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May L, Barnes M, Hardcastle N, Hernandez V, Saez J, Rosenfeld A, Poder J. Multi-institutional investigation into the robustness of intra-cranial multi-target stereotactic radiosurgery plans to patient setup errors. Phys Med 2024; 124:103423. [PMID: 38970949 DOI: 10.1016/j.ejmp.2024.103423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 06/06/2024] [Accepted: 06/29/2024] [Indexed: 07/08/2024] Open
Abstract
PURPOSE This study aimed to analyse correlations between planning factors including plan geometry and plan complexity with robustness to patient setup errors. METHODS Multiple-target brain stereotactic radiosurgery (SRS) plans were obtained through the Trans-Tasman Radiation Oncology Group (TROG) international treatment planning challenge (2018). The challenge dataset consisted of five intra-cranial targets with a 20 Gy prescription. Setup error was simulated using an in-house tool. Dose to targets was assessed via dose covering 99 % (D99 %) of gross tumour volume (GTV) and 98 % of planning target volume (PTV). Dose to organs at risk was assessed using volume of normal brain receiving 12 Gy and maximum dose covering 0.03 cc of brainstem. Plan complexity was assessed via edge metric, modulation complexity score, mean multi-leaf collimator (MLC) gap, mean MLC speed and plan modulation. RESULTS Even for small (0.5 mm/°) errors, GTV D99 % was reduced by up to 20 %. The strongest correlation was found between lower complexity plans (larger mean MLC gap and lower edge metric) and higher robustness to setup error. Lower complexity plans had 1 %-20 % fewer targets/scenarios with GTV D99 % falling below the specified tolerance threshold. These complexity metrics correlated with 100 % isodose volume sphericity and dose conformity, though similar conformity was achievable with a range of complexities. CONCLUSIONS A higher level of importance should be directed towards plan complexity when considering plan robustness. It is recommended when planning multi-target SRS, larger MLC gaps and lower MLC aperture irregularity be considered during plan optimisation due to higher robustness should patient positioning errors occur.
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Affiliation(s)
- Lauren May
- Centre for Medical and Radiation Physics, University of Wollongong, NSW, Australia.
| | - Micah Barnes
- Centre for Medical and Radiation Physics, University of Wollongong, NSW, Australia; Australian Synchrotron, Australian Nuclear Science and Technology Organisation (ANSTO), 800 Blackburn Road, Clayton, VIC 3168, Australia; Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Nicholas Hardcastle
- Centre for Medical and Radiation Physics, University of Wollongong, NSW, Australia; Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Victor Hernandez
- Department of Medical Physics, Hospital Universitari Sant Joan de Reus, IISPV, Tarragona, Spain
| | - Jordi Saez
- Department of Radiation Oncology, Hospital Clínic de Barcelona, Spain
| | - Anatoly Rosenfeld
- Centre for Medical and Radiation Physics, University of Wollongong, NSW, Australia
| | - Joel Poder
- Centre for Medical and Radiation Physics, University of Wollongong, NSW, Australia; St George Cancer Care Centre, St George Hospital, Kogarah, NSW, Australia; School of Physics, University of Sydney, Camperdown, NSW, Australia
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Sun X, Guan F, Yun Q, Jennings M, Biggs S, Wang Z, Wang W, Zhang T, Shi M, Zhao L. Impact of setup errors on the robustness of linac-based single-isocenter coplanar and non-coplanar VMAT plans for multiple brain metastases. J Appl Clin Med Phys 2024; 25:e14317. [PMID: 38439583 PMCID: PMC11244668 DOI: 10.1002/acm2.14317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 12/21/2023] [Accepted: 02/13/2024] [Indexed: 03/06/2024] Open
Abstract
PURPOSE Patient setup errors have been a primary concern impacting the dose delivery accuracy in radiation therapy. A robust treatment plan might mitigate the effects of patient setup errors. In this reported study, we aimed to evaluate the impact of translational and rotational errors on the robustness of linac-based, single-isocenter, coplanar, and non-coplanar volumetric modulated arc therapy treatment plans for multiple brain metastases. METHODS Fifteen patients were retrospectively selected for this study with a combined total of 49 gross tumor volumes (GTVs). Single-isocenter coplanar and non-coplanar plans were generated first with a prescribed dose of 40 Gy in 5 fractions or 42 Gy in 7 fractions to cover 95% of planning target volume (PTV). Next, four setup errors (+1 and +2 mm translation, and +1° and +2° rotation) were applied individually to generate modified plans. Different plan quality evaluation metrics were compared between coplanar and non-coplanar plans. 3D gamma analysis (3%/2 mm) was performed to compare the modified plans (+2 mm and +2° only) and the original plans. Paired t-test was conducted for statistical analysis. RESULTS After applying setup errors, variations of all plan evaluation metrics were similar (p > 0.05). The worst case for V100% to GTV was 92.07% ± 6.13% in the case of +2 mm translational error. 3D gamma pass rates were > 90% for both coplanar (+2 mm and +2°) and the +2 mm non-coplanar groups but was 87.40% ± 6.89% for the +2° non-coplanar group. CONCLUSION Translational errors have a greater impact on PTV and GTV dose coverage for both planning methods. Rotational errors have a greater negative impact on gamma pass rates of non-coplanar plans. Plan evaluation metrics after applying setup errors showed that both coplanar and non-coplanar plans were robust and clinically acceptable.
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Affiliation(s)
- Xiaohuan Sun
- Department of Radiation Oncology, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Fada Guan
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Qinghui Yun
- Department of Equipment, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Matthew Jennings
- Department of Medical Physics, Townsville University Hospital, Douglas, Queensland, Australia
| | - Simon Biggs
- Radiotherapy AI Pty Ltd, Wagga Wagga, Australia
| | - Zhongfei Wang
- Department of Radiation Oncology, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Wei Wang
- Department of Radiation Oncology, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Te Zhang
- Department of Radiation Oncology, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Mei Shi
- Department of Radiation Oncology, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Lina Zhao
- Department of Radiation Oncology, Xijing Hospital, Air Force Medical University, Xi'an, China
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Nakano H, Shiinoki T, Tanabe S, Utsunomiya S, Kaidu M, Nishio T, Ishikawa H. Assessing tumor volumetric reduction with consideration for setup errors based on mathematical tumor model and microdosimetric kinetic model in single-isocenter VMAT for brain metastases. Phys Eng Sci Med 2024:10.1007/s13246-024-01451-8. [PMID: 38884671 DOI: 10.1007/s13246-024-01451-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 05/21/2024] [Indexed: 06/18/2024]
Abstract
The volumetric reduction rate (VRR) was evaluated with consideration for six degrees-of-freedom (6DoF) patient setup errors based on a mathematical tumor model in single-isocenter volumetric modulated arc therapy (SI-VMAT) for brain metastases. Simulated gross tumor volumes (GTV) of 1.0 cm and dose distribution were created (27 Gy/3 fractions). The distance between the GTV center and isocenter (d) was set at 0-10 cm. The GTV was translated within 0-1.0 mm (Trans) and rotated within 0-1.0° (Rot) in the three axis directions using affine transformation. The tumor growth volume was calculated using a multicomponent mathematical model (MCTM), and lethal effects of irradiation and repair from damage during irradiation were calculated by a microdosimetric kinetic model (MKM) for non-small cell lung cancer (NSCLC) A549 and NCI-H460 (H460) cells. The VRRs were calculated 5 days after the end of irradiation using the physical dose to the GTV for varying d and 6DoF setup errors. The tolerance value of VRR, the GTV volume reduction rate, was set at 5%, based on the pre-irradiation GTV volume. With the exception of the only one A549 condition where (Trans, Rot) = (1.0 mm, 1.0°) was repeated for 3 fractions, all conditions met all the tolerance VRR values for A549 and H460 cells with varying d from 0 to 10 cm. Evaluation based on the mathematical tumor model suggested that if the 6DoF setup errors at each irradiation could be kept within 1.0 mm and 1.0°, there would be little effect on tumor volume regardless of the distance from the isocenter in SI-VMAT.
