Side-by-Side Comparison of Photodynamic Therapy and Pulsed-dye Laser Treatment of Port-wine Stain Birthmarks

K. Gao; Z. Huang; K.-H. Yuan; B. Zhang; Z.-Q. Hu

Disclosures

The British Journal of Dermatology. 2013;168(5):1040-1046. 

In This Article

Abstract and Introduction

Abstract

Background Pulsed-dye laser (PDL)-mediated photothermolysis is the current standard treatment for port-wine stain (PWS) birthmarks. Vascular-targeted photodynamic therapy (PDT) might be an alternative for the treatment of PWS.

Objectives To compare clinical outcomes of PDT and PDL treatment of PWS.

Methods Two adjacent flat areas of PWS lesions were selected from each of 15 patients (two male and 13 female; age 11–36 years) and randomly assigned to either single-session PDL or PDT. PDL was delivered using a 585-nm pulsed laser. PDT was carried out with a combination of haematoporphyrin monomethyl ether (HMME) and a low-power copper vapour laser (510·6 and 578·2 nm). Clinical outcomes were evaluated colorimetrically and visually during follow-up.

Results A total of nine red PWS lesions and six purple PWS lesions were treated. For red PWS, colorimetric assessment showed that the blanching rates of PDL and PDT at 2 months ranged from −11% to 24% and 22% to 55%, respectively. For purple PWS, blanching rates of PDL and PDT ranged from 8% to 33% and 30% to 45%, respectively. Overall, there was a significant difference between the blanching effect of single-session PDL treatment and a single-session PDT treatment.

Conclusions This side-by-side comparison demonstrates that PDT is at least as effective as PDL and, in some cases, superior. The true value of PDT for the treatment of PWS deserves further investigation.

Introduction

Port-wine stain (PWS) birthmarks are congenital and progressive vascular lesions of human skin that affect 0·3–0·5% of newborns.[1] PWS are characterized by ectatic capillaries that are 10–150 μm in diameter and are located predominantly in the upper dermis at a depth of 300–600 μm. The colour of PWS can range from pale pink to red to purple, with varying degrees of hypertrophy of overlying soft tissue. PWS do not regress spontaneously, but if left untreated may worsen with age (e.g. darken and thicken). Although PWS can affect any part of the body, they are mainly located on the face and neck areas and therefore can cause serious emotional and physical impact.[2]

Pulsed-dye laser (PDL)-mediated selective photothermolysis is the current standard treatment for PWS.[3–5] Clinically, good blanching responses are associated with complete photocoagulation of the target vessels. Yellow light (e.g. 585 or 595 nm) produced by the PDL can be preferentially absorbed by the haemoglobin and cause the selective closure of the dilated ectatic capillaries in the upper dermis and subsequent PWS colour blanching. Although PDL treatment is safe and effective, only 10–20% of patients achieve complete blanching of their PWS after PDL treatment. Moreover, about 20% of PWS are resistant to PDL.[6–9] Alternative therapies, including photodynamic therapy (PDT), have been studied for the treatment of PWS in both children and adult patients.[10–12]

The feasibility of vascular-targeted PDT for the treatment of PWS has been studied extensively in China since the early 1990s.[13] In this two-step drug–device modality, a photosensitizer is administered intravenously and accumulates in the ectatic capillaries. Subsequent irradiation with either coherent or noncoherent light of appropriate wavelength(s) generates oxygen-derived free radicals (e.g. singlet oxygen) that selectively damage the PWS vessel wall and cause vessel closure without the destruction of surrounding skin tissue. Several clinical studies have demonstrated that PDT is safe and effective in the treatment of PWS at all ages.[12–17] Our retrospective study suggested that PDT is as effective as PDL for treating pink PWS and more effective than PDL for purple PWS.[18] The true value of PDT for the treatment of PWS certainly deserves further investigation. In this prospective study, for the first time, we carried out an inter- and intrapatient side-by-side comparison of the therapeutic responses of PDL and PDT in a small series of patients with PWS. The clearance of PWS lesions after a single session of PDL and PDT treatment were assessed colorimetrically and visually.

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