Photodynamic therapy using Verteporfin (benzoporphyrin derivative monoacid ring A, BPD-MA) and 630 nm laser light in canine esophagus.
OBJECTIVE
Verteporfin is a new photosensitizer with short-term skin photosensitivity. The objective of this preclinical study was to find the light dose that effectively ablates canine esophageal mucosa when delivered 30 minutes after Verteporfin injection.


METHODS
Verteporfin was administered intravenously (0.75 mg/kg). 630 nm light from KTP/Dye laser was delivered using an esophageal Photodynamic therapy (PDT) balloon. In Phase I study, animals were treated 30 minutes after drug injection using 40, 60, and 80 J/cm to find the desired light dose. Using results from phase I and application of reciprocity principle (light dose vs. plasma concentration of drug), additional light doses were calculated for delivery at other times. In phase II, animals were treated at 15, 60, and 120 minutes, using the calculated light doses of 60, 145, and 200 J/cm, respectively. Animals were followed for 2 days to 4 weeks.


RESULTS
In Phase I, 80 J/cm at 30 minutes induced total mucosal ablation. In Phase II, light doses of 60, 145, and 200 J/cm induced similar mucosal injuries when delivered at 15, 60, and 120 minutes, respectively.


CONCLUSIONS
Effective mucosal ablation in canine esophagus was achieved using Verteporfin and 630 nm light doses of 60, 80, 145, and 200 J/cm when delivered at 15, 30, 60, and 120 minutes after the drug injection, respectively.
Panjehpour
Masoud
M
Laser Center, Thompson Cancer Survival Center, Knoxville, Tennessee 37916, USA. mpanjehp@covhlth.com
DeNovo
Robert C
RC
Petersen
Mark G
MG
Overholt
Bergein F
BF
Bower
Robert
R
Rubinchik
Valery
V
Kelly
Barbara
B
D000818:Animals; D004285:Dogs; D004945:Esophagoscopy; D004947:Esophagus / Q000187:drug effects / Q000473:pathology*; D053685:Laser Therapy; D009092:Mucous Membrane / Q000187:drug effects / Q000473:pathology; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000493:pharmacokinetics / Q000627:therapeutic use*; D011166:Porphyrins / Q000493:pharmacokinetics / Q000627:therapeutic use*; D000077362:Verteporfin
D017319:Photosensitizing Agents; D011166:Porphyrins; D000077362:Verteporfin