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Xu H, Cheston SB, Gopal A, Zhang B, Chen S, Yu S, Hall A, Dudley S. A study of skin marker alignment using different diamond-shaped light fields for prone breast external-beam radiation therapy. J Appl Clin Med Phys 2022; 23:e13772. [PMID: 36029043 DOI: 10.1002/acm2.13772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 07/29/2022] [Accepted: 08/10/2022] [Indexed: 11/06/2022] Open
Abstract
For breast cancer patients treated in the prone position with tangential fields, a diamond-shaped light field (DSLF) can be used to align with corresponding skin markers for image-guided radiation therapy (IGRT). This study evaluates and compares the benefits of different DSLF setups. Seventy-one patients who underwent daily tangential kilovoltage (kV) IGRT were categorized retrospectively into four groups: (1) DSLF field size (FS) = 10 × 10 cm2 , gantry angle = 90° (right breast)/270° (left breast), with the same isocenter as treatment tangential beams; (2) same as group 1, except DSLF FS = 4 × 4 cm2 ; (3) DSLF FS = 4 × 4-6 × 8 cm2 , gantry angle = tangential treatment beam, off-isocenter so that the DSLF was at the approximate breast center; and (4) No-DSLF. We compared their total setup time (including any DSLF/marker-based alignment and IGRT) and relative kV-based couch shift corrections. For groups 1-3, DSLF-only dose distributions (excluding kV-based correction) were simulated by reversely shifting the couch positions from the computed tomography plans, which were assumed equivalent to the delivered dose when both DSLF and IGRT were used. For patient groups 1-4, the average daily setup time was 2.6, 2.5, 5.0, and 8.3 min, respectively. Their mean and standard deviations of daily kV-based couch shifts were 0.64 ± 0.4, 0.68 ± 0.3, 0.8 ± 0.6, and 1.0 ± 0.6 cm. The average target dose changes after excluding kV-IGRT for groups 1-3 were-0.2%, -0.1%, and +0.4%, respectively, whereas DSLF-1 was most efficient in sparing heart and chest wall, DSLF-2 had lowest lung Dmax ; and DSLF-3 maintained the highest target coverage at the cost of highest OAR dose. In general, the use of DSLF greatly reduces patient setup time and may result in smaller IGRT corrections. If IGRT is limited, different DSLF setups yield different target coverage and OAR dose sparing. Our findings will help DSLF setup optimization in the prone breast treatment setting.
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Affiliation(s)
- Huijun Xu
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Sally B Cheston
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Arun Gopal
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Baoshe Zhang
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Shifeng Chen
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Suhong Yu
- Department of Radiation Oncology, University of Massachusetts Memorial Medical Center, Worcester, Massachusetts, USA
| | - Andrea Hall
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Sara Dudley
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Xiao A, Jutzy J, Hubert G, Edens M, Washington M, Hasan Y, Chmura SJ, Al-Hallaq HA. A study of the dosimetric impact of daily setup variations measured with cone-beam CT on three-dimensional conformal radiotherapy for early-stage breast cancer delivered in the prone position. J Appl Clin Med Phys 2020; 21:146-154. [PMID: 33124774 PMCID: PMC7769386 DOI: 10.1002/acm2.13080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/04/2020] [Accepted: 10/05/2020] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To evaluate the dosimetric impact of daily positioning variations measured with cone-beam computed tomography (CBCT) on whole-breast radiotherapy patients treated in the prone position. METHODS Daily CBCT was prospectively acquired for 30 consecutive patients positioned prone. Treatment for early-stage (≤II) breast cancer was prescribed with standard dose (50 Gy/25 fractions) or hypofractionation (42.56 Gy/16 fractions) for 13 and 17 patients, respectively. Systematic and random errors were calculated from the translational CBCT shifts and used to determine population-based setup margins. Mean translations (±one standard deviation) for each patient were used to simulate the dosimetric impact on targets (PTV_eval and lumpectomy cavity), heart, and lung. Paired Student's t tests at α = 0.01 were used to compare dose metrics after correction for multiple testing (P < 0.002). Significant correlation coefficients were used to identify associations (P < 0.01). RESULTS Of 597 total fractions, 20 ± 13% required patient rotation. Mean translations were 0.29 ± 0.27 cm, 0.41 ± 0.34 cm, and 0.48 ± 0.33 cm in the anterior-posterior, superior-inferior, and lateral directions leading to calculated setup margins of 0.63, 0.88, and 1.10 cm, respectively. Average three-dimensional (3D) shifts correlated with the maximum distance of breast tissue from the sternum (r = 0.62) but not with body-mass index. Simulated shifts showed significant, but minor, changes in dose metrics for PTV_eval, lung, and heart. For left-sided treatments (n = 18), mean heart dose increased from 109 ± 75 cGy to 148 ± 115 cGy. Shifts from the original plan caused PTV_eval hotspots (V105%) to increase by 5.2% ± 3.8%, which correlated with the total MU of wedged fields (r = 0.59). No significant change in V95% to the cavity was found. CONCLUSIONS Large translational variations that occur when positioning prone breast patients had small but significant dosimetric effects on 3DCRT plans. Daily CBCT may still be necessary to correct for rotational variations that occur in 20% of treatments. To maintain planned dose metrics, unintended beam shifts toward the heart and the contribution of wedged fields should be minimized.
