Photodynamic therapy for port wine stains assisted by a novel robotic system

Abstract

Port wine stains (PWS) is a vascular malformation consisting of dilated capillaries in the superficial dermis. Photodynamic therapy (PDT) is an effective approach in the treatment of PWS. However, the procedure of treatment is a low efficient and hard work, as the doctor need to hold laser fiber to irradiate for 20 min to 50 min per lesion. So an assisted novel robotic system was developed to instead part of doctor's work. The robotic system consisted of 7 degrees of freedom, in which there were 5 passive joints and 2 active joints. Binocular surveillance system was used as guidance for the robot. Clinical trial compared 20 patients (38 lesions) treated by the robotic system with another 20 patients (38 lesions) treated by a doctor. The patients in both groups were injected intravenously with photosensitizer (PSD-007, 4-5mg/kg) and irradiated with 532 nm laser (100mW/cm², 120-300J/cm²) immediately. Both groups had same good therapeutic results. The robotic system is helpful in the PWS-PDT and hopefully would become a part of PWS therapy machine in the future.