Efficacy and influential factors of hematoporphyrin monomethyl ether mediated photodynamic therapy in the treatment for port-wine stains

Backgrounds: Hematoporphyrin monomethyl ether mediated photodynamic therapy (HMME-PDT) has emerged as an alternative approach for port-wine stain (PWS), which was primarily treated with pulsed dye laser (PDL). This study was aimed to evaluate the efficacy and safety of HMME-PDT for PWS and to explore influential factors on the efficacy. Methods: A total of 254 patients were enrolled. Patients received an intravenous injection of HMME at 5 mg/kg. Lesion areas were irradiated with 532-nm light for 20-25 min. Efficacy was assessed according to fading of lesions and graded as excellent (>= 90 %), good (60 %-89 %), fair (20 %-59 %), or poor (<20 %). Adverse events were recorded. Clinical data were analyzed including gender, age, lesion sub-type, lesion location and number of treatments. Results: Overall, 72.4 % of patients achieved an effective response, with 27.6% showing excellent efficacy, 24.8 % showing good efficacy and 20.1 % showing fair efficacy. Only 27.6 % showed poor efficacy. Patients under the age of 18 obtained a better efficacy than adults. Lesions in face showed a better therapeutic outcome than those in neck or trunk and extremities. A more effective response was seen in pink type compared with nodular thickening type. Multiple HMME-PDT treatments could improve the clinical response. Lesion location, lesion sub-type, number of treatments were independent influential factors on efficacy. Adverse events included edema, blister, crust, hypopigmentation, hyperpigmentation, pain, itch and burning sensation. No severe systemic side events were observed. Conclusions: HMME-PDT was effective for treating PWS and was safe and well-tolerated by patients. It is worth further investigation in efficacy and safety involving more patients from medical institutions in different regions in China. The optimal treatment parameters and treatment protocols are still being explored in the clinical treatment for PWS.