1
|
Sukumaran AK, Raghavan RK, Mathew BS, Bhasi S, Koshi SM, Krishna KJ. Comparison of imaging modalities for the accurate delineation of arteriovenous malformations (AVM) and evaluation of setup accuracy with reference to non-invasive LINAC-based stereotactic radiosurgery (SRS). J Cancer Res Ther 2024; 20:874-880. [PMID: 39023594 DOI: 10.4103/jcrt.jcrt_938_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 04/04/2023] [Indexed: 07/20/2024]
Abstract
AIMS To compare the accuracy of nidus delineation using magnetic resonance angiography (MRA) to digital subtraction angiography (DSA) and to evaluate setup accuracy of non-invasive frame SRS treatments. SETTINGS AND DESIGN A prospective observational study of 16 patients who underwent non-invasive frame LINAC-based SRS for brain AVMs. MATERIALS AND METHODS The nidus was separately delineated using DSA and MRA after co-registration onto CT simulation images and compared with respect to their volume and maximum diameters. During treatment, the setup errors observed in x-, y-, and z-directions were recorded. STATISTICAL ANALYSIS Paired t-test (to compare volume and maximum diameter). Wilcoxon signed-rank test (for setup accuracy). RESULTS The mean volume of nidus contoured in MRA was 4.16 cc compared to 3.11 cc in DSA (P 0.297). The mean maximum diameters using MRA and DSA, respectively, in antro-posterior, cranio- caudal, and transverse diameters were 21.97 cc vs. 19.46 cc (P 0.2380), 6.59 cc vs. 9.63 cc (P 0.161), and 18.87 cc vs. 16.81 cc (P 0.178). But these modalities can potentially misinterpret the nidus volume, warranting caution for use of either modality alone. The mean translational shift observed in the x-, y-, and z-directions were 0.06 mm, 0.13 mm, and 0.13 mm, respectively, when couch was brought to neutral position after clockwise couch rotation and 0.07, 0, and 0, respectively, after counterclockwise couch rotation. CONCLUSION This study could not demonstrate any statistically significant differences in nidus delineation between MRA and DSA. Setup accuracy achieved with non-invasive thermoplastic mask-based immobilization is within acceptable limits for SRS.
Collapse
Affiliation(s)
- Anju K Sukumaran
- Department of Radiation Oncology, Regional Cancer Centre, Trivandrum, Kerala, India
| | - Rajeev K Raghavan
- Department of Radiation Oncology, Regional Cancer Centre, Trivandrum, Kerala, India
| | - Beela S Mathew
- Department of Radiation Oncology, Regional Cancer Centre, Trivandrum, Kerala, India
| | - Saju Bhasi
- Department of Radiation Physisics, Regional Cancer Centre, Trivandrum, Kerala, India
| | - Sumod M Koshi
- Department of Imageology, Regional Cancer Centre, Trivandrum, Kerala, India
| | - Km Jagathnath Krishna
- Department of Cancer Epidemiology and Bio-Statistics, Regional Cancer Centre, Trivandrum, Kerala, India
| |
Collapse
|
2
|
Cappelli L, Khan M, Vemula S, Hum C, Liu H, Yu Y, Chen Y, Zhang Y, Sharif M, Shi W. Novel frameless LINAC radiosurgery solution for uveal melanoma. Front Oncol 2024; 14:1365197. [PMID: 38590652 PMCID: PMC10999567 DOI: 10.3389/fonc.2024.1365197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 03/12/2024] [Indexed: 04/10/2024] Open
Abstract
Introduction Radiation treatment has replaced enucleation as an organ-preservation treatment for patients with uveal melanoma (UM). We developed a novel non-invasive, frameless LINAC based solution for fractionated stereotactic radiosurgery (fSRS) treatment. Methods We designed and constructed the a stereotactic ocular localization box that can be attached and indexed to a stereotactic LINAC tabletop. It contains adjustable LED lights as a gaze focus point and CCD camera for monitoring of the patient's eye position. The device also has 6 infrared spheres compatible with the ExacTRAC IGRT system. Treatment plans were developed using iPLAN Dose version 4.5, with conformal dynamic arcs and 6MV photon beam in flattening filter free mode, dosed to 50Gy in 5 fractions. During treatment, patients were instructed to stare at the light when a radiation beam is prepared and ready for delivery. Eye movement was tracked throughout treatment. Residual setup errors were recorded for evaluation. Results The stereotactic ocular localization box was 3D-printed with polylactic acid material and attached to the stereotactic LINAC tabletop. 10 patients were treated to evaluate the feasibility, tolerability and setup accuracy. Median treatment time for each arc is 17.3 ± 2.4 seconds (range: 13.8-23.4). After ExacTRAC setup, the residual setup errors are -0.1 ± 0.3 mm laterally, -0.1 ± 0.3 mm longitudinally, and 0 ± 0.2 mm vertically. The residue rotational errors are -0.1 ± 0.3 degree pitch, 0.1 ± 0.2 degree roll, and 0 ± 0.2 degree couch rotation. All patients received treatment successfully. Conclusion We successfully developed a novel non-invasive frameless mask-based LINAC solution for SRS for uveal melanoma, or other ocular tumors. It is well tolerated with high set up accuracy. Future directions for this localization box would include a multi-center trial to assess the efficacy and reproducibility in the fabrication and execution of such a solution for UM therapy.
