Photodynamic therapy of colorectal cancer using a new light source: from in vitro studies to a patient treatment.

Abstract

PURPOSE:

Photodynamic therapy (PDT) is a relatively new alternative modality for palliation of rectal cancer. Current source of light for PDT are laser systems that are expensive and not necessarily needed for PDT. We evaluated a new nonlaser light source for PDT, Versa-Light.

METHODS AND RESULTS:

In vitro PDT--CT26 murine colon carcinoma cells were incubated with aluminum phthalocyanine (AlPcS4) for 48 hours and subjected to photoradiation using Versa-Light, and viability was assessed. There was a significant decrease in viability of treated cells compared with controls. In vivo PDT--BALB/c mice were injected either subcutaneously or intrarectally with CT26 cancer cells. IP AlPcS4 (2.5 mg/kg) was injected when tumors were visible. After 24 hours, mice were subjected to photoradiation. Massive tumor necrosis in response to PDT was observed. PDT also prolonged survival of treated mice. Patient treatment--A 70-year-old woman with recurrent local rectal carcinoma received intravenous Photofrin II (2 mg/kg). After 48 and 96 hours, she was subjected to direct photoradiation. After the first light session, there was complete macroscopic disappearance of the tumor. Biopsies up to 10 weeks after the treatment showed no cancer cells in the treated area. Sixteen weeks later, a randomized biopsy from previous tumor site showed carcinoma cells.

CONCLUSIONS:

We believe that Versa-Light, is a good light source for PDT. It was effective in both in vitro and animal studies. It can also be safely used for clinical PDT.

• Authors: H Kashtan, R Haddad, Y Yossiphov, S Bar-On, Y Skornick
• Journal: Diseases of the colon and rectum (Dis Colon Rectum) Vol. 39 Issue 4 Pg. 379-83 (Apr 1996) ISSN: 0012-3706 [Print] United States
• PMID: 8878495 (Publication Type: Case Reports, Journal Article)

Chemical References

• Antineoplastic Agents
• Indoles
• Organometallic Compounds
• aluminum phthalocyanine
• Dihematoporphyrin Ether
• Aluminum

Topics

• Aged
• Aluminum (therapeutic use)
• Animals
• Antineoplastic Agents (therapeutic use)
• Colorectal Neoplasms (drug therapy)
• Dihematoporphyrin Ether (therapeutic use)
• Female
• Hematoporphyrin Photoradiation (instrumentation, methods)
• Humans
• In Vitro Techniques
• Indoles (therapeutic use)
• Mice
• Mice, Inbred BALB C
• Neoplasm Transplantation
• Organometallic Compounds (therapeutic use)
• Photochemotherapy (instrumentation, methods)
• Tumor Cells, Cultured