Five patients with a pleural malignancy (four malignant mesotheliomas and one localized low grade carcinoid) were treated with maximal surgical removal of the tumor followed by intraoperative adjuvant photodynamic therapy (PDT). The additional photodynamic treatment was performed with light from a high power diode laser, and meta-tetrahydroxy phenylchlorin as the photosensitizer. The position of the light delivery fiber was adjusted to achieve optimal light distribution, taking account of reflected and scattered light in this hollow cavity.
There was no 30-day post-operative mortality and only one patient suffered from a major complication (diaphragmatic rupture and and effusion of blood within the pericardium). The effect of the adjuvant PDT was monitored by examination of biopsies taken 24 hours after surgery under thoracoscopic guidance. Significant damage, including necrosis, was observed in the marker lesions with remaining malignancy compared with normal tissue samples, which showed only an infiltration with leukocyte cells and edema of the striated muscle cells. Of the five patients treated, four are alive with no signs of recurrent tumor, with a follow-up of nine to eleven months.
One patient was diagnosed as having a tumour dissemination in the skin around the thoracoscopy scar and died of abdominal tumour spread. Light delivery to large surfaces for adjuvant PDT is feasible in a relatively short period of time (one hour). This protocol is well suited for adjuvant treatment with PDT in malignant pleural tumours. Baas, et al., British Journal of Cancer, 76(6):819-26, 1997.
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