An evaluation of techniques for dose calculation on cone beam computed tomography

Valentina Giacometti, Raymond B King, Christina E Agnew, Denise M Irvine, Suneil Jain, Alan R Hounsell, Conor K McGarry

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

OBJECTIVE:: To assess the accuracy and efficiency of four different techniques, thus determining the optimum method for recalculating dose on cone beam CT (CBCT) images acquired during radiotherapy treatments.

METHODS:: Four established techniques were investigated and their accuracy assessed via dose calculations: (1) applying a standard planning CT (pCT) calibration curve, (2) applying a CBCT site-specific calibration curve, (3) performing a density override and (4) using deformable registration. Each technique was applied to 15 patients receiving volumetric modulated arc therapy to one of three treatment sites, head and neck, lung and prostate. Differences between pCT and CBCT recalculations were determined with dose volume histogram metrics and 2.0%/0.1 mm gamma analysis using the pCT dose distribution as a reference.

RESULTS:: Dose volume histogram analysis indicated that all techniques yielded differences from expected results between 0.0 and 2.3% for both target volumes and organs at risk. With volumetric gamma analysis, the dose recalculation on deformed images yielded the highest pass-rates. The median pass-rate ranges at 50% threshold were 99.6-99.9%, 94.6-96.0%, and 94.8.0-96.0% for prostate, head and neck and lung patients, respectively.

CONCLUSION:: Deformable registration, HU override and site-specific calibration curves were all identified as dosimetrically accurate and efficient methods for dose calculation on CBCT images.

ADVANCES IN KNOWLEDGE:: With the increasing adoption of CBCT, this study provides clinical radiotherapy departments with invaluable information regarding the comparison of dose reconstruction methods, enabling a more accurate representation of a patient's treatment. It can also integrate studies in which CBCT is used in image-guided radiation therapy and for adaptive radiotherapy planning processes.

Original languageEnglish
Article number20180383
Number of pages11
JournalBritish Journal of Radiology
Volume92
Issue number1096
Early online date26 Feb 2019
DOIs
Publication statusEarly online date - 26 Feb 2019

Fingerprint

Cone-Beam Computed Tomography
Calibration
Radiotherapy
Prostate
Neck
Head
Image-Guided Radiotherapy
Organs at Risk
Intensity-Modulated Radiotherapy
Lung
Therapeutics

Keywords

  • Cone-Beam Computed Tomography/methods
  • Head and Neck Neoplasms/diagnostic imaging
  • Humans
  • Image Processing, Computer-Assisted
  • Lung Neoplasms/diagnostic imaging
  • Male
  • Prostatic Neoplasms/diagnostic imaging
  • Radiotherapy Dosage
  • Radiotherapy Planning, Computer-Assisted/methods
  • Radiotherapy, Intensity-Modulated/methods
  • Reproducibility of Results

Cite this

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title = "An evaluation of techniques for dose calculation on cone beam computed tomography",
abstract = "OBJECTIVE:: To assess the accuracy and efficiency of four different techniques, thus determining the optimum method for recalculating dose on cone beam CT (CBCT) images acquired during radiotherapy treatments.METHODS:: Four established techniques were investigated and their accuracy assessed via dose calculations: (1) applying a standard planning CT (pCT) calibration curve, (2) applying a CBCT site-specific calibration curve, (3) performing a density override and (4) using deformable registration. Each technique was applied to 15 patients receiving volumetric modulated arc therapy to one of three treatment sites, head and neck, lung and prostate. Differences between pCT and CBCT recalculations were determined with dose volume histogram metrics and 2.0{\%}/0.1 mm gamma analysis using the pCT dose distribution as a reference.RESULTS:: Dose volume histogram analysis indicated that all techniques yielded differences from expected results between 0.0 and 2.3{\%} for both target volumes and organs at risk. With volumetric gamma analysis, the dose recalculation on deformed images yielded the highest pass-rates. The median pass-rate ranges at 50{\%} threshold were 99.6-99.9{\%}, 94.6-96.0{\%}, and 94.8.0-96.0{\%} for prostate, head and neck and lung patients, respectively.CONCLUSION:: Deformable registration, HU override and site-specific calibration curves were all identified as dosimetrically accurate and efficient methods for dose calculation on CBCT images.ADVANCES IN KNOWLEDGE:: With the increasing adoption of CBCT, this study provides clinical radiotherapy departments with invaluable information regarding the comparison of dose reconstruction methods, enabling a more accurate representation of a patient's treatment. It can also integrate studies in which CBCT is used in image-guided radiation therapy and for adaptive radiotherapy planning processes.",
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author = "Valentina Giacometti and King, {Raymond B} and Agnew, {Christina E} and Irvine, {Denise M} and Suneil Jain and Hounsell, {Alan R} and McGarry, {Conor K}",
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An evaluation of techniques for dose calculation on cone beam computed tomography. / Giacometti, Valentina; King, Raymond B; Agnew, Christina E; Irvine, Denise M; Jain, Suneil; Hounsell, Alan R; McGarry, Conor K.