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Affiliation(s)
- Hisashi Nakano
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-757 Asahimachi-dori, Chuo-ku, Niigata-shi, Niigata, Japan.
- Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, 1-7 Yamadaoka, Suita-shi, Osaka, Japan.
| | - Takehiro Shiinoki
- Department of Radiation Oncology, Yamaguchi University, Minamikogushi 1-1-1 Ube, Yamaguchi, Japan
| | - Satoshi Tanabe
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-757 Asahimachi-dori, Chuo-ku, Niigata-shi, Niigata, Japan
| | - Satoru Utsunomiya
- Department of Radiological Technology, Niigata University Graduate School of Health Sciences, 2-746 Asahimachi-dori, Chuo-ku, Niigata-shi, Niigata, Japan
| | - Motoki Kaidu
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-757 Asahimachi-dori, Chuo-ku, Niigata-shi, Niigata, Japan
| | - Teiji Nishio
- Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, 1-7 Yamadaoka, Suita-shi, Osaka, Japan
| | - Hiroyuki Ishikawa
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata-shi, Niigata, Japan
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Lai JL, Liu SP, Jiang XX, Liu J, Li A, Li B, Li XK, Ye XJ, Lei KJ, Zhou L. Can Optical Surface Imaging Replace Non-coplanar Cone-beam Computed Tomography for Non-coplanar Set-up Verification in Single-isocentre Non-coplanar Stereotactic Radiosurgery and Hypofractionated Stereotactic Radiotherapy for Single and Multiple Brain Metastases? Clin Oncol (R Coll Radiol) 2023; 35:e657-e665. [PMID: 37778972 DOI: 10.1016/j.clon.2023.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 08/03/2023] [Accepted: 09/18/2023] [Indexed: 10/03/2023]
Abstract
AIMS To conduct a direct comparison regarding the non-coplanar positioning accuracy between the optical surface imaging system Catalyst HDTM and non-coplanar cone-beam computed tomography (NC-CBCT) in intracranial single-isocentre non-coplanar stereotactic radiosurgery (SRS) and hypofractionated stereotactic radiotherapy (HSRT). MATERIALS AND METHODS Twenty patients with between one and five brain metastases who underwent single-isocentre non-coplanar volumetric modulated arc therapy (NC-VMAT) SRS or HSRT were enrolled in this study. For each non-zero couch angle, both Catalyst HDTM and NC-CBCT were used for set-up verification prior to beam delivery. The set-up error reported by Catalyst HDTM was compared with the set-up error derived from NC-CBCT, which was defined as the gold standard. Additionally, the dose delivery accuracy of each non-coplanar field after using Catalyst HDTM and NC-CBCT for set-up correction was measured with SRS MapCHECKTM. RESULTS The median set-up error differences (absolute values) between the two positioning methods were 0.30 mm, 0.40 mm, 0.50 mm, 0.15°, 0.10° and 0.10° in the vertical, longitudinal, lateral, yaw, pitch and roll directions, respectively. The largest absolute set-up error differences regarding translation and rotation were 1.5 mm and 1.1°, which occurred in the longitudinal and yaw directions, respectively. Only 35.71% of the pairs of measurements were within the tolerance of 0.5 mm and 0.5° simultaneously. In addition, the non-coplanar field with NC-CBCT correction yielded a higher gamma passing rate than that with Catalyst HDTM correction (P < 0.05), especially for evaluation criteria of 1%/1 mm with a median increase of 12.8%. CONCLUSIONS Catalyst HDTM may not replace NC-CBCT for non-coplanar set-up corrections in single-isocentre NC-VMAT SRS and HSRT for single and multiple brain metastases. The potential role of Catalyst HDTM in intracranial SRS/HSRT needs to be further studied in the future.
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Affiliation(s)
- J L Lai
- Radiotherapy Physics & Technology Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - S P Liu
- Radiotherapy Physics & Technology Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - X X Jiang
- Radiotherapy Physics & Technology Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - J Liu
- Department of Oncology, Chengdu First People's Hospital, Chengdu, Sichuan, China
| | - A Li
- Radiotherapy Physics & Technology Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - B Li
- Radiotherapy Physics & Technology Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - X K Li
- West China Clinical Medical College of Sichuan University, Chengdu, Sichuan, China
| | - X J Ye
- Department of Oncology, Yibin Second People's Hospital, Yibin, Sichuan, China
| | - K J Lei
- Department of Oncology, Yibin Second People's Hospital, Yibin, Sichuan, China
| | - L Zhou
- Thoracic Oncology Ward, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
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Lam CHM, Bernstein D, Wells E. Evaluation of PTV margins and plan robustness for single isocentre multiple target stereotactic radiosurgery. Phys Med 2023; 114:103137. [PMID: 37757499 DOI: 10.1016/j.ejmp.2023.103137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/12/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
PURPOSE Robustness to residual setup errors and linac delivery errors of BrainLab Elements single-isocentre-multiple-target stereotactic radiosurgery was evaluated. METHODS Residual setup errors of 13 patients were evaluated. Linac delivery error was quantified through multi-metastases-Winston-Lutz measurements. PTV margins were calculated using the van Herk recipe. Patient scans were translated and rotated by the median and 95th percentile of the combined uncertainties, and plans were recalculated subsequently. Previous patients' plans were then replanned with the derived margins, effects on GTV coverage and normal brain doses were assessed. RESULTS Mean (±stdev) coverage of all targets in the original plans were 99.4% (±0.9%) and 98.9% (±1.0%) for 1 and 3-fraction patients respectively. Median geometrical errors did not result in significant differences. A statistically significant reduction in coverage to 91.4% (±10.4%) and 93.0% (±9.6%) was seen under 95th percentile errors. Applying the derived optimal margin of 0.5 mm resulted in 78% of the GTVs retaining a coverage of 98% or above even in the presence of 95th percentile errors, compared to only 30% if no margins were applied. Replanning with margins also caused no significant increase to local normal brain doses, however global dose increases varied according to the number of metastases. CONCLUSIONS Plans were shown to be robust to average geometrical uncertainties despite targets having no margins, however occurrence of GTV under-coverage increased under 95th percentile scenarios. The margin was proven to substantially improve the target dose coverage with limited change to local normal brain doses, although not all sources of geometrical uncertainty were considered.
