Table 1. Summary of characteristics of various photosensitizers.

Photosensitizer	Mode of action	Activation wavelength	Route of administration	Advantages	Disadvantages
Porfimer sodium (Photofrin)	Tissue based	405 nm	Intravenous	Preparation less heterogenous than HpD derivatives	Prolonged skin photosensitivity; long drug- light intervals; suboptimal tumor selectivity
Aminolevulinic acid (5-ALA)	Tissue based	410 nm	Oral or topical	Selectivity for cancer cells; short drug light interval (up to 4 hours)	Less tissue penetration
Verteporfin	Tissue based	692 nm	Intravenous	Selectivity for cancer cells; short drug light interval (15-30 mins);	Visual disturbances reported
mTHPC (Foscan)	Tissue based	652 nm	Intravenous	Low dose required	Prolonged skin photosensitivity (upto 6 weeks); drug light interval of 3-5 days
Motexafin lutetium (MLu)	Vascular acting	732 nm	Intravenous	Short drug – light interval (3 hours); no reported skin photosensitivity	No disadvantage reported
TOOKAD	Vascular acting	763 nm	Intravenous	Short drug-light interval (mins); no reported skin photosensitivity	No disadvantage reported