Published in:
Tumori Journal, 88 (2002) 5, Seite 407-410
Language:
English
DOI:
10.1177/030089160208800511
ISSN:
0300-8916;
2038-2529
Origination:
Footnote:
Description:
Aims and background Ionizing irradiation is a well-established therapeutic modality for cancer. Photodynamic therapy (PDT), especially with 5-ALA and Photofrin, is highly effective in some tumor types. Chemical modifiers, so-called radiosensitizers, are used in order to increase the efficacy of radiotherapy. Most of the known and routinely used radiosensitizers are not tumor selective, so that the normal tissue reaction toxicity is also increased. In the present study we investigated whether a porphyrin derivative that is currently used as a tumor-photosensitizing agent in photodynamic therapy (PDT) may also act as a tumor-specific radiosensitizer. Materials and methods For our investigation we used Balb/c mice implanted with Lewis sarcoma and irradiated with 3 Gy combined with injection of 5-ALA or Photofrin at various concentrations before irradiation. Results 5-ALA had no effect as a radiosensitizer at any of the concentrations examined. Photofrin at a concentration of 5 mg/kg proved to be a chemical modifier of ionizing radiation, delaying tumor growth and reducing the overall tumor volume by about 50% after six days. Conclusion Photofrin has marked efficacy as a radiosensitizer and can be used in the future as a selective tumor radiosensitizer.