Photodynamic therapy of ocular melanoma with bis silicon 2,3-naphthalocyanine in a rabbit model.
OBJECTIVE
To investigate bis (tri-n-hexylsiloxy) silicon 2,3-naphthalocyanine (SINc; 0.5 mg/kg) for photodynamic therapy of an experimental ocular melanoma in pigmented rabbits.


METHODS
SINc was dissolved in canola oil by heating, emulsified with Tween 80, and administered by ear vein. Pharmacokinetics were studied in frozen tumor sections by fluorescence microscopy using a charge coupled device, camera-based, low-light detection system with digital image processing at 1 and 24 hours. A Ti:sapphire laser and a microlens were used to deliver the light (770 nm; 40 mW/cm2; 20 J/cm2). A control rabbit received light without SINc.


RESULTS
Localization studies of SINc showed intravascular distribution shifting to a tumor stromal and perivascular distribution 24 hours after treatment. Tissue thermal damage after irradiation was minimal in the control. Exudative retinal detachments were not observed. Tumor destruction was observed, with sharp demarcation to a depth of 3.5 mm.


CONCLUSIONS
Tumor light penetration was good at 770 nm, and thermal effects from the exciting light alone were minimal. Photodynamic therapy with SINc resulted in localized tumor destruction reflecting the light beam path without damage to adjacent tissue or intraocular complications.
Hill
R A
RA
Department of Ophthalmology, University of California, Irvine 92717, USA.
Reddi
S
S
Kenney
M E
ME
Ryan
J
J
Liaw
L H
LH
Garrett
J
J
Shirk
J
J
Cheng
G
G
Krasieva
T
T
Berns
M W
MW
D000818:Animals; D002830:Choroid Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D004337:Drug Carriers; D007275:Injections, Intravenous; D008546:Melanoma, Experimental / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D009368:Neoplasm Transplantation; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*; D011817:Rabbits; D012821:Silanes / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*
D004337:Drug Carriers; D017319:Photosensitizing Agents; D012821:Silanes; C052464:bis(tri-n-hexylsiloxy)(2,3-naphthalocyaninato)silicon