Influence of Segment Shape optimization parameter in radiotherapy Volumetric Modulated Arc Therapy planning of Cervical Cancer

Document Type : Original Paper


1 AIAS,Amity University,Noida,U.P.,India

2 Netaji Subhas Chandra Bose Cancer Hospital,3081,Nayabal




Aim: The aim of this study is to find out the influence of different Segment shape optimization (SSO) parameters in radiotherapy Volumetric Modulated Arc therapy (VMAT) planning of Cervical Cancer and to find out the optimized value for cervical cancer patients.

Material & Method: It was a retrospective study of 20 Ca cervix patients. Every patient had six plans named SL1, SL5, SL10, SL15, SL20, and NSL. In each case, the value of the shaping loop will be changed during the VMAT plan, while the other optimization parameters and constraint functions will remain the same in each case. All dosimetric parameters have been measured and analyzed for PTV and OAR dose, MU, memory, PDT, and GPR for comparison purposes.

Result: In NSL cases, the PTV dose derived from the DVH did not meet the clinical standards D95% = 86.8% (<95%) with a poorer homogeneity index (HI = 0.2). As the SL value increases, plan quality increases, monitor units increase slightly and plan delivery time decreases while there is a parallel increase in memory consumption. There is no statistical difference in target dose and OAR dose between the SL5 and SL1 plans (P > 0.05) compared with the other groups. SL5 has the least plan memory compared to other SL values.

Conclusion: Based on the plan quality, the dose accuracy, and the efficiency of delivery, SL1 and SL5 have similar characteristics in cervical cancer cases. Both SL1 and SL5 values should recommend for cervical cancer VMAT planning.

Keywords: Cervical Cancer, Segment Shape Optimization Parameter, Volumetric Modulated Arc Therapy, plan quality


Main Subjects

Articles in Press, Accepted Manuscript
Available Online from 16 May 2023
  • Receive Date: 29 November 2022
  • Revise Date: 29 April 2023
  • Accept Date: 16 May 2023