Planar EPID-Based Dosimetry for SRS and SRT Patient-Specific QA
Abstract
:1. Introduction
2. Material and Method
2.1. Appropriate SID for Reducing Saturation Effect
2.2. EPID-Based Dosimetry Model
2.2.1. Dose Linearity Calibration
2.2.2. 2-Dimensional Beam Profile Correction
2.2.3. Collimator Scatters Correction
2.2.4. Water Kernel
2.3. Model Validation
3. Results
3.1. Appropriate SID for Reducing Saturation Effect
3.2. EPID-Based Dosimetry Model
3.3. Model validation
4. Discussions
5. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Plan Parameters | Information (n = Number of Plan) |
---|---|
Dose prescription | 6 Gy × 5 fractions (2 plans), 5 Gy × 5 fractions (2 plans), 24 Gy × 1 fraction (2 plans), 18 Gy × 1 fraction (2 plans), 12 Gy × 1 fraction (2 plans) |
Arc numbers | 3 full arcs (3 plans), 3 full arcs + 2 partial arcs (3 plans), 5 partial arcs (2 plans), 3 full arcs + 2 partial arcs (2 plans) |
Target numbers | 2 targets (2 plans), 1 target (8 plans) |
Plan | Field Size (cm) | PTV Geometry | ||
---|---|---|---|---|
X-Jaws | Y-Jaws | Volume (cm3) | Equivalent Sphere Diameter (cm) | |
Plan No.1 | 5.28 ± 0.236 | 5.5 ± 0 | 30.31 | 3.9 |
Plan No.2 | 4.46 ± 0.115 | 5 ± 0.289 | 15.55 | 3.1 |
Plan No.3 | 2.92 ± 0.084 | 3.02 ± 0.045 | 4.46 | 2 |
Plan No.4 | 3.8 ± 0.082 | 4.1 ± 0.141 | 15.08 | 3.1 |
Plan No.5 * | 2.58 ± 0.206 | 2.55 ± 0.238 | 1.33, 2.78 | 1.4, 1.7 |
Plan No.6 | 4.3 ± 0 | 3.9 ± 0 | 13.86 | 3 |
Plan No.7 | 6 ± 0 | 5.8 ± 0 | 28.86 | 3.8 |
Plan No.8 | 4.9 ± 0.164 | 5.67 ± 0.418 | 17.9 | 3.2 |
Plan No.9 | 3.28 ± 0.096 | 3.25 ± 0.129 | 5.5 | 2.2 |
Plan No.10 * | 4.15 ± 0.173 | 4 ± 0 | 19.72, 5.77 | 3.4, 2.2 |
Mean ± SD | 4.06 ± 1.023 | 4.2 ± 1.124 | 13.43 ± 9.779 | 2.75 ± 0.823 |
SID (cm) | CU in Different Dose Rates | |||||||
---|---|---|---|---|---|---|---|---|
1400 MU/min | 1200 MU/min | 1000 MU/min | 800 MU/min | 600 MU/min | 400 MU/min | Average | SD | |
120 | 765.26 | 765.51 | 768.61 | 770.10 | 772.14 | 773.76 | 769.23 | 3.45 |
130 | 655.66 | 656.27 | 657.59 | 659.10 | 660.32 | 661.09 | 658.34 | 2.19 |
140 | 567.53 | 568.59 | 569.72 | 570.86 | 571.63 | 572.38 | 570.12 | 1.85 |
150 | 497.18 | 498.20 | 499.05 | 499.62 | 500.32 | 500.81 | 499.20 | 1.35 |
160 | 439.42 | 440.20 | 440.75 | 441.19 | 441.81 | 442.16 | 440.92 | 1.20 |
170 | 391.38 | 391.92 | 392.30 | 392.81 | 393.18 | 393.53 | 392.52 | 0.81 |
180 | 351.14 | 351.52 | 351.89 | 352.17 | 352.26 | 352.85 | 352.02 | 0.64 |
Plan | GPR (Mean ± SD) | |||
---|---|---|---|---|
EPID-Based Dosimetry | MapCHECK | |||
3%/3 mm | 2%/2 mm | 3%/3 mm | 2%/2 mm | |
Plan No.1 | 99.50 ± 0.34 | 97.38 ± 2.77 | 99.12 ± 1.85 | 96.45 ± 2.55 |
Plan No.2 | 99.32 ± 0.95 | 99.47 ± 3.12 | 98.85 ± 1.15 | 97.88 ± 2.39 |
Plan No.3 | 99.47 ± 0.63 | 98.36 ± 1.39 | 96.90 ± 1.57 | 94.83 ± 3.03 |
Plan No.4 | 99.19 ± 0.52 | 95.33 ± 2.95 | 98.75 ± 1.71 | 98.17 ± 2.63 |
Plan No.5 | 99.05 ± 0.63 | 98.42 ± 2.67 | 99.66 ± 2.1 | 98.61 ± 2.49 |
Plan No.6 | 99.8 ± 0.39 | 98.67 ± 1.86 | 99.42 ± 1.43 | 95.60 ± 3.37 |
Plan No.7 | 99.57 ± 0.59 | 98.24 ± 2.30 | 98.67 ± 2.31 | 96.37 ± 3.89 |
Plan No.8 | 99.77 ± 0.5 | 99.19 ± 2.69 | 97.64 ± 1.88 | 95.50 ± 3.91 |
Plan No.9 | 98.99 ± 0.73 | 95.55 ± 3.42 | 97.99 ± 2.14 | 96.45 ± 2.41 |
Plan No.10 | 99.18 ± 0.72 | 97.56 ± 2.65 | 98.67 ± 1.34 | 98.51 ± 2.75 |
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Thongsawad, S.; Chanton, T.; Saiyo, N.; Udee, N. Planar EPID-Based Dosimetry for SRS and SRT Patient-Specific QA. Life 2021, 11, 1159. https://doi.org/10.3390/life11111159
Thongsawad S, Chanton T, Saiyo N, Udee N. Planar EPID-Based Dosimetry for SRS and SRT Patient-Specific QA. Life. 2021; 11(11):1159. https://doi.org/10.3390/life11111159
Chicago/Turabian StyleThongsawad, Sangutid, Tadchapong Chanton, Nipon Saiyo, and Nuntawat Udee. 2021. "Planar EPID-Based Dosimetry for SRS and SRT Patient-Specific QA" Life 11, no. 11: 1159. https://doi.org/10.3390/life11111159