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Affiliation(s)
- Annie Xiao
- Pritzker School of Medicine, The University of Chicago, Chicago, IL, USA
| | - Jessica Jutzy
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, USA
| | - Greg Hubert
- Department of Radiation Oncology, The University of Minnesota, Minneapolis, MN, USA
| | - Meghan Edens
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, USA
| | - Maxine Washington
- Department of Radiation Oncology, Winship Cancer Institute of Emory University, Atlanta, GA, USA
| | - Yasmin Hasan
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, USA
| | - Steven J Chmura
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, USA
| | - Hania A Al-Hallaq
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, USA
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Meyer J, Smith W, Geneser S, Koger B, Kalet AM, Young LA, Cao N, Price RG, Norris C, Horton T, Womeldorf J, Alexandrian AN, Wootton LS. Characterizing a deformable registration algorithm for surface-guided breast radiotherapy. Med Phys 2019; 47:352-362. [PMID: 31724177 DOI: 10.1002/mp.13921] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 11/06/2019] [Accepted: 11/06/2019] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Surface-guided radiation therapy (SGRT) is a nonionizing imaging approach for patient setup guidance, intra-fraction monitoring, and automated breath-hold gating of radiation treatments. SGRT employs the premise that the external patient surface correlates to the internal anatomy, to infer the treatment isocenter position at time of treatment delivery. Deformations and posture variations are known to impact the correlation between external and internal anatomy. However, the degree, magnitude, and algorithm dependence of this impact are not intuitive and currently no methods exist to assess this relationship. The primary aim of this work was to develop a framework to investigate and understand how a commercial optical surface imaging system (C-RAD, Uppsala, Sweden), which uses a nonrigid registration algorithm, handles rotations and surface deformations. METHODS A workflow consisting of a female torso phantom and software-introduced transformations to the corresponding digital reference surface was developed. To benchmark and validate the approach, known rigid translations and rotations were first applied. Relevant breast radiotherapy deformations related to breast size, hunching/arching back, distended/deflated abdomen, and an irregular surface to mimic a cover sheet over the lower part of the torso were investigated. The difference between rigid and deformed surfaces was evaluated as a function of isocenter location. RESULTS For all introduced rigid body transformations, C-RAD computed isocenter shifts were determined within 1 mm and 1˚. Additional translational shifts to correct for rotations as a function of isocenter location were determined with the same accuracy. For yaw setup errors, the difference in shift corrections between a plan with an isocenter placed in the center of the breast (BrstIso) and one located 12 cm superiorly (SCFIso) was 2.3 mm/1˚ in lateral direction. Pitch setup errors resulted in a difference of 2.1 mm/1˚ in vertical direction. For some of the deformation scenarios, much larger differences up to 16 mm and 7˚ in the calculated shifts between BrstIso and SCFIso were observed that could lead to large unintended gaps or overlap between adjacent matched fields if uncorrected. CONCLUSIONS The methodology developed lends itself well for quality assurance (QA) of SGRT systems. The deformable C-RAD algorithm determined accurate shifts for rigid transformations, and this was independent of isocenter location. For surface deformations, the position of the isocenter had considerable impact on the registration result. It is recommended to avoid off-axis isocenters during treatment planning to optimally utilize the capabilities of the deformable image registration algorithm, especially when multiple isocenters are used with fields that share a field edge.
