In vitro and in vivo comparison of argon-pumped and diode lasers for photodynamic therapy using second-generation photosensitizers

Background and Objective: Three prototype microchannel-cooled stacked diode array lasers were compared with the currently used conventional argon ion laser-pumped tunable dye lasers for suitability as light sources in photodynamic therapy (PDT) treatment. Study Design/Materials and Methods: The PDT response of Chinese hamster ovary (CHO-K) cells in culture and SMT-F tumor bearing mice treated with chloro-aluminum sulfonated phthalocyanin (CASPc), benzoporphyrin derivative mono-acid (BPD-MA), and lutetium texaphyrin (Lutex) was determined using each laser light source. Survival of the CHO cells was measured using a cloning assay. Tumor regression/eradication was used to assess response in the mice. Results: Both sources of laser light produced comparable PDT responses in the two systems tested. Conclusion: It would be possible to replace the currently used argon ion laser-pumped dye laser systems with the diode lasers tested.