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Affiliation(s)
- Cheuk Him Michael Lam
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, Fulham Road, London SW3 6JJ, UK.
| | - David Bernstein
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, Fulham Road, London SW3 6JJ, UK.
| | - Emma Wells
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, Fulham Road, London SW3 6JJ, UK.
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Yock AD, Grees B, Luo G. Innovative margin design and optimized isocenter to minimize the normal tissue in target volumes for single-isocenter multi-target stereotactic radiosurgery. Phys Med Biol 2023; 68:195025. [PMID: 37673075 DOI: 10.1088/1361-6560/acf751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 09/06/2023] [Indexed: 09/08/2023]
Abstract
Objective.Treating multiple brain metastases in a single plan is a popular radiosurgery technique. However, targets positioned off-isocenter are subject to rotational uncertainties. This work introduces two new planning target volumes (PTVs) that address this increased uncertainty. The volume of normal tissue included in these PTVs when paired with optimized isocenters are evaluated and compared with conventional methods.Approach.Sets of 1000 random multi-target radiosurgery patients were simulated, each patient with a random number of spherical targets (2-10). Each target had a random volume (0.1-15 cc) and was randomly positioned between 5 and 50 mm or 100 mm from isocenter. Two new PTVs ('LensPTV' and 'SwipePTV') and conventional isotropic PTVs were created using isocenters derived from the center-of-centroids, the center-of-mass, or optimized per PTV type. The total volume of normal tissue in the PTVs for each patient was calculated and compared using 1 mm translations and 0.5°, 1.0°, and 2.0° rotations.Main results.Using the new PTVs and/or using optimized isocenters decreased the total volume of normal tissue in the PTVs per patient. The SwipePTV, in particular, provided the greatest decrease. Compared to the SwipePTV, the LensPTV and the conventional isotropic PTV included an extra 0.68 and 0.73 cc of normal tissue per patient (median), respectively, when using 50 mm max distance to isocenter and 1° max rotation angle. Under these conditions, 25% of patients had extra volume of normal tissue ≥ 0.96 and 1.04 cc. When using 100 mm max distance to isocenter and 2° max rotation angle, 25% of patients had extra volume of normal tissue ≥ 4.35 and 5.75 cc.Significance.PTVs like those presented here, especially when paired with optimized isocenters, can decrease the total volume of included normal tissue and reduce the risk of toxicity without compromising target coverage.
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Affiliation(s)
- Adam D Yock
- Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Beshoi Grees
- Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Guozhen Luo
- Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN, United States of America
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Yamada T, Nakano H, Tanabe S, Sakai T, Tanabe S, Oka T, Sakai H, Oshikane T, Nakano T, Ohta A, Kanazawa T, Kaidu M, Ishikawa H. Verification of Qfix Encompass™ couch modeling using the Acuros XB algorithm and HypeArc™ using a high-spatial-resolution two-dimensional diode array. Med Dosim 2023; 48:261-266. [PMID: 37455221 DOI: 10.1016/j.meddos.2023.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 05/15/2023] [Accepted: 06/20/2023] [Indexed: 07/18/2023]
Abstract
We modeled the Qfix Encompass™ immobilization system and further verified the calculated dose distribution of the AcurosXB (AXB) dose calculation algorithm using SRS MapCHECKⓇ (SRSMC) in the HyperArc™ (HA) clinical plan. An Encompass system with a StereoPHAN™ QA phantom was scanned by SOMATOM go.Sim and imported to an Eclipse™ treatment planning system to create a treatment plan for Encompass modeling. The Encompass modeling was performed in the StereoPHAN with a pinpoint ion chamber for 6 MV and 6 MV flattening filter free (6 MV FFF), and 2 × 2 cm2, 4 × 4 cm2, and 6 × 6 cm2 irradiation field sizes. The dose calculation algorithm used was AXB ver. 15.5 with a 1.0 mm calculation grid size. The Hounsfield unit (HU) values of the Encompass modeling were set to 400, -100, -200, and -300 for Encompass, and -400, -600, -700, and -800 for the Encompass base. We evaluated the dose distribution after Encompass modeling by SRSMC using gamma analysis in 12 patients. We adopted HU values of -200 for Encompass, -800 for Encompass base for 6 MV, and -200 for Encompass and -700 for Encompass. Base for 6 MV FFF was adopted as the HU values for the Encompass modeling based on the measurement results. The proposed Encompass modeling resulted in a mean pass rate evaluation >98% for both 6 MV and 6 MV FFF when the 1%/1 mm criterion was used, demonstrating that the proposed HU value can be adopted to calculate more accurate dose distributions.
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Affiliation(s)
- Takumi Yamada
- Section of Radiology, Department of Clinical Support, Niigata University Medical and Dental Hospital, Niigata, 951-8520, Japan
| | - Hisashi Nakano
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, Niigata 951-8520, Japan; Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan.
| | - Satoshi Tanabe
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, Niigata 951-8520, Japan
| | - Tatsuya Sakai
- Section of Radiology, Department of Clinical Support, Niigata University Medical and Dental Hospital, Niigata, 951-8520, Japan
| | - Shunpei Tanabe
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, Niigata 951-8520, Japan
| | - Tetsuya Oka
- Section of Radiology, Department of Clinical Support, Niigata University Medical and Dental Hospital, Niigata, 951-8520, Japan
| | - Hironori Sakai
- Section of Radiology, Department of Clinical Support, Niigata University Medical and Dental Hospital, Niigata, 951-8520, Japan
| | - Tomoya Oshikane
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, Niigata 951-8520, Japan
| | - Toshimichi Nakano
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, 951-8122, Japan
| | - Atsushi Ohta
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, Niigata 951-8520, Japan
| | - Tsutomu Kanazawa
- Section of Radiology, Department of Clinical Support, Niigata University Medical and Dental Hospital, Niigata, 951-8520, Japan
| | - Motoki Kaidu
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, 951-8122, Japan
| | - Hiroyuki Ishikawa
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, 951-8122, Japan
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Shen Z, Wang H, Shao Y, Duan Y, Gu H, Chen H, Feng A, Huang Y, Xu Z. Optimization of isocenter position for multiple brain metastases single-isocenter stereotactic radiosurgery to minimize dosimetric variations due to rotational uncertainty. Phys Med 2023; 111:102614. [PMID: 37295129 DOI: 10.1016/j.ejmp.2023.102614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 05/03/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023] Open
Abstract
PURPOSE This paper studied a novel calculation framework that can determine the optimal value isocenter position of single isocenter SRS treatment plan for multiple brain metastases, in order to minimize the dosimetric variations caused by rotational uncertainty. MATERIALS AND METHODS 21 patients with 2-4 GTVswho received SRS treatment for multiple brain metastases in our institution were selected for the retrospective study. The PTVwas obtained by expanding GTV 1 mm isotropic margin. We studied a stochastic optimization framework, which determined the optimal value isocenter location by maximizing the average target dose coverageCtarget,meanwith a rotation error of no more than 1°. We evaluated the performance of the optimal isocenter by comparing theCtarget,meanand average dice similarity coefficient (DSC)with the optimal value and the center of mass (CM) respectively as the treatment isocenter. The extra PTV margin to achieve 100% target dose coverage was calculated by our framework. RESULTS Compared to the CM method, the optimal value isocenter method increased the averageCtarget,meanof all targets from 97.0% to 97.7%and the average DSC from 0.794to 0.799. Throughout all the cases, the average extra PTV margin to obtain full target dose coverage was 0.7 mmwhen using the optimal value isocenter as the treatment isocenter. CONCLUSION We studied a novel computational framework using stochastic optimization to determine the optimal isocenter position of SRS treatment plan for multiple brain metastases. At the same time, our framework gave the extra PTV margin to obtain full target dose coverage.