Collapse
Affiliation(s)
- Louis Cappelli
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Mehak Khan
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States
| | - Sudheshna Vemula
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States
| | - Christina Hum
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States
| | - Haisong Liu
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Yan Yu
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Yingxuan Chen
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Yechi Zhang
- Department Mechanical Engineering, University of New York, City College, New York, NY, United States
| | - Muhammad Sharif
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Wenyin Shi
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA, United States
| |
Collapse
|
3
|
Grigo J, Szkitsak J, Höfler D, Fietkau R, Putz F, Bert C. "sCT-Feasibility" - a feasibility study for deep learning-based MRI-only brain radiotherapy. Radiat Oncol 2024; 19:33. [PMID: 38459584 PMCID: PMC10924348 DOI: 10.1186/s13014-024-02428-3] [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: 10/31/2023] [Accepted: 02/29/2024] [Indexed: 03/10/2024] Open
Abstract
BACKGROUND Radiotherapy (RT) is an important treatment modality for patients with brain malignancies. Traditionally, computed tomography (CT) images are used for RT treatment planning whereas magnetic resonance imaging (MRI) images are used for tumor delineation. Therefore, MRI and CT need to be registered, which is an error prone process. The purpose of this clinical study is to investigate the clinical feasibility of a deep learning-based MRI-only workflow for brain radiotherapy, that eliminates the registration uncertainty through calculation of a synthetic CT (sCT) from MRI data. METHODS A total of 54 patients with an indication for radiation treatment of the brain and stereotactic mask immobilization will be recruited. All study patients will receive standard therapy and imaging including both CT and MRI. All patients will receive dedicated RT-MRI scans in treatment position. An sCT will be reconstructed from an acquired MRI DIXON-sequence using a commercially available deep learning solution on which subsequent radiotherapy planning will be performed. Through multiple quality assurance (QA) measures and reviews during the course of the study, the feasibility of an MRI-only workflow and comparative parameters between sCT and standard CT workflow will be investigated holistically. These QA measures include feasibility and quality of image guidance (IGRT) at the linear accelerator using sCT derived digitally reconstructed radiographs in addition to potential dosimetric deviations between the CT and sCT plan. The aim of this clinical study is to establish a brain MRI-only workflow as well as to identify risks and QA mechanisms to ensure a safe integration of deep learning-based sCT into radiotherapy planning and delivery. DISCUSSION Compared to CT, MRI offers a superior soft tissue contrast without additional radiation dose to the patients. However, up to now, even though the dosimetrical equivalence of CT and sCT has been shown in several retrospective studies, MRI-only workflows have still not been widely adopted. The present study aims to determine feasibility and safety of deep learning-based MRI-only radiotherapy in a holistic manner incorporating the whole radiotherapy workflow. TRIAL REGISTRATION NCT06106997.
Collapse
Affiliation(s)
- Johanna Grigo
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, DE- 91054, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Juliane Szkitsak
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, DE- 91054, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Daniel Höfler
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, DE- 91054, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Rainer Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, DE- 91054, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Florian Putz
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, DE- 91054, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, DE- 91054, Erlangen, Germany.
