Comparison of IPSA and HIPO inverse planning optimization algorithms for cervical cancer intracavitary/interstitial brachytherapy / 中华放射医学与防护杂志

ABSTRACT

Objective To compare the difference of dose distribution between inverse planning simulated annealing (IPSA) and hybrid inverse treatment planning and optimization (HIPO) in 3D brachytherapy plan of cervical cancer,and to provide evidence for selection of reverse planning optimization method for cervical cancer brachytherapy.Methods From Dec 2016 to May 2017,totally 43 cases of patients with cervical cancer radical surgery were selected.Original IPSA brachytherapy treatment plan optimization was applied to all cases.Based on the information of original image,IPSA and HIPO plans were established according to the same initial conditions.Parameters of Dg0,D100,V100％,Homogeneity Index (HI),and conformal index (CI) of the bladder,rectum and sigmoid D2 cm3 data for High-Risk Clinical Target Volume (HR-CTV) were assessed.Results There was no statistically significant difference in D90,D100 and CI for HR-CTV between the two groups.But the V100％ of HR-CTV in HIPO group was significantly higher than that in IPSA group [(87.72 ±0.49)％ vs.(85.01 ± 0.55)％,t =2.54,P ＜0.05].Furthermore,HI in HIPO group was (0.51 ±0.08),which was higher than that in IPSA group (0.42 ± 0.06),and the difference was statistically significant (t =3.02,P ＜ 0.05).Compared with IPSA,bladder D2 cm3 and rectum D2 cm3 [(3.04 ± 0.37) Gy] for HIPO plan were lower [(3.42 ± 0.17) Gy vs.(3.57 ± 0.28) Gy,(3.04 ± 0.37) Gy vs.(3.57 ± 0.28) Gy],which had reached statistical significance (t =0.27,0.19,P ＜ 0.05).There was no statistical significance in the D2 cm3 dose of sigmoid.Conclusions In the treatment of cervical cancer,better target area HI and less irradiated dose of bladder and rectum can be obtained by HIPO optimization than IPSA optimization.