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Affiliation(s)
- Juergen Meyer
- Department of Radiation Oncology, University of Washington, 1959 NE Pacific Street, Box 356043, Seattle, WA, 98195, USA.,Department of Radiation Oncology, Seattle Cancer Care Alliance, 825 Eastlake Ave. E, Seattle, WA, 98109, USA
| | - Wade Smith
- Department of Radiation Oncology, University of Washington, 1959 NE Pacific Street, Box 356043, Seattle, WA, 98195, USA.,Department of Radiation Oncology, Northwest Hospital, 1560 N 115th St, Seattle, WA, 98125, USA
| | - Sarah Geneser
- Department of Radiation Oncology, University of Washington, 1959 NE Pacific Street, Box 356043, Seattle, WA, 98195, USA
| | - Brandon Koger
- Department of Radiation Oncology, University of Washington, 1959 NE Pacific Street, Box 356043, Seattle, WA, 98195, USA
| | - Alan M Kalet
- Department of Radiation Oncology, University of Washington, 1959 NE Pacific Street, Box 356043, Seattle, WA, 98195, USA.,Department of Radiation Oncology, Seattle Cancer Care Alliance, 825 Eastlake Ave. E, Seattle, WA, 98109, USA
| | - Lori A Young
- Department of Radiation Oncology, University of Washington, 1959 NE Pacific Street, Box 356043, Seattle, WA, 98195, USA.,Department of Radiation Oncology, Seattle Cancer Care Alliance, 825 Eastlake Ave. E, Seattle, WA, 98109, USA
| | - Ning Cao
- Department of Radiation Oncology, University of Washington, 1959 NE Pacific Street, Box 356043, Seattle, WA, 98195, USA.,Department of Radiation Oncology, Seattle Cancer Care Alliance, 825 Eastlake Ave. E, Seattle, WA, 98109, USA
| | - Ryan G Price
- Department of Radiation Oncology, University of Washington, 1959 NE Pacific Street, Box 356043, Seattle, WA, 98195, USA.,Department of Radiation Oncology, Northwest Hospital, 1560 N 115th St, Seattle, WA, 98125, USA
| | - Chris Norris
- Department of Radiation Oncology, Seattle Cancer Care Alliance, 825 Eastlake Ave. E, Seattle, WA, 98109, USA
| | - Tony Horton
- Department of Radiation Oncology, Seattle Cancer Care Alliance, 825 Eastlake Ave. E, Seattle, WA, 98109, USA
| | - Jeff Womeldorf
- Department of Radiation Oncology, Northwest Hospital, 1560 N 115th St, Seattle, WA, 98125, USA
| | - Ara N Alexandrian
- Department of Radiation Oncology, University of Washington, 1959 NE Pacific Street, Box 356043, Seattle, WA, 98195, USA
| | - Landon S Wootton
- Department of Radiation Oncology, University of Washington, 1959 NE Pacific Street, Box 356043, Seattle, WA, 98195, USA.,Department of Radiation Oncology, Seattle Cancer Care Alliance, 825 Eastlake Ave. E, Seattle, WA, 98109, USA
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Yao S, Zhang Y, Nie K, Liu B, Haffty BG, Ohri N, Yue NJ. Setup uncertainties and the optimal imaging schedule in the prone position whole breast radiotherapy. Radiat Oncol 2019; 14:76. [PMID: 31072388 PMCID: PMC6509791 DOI: 10.1186/s13014-019-1282-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 04/25/2019] [Indexed: 12/25/2022] Open
Abstract
Background To investigate the setup uncertainties and to establish an optimal imaging schedule for the prone-positioned whole breast radiotherapy. Methods Twenty prone-positioned breast patients treated with tangential fields from 2015 to 2017 were retrospectively enrolled in this study. The prescription dose for the whole breast treatment was 266 cGy × 16 for all of the patients and the treatments were delivered with the SSD setup technique. At every fraction of treatment, patient was firstly set up based on the body localization tattoos. MV portal imaging was then taken to confirm the setup; if discrepancy (> 3 mm) was found between the portal images and corresponding plan images, the patient positioning was adjusted accordingly with couch movement. Based on the information acquired from the daily tattoo and portal imaging setup, three sets of data, named as weekly imaging guidance (WIG), no daily imaging guidance (NIG), and initial 3 days then weekly imaging guidance (3 + WIG) were sampled, constructed, and analyzed in reference to the benchmark of the daily imaging guidance (DIG). We compared the setup uncertainties, target coverage (D95, Dmax), V5 of the ipsilateral lung, the mean dose of heart, the mean and max dose of the left-anterior-descending coronary artery (LAD) among the 4 imaging guidance (IG) schedules. Results Relative to the daily imaging guidance (IG) benchmark, the NIG schedule led to the largest residual setup uncertainties; the uncertainties were similar for the WIG and 3 + WIG schedules. Little variations were observed for D95 of the target among NIG, DIG and WIG. The target Dmax also exhibited little changes among all the IG schedules. While V5 of the ipsilateral lung changed very little among all 4 schedules, the percent change of the mean heart dose was more pronounced; but its absolute values were still within the tolerance. However, for the left-sided breast patients, the LAD dose could be significantly impacted by the imaging schedules and could potentially exceed its tolerance criteria in some patients if NIG, WIG and 3 + WIG schedules were used. Conclusions For left-side whole breast treatment in the prone position using the SSD treatment technique, the daily imaging guidance can ensure dosimetric coverage of the target as well as preventing critical organs, especially LAD, from receiving unacceptable levels of dose. For right-sided whole breast treatment in the prone position, the weekly imaging setup guidance appears to be the optimal choice.
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Affiliation(s)
- Shengyu Yao
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey and Rutgers Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA.,Department of Radiation Oncology, Shanghai General Hospital, Shanghai, China
| | - Yin Zhang
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey and Rutgers Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Ke Nie
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey and Rutgers Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Bo Liu
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey and Rutgers Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Bruce G Haffty
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey and Rutgers Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Nisha Ohri
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey and Rutgers Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Ning J Yue
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey and Rutgers Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA.
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