Photofrin II as an efficient radiosensitizing agent in an experimental tumor.
OBJECTIVE
The use of ionizing irradiation as radiation therapy (RT) for tumor treatment represents a well-established method. The use of photodynamic therapy (PDT), especially with Photofrin II, for tumor treatment is also known. Chemical modifiers enhancing the action of radiation therapy are well known and widely used in medicine. None of these compounds, however, is a selective radiosensitizer.


METHODS
Several series of animal experiments were performed. The highly differentiated human bladder cancer cell line RT4 was implanted subcutaneously in nude mice. The mice were injected 10 mg/kg Photofrin II and irradiated with 5 Gy.


RESULTS
Photofrin II has proved to be a chemical modifier of ionizing irradiation, enhancing the tumor doubling time (tumor growth) from 6.2 to 10.9 days in the control group with the use of irradiation and injection of porphyrin.


CONCLUSIONS
Photofrin II shows a high activity as radiosensitizer and, in the future, can be used as a selective radiosensitizer for tumor treatment with ionizing radiation.
Schaffer
M
M
Department of Radiation Oncology, University of Munich, Germany. m.schaffer@debitel.net
Schaffer
P M
PM
Corti
L
L
Sotti
G
G
Hofstetter
A
A
Jori
G
G
Dühmke
E
E
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D017323:Dihematoporphyrin Ether / Q000494:pharmacology*; D005260:Female; D006414:Hematoporphyrin Photoradiation; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy* / Q000473:pathology
D017323:Dihematoporphyrin Ether