Objective:To design two kinds of intensity modulated radiotherapy (IMRT) plans with different radiation field distributions,and to compare the dose differences of that at the dose of target region and organs at risk (OAR) for middle and lower esophageal cancer,so as to provide a reference for the design of IMRT plan. Methods:The data of 17 patients with middle and lower esophageal cancer who received IMRT at Shangluo Central Hospital from November 2022 to May 2023 were retrospectively analyzed. IMRT plans with different radiation fields for Plan 1 and Plan 2 were designed for each patient. The angles of radiation field for Plan 1 were 0°,80°,120°,160° and 200°,and those for Plan 2 were 30°,130°,180°,230° and 330°,respectively. The prescribed dose to the planning target volume (PTV) was 60 Gy/30 F. The differences in dosimetric parameters between the two plans were compared. Results:There were no statistically significant differences in the dose parameters of 2％,98％,50％ target dose (D2％,D98％,D50％),homogeneity index (HI),conformity index (CI) and monitor unit between the two groups (P>0.05). There were no significant differences in V5 of dual lungs,the mean dose (Dmean) of heart,and the maximum dose (Dmax) of spinal-cord between two groups (P>0.05). The volume percentage (V10,V20,V30) of dual lungs received radiation doses of 10,20 and 30 Gy,and the mean dose (Vmean) of lung in the Plan1 group reduced respectively 7.44％,21.16％,10.09％ and 5.31％ than those in the Plan2 group,and the differences of them were statistically significant (t=-5.845,-7.729,-2.247,-3.960,P<0.05). Heart V10 and V20 in the Plan1 group decreased respectively by 7.23％ and 5.78％,with statistical significance (t=-4.376,-3.523,P<0.01),while V30 and V40 of Plan 1 increased respectively by 2.7％ and 4.92％,without statistical significance (P>0.05). There was no significant difference in heart Dmean between the Plan1 group and the Plan2 group (P>0.05). Conclusion:Both two methods of distribution field can meet the clinical requirements,and Plan1 has more advantages in protecting organs at risk under the premise of meeting the requirements of target region.

Objective:To design two kinds of intensity modulated radiotherapy (IMRT) plans with different radiation field distributions,and to compare the dose differences of that at the dose of target region and organs at risk (OAR) for middle and lower esophageal cancer,so as to provide a reference for the design of IMRT plan. Methods:The data of 17 patients with middle and lower esophageal cancer who received IMRT at Shangluo Central Hospital from November 2022 to May 2023 were retrospectively analyzed. IMRT plans with different radiation fields for Plan 1 and Plan 2 were designed for each patient. The angles of radiation field for Plan 1 were 0°,80°,120°,160° and 200°,and those for Plan 2 were 30°,130°,180°,230° and 330°,respectively. The prescribed dose to the planning target volume (PTV) was 60 Gy/30 F. The differences in dosimetric parameters between the two plans were compared. Results:There were no statistically significant differences in the dose parameters of 2％,98％,50％ target dose (D2％,D98％,D50％),homogeneity index (HI),conformity index (CI) and monitor unit between the two groups (P>0.05). There were no significant differences in V5 of dual lungs,the mean dose (Dmean) of heart,and the maximum dose (Dmax) of spinal-cord between two groups (P>0.05). The volume percentage (V10,V20,V30) of dual lungs received radiation doses of 10,20 and 30 Gy,and the mean dose (Vmean) of lung in the Plan1 group reduced respectively 7.44％,21.16％,10.09％ and 5.31％ than those in the Plan2 group,and the differences of them were statistically significant (t=-5.845,-7.729,-2.247,-3.960,P<0.05). Heart V10 and V20 in the Plan1 group decreased respectively by 7.23％ and 5.78％,with statistical significance (t=-4.376,-3.523,P<0.01),while V30 and V40 of Plan 1 increased respectively by 2.7％ and 4.92％,without statistical significance (P>0.05). There was no significant difference in heart Dmean between the Plan1 group and the Plan2 group (P>0.05). Conclusion:Both two methods of distribution field can meet the clinical requirements,and Plan1 has more advantages in protecting organs at risk under the premise of meeting the requirements of target region.

Objective:To study the dosimetry effects of differently selected values of control point(CP)in Monaco radiotherapy planning system on dynamic intensity modulated radiation therapy(dIMRT)for esophageal cancer of middle and lower segment.Methods:Thirteen patients with esophageal cancer at middle and lower segment who received dIMRT in Shangluo Central Hospital from January to June 2023 were selected.In the Monaco radiotherapy planning system,nine groups of dIMRT plans were designed for each patient according to the 9 kinds of CP limit values(10,20,30,40,50,60,70,80 and 90).There were not changes in other optimized parameters except CP parameter.The differences of the dosimetry between target region and organs at risk(OAR)included lung,heart and spinal cord were analyzed.Results:With the increase of the CP limit value,the maximum dose of the target region which was radiation dose(D2%)of 2%volume of target region,the mean dose,which was radiation dose(D50%)of 50%volume of target region,and the homogeneity index(HI)appeared a trend of gradual stability after reduction,and the radiation dose(D98%)of 98%volume of target region which was the minimum dose of target region and the conformance index(CI)appeared a trend of gradual stability after increase.There was not significant in each dose indicator of OAR(P>0.05).The variation ranges of lung at 5,10,20,30 Gy dose(V5,V10,V20 and V30)were respectively 1.13%,0.75%,0.29%and 0.19%,and the maximum deviation of mean dose(Vmean)of lung was 18.7 cGy.The variation ranges of V10,V20,V30 and V40 in the heart were respectively 2.2%,1.23%,1.39%and 1.12%,and the maximum deviation of Vmean in the heart was 63.85 cGy,and the maximum deviation of Dmax in the spinal-cord was 70.78 cGy.There were statistically significant differences in the actual CP number(CPs),execution time(DT)of plan,and ratio value of machine unit(MU)of the complexity of plan to CPs(MU/CPs)among the plans of 9 groups(F=2.857,25.145,135.467,P<0.05),respectively.Conclusion:In the dIMRT plan of esophageal cancer of middle and lower segment,the maximum CP value is set at between 40-50,which can reduce the optimization time of the plan,the number of subfields and the treatment time of patients under the premise of meeting the dose of the target region and the OAR.

EZH2 is over-expressed in human colon cancer and is closely associated with tumor proliferation, metastasis and poor prognosis. Targeting and inhibiting EZH2 may be an effective therapeutic strategy for colon cancer. 3-Deazaneplanocin A (DZNep), as an EZH2 inhibitor, can suppress cancer cell growth. However, the anti-cancer role of DZNep in colon cancer cells has been rarely studied. In this study, we demonstrate that DZNep can inhibit the growth and survival of colon cancer HCT116 cells by inducing cellular senescence and apoptosis. The study provides a novel view of anti-cancer mechanisms of DZNep in human colon cancer cells.