| Backgrounds and Objective Gliomas are highly vascularized neoplasms, thereforeconsidered as sttong candidates for atiangiogenic theraPy Most investigators usedsubcutaneous tUInor model in glioma antiangiogenic Studies at present, and acquired someachievement. However, Read et al found that the reaction of intracranial and subcutaneousglioma to amiangiogenic theraPy wasn't complcte coincidence, it directs that the ootcome ofsubcutaneous tumor model doesn't comPletCly represent of orthotopic glioma. In addition, thereaction index of angiogenic inhibitor frequently adopted is the change of tumor volume invivo, othedrise the change needs so long a time that the reaction is difficult to be judged asearly as possible. Stereotactic radiosurgery (X-knife) is a new technique, which has been usedto treat some dieases such as glioma, but the discrepancy of reaction was large amongindividual, and early evaluated method is absent. Giannopoulou et al fOund that X-knife caninhibit angiogenesis of neoplasms, Which makes it possible for us to observe the change oItumor vessel to expect the reaction at early stage. MR peffosion weighed imaging (PWI) is anewly developed techique to be used to detect signa change before, during and after contrasmedium passing thrOugh region of interest (ROI) with fast imaging sequences, thus bloodkinetics parameters can be calculated. ln this subject, on the basis of establishing a rat C6brain-boor model, MR peffosion weighed imaging (PWI) was performed before and afterthe treatment with endostatin and X-knife, to study the value of PWI in predicting the earlyresponse of the tUmor to those theraPy, the mechanisms of X-kllife theraPy and the role olendostatin and X-knife in glioma treatInent were probed as well.Materials and Mcthods C6 glioma cells were stereotacic imPlanted into 30 SD ratsintracranially. At the l5 day after tUInor implantaion, X-trife was performed only once(n=6, central radiation dose of 25Gy ) or the recombinan human endostatin wassubcutaneously injected (5mg/kg/d, n=6; l0mg/kg/d, n=6; 20mg/kg/d, n=6; the treatment wasmaintained fOr 7 days), control was treated by saline(n=6). MR PWI was performed tomeasure relative cerebral blood volume (rCBV) and maximum signal reduction ratio (SRRmax)of the tUrnor and the normal cerebral parenchyma before and 48 hours after treatment, the Qvalue which represented the ratio of rCBV or SW. in tUInor to thOse in normal brainparenchyma was calculated, and tUmor volume was measured to decided the rate of triorgrowth suPpression compared with control. The relation between % Which was the change ofQ value and the rate of tUmor growth suppression or survival time was compared byregression analysis.Results All implaned Tats had boor growth illtracerebrally wtth very good shaPe andaccurate location. The average survival time of non-trC8ted group was 22.8 l 3.2 days with anaverage tuInor volume of 575.50 l l03.70nun3 at 22 days after implanation.The QrcBV was decreased 23.82% f 7.32%, 47.7l% l 7.94% and 5l.38% f 5.l2soaccording to thiee different doses resPectively and the change of Qsax.. was 22.88%I3.77%, 42.43% f 7.l l% and 42.88%i 5.96% 48hours ther endostatin treatInent. The rate oftUmor growth suPpression in these grOuPs were 28.29%f3.4l%, 53.77%l7.08% and59.46%l3.20% accordingly. Regression analysis demonstrated that RQ was significantlycorrelated with the rate oftUInor growth suPPression (rQroBv=0'86' rQsbo.=0'8l' P<0.0l).All rats were alive during endostatin theraPy, but they all died wimin 72hours as the withdrawofendostatin.Ras in X-bof e-treated grouP had survived fOr 26.3i l.0 days, of which QreBV axdQSRR.. was declined 35.79% t 3.38% and 26.0l% i 3.94% respectively. RQ&BV wassignificanly correlated with the survival time (rr0.82, P < 0.05 ), but RQsthe. hads't5significant correlation with the survival time(r=0.77, P > 0.05).Conclusions Both endostatin and X-knife could inhibit the angiogensis of...
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