Related Experiment Video
Updated: Feb 7, 2026

Radiation Planning Assistant - A Streamlined, Fully Automated Radiotherapy Treatment Planning System
Published on: April 11, 2018
A study of minimum segment width parameter on VMAT plan quality, delivery accuracy, and efficiency for cervical
Yuanyuan Wang1, Li Chen2, Fengying Zhu3
1Department of Radiation Oncology, Hefei Ion Medical Center, Hefei, China.
Purpose:
The purpose of this study was to study the influence of the minimum segment width (MSW) on volumetric modulated arc therapy (VMAT) plan quality, delivery accuracy, and efficiency for cervical cancer treatment.
Methods:
Nineteen patients with cervical cancer were randomly selected to design VMAT plans. Three VMAT plans were generated for each patient incorporating MSWs of 0.5, 1.0, and 1.5 cm while other planning parameters remained constant using the Monaco treatment planning system (TPS) with 6 MV X rays delivered from an Elekta Synergy linear accelerator. Plan quality and delivery efficiency were evaluated based on dose-volume histograms (DVHs), control points, monitor units (MUs), dosimetric measurement verification results, and plan delivery time.
Results:
Except for the small difference in target dose coverage and maximum dose, there were no statistically significant differences between the other dosimetric parameters in the planning target volumes. The 1.0 and 1.5 cm MSW plans showed lower maximum doses to the spinal cord than the 0.5 cm plan; doses to other organs at risks were similar regardless of MSWs. The mean reductions of total MUs when compared with the 0.5 cm plan were 14.5 ± 6.1% and 20.9 ± 7.9% for MSWs of 1.0 and 1.5 cm, respectively. The calculated gamma indices using the 3% and 3 mm criteria were 96.2 ± 0.6%, 97.0 ± 0.6%, and 97.6 ± 0.6% for the 0.5, 1.0 and 1.5 cm MSW plans, respectively. The plan delivery times decreased with increasing MSWs (p < 0.05).
Conclusion:
Increasing the MSW allows for improved plan delivery accuracy and efficiency without significantly affecting the VMAT plan quality. MSWs of 1.0 and 1.5 cm improved the plan quality, delivery accuracy, and efficiency for cervical VMAT radiation therapy.
Related Concept Videos
Determination of Multiple Dosing Parameters: Steady-State, Minimum and Maximum Concentrations
Uncertainty in Measurement: Accuracy and Precision
Improving Translational Accuracy
Improving Translational Accuracy
Accuracy and Precision
Sampling Plans
Random sampling is a method where each member of the population has an equal chance of being selected for the sample. It involves selecting individuals randomly, often using random number generators or lottery-type methods. For example, when analyzing the properties of a...

