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Does CyberKnife improve dose distribution versus IMRT and VMAT on a linear accelerator in low-risk prostate cancer? Cover

Does CyberKnife improve dose distribution versus IMRT and VMAT on a linear accelerator in low-risk prostate cancer?

Radiology and Oncology
Volume 56 (2022): Issue 2 (June 2022)
By:
Open Access
|Mar 2022

Figures & Tables

Figure 1

Example dose distributions on a transversal scan for (A) IMRT plan, (B) VMAT plan and (C) CyberKnife plan for the same patient.
Example dose distributions on a transversal scan for (A) IMRT plan, (B) VMAT plan and (C) CyberKnife plan for the same patient.

Figure 2

Gamma index for verification plans.
Gamma index for verification plans.

Figure 3

IMRT gamma index (2%/2mm) values for each patient.
IMRT gamma index (2%/2mm) values for each patient.

Figure 4

Gamma Index for IMRT for each treatment beam and all plans.
Gamma Index for IMRT for each treatment beam and all plans.

Mean conformity and homogeneity index values

VMATIMRTCyberKnifep
CI1.17 ± 0.041.25 ± 0.071.07 ± 0.03p < 0.001
HI1.07 ± 0.011.04 ± 0.011.25 ± 0.03p < 0.001

Treatment plan acceptance criteria

StructureCriteria
PTV: IMRT and VMATDMax:107% of the prescribed dose
DMin: 95% of the prescribed dose
Prescribed isodose: 78%–82%
PTV: Cyber KnifeTotal dose of prescribed isodose covering at least 95% of PTV volume
V18 Gy < 50% Vol
V29 Gy < 20% Vol
RectumV32.6 Gy < 10% Vol
V36.25 Gy < 5% Vol
V36 Gy < 1 mm3
V18 Gy < 55% Vol
V29 Gy < 25% Vol
BladderV32.6 Gy < 15% Vol
V36.25 Gy < 10% Vol
V37 Gy < 10 mm3
Femoral heads: left and rightV25 Gy < 45% Vol

Dosimetric parameters for VMAT, IMRT and CyberKnife

VMATIMRTCyberKnifep
D mean PTVMean ± SD36.2536.2539.59±1.11-
D min PTVMean ± SD34.6±0.4134.67±0.5231.48±0.99p < 0.001
D max PTVMean ± SD38.76±0.4737.57±0.445.89±0.94p < 0.001
Target coverage D98%Mean ± SD97.36±1.0299.25±0.7596.08±0.76p < 0.001

Mean dosimetric parameters for the three techniques

VMATIMRTCyberKnifep
Rectum
V18 Gy [%]15.33 ± 2.9715.17 ± 2.7922.58 ± 6.6p < 0.001
V29 Gy [%]7.13 ± 27.25 ± 1.897.18 ± 2.82p < 0.911

p values > 0.05 were considered non-significant

V32.6 Gy [%]4.75 ± 1.514.82 ± 1.583.23 ± 1.66p < 0.001
V36.25 Gy [%]0.54 ± 0.290.32 ± 0.250.24 ± 0.25p < 0.001
V36 Gy in mm3591.59 ± 226.53422.62 ± 236.64219.78 ± 235.02p < 0.001
Bladder
V18 Gy [%]11.98 ± 5.3314.93 ± 5.5619.25 ± 8.62p < 0.001
V29 Gy [%]5.87 ± 2.328 ± 2.737.35 ± 3.27p < 0.001
V32.6 Gy [%]4.38 ± 1.725.7 ± 2.084.71 ± 2.14p < 0.001
V36.25 Gy [%]2 ± 0.931.22 ± 0.812.16 ± 1.09p < 0.001
V37 Gy in mm31090.75 ± 610.814.5 ± 15.73256 ± 1518.84p < 0.001
Left femoral head V25 Gy00.12 ± 0.250< p 0.001
Right femoral head V25 Gy00.12 ± 0.30< p 0.001
DOI: https://doi.org/10.2478/raon-2022-0010 | Journal eISSN: 1581-3207 | Journal ISSN: 1318-2099
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Language: English
Page range: 259 - 266
Submitted on: Oct 21, 2021
Accepted on: Jan 31, 2022
Published on: Mar 28, 2022
Published by: Association of Radiology and Oncology
In partnership with: Paradigm Publishing Services
Publication frequency: 4 times per year
Keywords:
prostate carcinoma,
stereotactic radiotherapy,
intensity-modulated radiotherapy,
CyberKnife
Related subjects:
Medicine,
Clinical medicine,
Internal medicine,
Haematology, oncology,
Radiology

© 2022 Dorota Maria Borowicz, Agnieszka Skrobała, Marta Kruszyna-Mochalska, Julian Malicki, published by Association of Radiology and Oncology
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

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