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany.
| |
Collapse
|
4
|
Chen X, Liu L, Wang Y, Huang X, Cai W, Rong X, Lin L, Liu J, Jiang X. Surface guided radiation therapy with an innovative open-face mask and mouth bite: patient motion management in brain stereotactic radiotherapy. Clin Transl Oncol 2024; 26:424-433. [PMID: 37395988 DOI: 10.1007/s12094-023-03260-z] [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: 03/30/2023] [Accepted: 06/18/2023] [Indexed: 07/04/2023]
Abstract
INTRODUCTION To guarantee treatment reproducibility and stability, immobilization devices are essential. Additionally, surface-guided radiation therapy (SGRT) serves as an accurate complement to frameless stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) by aiding patient positioning and real-time monitoring, especially when non-coplanar fields are in use. At our institute, we have developed a surface-guided SRS (SG-SRS) workflow that incorporates our innovative open-face mask (OM) and mouth bite (MB) to guarantee a precise and accurate dose delivery. METHODS This study included 40 patients, and all patients were divided into closed mask (CM) and open-face mask (OM) groups according to different positioning flow. Cone beam computed tomography (CBCT) scans were performed, and the registration results were recorded before and after the treatment. Then Bland-Altman method was used to analyze the consistency of AlignRT-guided positioning errors and CBCT scanning results in the OM group. The error changes between 31 fractions in one patient were recorded to evaluate the feasibility of monitoring during treatment. RESULTS The median of translation error between stages of the AlignRT positioning process was (0.03-0.07) cm, and the median of rotation error was (0.20-0.40)°, which were significantly better than those of the Fraxion positioning process (0.09-0.11) cm and (0.60-0.75)°. The mean bias values between the AlignRT guided positioning errors and CBCT were 0.01 cm, - 0.07 cm, 0.03 cm, - 0.30°, - 0.08° and 0.00°. The 31 inter-fractional errors of a single patient monitored by SGRT were within 0.10 cm and 0.50°. CONCLUSIONS The application of the SGRT with an innovative open-face mask and mouth bite device could achieve precision positioning accuracy and stability, and the accuracy of the AlignRT system exhibits excellent constancy with the CBCT gold standard. The non-coplanar radiation field monitoring can provide reliable support for motion management in fractional treatment.
Collapse
Affiliation(s)
- Xuemei Chen
- Department of Radiotherapy, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Lu Liu
- Department of Radiotherapy, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Yajuan Wang
- Department of Radiotherapy, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Xiaotong Huang
- Department of Radiotherapy, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Weixun Cai
- Department of Radiotherapy, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Xiaodong Rong
- Department of Radiotherapy, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Liuwen Lin
- Department of Radiotherapy, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Jindi Liu
- Department of Radiotherapy, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.
| | - Xiaobo Jiang
- Department of Radiotherapy, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.
| |
Collapse
|
5
|
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.
Collapse
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.
| |
Collapse
|
6
|
Faccenda V, Panizza D, Pisoni V, Trivellato S, Daniotti MC, Bianchi SP, De Ponti E, Arcangeli S. Single-Isocenter Linac-Based Radiosurgery for Brain Metastases with Coplanar Arcs: A Dosimetric and Clinical Analysis. Cancers (Basel) 2023; 15:4496. [PMID: 37760466 PMCID: PMC10526167 DOI: 10.3390/cancers15184496] [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: 07/11/2023] [Revised: 09/04/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023] Open
Abstract
The efficacy of linac-based SRS/fSRS treatments using the single-isocenter coplanar FFF-VMAT technique for both single and multiple BM was investigated. Seventy patients (129 BM) treated with 15-21 Gy in 1 (n = 59) or 27 Gy in 3 (n = 11) fractions were analyzed. For each fraction, plans involving the intra-fractional errors measured by post-treatment CBCT were recalculated. The relationships of BM size, distance-to-isocenter, and barycenter shift with the difference in target coverage were evaluated. Clinical outcomes were assessed using logistic regression and Kaplan-Meier analysis. The median delivery time was 3.78 min (range, 1.83-9.25). The median post-treatment 3D error was 0.5 mm (range, 0.1-2.7) and the maximum rotational error was 0.3° (range, 0.0-1.3). In single BM patients, the GTV D95% was never reduced by >5%, whereas PTV D95% reductions >1% occurred in only 11 cases (29%). In multiple BM patients, dose deficits >5% and >1% occurred in 2 GTV (2%) and 34 PTV (37%), respectively. The differences in target coverage showed a moderate-to-strong correlation only with barycenter shift. Local failure of at least one treated BM occurred in 13 (21%) patients and the 1-year and 2-year local control rates for all lesions were 94% and 90%, respectively. The implemented workflow ensured that the degradation of target and brain dose metrics in delivered treatments was negligible. Along with encouraging clinical outcomes, these findings warrant a reduction in the PTV margins at our institution.
