|
KMID : 0364920210460020048
|
|
Journal of Radiation Protection and Research
2021 Volume.46 No. 2 p.48 ~ p.57
|
|
|
Quantifications of Intensity-Modulated Radiation Therapy Plan Complexities in Magnetic Resonance Image Guided Radiotherapy Systems
|
|
Chun Min-Soo
Kwon O-Hyun
Park Jong-Min
Kim Jung-In
|
|
|
Abstract
|
|
|
Background: In this study, the complexities of step-and-shoot intensity-modulated radiation therapy (IMRT) plans in magnetic resonance-guided radiation therapy systems were evaluated.
Materials and Methods: Overall, 194 verification plans from the abdomen, prostate, and breast sites were collected using a 60Co-based ViewRay radiotherapy system (ViewRay Inc., Cleveland, OH, USA). Various plan complexity metrics (PCMs) were calculated for each verification plan, including the modulation complexity score (MCS), plan-averaged beam area (PA), plan-averaged beam irregularity, plan-averaged edge (PE), plan-averaged beam modulation, number of segments, average area among all segments (AA/Seg), and total beam-on time (TBT). The plan deliverability was quantified in terms of gamma passing rates (GPRs) with a 1 mm/2% criterion, and the Pearson correlation coefficients between GPRs and various PCMs were analyzed.
Results and Discussion: For the abdomen, prostate, and breast groups, the average GPRs with the 1 mm/2% criterion were 77.8±6.0%, 79.8±4.9%, and 84.7±7.3%; PCMs were 0.263, 0.271, and 0.386; PAs were 15.001, 18.779, and 35.683; PEs were 1.575, 1.444, and 1.028; AA/Segs were 15.37, 19.89, and 36.64; and TBTs were 18.86, 19.33, and 5.91 minutes, respectively. The various PCMs, i.e., MCS, PA, PE, AA/Seg, and TBT, showed statistically significant Pearson correlation coefficients of 0.416, 0.627, ?0.541, 0.635, and ?0.397, respectively, with GPRs.
Conclusion: The area-related metrics exhibited strong correlations with GPRs. Moreover, the AA/Seg metric can be used to estimate the IMRT plan accuracy without beam delivery in the 60Co-based ViewRay radiotherapy system.
|
|
|
KEYWORD
|
|
|
MRI-Guided Radiotherapy System, Step-and-Shoot Intensity-Modulated Radiation Therapy, Gamma Analysis, Plan Complexity Metric
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|