Experiences of photodynamic therapy in dermatology

From March 1988 to May 1994, 15 patients underwent the treatment protocol of superficial photodynamic therapy (PDT) in dermatological localized malignancies. Two tumours (one M. Queyrat of the penis, one basalioma) were treated primarily; the other 13 patients experienced relapses of underlying disease after treatment by surgery, radiotherapy or chemotherapy. Most of the patients (10/15) received doses of 2 mg Photosan III kg-1 body weight (BW), four received a lower dose of 1-1.5 mg kg-1 BW and one patient received 3 mg kg-1 BW. Only one remarkable side-effect (tachyarrhythmia) during Photosan III infusion occurred. All patients were treated by an argon dye laser system. The light dose was 200 J cm-2 (11 patients) and 150 J cm-2 (four patients). Complete response occurred in six lesions, including one M. Queyrat and five basaliomas. Two patients had significant partial response with distinct regression of tumour (one pretreated basalioma of the upper lip and one superficially spreading mesothelioma of the scrotum). Five patients (all basaliomas) demonstrated only local response and two patients gave no response (one basalioma, one melanoma metastasis). The results obtained from this small sample suggest the necessity of an optical dosimetric system. At present, PDT should be restricted for selected or pretreated cases.