In: British Journal of Radiology, Vol. 92, No. 1096, 20180383, 26.02.2019.

Research output: Contribution to journalArticle

TY - JOUR

T1 - An evaluation of techniques for dose calculation on cone beam computed tomography

AU - Giacometti, Valentina

AU - King, Raymond B

AU - Agnew, Christina E

AU - Irvine, Denise M

AU - Jain, Suneil

AU - Hounsell, Alan R

AU - McGarry, Conor K

PY - 2019/2/26

Y1 - 2019/2/26

N2 - OBJECTIVE:: To assess the accuracy and efficiency of four different techniques, thus determining the optimum method for recalculating dose on cone beam CT (CBCT) images acquired during radiotherapy treatments.METHODS:: Four established techniques were investigated and their accuracy assessed via dose calculations: (1) applying a standard planning CT (pCT) calibration curve, (2) applying a CBCT site-specific calibration curve, (3) performing a density override and (4) using deformable registration. Each technique was applied to 15 patients receiving volumetric modulated arc therapy to one of three treatment sites, head and neck, lung and prostate. Differences between pCT and CBCT recalculations were determined with dose volume histogram metrics and 2.0%/0.1 mm gamma analysis using the pCT dose distribution as a reference.RESULTS:: Dose volume histogram analysis indicated that all techniques yielded differences from expected results between 0.0 and 2.3% for both target volumes and organs at risk. With volumetric gamma analysis, the dose recalculation on deformed images yielded the highest pass-rates. The median pass-rate ranges at 50% threshold were 99.6-99.9%, 94.6-96.0%, and 94.8.0-96.0% for prostate, head and neck and lung patients, respectively.CONCLUSION:: Deformable registration, HU override and site-specific calibration curves were all identified as dosimetrically accurate and efficient methods for dose calculation on CBCT images.ADVANCES IN KNOWLEDGE:: With the increasing adoption of CBCT, this study provides clinical radiotherapy departments with invaluable information regarding the comparison of dose reconstruction methods, enabling a more accurate representation of a patient's treatment. It can also integrate studies in which CBCT is used in image-guided radiation therapy and for adaptive radiotherapy planning processes.

AB - OBJECTIVE:: To assess the accuracy and efficiency of four different techniques, thus determining the optimum method for recalculating dose on cone beam CT (CBCT) images acquired during radiotherapy treatments.METHODS:: Four established techniques were investigated and their accuracy assessed via dose calculations: (1) applying a standard planning CT (pCT) calibration curve, (2) applying a CBCT site-specific calibration curve, (3) performing a density override and (4) using deformable registration. Each technique was applied to 15 patients receiving volumetric modulated arc therapy to one of three treatment sites, head and neck, lung and prostate. Differences between pCT and CBCT recalculations were determined with dose volume histogram metrics and 2.0%/0.1 mm gamma analysis using the pCT dose distribution as a reference.RESULTS:: Dose volume histogram analysis indicated that all techniques yielded differences from expected results between 0.0 and 2.3% for both target volumes and organs at risk. With volumetric gamma analysis, the dose recalculation on deformed images yielded the highest pass-rates. The median pass-rate ranges at 50% threshold were 99.6-99.9%, 94.6-96.0%, and 94.8.0-96.0% for prostate, head and neck and lung patients, respectively.CONCLUSION:: Deformable registration, HU override and site-specific calibration curves were all identified as dosimetrically accurate and efficient methods for dose calculation on CBCT images.ADVANCES IN KNOWLEDGE:: With the increasing adoption of CBCT, this study provides clinical radiotherapy departments with invaluable information regarding the comparison of dose reconstruction methods, enabling a more accurate representation of a patient's treatment. It can also integrate studies in which CBCT is used in image-guided radiation therapy and for adaptive radiotherapy planning processes.

KW - Cone-Beam Computed Tomography/methods

KW - Head and Neck Neoplasms/diagnostic imaging

KW - Humans

KW - Image Processing, Computer-Assisted

KW - Lung Neoplasms/diagnostic imaging

KW - Male

KW - Prostatic Neoplasms/diagnostic imaging

KW - Radiotherapy Dosage

KW - Radiotherapy Planning, Computer-Assisted/methods

KW - Radiotherapy, Intensity-Modulated/methods

KW - Reproducibility of Results

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DO - 10.1259/bjr.20180383

M3 - Article

C2 - 30433821

VL - 92

JO - British Journal of Radiology

JF - British Journal of Radiology

SN - 0007-1285

IS - 1096

M1 - 20180383

ER -