Shading correction for cone-beam CT in radiotherapy: validation of dose calculation accuracy using clinical imagesCitation formats

Standard

Shading correction for cone-beam CT in radiotherapy: validation of dose calculation accuracy using clinical images. / Marchant, Thomas; Joshi, Kiran; Moore, Christopher.

Proc. SPIE 10132, Medical Imaging 2017: Physics of Medical Imaging. Vol. 10132 SPIE, 2017. p. 101320J1-101320J11 101320J.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Harvard

Marchant, T, Joshi, K & Moore, C 2017, Shading correction for cone-beam CT in radiotherapy: validation of dose calculation accuracy using clinical images. in Proc. SPIE 10132, Medical Imaging 2017: Physics of Medical Imaging. vol. 10132, 101320J, SPIE, pp. 101320J1-101320J11. https://doi.org/10.1117/12.2254059

APA

Marchant, T., Joshi, K., & Moore, C. (2017). Shading correction for cone-beam CT in radiotherapy: validation of dose calculation accuracy using clinical images. In Proc. SPIE 10132, Medical Imaging 2017: Physics of Medical Imaging (Vol. 10132, pp. 101320J1-101320J11). [101320J] SPIE. https://doi.org/10.1117/12.2254059

Vancouver

Marchant T, Joshi K, Moore C. Shading correction for cone-beam CT in radiotherapy: validation of dose calculation accuracy using clinical images. In Proc. SPIE 10132, Medical Imaging 2017: Physics of Medical Imaging. Vol. 10132. SPIE. 2017. p. 101320J1-101320J11. 101320J https://doi.org/10.1117/12.2254059

Author

Marchant, Thomas ; Joshi, Kiran ; Moore, Christopher. / Shading correction for cone-beam CT in radiotherapy: validation of dose calculation accuracy using clinical images. Proc. SPIE 10132, Medical Imaging 2017: Physics of Medical Imaging. Vol. 10132 SPIE, 2017. pp. 101320J1-101320J11

Bibtex

@inproceedings{2e5d9aafb4fe490f9510a0cc106221aa,
title = "Shading correction for cone-beam CT in radiotherapy: validation of dose calculation accuracy using clinical images",
abstract = "Cone-beam CT (CBCT) images are routinely acquired to verify patient position in radiotherapy (RT), but are typically not calibrated in Hounsfield Units (HU) and feature non-uniformity due to X-ray scatter and detector persistence effects. This prevents direct use of CBCT for re-calculation of RT delivered dose. We previously developed a prior-image based correction method to restore HU values and improve uniformity of CBCT images. Here we validate the accuracy with which corrected CBCT can be used for dosimetric assessment of RT delivery, using CBCT images and RT plans for 45 patients including pelvis, lung and head sites. Dose distributions were calculated based on each patient's original RT plan and using CBCT image values for tissue heterogeneity correction. Clinically relevant dose metrics were calculated (e.g. median and minimum target dose, maximum organ at risk dose). Accuracy of CBCT based dose metrics was determined using an {"}override ratio{"} method where the ratio of the dose metric to that calculated on a bulk-density assigned version of the image is assumed to be constant for each patient, allowing comparison to “gold standard” CT. For pelvis and head images the proportion of dose errors >2{\%} was reduced from 40{\%} to 1.3{\%} after applying shading correction. For lung images the proportion of dose errors >3{\%} was reduced from 66{\%} to 2.2{\%}. Application of shading correction to CBCT images greatly improves their utility for dosimetric assessment of RT delivery, allowing high confidence that CBCT dose calculations are accurate within 2-3{\%}.",
author = "Thomas Marchant and Kiran Joshi and Christopher Moore",
year = "2017",
month = "3",
day = "9",
doi = "10.1117/12.2254059",
language = "English",
volume = "10132",
pages = "101320J1--101320J11",
booktitle = "Proc. SPIE 10132, Medical Imaging 2017: Physics of Medical Imaging",
publisher = "SPIE",
address = "United States",

}

RIS

TY - GEN

T1 - Shading correction for cone-beam CT in radiotherapy: validation of dose calculation accuracy using clinical images

AU - Marchant, Thomas

AU - Joshi, Kiran

AU - Moore, Christopher

PY - 2017/3/9

Y1 - 2017/3/9

N2 - Cone-beam CT (CBCT) images are routinely acquired to verify patient position in radiotherapy (RT), but are typically not calibrated in Hounsfield Units (HU) and feature non-uniformity due to X-ray scatter and detector persistence effects. This prevents direct use of CBCT for re-calculation of RT delivered dose. We previously developed a prior-image based correction method to restore HU values and improve uniformity of CBCT images. Here we validate the accuracy with which corrected CBCT can be used for dosimetric assessment of RT delivery, using CBCT images and RT plans for 45 patients including pelvis, lung and head sites. Dose distributions were calculated based on each patient's original RT plan and using CBCT image values for tissue heterogeneity correction. Clinically relevant dose metrics were calculated (e.g. median and minimum target dose, maximum organ at risk dose). Accuracy of CBCT based dose metrics was determined using an "override ratio" method where the ratio of the dose metric to that calculated on a bulk-density assigned version of the image is assumed to be constant for each patient, allowing comparison to “gold standard” CT. For pelvis and head images the proportion of dose errors >2% was reduced from 40% to 1.3% after applying shading correction. For lung images the proportion of dose errors >3% was reduced from 66% to 2.2%. Application of shading correction to CBCT images greatly improves their utility for dosimetric assessment of RT delivery, allowing high confidence that CBCT dose calculations are accurate within 2-3%.

AB - Cone-beam CT (CBCT) images are routinely acquired to verify patient position in radiotherapy (RT), but are typically not calibrated in Hounsfield Units (HU) and feature non-uniformity due to X-ray scatter and detector persistence effects. This prevents direct use of CBCT for re-calculation of RT delivered dose. We previously developed a prior-image based correction method to restore HU values and improve uniformity of CBCT images. Here we validate the accuracy with which corrected CBCT can be used for dosimetric assessment of RT delivery, using CBCT images and RT plans for 45 patients including pelvis, lung and head sites. Dose distributions were calculated based on each patient's original RT plan and using CBCT image values for tissue heterogeneity correction. Clinically relevant dose metrics were calculated (e.g. median and minimum target dose, maximum organ at risk dose). Accuracy of CBCT based dose metrics was determined using an "override ratio" method where the ratio of the dose metric to that calculated on a bulk-density assigned version of the image is assumed to be constant for each patient, allowing comparison to “gold standard” CT. For pelvis and head images the proportion of dose errors >2% was reduced from 40% to 1.3% after applying shading correction. For lung images the proportion of dose errors >3% was reduced from 66% to 2.2%. Application of shading correction to CBCT images greatly improves their utility for dosimetric assessment of RT delivery, allowing high confidence that CBCT dose calculations are accurate within 2-3%.

U2 - 10.1117/12.2254059

DO - 10.1117/12.2254059

M3 - Conference contribution

VL - 10132

SP - 101320J1-101320J11

BT - Proc. SPIE 10132, Medical Imaging 2017: Physics of Medical Imaging

PB - SPIE

ER -