Feasibility of Photofrin II as a radiosensitizing agent in solid tumors - Preliminary results

Background: Photofrin II has been demonstrated to serve as a
specific and selective radiosensitizing agent in in vitro and in
vivo tumor models. We aimed to investigate the feasibility of a
clinical application of Photofrin II. Material and Methods: 12
patients were included in the study (7 unresectable solid tumors of
the pelvic region, 3 malignant gliomas, 1 recurrent oropharyngeal
cancer, 1 recurrent adenocarcinoma of the sphenoid sinus). The dose
of ionizing irradiation was 30-50.4 Gy; a boost irradiation of 14
Gy was added for the pelvic region. All patients were intravenously
injected with 1 mg/kg Photofrin II 24 h prior to the commencement
of radiotherapy. Magnetic resonance imaging (MRI) controls and in
some cases positron emission tomography (PET) were performed in
short intervals. The mean follow-up was 12.9 months. Results: No
major adverse events were noted. Minor adverse events consisted of
mild diarrhea, nausea and skin reactions. A complete remission was
observed in 4/12 patients. A reduction in local tumor volume of
> 45% was achieved in 4/12 patients. Stable disease was observed
in 4/12 patients. 1 patient showed local disease progression after
5 months. Conclusion: The early follow-up results are encouraging
regarding the feasibility of the application of Photofrin II as a
radiosensitizing agent.