TY - JOUR
T1 - Metal artifact reduction in cervix brachytherapy with titanium applicators using dual‐energy CT through virtual monoenergetic images and an iterative algorithm
T2 - A phantom study
AU - Kanani, Abolfazl
AU - Yazdi, Mehran
AU - Owrangi, Amir M.
AU - Karbasi, Sareh
AU - Mosleh-Shirazi, Mohammad Amin
N1 - Funding Information:
This work is a part of a postgraduate thesis by AK, supported by the Vice-Chancellery of Research, Shiraz University of Medical Sciences (project number 12353). The authors would like to thank the following companies and colleagues for their helpful co-operation: Eckert & Ziegler BEBIG GmbH and Saman Tabesh companies, staff at our Radio-oncology Department and Ms Hanieh Mansourabadi.
Publisher Copyright:
© 2022 American Brachytherapy Society
PY - 2022
Y1 - 2022
N2 - PURPOSE: To evaluate an iterative metal-artifact reduction (iMAR) algorithm, dual-energy CT (DECT) through virtual monoenergetic images (VMI), and a combination of iMAR and DECT for reducing metal artifact severity (AS) induced by Fletcher titanium applicators used in cervix brachytherapy, the efficacy of which are hitherto unreported. METHODS AND MATERIALS: 120 kVp single-energy CT (SECT) (Siemens) of BEBIG tandem applicators, varying in shape (straight or curved) and diameter (3.5 mm or 5 mm) in a custom-made water-filled phantom, and their DECT images obtained from extrapolation of 80 kVp and 140 kVp, were reconstructed using four methods: DECT through VMI±iMAR, and SECT±iMAR. The DECT images were reconstructed monoenergetically at 70, 150, and 190 keV. AS was evaluated using measured values and statistical analysis. RESULTS: iMAR, DECT, and combined DECT and iMAR reduced AS (p < 0.05). DECT had a lower AS than SECT, even without iMAR (p < 0.025). SECT+iMAR was more effective than DECT-iMAR with VMI at 70 and 190 keV (p < 0.05), whereas showing no statistically significant difference at 150 keV. With DECT and iMAR combined, AS was reduced more effectively compared to the SECT+iMAR or DECT alone. It also reduced the mean interobserver uncertainty by 0.2 mm. CONCLUSIONS: These findings indicate that iMAR reduces the AS caused by Fletcher titanium applicators for both SECT and DECT, a combination of iMAR and DECT is superior to either strategy alone, and at low energies, DECT+iMAR also produces similar artifact reduction. These practical strategies promise more accurate source-position and structure definitions in CT-based gynecological brachytherapy treatment planning.
AB - PURPOSE: To evaluate an iterative metal-artifact reduction (iMAR) algorithm, dual-energy CT (DECT) through virtual monoenergetic images (VMI), and a combination of iMAR and DECT for reducing metal artifact severity (AS) induced by Fletcher titanium applicators used in cervix brachytherapy, the efficacy of which are hitherto unreported. METHODS AND MATERIALS: 120 kVp single-energy CT (SECT) (Siemens) of BEBIG tandem applicators, varying in shape (straight or curved) and diameter (3.5 mm or 5 mm) in a custom-made water-filled phantom, and their DECT images obtained from extrapolation of 80 kVp and 140 kVp, were reconstructed using four methods: DECT through VMI±iMAR, and SECT±iMAR. The DECT images were reconstructed monoenergetically at 70, 150, and 190 keV. AS was evaluated using measured values and statistical analysis. RESULTS: iMAR, DECT, and combined DECT and iMAR reduced AS (p < 0.05). DECT had a lower AS than SECT, even without iMAR (p < 0.025). SECT+iMAR was more effective than DECT-iMAR with VMI at 70 and 190 keV (p < 0.05), whereas showing no statistically significant difference at 150 keV. With DECT and iMAR combined, AS was reduced more effectively compared to the SECT+iMAR or DECT alone. It also reduced the mean interobserver uncertainty by 0.2 mm. CONCLUSIONS: These findings indicate that iMAR reduces the AS caused by Fletcher titanium applicators for both SECT and DECT, a combination of iMAR and DECT is superior to either strategy alone, and at low energies, DECT+iMAR also produces similar artifact reduction. These practical strategies promise more accurate source-position and structure definitions in CT-based gynecological brachytherapy treatment planning.
KW - Cervix HDR brachytherapy
KW - CT/MRI compatible applicator
KW - Dual energy CT
KW - Image-based Brachytherapy
KW - Metal artifact reduction
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U2 - 10.1016/j.brachy.2022.07.003
DO - 10.1016/j.brachy.2022.07.003
M3 - Article
C2 - 35933273
AN - SCOPUS:85135417282
SN - 1538-4721
JO - Brachytherapy
JF - Brachytherapy
ER -