Comparative study of peritumoral area of high-and low-grade astrocytoma with CTP

Objective: To probe the difference of CT perfusion(CTP) parameters of peritumoral area between high-and low-grade intracranial astrocytoma,and to explore the pathologic basis.Methods: Thirty cases of intracranial asytrocytoma,proven by surgery and pathologic examination,including 10 cases of low-grade tumors(WHO grade Ⅰ and Ⅱ) and 20 cases of high-grade tumors,were examined for precontrast CT,postcontrast CT and CTP.We mearsured the CTP parameters,including CBF,CBV,MTT and PS at the area of 1cm from the margin of enhancement or the margin of the non-enhanced lesion.Paired t test was made for comparison of the CTP parameters of high-and low-grade astrocytoma with the software SPSS 17.0 for refering CTP and postcontrast CT maps,biopsy was made before incision.And the pathologic findings of peritumoral area was observed.Results: CBF,CBV,MTT and PS of peritumoral area of high-grade astrocytoma were higher than those of low-grade astrocytoma.The CBF,CBV,MTT and PS value,peritumoral area of high-grade astrocytoma were(50.05±14.05)ml/(min·100g),(3.50±1.79)ml/100g,(5.84±2.95)s and(1.23±1.75)ml/(min·100g) respectively.And low-grade astrocytoma were(25.20±8.67)ml/(min·100g),(1.61±0.68)ml/100g,(4.83±1.63)s and(0.33±0.27)ml/(min·100g) respectively.There were significant difference of CBF and CBV between high-and low-grade astrocytoma(P0.05).But no obvious difference was found for MTT and PS between high-and low-grade astrocytoma(P0.05).Discrete tumor cells were detected in peritumoral area for both high-and low-grade astrocytoma.Whereas more neoplastic cells and vascularity were found in peritumoral area of high-grade astrocytoma.Conclusion: Because of different pathologic basis,there was significant distinction of CTP parameters of peritumoral area between high-and low-grade astrocytoma.This distinction is due to their different findings on pathology.