Dose Distribution Of Afterloading Intracavitary Brachytherapy For Cervix Carcinoma

Purposes:To investigate the therapeutic plan of afterloading intracavitary brachytherapy for cervix carcinoma through making use of female pelvis afterloading graph,to make thorourh inquiry of the theoretic different of point B,reference-point rectal and bladder dose between one-tube -applicator and three-tube-applicator;To observe the therapeutic plan of afterloading intracavitary brachytherapy for cervix carcinoma through making use of reconstructed-CT-based image,to make thorourh inquiry of the practical different of point B,original tumor,reference-point rectal and bladder dose between one-tube-applicator and three-tube-applicator,as well as the differences volume of 1000cGy,750cGy,500cGy,200cGy isodose curves between one-tube-applicator and three-tube-applicator;To investigate dose distribution of afterloading intracavitary brachytherapy in the vacuum and the filling status of the bladder,to find out the influence of the status of the bladder on dose distribution.Methods:Making use of female pelvis afterloading graph,we assumed point A dose is 750cGy,canculated point B,reference-point rectal and bladder dose by one-tube-applicator and three-tube-applicator afterloading therapeutic plans;assumed point A dose is 750cGy,brachytherapy treatment planning was performed in 5 patients with cervix carcinoma by reconstructed-CT-based image,we canculated point B,original tumor,reference-point rectal,reference-point bladder and bottom of bladder dose by two aflerloading therapeutic plans,as well as volume of 1000cGy,750cGy,500cGy,200cGy isodose curves;assumed point A dose is 750cGy,brachytherapy treatment planning was performed in 5 patients with cervix carcinoma by reconstructed CT-based image,we canculated point B,original rumor,reference-point rectal and bladder dose in the vacuum and the filling status of the bladder,as well as reference-point bottom of bladder dose in the filling status of the bladder.All the data was processed through the software SPSS11.0.Results:1.In theory,point B dose was 26.25%(196.850±3.328 cGy) of point A's in one-tube-applicator plan and was 27.15%(203.612±5.074cGy) of point A's in three-tube-applicator plan(P=0.01 );RP's was 32.30%(242.245±18.874cGy),29.96%(224.670±13.763cGy)(P=0.023);R₁'s was 27.11%(203.328±11.695cGy),25.87%(194.055±9.704cGy)(P=0.023);R₂'s was 22.09%(165.663±7.989cGy),21.36%(160.233±7.123cGy)(P=0.034);R₃'s was 18.61%,(139.610±5.245cGy),17.23%(129.188±5.196 cGy)(P=0.001);BL's was 36.45%(247.898±22.715cGy),28.37%(212.773±24.352cGy)(P=0.001),respectively.2.In practice,point B dose was 26.43%(198.1750±8.7610cGy) of point A's in one-tube-applicator plan and was 26.77%(200.7763±8.3207cGy) of point A's in three-tube-applicator plan(P=0.545);point Y dose was 1716%(12869.21±3564.82 cGy),1496%(11223.35±4161.25cGy)(P=0.408)of point A's,;R₁'s was 80.68% (605.1130±93.8205cGy),61.02%(457.6480±40.5043cGy)(P=0.000);R₂'s was 81.56% (611.6710±115.0840cGy),60.60%(454.5210±51.7244cGy)(P=0.000) of point A's; RP's was 78.52%(588.9130±25.4134 cGy),68.83%(516.2140±53.2352cGy)(P=0.002) of point A's:R₃'s was 60.72%(455.3820±20.9903cGy),50.91%(381.7930±10.7421cGy) (P=0.000) of point A's;R₄'s was 49.79%(373.4110±16.8815 cGy),44.75%(335.6170±20.8150 cGy)(P=0.001) of point A's;BL's was 81.03%(607.7300±24.0790cGy),76.24 %(571.8070±33.1536cGy)(P=0.035) of point A's;bx's was 124.88%(936.6120±25.2966cGy ),111.99%(832.3880±17.4784cGy)(P=0.013) of point A's,respectively. The volume in 1000cGy isodose curves was 45.000±9.447cm³ in one-tube-applicator and was 63.075±10.114cm³(p=0.000)in three- tube- applicator;The volume in 750cGy isodose curves was 80.864±15.912cm³,98.136±17.319cm³(P=0.000);The volume in 500cGy isodose curves was 162.240±10.068cm³,180.200±18.048cm³(P=0.001);The volume in 200cGy isodose curves was 605.176±16.447cm³,612.104±15.64cm³ (P=0.088),respectively.3.Point B dose was 26.17%(196.2475±8.0306cGy) of point A's in the vacuum status of the bladder and was 27.03%(202.7038±7.8452cGy)(P=0.182) in the filling status of the bladder;point Y dose was 1509%(11317.08±4631.03 cGy),1703% (12775.48±2984.98cGy)(P=0.499) of point A's;Paired-Samples T Test referencepoint R₁,R₂,RP,R₃,R₄ between the vacuum and the filling status of the bladder respectively,each was significant;reference-point BL dose was 76.31%(572.3070±30.0000cGy),80.96%(607.2300±28.6062cGy )(P=0.043) of point A's,respectively; contrasting reference-point BL dose and reference-point bx dose,Value P was 0.000.Conclusion:1.In theory,using the three-tube-applicator afterloading brachytherapy for cervix carcinoma is suprior to the one-tube-applicator's and can reduce reference-point rectal and bladder dose through making use of female pelvis afterloading graph.2.In practice,making use of the three-tube-applicator afterloading therapy for cervix carcinoma can reduce reference-point rectal and bladder dose contrast to using the one-tube-applicator's,but no significant in poit B dose.3.Making use of the three-tube-applicator afterloading brachytherapy for cervix carcinoma is well in using the one-tube-applicator's in volume of 750cGy isodose curves.The more far away the center,the little distinguish in volume of isodose curves between the three-tube-applicator and the one-tube-applicator.4.There is no significant in poit B,Y,reference-point rectal dose between in the vacuum and in the filling status of the bladder,but reference-point BL dose is higher in the filling status of the bladder. 5.Reference-point bx dose is far more than reference-point BL dose in the filling status of the bladder.