INDOCYANINE GREEN AND LASER-LIGHT FOR THE TREATMENT OF AIDS-ASSOCIATED CUTANEOUS KAPOSIS-SARCOMA

Indocyanine green (ICG) is clinically approved for the determination o f liver function, cardiac output and plasma volume. In this pilot stud y, ICG was used as photosensitizer in combination with a diode laser t o treat AIDS-associated Kaposi's sarcoma (KS) in three patients. Direc tly and up to 50 min after intravenous administration of ICG (2-4 mg k g(-1) body weight), KS (n = 57), mainly plaque-type, were irradiated u sing a diode laser (lambda(em) = 805 nm, 100 J cm(-2), 0.5-5 W cm(-2)) matching the absorption maximum. Complete remission of KS (n = 16) wa s achieved when irradiated 1-30 min after injection of the second dose of ICG (2 x 2 mg kg(-1) b.w., 30 min apart) with 3-5 W cm(-2) and 100 J cm(-2). Biopsies (n = 3) revealed necrosis of the tumour 24 h and c omplete remission 4 weeks after therapy. In general, systemic side-eff ects were not observed and cosmetic results were very good. However, h yperpigmentation occurred temporarily in lesions located on the lower extremities. These findings show that AIDS-associated KS can be effect ively treated after photosensitization with ICG and subsequent irradia tion with an appropriate diode laser. However, additional investigatio ns need to elucidate the exact mechanism of action of ICG-mediated pho totherapy and have to show the efficacy for the treatment of other hig hly vascularized solid tumours.