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Affiliation(s)
- Zhenjiong Shen
- Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hao Wang
- Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yan Shao
- Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yanhua Duan
- Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hengle Gu
- Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hua Chen
- Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Aihui Feng
- Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ying Huang
- Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhiyong Xu
- Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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Nakano H, Shiinoki T, Tanabe S, Nakano T, Takizawa T, Utsunomiya S, Sakai M, Tanabe S, Ohta A, Kaidu M, Nishio T, Ishikawa H. Multicomponent mathematical model for tumor volume calculation with setup error using single-isocenter stereotactic radiotherapy for multiple brain metastases. Phys Eng Sci Med 2023; 46:945-953. [PMID: 36940064 DOI: 10.1007/s13246-023-01241-8] [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: 09/30/2022] [Accepted: 03/06/2023] [Indexed: 03/21/2023]
Abstract
We evaluated the tumor residual volumes considering six degrees-of-freedom (6DoF) patient setup errors in stereotactic radiotherapy (SRT) with multicomponent mathematical model using single-isocenter irradiation for brain metastases. Simulated spherical gross tumor volumes (GTVs) with 1.0 (GTV 1), 2.0 (GTV 2), and 3.0 (GTV 3)-cm diameters were used. The distance between the GTV center and isocenter (d) was set at 0-10 cm. The GTV was simultaneously translated within 0-1.0 mm (T) and rotated within 0°-1.0° (R) in the three axis directions using affine transformation. We optimized the tumor growth model parameters using measurements of non-small cell lung cancer cell lines' (A549 and NCI-H460) growth. We calculated the GTV residual volume at the irradiation's end using the physical dose to the GTV when the GTV size, d, and 6DoF setup error varied. The d-values that satisfy tolerance values (10%, 35%, and 50%) of the GTV residual volume rate based on the pre-irradiation GTV volume were determined. The larger the tolerance value set for both cell lines, the longer the distance to satisfy the tolerance value. In GTV residual volume evaluations based on the multicomponent mathematical model on SRT with single-isocenter irradiation, the smaller the GTV size and the larger the distance and 6DoF setup error, the shorter the distance that satisfies the tolerance value might need to be.
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Affiliation(s)
- Hisashi Nakano
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-757 Asahimachi-Dori, Chuo-Ku, Niigata-Shi, Niigata, Japan. .,Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, 1-7 Yamadaoka, Suita-Shi, Osaka, Japan.
| | - Takehiro Shiinoki
- Department of Radiation Oncology, Yamaguchi University, Minamikogushi 1-1-1 Ube, Yamaguchi, Japan
| | - Satoshi Tanabe
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-757 Asahimachi-Dori, Chuo-Ku, Niigata-Shi, Niigata, Japan
| | - Toshimichi Nakano
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-Dori, Chuo-Ku, Niigata-Shi, Niigata, Japan
| | - Takeshi Takizawa
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-Dori, Chuo-Ku, Niigata-Shi, Niigata, Japan.,Department of Radiation Oncology, Niigata Neurosurgical Hospital, 3057 Yamada, Nishi-Ku, Niigata-Shi, Niigata, Japan
| | - Satoru Utsunomiya
- Department of Radiological Technology, Niigata University Graduate School of Health Sciences, 2-746 Asahimachi-Dori, Chuo-Ku, Niigata-Shi, Niigata, Japan
| | - Madoka Sakai
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-757 Asahimachi-Dori, Chuo-Ku, Niigata-Shi, Niigata, Japan
| | - Shunpei Tanabe
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-757 Asahimachi-Dori, Chuo-Ku, Niigata-Shi, Niigata, Japan
| | - Atsushi Ohta
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, 1-757 Asahimachi-Dori, Chuo-Ku, Niigata-Shi, Niigata, Japan
| | - Motoki Kaidu
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-Dori, Chuo-Ku, Niigata-Shi, Niigata, Japan
| | - Teiji Nishio
- Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, 1-7 Yamadaoka, Suita-Shi, Osaka, Japan
| | - Hiroyuki Ishikawa
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-Dori, Chuo-Ku, Niigata-Shi, Niigata, Japan
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10
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Ono T, Kido T, Nakamura M, Iramina H, Kakino R, Mizowaki T. Automatic measurement of beam-positioning accuracy at off-isocenter positions. J Appl Clin Med Phys 2023; 24:e13844. [PMID: 36420973 PMCID: PMC10018661 DOI: 10.1002/acm2.13844] [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: 08/07/2022] [Revised: 10/22/2022] [Accepted: 10/26/2022] [Indexed: 11/25/2022] Open
Abstract
PURPOSE This study performed an automatic measurement of the off-axis beam-positioning accuracy at a single isocenter via the TrueBeam Developer mode and evaluated the beam-positioning accuracy considering the effect of couch rotational errors. METHODS TrueBeam STx and the Winston-Lutz test-dedicated phantom, with a 3 mm diameter steel ball, were used in this study. The phantom was placed on the treatment couch, and the Winston-Lutz test was performed at the isocenter for four gantry angles (0°, 90°, 180°, and 270°) using an electronic portal imaging device. The phantom offset positions were at distances of 0, 25, 50, 75, and 100 mm from the isocenter along the superior-inferior, anterior-posterior, and left-right directions. Seventeen patterns of multileaf collimator-shaped square fields of 10 × 10 mm2 were created at the isocenter and off-axis positions for each gantry angle. The beam-positioning accuracy was evaluated with couch rotation along the yaw-axis (0°, ± 0.5°, and ± 1.0°). RESULTS The mean beam-positioning errors at the isocenter and off-isocenter distances (from the isocenter to ±100 mm) were 0.46-0.60, 0.44-0.91, and 0.42-1.11 mm for the couch angles of 0°, ±0.5°, and ±1°, respectively. The beam-positioning errors increased as the distance from the isocenter and couch rotation increased. CONCLUSION These findings suggest that the beam-positioning accuracy at the isocenter and off-isocenter positions can be evaluated quickly and automatically using the TrueBeam Developer mode. The proposed procedure is expected to contribute to an efficient evaluation of the beam-positioning accuracy at off-isocenter positions.
