, NYU Langone, NewYork, NY cNew York University School of Medicine, New York, NY dDepartment of Dermatology, University of Pennsylvania, Philadelphia, PA eWeill Cornell Department of Dermatology, New York, NY
Abstract
BACKGROUND: Photodynamic therapy (PDT) is an FDA approved treatment for actinic keratoses (AK’s) although multiple off-label indi- cations are reported. Despite frequent use for AK’s, no clear consensus exists regarding protocols for overall treatment parameters.
METHODS: Retrospective chart review of 1,491 subjects who underwent PDT between 2007 and 2011 at a high volume laser surgery center. Demographic information, clinical history, treatment data, and subsequent diagnosis of skin cancers were recorded. An ex- ploratory subgroup analysis was performed for patients treated for AK and/or squamous cell carcinoma (SCC) that developed SCC or remained SCC-free one year after treatment.
RESULTS: The most common indications for PDT were actinic keratoses (n=1404, 94.9%) then NMSC (n=45, 3.0%) The most common treatment site was the head and neck (n=1274, 86.1%). Blue light activation (405-420nm) was used more frequently than red light and visible light. (73.8% vs. 22.8% vs. 6.8%). The most commonly used photosensitizer was aminolevulinic acid (ALA) (98.6%, n=1456). Topical application (97.7% n=1437) of photosensitizer was used more frequently than intralesional administration (2.0%, n=29). 580 patients met subgroup analysis criteria. 66 developed SCC at treatment site (11%). Factors associated with developing SCC were older age, SCC history, Fitzpatrick skin-type 1, and sixty-minute or less incubation times (P less than 0.05 for all factors). The SCC subgroup had a unique distribution of treatment sites (P less than.001). No statistically significant differences were observed for gender or wavelength.
CONCLUSION: There are differences in protocols based on indication and location of lesion. Blue light is preferable for superFIcial lesions and red light for deeper lesions. Intralesional delivery is used more commonly for NMSC. Extremities require longer incubation times. PDT may be more effective with younger patients and longer than sixty-minute incubation times. PDT chemoprevention is independent of light source used.
J Drugs Dermatol. 2016;15(11):1420-1426.
INTRODUCTION
PhotodynamicTherapy (PDT) is a minimally invasive treatment modality that is extremely effective for the management of many dermatologic conditions and provides a better cosmetic outcome compared to similar treatment mo- dalities.1 PDT consists of the application of a photosensitizing agent followed by light exposure to generate reactive oxygen species, most signi cantly singlet oxygen species.These singlet oxygen species build up in pathogenic tissue, which are then activated by light to induce apoptosis, necrosis, and thrombo- sis to promote cell death of desired target.2 In the United States, PDT is approved for the treatment of non- hyperkeratotic actinic keratoses (AK’s) of the face and scalp.2 In addition to this approved indication, many off-label indica- tions have been reported in the literature. Examples include non-melanoma skin cancer (NMSCs), mycosis fungoides, acne, photoaging, psoriasis, and vascular anomalies.1,3-7 Despite PDT’s increase in popularity, various opinions still exist regard- ing the optimal protocols for photosensitizers, light sources, incubation times, and overall parameters for different indica- tions of PDT.2 It is the goal of this study to describe the most common indications, treatment protocols, and select outcome data at a high-volume laser practice.
MATERIALS AND METHODS
This retrospective cohort study was approved by Essex IRB and was restricted to subjects who received PDT at the Laser & Skin Surgery Center of NewYork (New York, NY) from 2007 to 2011. Subjects were identified using PDT billing codes, and their charts were reviewed. Subjects missing data on treatment indication, anatomic site, photosensitizer, or light source were excluded.
