| Objective: Prospective analysis of the positioning error of cervical cancer in image-guided radiotherapy(IGRT)and its effect on the target area and endangered organ dose changes,at the same time evaluate the clinical treatment efficacy and safety,and explore the significance of IGRT in cervical radiotherapy.Methods: Sixty patients with cervical cancer who underwent radical radiotherapy in our department were collected.Among them,30 patients underwent IGRT were the observation group.Each patient in this group was guided by the image once a week.,Y-axis(head and foot),Z-axis(ventral back)errors and analyze their distribution.The CBCT image before the correction of the first positioning error was automatically matched with the localized CT,and the effect of the positioning error on the target area and the dose of endangered organs was compared and analyzed.During the same period,30 patients who did not undergo IGRT were selected as the control group,and the shortterm efficacy and radiotherapy-related toxic and side effects of the two groups were compared and observed.Results:(1)The X,Y,and Z axis error values of 30 patients with cervical cancer undergoing IGRT were(0.23 ± 0.153),(0.67 ± 0.679),and(0.077 ± 0.082),showing head and foot directions(Y axis)The position error is the largest;there are still errors in the X,Y,and Z axes after rematching,which are(0.020 ± 0.041),(0.083± 0.075),and(0.043 ± 0.057).The comparison shows the swing in all directions after rematch The bit error value was significantly smaller than before matching(P<0.05);(2)Comparison of dose parameters of target area and crisis organs before and after correction of 30 patients with IGRT showed no statistical difference before and after GTV correction(P> 0.05);The differences between D98,D95,and D2 before and after CTV correction were statistically significant(P <0.05).The dose of CTV exposure after correction was significantly higher than before correction;the differences between D98,D95,D50,D5,D2,and V95 before and after PTV correction were statistically significant.(P <0.05),the radiation dose of PTV after correction was significantly higher than before correction;the D5 difference in right femoral head was statistically significant(P <0.05),and the radiation dose of right femoral head after correction was significantly lower than before correction.(3)CR,PR,SD,and PD of 30 patients in theobservation group who underwent IGRT were 22(73.3%),7(23.3%),1(3.3%),and 0(0%),with objective remission.The rate(CR + PR)was 96.67%;CR,PR,SD,and PD in 30 patients without IGRT were 19(63.3%),9(30%),2(6.67%),0 Case(0%),the objective response rate(CR + PR)was 93.33%;there was no significant difference in data between the two groups(P> 0.05);(4)comparison of toxic and side effects between the two groups with and without IGRT:(1)30 patients received IGRT In the observation group,I,II,III,and IV bone marrow suppression occurred in 10(33.33%),13(43.33%),2(6.7%),and 0(0%)patients;30 patients did not undergo IGRT.The control group of patients with grade I,II,III,and IV bone marrow suppression were 10(33.33%),12(40%),4(13.33%),and 1(3.33%).Although there was no statistical difference in the incidence of myelosuppression between the two groups(P> 0.05),the number of myelosuppression of the control group> 2 or higher was more.(2)There were 8 cases(26.67%)and 1 case(3.33%)of Grade 1 and Grade 2 acute radiation cystitis in the observation group that received IGRT.Grade 1 and Grade 2 acute radiation bladder occurred in the control group without IGRT.The inflammation was 12cases(40%)and 2 cases(6.67%).There were no cases of grade 2 or higher in both groups.There was no significant difference in the incidence of acute radioactive cystitis between the two groups(P> 0.05),but there were more cases of mild radioactive cystitis in the control group;(3)30 cases of IGRT observation group had acute radioactive cystitis grade 1 and 2 Enteritis was reported in 16 cases(53.33%)and 4 cases(13.33%);30 cases of the control group without IGRT had 19 cases(63.33%)and 6 cases(20%)of grade 1 and 2 acute radiation proctitis,respectively..There were no cases of grade 2 or higher in both groups.There was no significant difference in the incidence of acute radiation proctitis between the two groups(P> 0.05),but the number of patients with mild acute radiation proctitis in the control group was higher;(4)30 cases of IGRT observation group had advanced radiation prostatitis There were 3 cases(10%)and 0cases(0%)respectively;30 cases of the control group without IGRT developed grade 1and 2 advanced radiation proctitis in 8 cases(26.67%)and 1 case(3.33%).There were no cases of grade 2 or higher in both groups.The incidence of advanced radiation proctitis in the observation group was significantly lower than that in the control group,and the difference was statistically significant(P <0.05).Conclusions:(1)There is a positioning error in the staged treatment of cervical cancer.The head and foot direction difference is the largest in the translation direction.Image-guided radiotherapy can reduce the error between the staged treatments.(2)Theactual target area before the correction of the positioning error is corrected There are few or missing exposures,which increase the exposure to endangered organs.The application of IGRT can maximize the target dose and limit the maximum exposure to endangered organs.(3)The short-term efficacy of image-guided radiotherapy for cervical cancer is good.The side effects of radiotherapy are small,especially the incidence of toxic side effects associated with late radiotherapy is significantly reduced. |
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