ABSTRACT
Objective To investigate the clinical application of multi-criteria optimization (MCO) in radiotherapy for cervical cancer. Methods A retrospective analysis was performed on the clinical data of 15 patients who received radiotherapy for cervical cancer in Shandong Cancer Hospital and Institute. A fixed field intensity-modulated radiotherapy plan was re-optimized using 9 fields on the Halcyon platform, with the goal of achieving a target coverage of > 95% and the lowest dose to organs at risk. The plan was refined until it reached the goal (Plan I) and was calculated using MCO to reach the goal (Plan MI), and the quality assurance verification was performed. The Wilcoxon rank-sum test was used to compare design time, target coverage, radiation dose to organs at risk, and number of monitor units between the plans. Results Both plans met the clinical requirements. There were no significant differences in target dose indices between Plan I and Plan MI (P > 0.05). Plan MI reduced the maximum dose to the small intestine by 0.51 Gy (P < 0.05). There was no significant difference in dose coverage between the bladder and the rectum (P > 0.05). Compared with Plan I, Plan MI saved 34.04 min in design time (P < 0.05). Conclusion MCO can improve the optimization and adjustment, significantly shorten the design time, and improve the efficiency of the plan.
ABSTRACT
Objective To study the novel methods of VMAT planning based dose volume histogram ( DVH) optimization, evaluated the dosimetry and planning efficiency in VMAT planning for Esophageal Carcinoma. Methods Twelve Esophageal carcinoma patients were enrolled in this study. The conventional VMAT planning as the reference, using multi?criterion optimization DVH ( MCO?DVH ) and overlapping volume histogram prediction DVH ( OVH?DVH ) two different methods to get ideal objectives function for informing VMAT plans, Then evaluate the dosimetric, planning efficiency for all new VMAT plans. The difference between the paired t?test groups. Results The two VMAT plans based DVH objective function can meet the clinical needs. Compared with the conventional VMAT plan, Conformity index ( CI ) and Homogeneity index ( 0. 77 vs. 0. 72, P=0. 017 and 0. 10 vs. 0. 12, P=0. 047 ) is better in DVH informed plans;lung V5 and spinal cord V50 are better in MCO?DVH informed plan (54. 66 vs.60. 23,P=0. 013 and 0. 98 vs.0. 49,P=0. 037).Furthermore,the DVH informed plans had higher planning efficiency (8. 2 vs. 19. 5,P=0. 023) . Conclusions DVH Objective informed VMAT Planning can achieve clinical needs with much uniform dose to target,lower OAR dose and higher planning efficiency.