Collapse
Affiliation(s)
- Valeria Faccenda
- Medical Physics Department, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy; (V.F.); (D.P.); (S.T.); (M.C.D.); (E.D.P.)
| | - Denis Panizza
- Medical Physics Department, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy; (V.F.); (D.P.); (S.T.); (M.C.D.); (E.D.P.)
- School of Medicine and Surgery, University of Milan Bicocca, 20126 Milan, Italy;
| | - Valerio Pisoni
- Radiation Oncology Department, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy;
| | - Sara Trivellato
- Medical Physics Department, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy; (V.F.); (D.P.); (S.T.); (M.C.D.); (E.D.P.)
| | - Martina Camilla Daniotti
- Medical Physics Department, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy; (V.F.); (D.P.); (S.T.); (M.C.D.); (E.D.P.)
| | - Sofia Paola Bianchi
- School of Medicine and Surgery, University of Milan Bicocca, 20126 Milan, Italy;
| | - Elena De Ponti
- Medical Physics Department, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy; (V.F.); (D.P.); (S.T.); (M.C.D.); (E.D.P.)
- School of Medicine and Surgery, University of Milan Bicocca, 20126 Milan, Italy;
| | - Stefano Arcangeli
- School of Medicine and Surgery, University of Milan Bicocca, 20126 Milan, Italy;
- Radiation Oncology Department, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy;
| |
Collapse
|
7
|
Masitho S, Grigo J, Brandt T, Lambrecht U, Szkitsak J, Weiss A, Fietkau R, Putz F, Bert C. Synthetic CTs for MRI-only brain RT treatment: integration of immobilization systems. Strahlenther Onkol 2023; 199:739-748. [PMID: 37285037 PMCID: PMC10361877 DOI: 10.1007/s00066-023-02090-w] [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: 12/29/2022] [Accepted: 04/25/2023] [Indexed: 06/08/2023]
Abstract
PURPOSE Auxiliary devices such as immobilization systems should be considered in synthetic CT (sCT)-based treatment planning (TP) for MRI-only brain radiotherapy (RT). A method for auxiliary device definition in the sCT is introduced, and its dosimetric impact on the sCT-based TP is addressed. METHODS T1-VIBE DIXON was acquired in an RT setup. Ten datasets were retrospectively used for sCT generation. Silicone markers were used to determine the auxiliary devices' relative position. An auxiliary structure template (AST) was created in the TP system and placed manually on the MRI. Various RT mask characteristics were simulated in the sCT and investigated by recalculating the CT-based clinical plan on the sCT. The influence of auxiliary devices was investigated by creating static fields aimed at artificial planning target volumes (PTVs) in the CT and recalculated in the sCT. The dose covering 50% of the PTV (D50) deviation percentage between CT-based/recalculated plan (∆D50[%]) was evaluated. RESULTS Defining an optimal RT mask yielded a ∆D50[%] of 0.2 ± 1.03% for the PTV and between -1.6 ± 3.4% and 1.1 ± 2.0% for OARs. Evaluating each static field, the largest ∆D50[%] was delivered by AST positioning inaccuracy (max: 3.5 ± 2.4%), followed by the RT table (max: 3.6 ± 1.2%) and the RT mask (max: 3.0 ± 0.8% [anterior], 1.6 ± 0.4% [rest]). No correlation between ∆D50[%] and beam depth was found for the sum of opposing beams, except for (45° + 315°). CONCLUSION This study evaluated the integration of auxiliary devices and their dosimetric influence on sCT-based TP. The AST can be easily integrated into the sCT-based TP. Further, we found that the dosimetric impact was within an acceptable range for an MRI-only workflow.
Collapse
Affiliation(s)
- Siti Masitho
- Department of Radiation Oncology, Strahlenklinik, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, 91054, Erlangen, Germany.
