Photodynamic therapy of experimental subchoroidal melanoma using chloroaluminum sulfonated phthalocyanine
S. A. Ozler, J. S. Nelson, P. E. Liggett, J. M. de Queiroz Jr and M. W. Berns
Doheny Eye Institute, University of Southern California, Los Angeles.
Although photodynamic therapy has shown great promise for the treatment of
a variety of malignant neoplasms, the role of this new therapeutic modality
in the clinical management of intraocular tumors remains incompletely
understood. This study examines the effects of photodynamic therapy using
chloroaluminum sulfonated phthalocyanine on Greene hamster melanoma
transplanted into the subchoroidal space in rabbits. Twenty-four hours
after intravenous administration of chloroaluminum sulfonated
phthalocyanine (5 mg/kg), tumors were irradiated with 675 nm of light at
total light doses of 7 to 60 J/cm2. The results show that tumor growth was
arrested at total light doses of 22 to 60 J/cm2. At total light doses of 15
to 21 J/cm2, tumor growth was initially arrested. However, regrowth of
these tumors was apparent within 7 days. Total light doses of less than 15
J/cm2 showed no response. Complications of photodynamic therapy, such as
intraretinal or subretinal hemorrhages and retinal detachment, were seen
only in animals who received total light doses in excess of 43 J/cm2.
