Skip to main content
Have a personal or library account? Click to login
Dosimetry and efficiency comparison of knowledge-based and manual planning using volumetric modulated arc therapy for craniospinal irradiation Cover

Dosimetry and efficiency comparison of knowledge-based and manual planning using volumetric modulated arc therapy for craniospinal irradiation

Open Access
|Mar 2024

Figures & Tables

FIGURE 1.

Flowchart of the study design.CSI = craniospinal irradiation; CT = computed tomography; KBP = knowledge-based planning; VMAT = volumetric modulated arc therapy

FIGURE 2.

Example of the target and field setup. (A) The arrangement of the brain field (dotted lines), spine-superior field (solid lines), spine-inferior field (dashed lines), and their isocenters. Each field overlaps at least 5 cm for the low-dose gradient junction. (B) Full arc was used on the brain field. (C) Partial arc was used in the spinal fields for arm sparing.

FIGURE 3.

(A) Population-averaged dose-volume histogram (DVH) for all organs at risk and targets. (B) The population-averaged DVH for targets only.CTV = clinical target volume; MP = manual optimization plan; PTV = planning target volumes; RPI = RapidPlan initial; RPF = final RapidPlan after manual re-optimization

FIGURE 4.

Comparison of the planning time for MP, RPI, and RPF. The error bar represents one standard deviation.MP = manual optimization plan; RPI = RapidPlan initial; RPF = final RapidPlan after manual re-optimization

Dosimetric goals and results for organs at risk

OAR parametersGoalsResultsP value

MPRPIRPFMP vs. RPFMP vs. RPFRPI vs. RPI
Brain
  Dmax [Gy]< 6039.34 ± 0.3940.24 ± 0.6139.28 ± 0.37< 0.01**0.46< 0.01**
Brain stem
  Dmax [Gy]< 5438.48 ± 0.4139.03 ± 0.4638.51 ± 0.28< 0.01**0.91< 0.01**
Chiasm
  Dmean [Gy]< 5037.15 ± 0.3537.10 ± 0.3236.95 ± 0.320.690.070.06
  Dmax [Gy]< 5538.13 ± 0.4038.73 ± 0.5538.20 ± 0.260.01*0.46< 0.01**
Optic nerves
  Dmean [Gy]< 5027.61 ± 3.4022.90 ± 2.3922.42 ± 2.29< 0.01**< 0.01**0.05
  Dmax [Gy]< 5537.13 ± 0.6936.36 ± 1.7236.15 ± 1.390.130.02*0.13
Eyes
  Dmax [Gy]< 5025.55 ± 3.5722.52 ± 3.8321.60 ± 3.860.02*0.01*0.01*
Lens
  Dmax [Gy]< 108.40 ± 0.688.87 ± 1.008.10 ± 0.550.110.21< 0.01**
Parotid glands
  Dmean [Gy]< 257.38 ± 2.525.16 ± 0.394.95 ± 0.39< 0.01**< 0.01**< 0.01**
Spinal cord
  Dmax [Gy]< 5038.93 ± 0.5139.81 ± 0.6739.04 ± 0.56< 0.01**< 0.01**< 0.01**
Thyroid
  Dmax [Gy]< 4517.23 ± 4.0416.68 ± 2.1316.38 ± 2.040.590.360.07
Lungs
  Dmean [Gy]< 134.63 ± 0.304.95 ± 0.434.63 ± 0.240.03*0.73< 0.01**
  V20Gy [%]< 220.06 ± 0.110.04 ± 0.080.03 ± 0.040.640.440.33
  V5Gy [%]< 4236.48 ± 2.8842.77 ± 5.6237.11 ± 2.870.01*0.69< 0.01**
Heart
  Dmean [Gy]< 106.76 ± 1.475.53 ± 0.825.70 ± 0.930.01*0.02*0.33
  V40Gy [%]< 30.00 ± 0.000.00 ± 0.000.00 ± 0.00---
  V18Gy [%]< 50.04 ± 0.100.01 ± 0.030.01 ± 0.020.310.230.41
Esophagus
  Dmean [Gy]< 3414.34 ± 1.6213.23 ± 1.6313.30 ± 1.740.01*< 0.01**0.96
Liver
  Dmean [Gy]< 304.82 ± 0.944.57 ± 0.734.45 ± 0.700.610.33< 0.01**
Kidneys
  Dmean [Gy]< 182.81 ± 1.172.47 ± 0.462.38 ± 0.430.960.73< 0.01**

