Application Of ASL In Delineation Of Radiotherapy Target For Patients With Glioma

Objective:To observe the effect of magnetic resonance artery spin labeling perfusion imaging(ASL)on the target area of brain glioma in the radiotherapy target area,so as to provide help for accurate imaging of the target area of the postoperative radiotherapy for the patients with glioma.Methods:A total of 9 cases of newly diagnosed glioma admitted to the Department of Oncology Radiology at the Affiliated Hospital of Qingdao University from March 2017 to May 2017were collected.It including seven males and two females,aged seventy-five years old and youngest forty-five years old.Age 54.7 years old,five cases of glioblastoma(WHO IV grade),two cases of anaplastic oligoastrocytoma(WHO III grade),one case of diffuse astrocytoma(WHO II grade),meningioma(WHO II grade)one case.CT,MR plain scan,and ASL perfusion examinations were performed before radiotherapy,and the images were transmitted to the Radiation Planning System(TPS)system for CT and MR fusion,CT and ASL fusion,and MR and ASL fusion.The fusion inspection images are respectively drawn to the radiotherapy target area.The TPS system is used for the design of the injection field and the dose distribution calculation,and the three target CTV are obtained.The maximum volume and mean dose of the PTV,The maximum volume and mean dose of the brain stem,left and right optic nerves,and optic chiasm.SPSS 22.0 statistical software was used for statistical analysis.SPSS 22.0 statistical software was used for statistical analysis.The measurement data of each group were described by mean±standard deviation(x±s).The difference in volume and dose between different groups was analyzed by paired t test.P<0.05 was statistically significant.Results:The clinical target volume(CTV),CT is(184.85±67.25)cm~3,MR is(153.95±51.65)cm~3,ASL is(14.30±1.40)cm~3,CT is 0.233 compared with MR,MR is compared with ASL.The P value was 0.000.The P value of CT and ASL was 0.000.Compared with ASL,MR and ASL,there was a statistically significant difference between CT and ASL.There was no statistical significance between CT and MR;PTV was the target volume,CT was(242.65±81.75)cm~3,MR was(211.50±68.70)cm~3,ASL was(23.60±10.00)cm~3,P was 0.145 when compared with MR,P was 0.000 when MR was compared with ASL,and CT was compared with ASL.The P value was 0.000.There was a statistically significant difference between CT and ASL,and between MR and ASL.There was no significant difference between CT and MR.The maximum brain tissue dose(brain max dose)was CT(6035±765)cGy,MR.It is(6025±665)cGy,and ASL is(6110±690)cGy.The P value of CT is 0.757 compared with MR.The P value of MR is 0.310 compared with ASL.The P value of CT is 0.402 compared with ASL.CT and MR There was no statistically significant difference between CT,ASL,MR,and ASL;mean dose(brain mean dose),CT was(2270±510)cGy,MR was(2365±485)cGy,and ASL was(19%).05±695)cGy,CT and MR compared P value of 0.627,MR compared with ASL P value of 0.122,CT and ASL P value of 0.038,CT and ASL were statistically significant,CT and MR,MR There was no statistically significant difference compared with ASL.Brain stem,optic chiasm,optic nerve,and other organs at risk of maximal dose and average dose did not differ between groups(P>0.05).Conclusion:ASL perfusion technique can effectively identify postoperative residual lesions,identify the suspicious lesions in CT and MR,and provide radiological support for radiotherapists to accurately outline the radiotherapy target region.The use of CT,MR,and ASL in combination with the radiotherapy target area can reduce the average dose of normal brain tissue,reduce the risk of organ exposure to radiation,and reduce radiation damage to brain tissue and endangered organs.