The light-sensitive photosensitizer is administered by infusion and activated through systemic (intravenous) laser therapy.

After about 2-3 hours, the photosensitizer binds selectively to the tumor. The laser can now irradiate and destroy the diseased tissue locally (interstitially, endoscopically or with special catheter technique).

The photosensitizers (Indocyanine green, Chlorin E6, Curcumin and Hypericin) are highly specific and natural. Side effects are therefore relatively low.