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Affiliation(s)
- Tomohiro Ono
- Department of Radiation Oncology and Image‐Applied TherapyKyoto UniversityKyotoJapan
| | - Takahisa Kido
- Department of Information Technology and Medical EngineeringHuman Health SciencesGraduate School of MedicineKyoto UniversityKyotoJapan
| | - Mitsuhiro Nakamura
- Department of Information Technology and Medical EngineeringHuman Health SciencesGraduate School of MedicineKyoto UniversityKyotoJapan
| | - Hiraku Iramina
- Department of Radiation Oncology and Image‐Applied TherapyKyoto UniversityKyotoJapan
| | - Ryo Kakino
- Kansai BNCT Medical Center, OsakaMedical and Pharmaceutical UniversityTakatsukiJapan
| | - Takashi Mizowaki
- Department of Radiation Oncology and Image‐Applied TherapyKyoto UniversityKyotoJapan
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Yoon JW, Kim MY, Park S, Cheong KH, Kang SK, Koo T, Han TJ. Cross-irradiation in multiple isocenter frameless treatment for limited number of multiple brain metastases with volumetric modulated arc therapy. JOURNAL OF RADIATION RESEARCH AND APPLIED SCIENCES 2023. [DOI: 10.1016/j.jrras.2023.100529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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12
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Lai J, Liu S, Liu J, Li X, Chen J, Jia Y, Lei K, Zhou L. Clinical Feasibility of Using Single-isocentre Non-coplanar Volumetric Modulated Arc Therapy Combined with Non-coplanar Cone Beam Computed Tomography in Hypofractionated Stereotactic Radiotherapy for Five or Fewer Multiple Intracranial Metastases. Clin Oncol (R Coll Radiol) 2023; 35:408-416. [PMID: 37002009 DOI: 10.1016/j.clon.2023.03.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 01/08/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023]
Abstract
AIMS To evaluate the clinical feasibility of single-isocentre non-coplanar volumetric modulated arc therapy (NC-VMAT) with non-coplanar cone beam computed tomography (NC-CBCT) in hypofractionated stereotactic radiotherapy (HSRT) for five or fewer multiple brain metastases. MATERIALS AND METHODS Ten patients with multiple brain metastases who underwent single-isocentre NC-VMAT HSRT with limited couch rotations (within ±45°) and NC-CBCT with a limited scanning range (150-200°) were included in the current analysis. Conventional single-isocentre coplanar VMAT (C-VMAT) plans were generated and compared with NC-VMAT plans. The intracranial response and toxicities of single-isocentre NC-VMAT HSRT were also evaluated. RESULTS Compared with C-VMAT, NC-VMAT generated better target conformity (P < 0.05), a lower gradient index (P < 0.05) and better normal brain tissue sparing, especially for volume ≥12 Gy, with a median reduction of 12.65 cm3. For 45° couch rotation, NC-CBCT produced sufficient image quality to differentiate bony anatomy, even with a 150° scanning range, which could be successfully used for patient set-up correction. After NC-CBCT, 57.1% of the measured non-coplanar set-up errors exceeded the threshold value. The median gamma passing rate of NC-VMAT was higher than that of C-VMAT plans (P < 0.05). The non-coplanar beam of NC-VMAT with NC-CBCT corrections exhibited superior gamma passing rate to that without NC-CBCT corrections. The intracranial objective response rate and disease control rate for all patients were 80% (8/10) and 100% (10/10), respectively, and the most common toxicities were headache (20%) and dizziness (20%). CONCLUSION NC-VMAT with limited couch rotation (within ±45°) combined with NC-CBCT with a limited scanning range (150-200°) markedly improves the plan quality and set-up accuracy in single-isocentre multiple-target HSRT.
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13
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Dial C, Sarkar V, Nelson G, Paxton A, Salter B. Technical note: A method for generating lesion-specific nonuniform rotational margins for targets remote from isocenter. Med Phys 2022; 49:7438-7446. [PMID: 36201254 DOI: 10.1002/mp.16013] [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: 11/30/2021] [Revised: 08/27/2022] [Accepted: 09/04/2022] [Indexed: 12/27/2022] Open
Abstract
PURPOSE To present a novel method for generating nonuniform lesion-specific rotational margins for targets remote from isocenter, as encountered in single isocenter multiple metastasis radiotherapy. METHODS Target contours are rotated using a large series of 3D rotations, corresponding to a given range of rotational uncertainty, and combined to create a rotational envelope that encompasses potential motion. A set of artificial spherical targets ranging from 0.5 to 2.0 cm in diameter, and residing a distance of 1 - 15 cm from isocenter, is used to generate rotational envelopes assuming uncertainties of 0.5-3.0°. Computing time and number of samples are reported for simulated scenarios. Hausdorff distances (HD) between rotational envelopes and original target structures are calculated to represent the magnitude of uniform expansion required to encompass potential rotation. Volume differences between uniform expansions (based on HD) and rotational envelopes are reported to articulate potential advantages. RESULTS Median time to generate rotational envelopes was 60 s (31-974 s). Median required samples was 86 (61-851). Maximum HD for all targets located 10 cm from isocenter was 1.5 mm, 3.0 mm, 5.8 mm, and 8.6 mm assuming 0.5°, 1.0°, 2.0°, and 3.0° of rotational uncertainty, respectively. At 5 cm from isocenter and assuming 0.5° of rotational uncertainty, volumes were decreased by 0.07 cc (60%), 0.24 cc (39%), and 1.08 cc (19%) for 5 mm, 10 mm, and 20 mm targets respectively. At 10 cm from isocenter and 1.0° of uncertainty, volumes decreased by 0.42 cc (58%), 2.0 cc (40%), and 2.5 cc (27%). On average target volumes decreased 45% (SD = 17%) when compared with uniform expansions based on HD. CONCLUSION Rotational margins may be generated by sampling a set of 3D rotations. Resulting margins explicitly account for target shape, distance from isocenter, and magnitude of rotational uncertainty, while reducing treated volumes when compared with uniform expansions.