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany.
| | - Johanna Grigo
- Department of Radiation Oncology, Strahlenklinik, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, 91054, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Tobias Brandt
- Department of Radiation Oncology, Strahlenklinik, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, 91054, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Ulrike Lambrecht
- Department of Radiation Oncology, Strahlenklinik, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, 91054, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Juliane Szkitsak
- Department of Radiation Oncology, Strahlenklinik, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, 91054, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Alexander Weiss
- Department of Radiation Oncology, Strahlenklinik, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, 91054, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Rainer Fietkau
- Department of Radiation Oncology, Strahlenklinik, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, 91054, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Florian Putz
- Department of Radiation Oncology, Strahlenklinik, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, 91054, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Strahlenklinik, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Universitätsstraße 27, 91054, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| |
Collapse
|
8
|
Janssen J, Brouwer CL, Staal FH, van Herpt HE, Both S, Langendijk JA, Aluwini S. Simple immobilization for stereotactic radiotherapy aimed at pelvic metastases. Phys Imaging Radiat Oncol 2023; 27:100460. [PMID: 37435559 PMCID: PMC10331836 DOI: 10.1016/j.phro.2023.100460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 06/15/2023] [Accepted: 06/15/2023] [Indexed: 07/13/2023] Open
Abstract
Stereotactic body radiotherapy (SBRT) is increasingly applied for pelvic oligometastases of prostate cancer, and currently no simple immobilization method is available for cone beam computed tomography (CBCT)-guided treatment. We assessed patient set-up and intrafraction motion using simple immobilization during CBCT-guided pelvic SBRT. Forty patients were immobilized with basic arm- head- and knee support and either a thermoplastic cushion or a foam cushion. Analysis of 454 CBCTs showed mean intrafraction translation <3.0 mm in 94% of fractions and mean intrafraction rotation <1.5° in 95% of fractions. Therefore, simple immobilization ensured stable patient positioning during CBCT-guided pelvic SBRT.
Collapse
Affiliation(s)
- Jorinde Janssen
- Corresponding author at: University Medical Center Groningen, Department of Radiation Oncology, Hanzeplein 1, 9713GZ Groningen, the Netherlands.
| | | | | | | | | | | | | |
Collapse
|
9
|
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]
|
10
|
Church C, MacDonald RL, Parsons D, Syme A. Evaluation of plan quality and treatment efficiency in cranial stereotactic radiosurgery treatment plans with a variable source-to-axis distance. Med Phys 2023; 50:3039-3054. [PMID: 36774531 DOI: 10.1002/mp.16288] [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: 04/26/2022] [Revised: 10/03/2022] [Accepted: 01/31/2023] [Indexed: 02/13/2023] Open
Abstract
INTRODUCTION Radiotherapy deliveries with dynamic couch motions that shorten the source-to-axis distance (SAD) on a C-arm linac have the potential to increase treatment efficiency through the increase of the effective dose rate. In this investigation, we convert clinically deliverable volumetric modulated arc therapy (VMAT) and dynamic conformal arc (DCA) plans for cranial radiosurgery into virtual isocenter plans through implementation of couch trajectories that maintain the target at a shortened but variable SAD throughout treatment. MATERIALS AND METHODS A randomly sampled population of patients treated with cranial radiosurgery from within the last three years were separated into groups with one, two, and three lesions. All plans had a single isocenter (regardless of number of targets), and a single prescription dose. Patient treatment plans were converted from their original delivery at a standard isocenter to a dynamic virtual isocenter in MATLAB. The virtual isocenter plan featured a variable isocenter position based upon the closest achievable source-to-target distance (referred to herein as a virtual source-to-axis distance [vSAD]) which avoided collision zones on a TrueBeam STx platform. Apertures were magnified according to the vSAD and monitor units at a given control point were scaled based on the inverse square law. Doses were calculated for the plans with a virtual isocenter in the Eclipse (v13.6.23) treatment planning system (TPS) and were compared with the clinical plans. Plan metrics (MU, Paddick conformity index, gradient index, and the volume receiving 12 Gy or more), normal brain dose-volume differences, as well as maximum doses received by organs at risk (OARs) were assessed. The values were compared between standard and virtual isocenter plans with Wilcoxon Sign Ranked tests to determine significance. A subset of the plans were mapped to the MAX-HD anthropomorphic phantom which contained an insert housing EBT3 GafChromic film and a PTW 31010 microion chamber for dose verification on a linac. RESULTS Delivering plans at a virtual isocenter resulted in an average reduction of 20.9% (p = 3×10-6 ) and 20.6% (p = 3.0×10-6 ) of MUs across all VMAT and all DCA plans, respectively. There was no significant change in OAR max doses received by plans delivered at a virtual isocenter. The low dose wash (1.0-2.0 Gy or 5-11% of the prescription dose) was increased (by approximately 20 cc) for plans with three lesions. This was equivalent to a 2.7%-3.8% volumetric increase in normal tissue receiving the respective dose level when comparing the plan with a virtual isocenter to a plan with a standard isocenter. Gamma pass rates with a 5%/1mm analysis criteria were 96.40% ± 2.90% and 95.07% ± 3.10% for deliveries at standard and virtual isocenter, respectively. Absolute point dose agreements were within -0.36% ± 3.45% and -0.55% ± 3.39% for deliveries at a standard and virtual isocenter, respectively. Potential time savings per arc were found to have linear relationship with the monitor units delivered per arc (savings of 0.009 s/MU with an r2 = 0.866 when fit to plans with a single lesion). CONCLUSIONS Converting clinical plans at standard isocenter to a virtual isocenter design did not show any losses to plan quality while simultaneously improving treatment efficiency through MU reductions.