The mean dose of the OARs outside the targets contours

OrganMean doseP value

MPRPIRPFMP vs. RPIMP vs. RPFRPI vs. RPF
Optic nerves27.61 ± 3.4022.90 ± 2.3922.42 ± 2.29< 0.01**< 0.01**0.05
Eyes12.11 ± 1.9910.16 ± 0.559.83 ± 0.740.01*0.01*0.02*
Lens7.09 ± 0.677.21 ± 0.526.78 ± 0.390.430.16< 0.01**
Parotid glands7.38 ± 2.525.16 ± 0.394.95 ± 0.39< 0.01**< 0.01**< 0.01**
Thyroid10.41 ± 3.379.00 ± 1.948.51 ± 2.070.060.04*< 0.01**
Lungs4.63 ± 0.304.95 ± 0.434.63 ± 0.240.03*0.73< 0.01**
Heart6.76 ± 1.475.53 ± 0.825.70 ± 0.930.01*0.02*0.33
Liver4.82 ± 0.944.57 ± 0.734.45 ± 0.700.610.33< 0.01**
Kidneys2.81 ± 1.172.47 ± 0.462.38 ± 0.430.960.73< 0.01**

Dosimetric comparison between manual plans, RapidPlan initial, and RapidPlan final

ParametersGoalsResultsP value

MPRPIRPFMP vs. RPIMP vs. RPFRPI vs. RPF
CTV
  V95 [%]> 9999.99 ± 0.0399.98 ± 0.0399.97 ± 0.030.360.03*0.09
  V100 [%]> 9999.20 ± 0.1798.37 ± 0.3399.37 ± 0.23< 0.01**0.07< 0.01**
  V107 [%]Minimize0.62 ± 0.592.94 ± 4.330.46 ± 0.66< 0.01**0.16< 0.01**
  Dmean [Gy]3637.23 ± 0.1837.31 ± 0.2137.22 ± 0.240.070.870.13
  Dmax [Gy]Minimize39.38 ± 0.4040.38 ± 0.5739.42 ± 0.41< 0.01**0.78< 0.01**
  D2 [%]< 107106.12 ± 0.73106.95 ± 0.96105.72 ± 0.84< 0.01**0.19< 0.01**
PTV
  V95 [%]> 9899.68 ± 0.1599.55 ± 0.2399.24 ± 0.320.03*< 0.01**< 0.01**
  V100 [%]= 9595.00 ± 0.0095.00 ± 0.0095.00 ± 0.00---
  V107 [%]Minimize0.62 ± 0.573.01 ± 4.120.44 ± 0.61< 0.01**0.17< 0.01**
  Dmean [Gy]3637.10 ± 0.1637.22 ± 0.1837.08 ± 0.200.050.730.01*
  Dmax [%]< 112109.99 ± 1.17112.89 ± 1.78110.17 ± 1.14< 0.01**0.57< 0.01**
  D2 [%]< 107106.09 ± 0.73107.00 ± 0.93105.71 ± 0.80< 0.01**0.21< 0.01**
  CI10.98 ± 0.011.01 ± 0.011.00 ± 0.01< 0.01**< 0.01**0.01*
  HI11.10 ± 0.011.13 ± 0.021.10 ± 0.01< 0.01**0.57< 0.01**
DOI: https://doi.org/10.2478/raon-2024-0018 | Journal eISSN: 1581-3207 | Journal ISSN: 1318-2099
Language: English
Page range: 289 - 299
Submitted on: Nov 4, 2023
Accepted on: Jan 3, 2024
Published on: Mar 7, 2024
In partnership with: Paradigm Publishing Services
Publication frequency: 4 issues per year

© 2024 Wei-Ta Tsai, Hui-Ling Hsieh, Shih-Kai Hung, Chi-Fu Zeng, Ming-Fen Lee, Po-Hao Lin, Chia-Yi Lin, Wei-Chih Li, Wen-Yen Chiou, Tung-Hsin Wu, published by Association of Radiology and Oncology
This work is licensed under the Creative Commons Attribution 4.0 License.