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Affiliation(s)
- Christian Dial
- Department of Radiation Oncology, University of Utah, 1950 Circle of Hope Dr., Salt Lake City, Utah, USA
| | - Vikren Sarkar
- Department of Radiation Oncology, University of Utah, 1950 Circle of Hope Dr., Salt Lake City, Utah, USA
| | - Geoff Nelson
- Department of Radiation Oncology, University of Utah, 1950 Circle of Hope Dr., Salt Lake City, Utah, USA
| | - Adam Paxton
- Department of Radiation Oncology, University of Utah, 1950 Circle of Hope Dr., Salt Lake City, Utah, USA
| | - Bill Salter
- Department of Radiation Oncology, University of Utah, 1950 Circle of Hope Dr., Salt Lake City, Utah, USA
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14
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Retif P, Djibo Sidikou A, Mathis C, Letellier R, Verrecchia-Ramos E, Dupres R, Michel X. Evaluation of the ability of the Brainlab Elements Cranial Distortion Correction algorithm to correct clinically relevant MRI distortions for cranial SRT. Strahlenther Onkol 2022; 198:907-918. [PMID: 35980455 DOI: 10.1007/s00066-022-01988-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 07/10/2022] [Indexed: 11/29/2022]
Abstract
PURPOSE Cranial stereotactic radiotherapy (SRT) requires highly accurate lesion delineation. However, MRI can have significant inherent geometric distortions. We investigated how well the Elements Cranial Distortion Correction algorithm of Brainlab (Munich, Germany) corrects the distortions in MR image-sets of a phantom and patients. METHODS A non-distorted reference computed tomography image-set of a CIRS Model 603-GS (CIRS, Norfolk, VA, USA) phantom was acquired. Three-dimensional T1-weighted images were acquired with five MRI scanners and reconstructed with vendor-derived distortion correction. Some were reconstructed without correction to generate heavily distorted image-sets. All MR image-sets were corrected with the Brainlab algorithm relative to the computed tomography acquisition. CIRS Distortion Check software measured the distortion in each image-set. For all uncorrected and corrected image-sets, the control points that exceeded the 0.5-mm clinically relevant distortion threshold and the distortion maximum, mean, and standard deviation were recorded. Empirical cumulative distribution functions (eCDF) were plotted. Intraclass correlation coefficient (ICC) was calculated. The algorithm was evaluated with 10 brain metastases using Dice similarity coefficients (DSC). RESULTS The algorithm significantly reduced mean and standard deviation distortion in all image-sets. It reduced the maximum distortion in the heavily distorted image-sets from 2.072 to 1.059 mm and the control points with > 0.5-mm distortion fell from 50.2% to 4.0%. Before and especially after correction, the eCDFs of the four repeats were visually similar. ICC was 0.812 (excellent-good agreement). The algorithm increased the DSCs for all patients and image-sets. CONCLUSION The Brainlab algorithm significantly and reproducibly ameliorated MRI distortion, even with heavily distorted images. Thus, it increases the accuracy of cranial SRT lesion delineation. After further testing, this tool may be suitable for SRT of small lesions.
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Affiliation(s)
- Paul Retif
- Medical Physics Unit, CHR Metz-Thionville, Metz, France. .,Université de Lorraine, CNRS, CRAN, 54000, Nancy, France.
| | | | | | | | | | - Rémi Dupres
- Medical Imaging Department, CHR Metz-Thionville, Metz, France
| | - Xavier Michel
- Radiation Therapy Department, CHR Metz-Thionville, Metz, France
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15
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Tomihara J, Takatsu J, Hara N, Sugimoto S, Shikama N, Sasai K. Intracranial stereotactic radiotherapy in off-isocenter target with SyncTraX FX4. Phys Med 2022; 100:105-111. [DOI: 10.1016/j.ejmp.2022.06.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 06/13/2022] [Accepted: 06/29/2022] [Indexed: 11/29/2022] Open
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16
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Prentou G, Pappas EP, Prentou E, Yakoumakis N, Paraskevopoulou C, Koutsouveli E, Pantelis E, Papagiannis P, Karaiskos P. Impact of systematic MLC positional uncertainties on the quality of single-isocenter multi-target VMAT-SRS treatment plans. J Appl Clin Med Phys 2022; 23:e13708. [PMID: 35733367 PMCID: PMC9359048 DOI: 10.1002/acm2.13708] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 06/08/2022] [Indexed: 12/02/2022] Open
Abstract
Purpose To study the impact of systematic MLC leaf positional uncertainties (stemming from mechanical inaccuracies or sub‐optimal MLC modeling) on the quality of intracranial single‐isocenter multi‐target VMAT‐SRS treatment plans. An estimation of appropriate tolerance levels is attempted. Methods Five patients, with three to four metastases and at least one target lying in close proximity to organs‐at‐risk (OARs) were included in this study. A single‐isocenter multi‐arc VMAT plan per patient was prepared, which served as the reference for dosimetric impact evaluation. A range of leaf offsets was introduced (±0.03 mm up to ±0.30 mm defined at the MLC plane) to both leaf banks, by varying the leaf offset MLC modeling parameter in Monaco for all the prepared plans, in order to simulate projected leaf offsets of ±0.09 mm up to ±0.94 mm at the isocenter plane, respectively. For all offsets simulated and cases studied, dose distributions were re‐calculated and compared with the corresponding reference ones. An experimental dosimetric procedure using the SRS mapCHECK diode array was also performed to support the simulation study results and investigate its suitability to detect small systematic leaf positional errors. Results Projected leaf offsets of ±0.09 mm were well‐tolerated with respect to both target dosimetry and OAR‐sparing. A linear relationship was found between D95% percentage change and projected leaf offset (slope: 12%/mm). Impact of projected offset on target dosimetry was strongly associated with target volume. In two cases, plans that could be considered potentially clinically unacceptable (i.e., clinical dose constraint violation) were obtained even for projected offsets as small as 0.19 mm. The performed experimental dosimetry check can detect potential small systematic leaf errors. Conclusions Plan quality indices and dose–volume metrics are very sensitive to systematic sub‐millimeter leaf positional inaccuracies, projected at the isocenter plane. Acceptable and tolerance levels in systematic MLC uncertainties need to be tailored to VMAT‐SRS spatial and dosimetric accuracy requirements.
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Affiliation(s)
- Georgia Prentou
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Eleftherios P Pappas
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Eleni Prentou
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | | | | | | | - Evaggelos Pantelis
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Panagiotis Papagiannis
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Pantelis Karaiskos
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, Greece
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17
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Tsuruta Y, Nakamura M, Nakata M, Hirashima H, Zhou D, Uto M, Takehana K, Fujimoto T, Mizowaki T. Evaluation of correlation between intrafractional residual setup errors and accumulation of delivered dose distributions in single isocenter volumetric modulated arc therapy for multiple brain metastases. Phys Med 2022; 98:45-52. [DOI: 10.1016/j.ejmp.2022.04.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 03/30/2022] [Accepted: 04/22/2022] [Indexed: 11/25/2022] Open
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18
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Rotational effect and dosimetric impact: HDMLC vs 5-mm MLC leaf width in single isocenter multiple metastases radiosurgery with Brainlab Elements™. JOURNAL OF RADIOTHERAPY IN PRACTICE 2022. [DOI: 10.1017/s1460396922000048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
Purpose:
To analyse the impact of multileaf collimator (MLC) leaf width in multiple metastases radiosurgery (SRS) considering the target distance to isocenter and rotational displacements.
