Photodynamic therapy for the hypercalcemic type of the small cell carcinoma of the ovary in a mouse xenograft model

Objective. The hypercalcemic type of the small cell carcinoma of the ovary (HTSCCO) is a rapidly fatal ovarian tumor in young women. Photodynamic ther apy (PDT) induces selective necrosis to malignant tissues. The aim of this study was to determine the sensitivity of the HTSCCO to PDT in a mouse xeno graft model. Methods. Tumors were obtained from a patient with a HTSCCO and were transpl anted into nude mice. Following photosensitization with m-THPC, either supe rficial or interstitial laser light was administered to the tumors. Necrose s were measured by morphometry. Serum calcium levels were determined prior to and after PDT. Results. Superficial irradiation of m-THPC sensitized tumors showed over th ree times more necrosis than control tumors (P = 0.037). Interstitially irr adiated tumors showed over seven times more necrosis than control tumors (P = 0.0012). All animals showed a highly significant hypercalcemia prior to PDT (P < 0.0001). PDT induced a significant decrease in serum calcium level s (P = 0.0297). Conclusion. This study suggests that PDT may be of therapeutic value for th e HTSCCO, (C) 1999 Academic Press.