| Objectives: To evaluate the therapeutical effect and the safety of single photodynamic therapy (PDT) ,which use hematoprophyrin derivative (HPD) produced by the institut of Chinese Academy of Science,and provide experimental director for human brain tumor PDT.Methods: 72 New Zealand adult rabbits were divided randomly into normal control group(3), pseudo- operation group(9),VX2 carcinoma group(24), and PDT group(36). The rabbits in normal control group were injected Evans blue 1 hour before sacrificed and histological examinations. The rabbits in the pseudo- operation group were injected 0.5mg/kg HPD 24 hours before craniotomy and exposure to the light. The ICP was monitored every day and the specimens of brain were obtained in day 1,3,5 after light irradiation. The brain water contents in the remained cerebral hemispheres were measured by dry-wet weight method. One 1.5×1.5×1.5mm3 VX2 carcinoma mass was implanted by craniotomy in each rabbit's brain in the VX2 carcinoma group and PDT group. The growth of implanted tumor was observed by B-mode ultrasonography. 24 rabbits in VX2 carcinoma group without any therapy, were examinated the ICP and CT from 16th day after tumor implanted. Rabbits were sacrificed in day 13,17,19,21,23 and 25 respectively for pathology observations. The brain water contents in the remained cerebral hemispheres were measured. The survival time was observed in 6 rabbits. 36 rabbits in PDT group were proceeded photodynamic therapy which referenced to the neurosurgery department of Royal Melbourne Hospital in Australia for clinical brain tumor therapy in the 16th day after tumor was implanted. The experimental rabbits were injected 0.5 mg/kg HPD from oto-margin veins 24 hours before light irradiation. The light wave-length was 628 nm,the out-put rate was 500 mW, the total capacity was 240 J/cm2 and the time of irradiation was adjusted according to the tumor volume. ICP was monitored every day and CT proceeded in day 3,5,9 after PDT. Specimens of tumor and brain -adjacent - to - tumor (BAT) were proceeded pathological examinations in day 1,3,5,7 and 9 after irradiation. The brain water contents in the remained cerebralhemispheres were measured. The survival time was observed in 6 rabbits.Results:1. All rabbits survived after VX2 carcinoma implantation. Neurologic deteriorations as anorexia, weakness, and hemiplegia appeared from 21 days after implantation in VX2 group. Rabbits in PDT group lost appetite and demonstrated weakness after PDT, but turned better 3 to 4 days later and turned normal by day 5.The median survival time was 24.5 days and the average was 24.8 days for VX2 group, the median was 47.5 days and the average was 63.8 days for PDT group.2. After 17 days of tumor implantation, the tumors of VX2 group showed a brown coloration and appeared like fish meat and metastasized to the liver. In PDT group,the tumors showed hemorrhagic necrosis immediately after treatment and were absorbed gradually 3 days later.The log-transformed plots of tumor volume in VX2 group approximate a straight line. The tumor volume in PDT group stopped increasing after PDT.3. The ICP in VX2 group increased rapidly on day 17 to 21 after tumor implantation, and which in PDT group increased immediately after therapy and elevated to the top in 24 hours ,then dropped gradually to normal in 6 days.The brain water content in VX2 group also increased rapidly during day 17 and 21 after tumor implantation and arrived 82.021±0.690％ on day 25. In PDT group,it increased after therapy and elevated to 81.087±0.966％ in 24 hours ,then dropped gradually to normal by day 7.4. Contrast enhancement at the tumor was present in images of 21 days after tumor implantation of VX2 group, but was not present in PDT group.Evans blue extravasation appeared within and around the tumor after day 17 in VX2 group. In PDT animals sever extravasation on the surface of the tumor and the around brain was detected on day 1 after PDT, decreased gradually on day 3,and disappeared by day 5. 5. The... |
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