Methods:
Ten plans were optimised. The plans were created with Elements Multiple Mets SRS v2·0 (Brainlab AG, Munchen, Germany). The mean number of metastases per plan was 5 ± 2 [min 3, max 9], and the mean volume of gross tumour volume (GTV) was 1·1 ± 1·3 cc [min 0·02, max 5·1]. Planning target volume margin criterion was based on GTV-isocenter distance and target dimensions. Plans were performed using 6 MV with high-definition MLC (HDMLC) and reoptimised using 5-mm MLC (MLC-5). Plans were compared using Paddick conformity index (PCI), gradient index, monitor units , volume receiving half of prescription isodose (PIV50), maximum dose to brainstem, optic chiasm and optic nerves, and V12Gy, V10Gy and V5Gy for healthy brain were analysed. The maximum displacement due to rotational combinations was optimised by a genetic algorithm for both plans. Plans were reoptimised and compared using optimised margin.
Results:
HDMLC plans had better conformity and higher dose falloff than MLC-5 plans. Dosimetric differences were statistically significant (p < 0·05). The smaller the lesion volume, the higher the dosimetric differences between both plans. The effect of rotational displacements produced for each target in SRS was not dependent on the MLC (p > 0·05).
Conclusions:
The finer HDMLC offers dosimetric advantages compared with the MLC-5 in terms of target conformity and dose to the surrounding organs at risk. However, only dose falloff differences due to rotations depend on MLC.
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Takizawa T, Tanabe S, Nakano H, Utsunomiya S, Sakai M, Maruyama K, Takeuchi S, Nakano T, Ohta A, Kaidu M, Ishikawa H, Onda K. The impact of target positioning error and tumor size on radiobiological parameters in robotic stereotactic radiosurgery for metastatic brain tumors. Radiol Phys Technol 2022; 15:135-146. [DOI: 10.1007/s12194-022-00655-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 02/25/2022] [Accepted: 02/26/2022] [Indexed: 12/01/2022]
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20
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Yoshida Y, Soyama M, Azumi R. Evaluation of additional treatment margins for compensating rotational random errors in linac-based single-isocenter stereotactic radiotherapy for multiple brain metastases. JOURNAL OF RADIOSURGERY AND SBRT 2022; 8:59-62. [PMID: 35387407 PMCID: PMC8930059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 08/23/2021] [Indexed: 01/03/2023]
Affiliation(s)
- Yasuhisa Yoshida
- Department of Radiology, Nishi-Niigata Chuo National Hospital, 1-14-1 Masago, Nishi-ku, Niigata 950-2085 Japan
| | - Maki Soyama
- Department of Radiology, Nishi-Niigata Chuo National Hospital, 1-14-1 Masago, Nishi-ku, Niigata 950-2085 Japan
| | - Rieko Azumi
- Department of Radiology, Nishi-Niigata Chuo National Hospital, 1-14-1 Masago, Nishi-ku, Niigata 950-2085 Japan
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Yoon JW, Park S, Cheong KH, Kang SK, Han TJ. Combined effect of dose gradient and rotational error on prescribed dose coverage for single isocenter multiple brain metastases in frameless stereotactic radiotherapy. Radiat Oncol 2021; 16:169. [PMID: 34465331 PMCID: PMC8406565 DOI: 10.1186/s13014-021-01893-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 08/25/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To evaluate the combined effect of rotational error and dose gradient on target dose coverage in frameless stereotactic radiotherapy. METHODS Three spherical targets of different diameters (1, 1.5, and 2 cm) were drawn and placed equidistantly on the same axial brain computed tomography (CT) images. To test the different isocenter-target distances, 2.5- and 5-cm configurations were prepared. Volumetric modulated arc therapy plans were created for different dose gradients from the target, in which the dose gradients were modified using the maximum dose inside the target. To simulate the rotational error, CT images and targets were rotated in two ways by 0.5°, 1°, and 2°, in which one rotation was in the axial plane and the other was in three dimensions. The initial optimized plan parameters were copied to the rotated CT sets, and the doses were recalculated. The coverage degradation after rotation was analyzed according to the target dislocation and 12-Gy volume. RESULTS A shallower dose gradient reduced the loss of target coverage under target dislocation, and the effect was clearer for small targets. For example, the coverage of the 1-cm target under 1-mm dislocation increased from 93 to 95% by increasing the Paddick gradient index from 5.0 to 7.9. At the same time, the widely accepted necrosis indicator, the 12-Gy volume, increased from 1.2 to 3.5 cm3, which remained in the tolerable range. From the differential dose volume histogram (DVH) analysis, the shallower dose gradient ensured that the dose-deficient under-covered target volume received a higher dose similar to that in the prescription. CONCLUSIONS For frameless stereotactic brain radiotherapy, the gradient, alongside the margin addition, can be adjusted as an ancillary parameter for small targets to increase target coverage or at least limit coverage reduction in conditions with probable positioning error.
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Affiliation(s)
- Jai-Woong Yoon
- Department of Radiation Oncology, Dongtan Sacred Heart Hospital, Hwaseong, Korea
| | - Soah Park
- Department of Radiation Oncology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Kwang-Ho Cheong
- Department of Radiation Oncology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea
| | - Sei-Kwon Kang
- Department of Radiation Oncology, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
| | - Tae Jin Han
- Department of Radiation Oncology, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
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Tomihara J, Takatsu J, Sugimoto S, Shikama N, Sasai K. Intrafraction stability using full head mask for brain stereotactic radiotherapy. J Appl Clin Med Phys 2021; 22:360-370. [PMID: 34347933 PMCID: PMC8425876 DOI: 10.1002/acm2.13382] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 06/09/2021] [Accepted: 07/19/2021] [Indexed: 11/11/2022] Open
Abstract
Purpose We investigated the immobilization accuracy of a new type of thermoplastic mask—the Double Shell Positioning System (DSPS)—in terms of geometry and dose delivery. Methods Thirty‐one consecutive patients with 1–5 brain metastases treated with stereotactic radiotherapy (SRT) were selected and divided into two groups. Patients were divided into two groups. One group of patients was immobilized by the DSPS (n = 9). Another group of patients was immobilized by a combination of the DSPS and a mouthpiece (n = 22). Patient repositioning was performed with cone beam computed tomography (CBCT) and six‐degree of freedom couch. Additionally, CBCT images were acquired before and after treatment. Registration errors were analyzed with off‐line review. The inter‐ and intrafractional setup errors, and planning target volume (PTV) margin were also calculated. Delivered doses were calculated by shifting the isocenter according to inter‐ and intrafractional setup errors. Dose differences of GTV D99% were compared between planned and delivered doses against the modified PTV margin of 1 mm. Results Interfractional setup errors associated with the mouthpiece group were significantly smaller than the translation errors in another group (p = 0.03). Intrafractional setup errors for the two groups were almost the same in all directions. PTV margins were 0.89 mm, 0.75 mm, and 0.90 mm for the DSPS combined with the mouthpiece in lateral, vertical, and longitudinal directions, respectively. Similarly, PTV margins were 1.20 mm, 0.72 mm, and 1.37 mm for the DSPS in the lateral, vertical, and longitudinal directions, respectively. Dose differences between planned and delivered doses were small enough to be within 1% for both groups. Conclusions The geometric and dosimetric assessments revealed that the DSPS provides sufficient immobilization accuracy. Higher accuracy can be expected when the immobilization is combined with the use of a mouthpiece.
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Affiliation(s)
- Jun Tomihara
- Department of Radiation Oncology, Graduate School of Medicine, Juntendo University, Tokyo, Japan.,Department of Radiology, Juntendo University Hospital, Tokyo, Japan
| | - Jun Takatsu
- Department of Radiation Oncology, Juntendo University, Tokyo, Japan
| | - Satoru Sugimoto
- Department of Radiation Oncology, Juntendo University, Tokyo, Japan
| | - Naoto Shikama
- Department of Radiation Oncology, Juntendo University, Tokyo, Japan
| | - Keisuke Sasai
- Department of Radiation Oncology, Juntendo University, Tokyo, Japan
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Nakano H, Tanabe S, Sasamoto R, Takizawa T, Utsunomiya S, Sakai M, Nakano T, Ohta A, Kaidu M, Ishikawa H. Radiobiological evaluation considering setup error on single-isocenter irradiation in stereotactic radiosurgery. J Appl Clin Med Phys 2021; 22:266-275. [PMID: 34151498 PMCID: PMC8292684 DOI: 10.1002/acm2.13322] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 05/19/2021] [Accepted: 05/24/2021] [Indexed: 11/06/2022] Open
Abstract
Purpose We calculated the dosimetric indices and estimated the tumor control probability (TCP) considering six degree‐of‐freedom (6DoF) patient setup errors in stereotactic radiosurgery (SRS) using a single‐isocenter technique. Methods We used simulated spherical gross tumor volumes (GTVs) with diameters of 1.0 cm (GTV 1), 2.0 cm (GTV 2), and 3.0 cm (GTV 3), and the distance (d) between the target center and isocenter was set to 0, 5, and 10 cm. We created the dose distribution by convolving the blur component to uniform dose distribution. The prescription dose was 20 Gy and the dose distribution was adjusted so that D95 (%) of each GTV was covered by 100% of the prescribed dose. The GTV was simultaneously rotated within 0°–1.0° (δR) around the x‐, y‐, and z‐axes and then translated within 0–1.0 mm (δT) in the x‐, y‐, and z‐axis directions. D95, conformity index (CI), and conformation number (CN) were evaluated by varying the distance from the isocenter. The TCP was estimated by translating the calculated dose distribution into a biological response. In addition, we derived the x‐y‐z coordinates with the smallest TCP reduction rate that minimize the sum of squares of the residuals as the optimal isocenter coordinates using the relationship between 6DoF setup error, distance from isocenter, and GTV size. Results D95, CI, and CN were decreased with increasing isocenter distance, decreasing GTV size, and increasing setup error. TCP of GTVs without 6DoF setup error was estimated to be 77.0%. TCP were 25.8% (GTV 1), 35.0% (GTV 2), and 53.0% (GTV 3) with (d, δT,δR) = (10 cm, 1.0 mm, 1.0°). The TCP was 52.3% (GTV 1), 54.9% (GTV 2), and 66.1% (GTV 3) with (d, δT,δR) = (10 cm, 1.0 mm, 1.0°) at the optimal isocenter position. Conclusion The TCP in SRS for multiple brain metastases with a single‐isocenter technique may decrease with increasing isocenter distance and decreasing GTV size when the 6DoF setup errors are exceeded (1.0 mm, 1.0°). Additionally, it might be possible to better maintain TCP for GTVs with 6DoF setup errors by using the optimal isocenter position.
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Affiliation(s)
- Hisashi Nakano
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, Niigata, Japan
| | - Satoshi Tanabe
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, Niigata, Japan
| | - Ryuta Sasamoto
- Department of Radiological Technology, Niigata University Graduate School of Health Sciences, Niigata, Japan
| | - Takeshi Takizawa
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, Niigata, Japan.,Department of Radiation Oncology, Niigata Neurosurgical Hospital, Niigata, Japan
| | - Satoru Utsunomiya
- Department of Radiological Technology, Niigata University Graduate School of Health Sciences, Niigata, Japan
| | - Madoka Sakai
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, Niigata, Japan
| | - Toshimichi Nakano
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Atsushi Ohta
- Department of Radiation Oncology, Niigata University Medical and Dental Hospital, Niigata, Japan
| | - Motoki Kaidu
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Hiroyuki Ishikawa
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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Rojas-López JA, Díaz Moreno RM, Venencia CD. Use of genetic algorithm for PTV optimization in single isocenter multiple metastases radiosurgery treatments with Brainlab Elements™. Phys Med 2021; 86:82-90. [PMID: 34062337 DOI: 10.1016/j.ejmp.2021.05.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/15/2021] [Accepted: 05/22/2021] [Indexed: 11/29/2022] Open
Abstract
PURPOSE To optimize PTV margins for single isocenter multiple metastases stereotactic radiosurgery through a genetic algorithm (GA) that determines the maximum effective displacement of each target (GTV) due to rotations. METHOD 10 plans were optimized. The plans were created with Elements Multiple Mets™ (Brainlab AG, Munchen, Germany) from a predefined template. The mean number of metastases per plan was 5 ± 2 [3,9] and the mean volume of GTV was 1.1 ± 1.3 cc [0.02, 5.1]. PTV margin criterion was based on GTV-isocenter distance and target dimensions. The effective displacement to perform specific rotational combination (roll, pitch, yaw) was optimized by GA. The original plans were re-calculated using the PTV optimized margin and new dosimetric variations were obtained. The Dmean, D99, Paddick conformity index (PCI), gradient index (GI) and dose variations in healthy brain were studied. RESULTS Regarding targets located shorter than 50 mm from the isocenter, the maximum calculated displacement was 2.5 mm. The differences between both PTV margin criteria were statistically significant for Dmean (p = 0.0163), D99 (p = 0.0439), PCI (p = 0.0242), GI (p = 0.0160) and for healthy brain V12 (p = 0.0218) and V10 (p = 0.0264). CONCLUSION The GA allows to determine an optimized PTV margin based on the maximum displacement. Optimized PTV margins reduce the detriment of dosimetric parameters. Greater PTV margins are associated with an increase in healthy brain volume.
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