Collapse
Affiliation(s)
- Cody Church
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
| | - R Lee MacDonald
- Department of Radiation Oncology and Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
| | - David Parsons
- Department of Radiation Oncology, University of Texas Southwestern Medical Centre, Dallas, Texas, USA
| | - Alasdair Syme
- Department of Radiation Oncology and Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
| |
Collapse
|
11
|
Geometric and dosimetric consequences of intra-fractional movement in single isocenter non-coplanar stereotactic radiosurgery. Radiat Oncol 2023; 18:9. [PMID: 36631832 PMCID: PMC9835346 DOI: 10.1186/s13014-022-02195-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 12/29/2022] [Indexed: 01/13/2023] Open
Abstract
PURPOSE To investigate the geometric and dosimetric impacts of intra-fractional movement for patients with single or multiple brain metastasis treated using Varian Hyperarc™ mono-isocentric radiosurgery. METHODS A total of 50 single or hypo-fractionated Hyperarc™ treatment courses (118 lesions) were included in the analysis. Intra-fractional translational and rotational movements were quantified according to the post-treatment cone-beam CT (CBCT). Geometric displacements of all targets were calculated individually based on the assessed head movement in each treatment fraction and their relationships with treatment time and target-to-isocenter distances were studied. For dosimetric analysis, only single-fraction treatments (56 lesions) were included. Re-planning was performed with 0, 1, and 2 mm planning target volume (PTV) margins. Doses were then re-calculated on rotated CT images with isocenter shifted which emulate the change in patient treatment position. Target coverage, target and normal brain doses before and after intra-fractional movement were compared. RESULTS The mean 3D target displacements was 0.6 ± 0.3 (SD) mm. Target shifts for patients treated within 10 min were significantly smaller than those treated in longer sessions. No correlation was found between target shift and target-to-isocenter distance as the origin of head rotation was not located at the isocenter. Loss of target coverage and minimum Gross Tumor Volume (GTV) dose due to intra-fractional movement were apparent only when no margin was used, leading to an extra 23% of the targets violating the dose acceptance criteria, in contrast, the effects on normal brain V12Gy were negligible regardless of the margin used. The use of 1 mm PTV margin can compensate clinically significant geographical miss caused by intra-fractional movements while limiting V12Gy to within dose criteria for 88% of the cases. The plan acceptance rate (fulfillment of both target and normal brain dose criteria) after intra-fractional movement was also the highest with the 1 mm margin. CONCLUSION Although intra-fractional movements during Hyperarc™ treatments were small, there were substantial dosimetric effects due to the sharp dose fall-off near target boundaries. These effects could be mitigated by using a 1 mm PTV margin and maintaining the effective treatment time to within 10 min.
Collapse
|
12
|
Church C, Parsons D, Syme A. Region-of-interest intra-arc MV imaging to facilitate sub-mm positional accuracy with minimal imaging dose during treatment deliveries of small cranial lesions. J Appl Clin Med Phys 2022; 23:e13769. [PMID: 36052995 PMCID: PMC9680576 DOI: 10.1002/acm2.13769] [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: 04/04/2022] [Revised: 07/15/2022] [Accepted: 08/09/2022] [Indexed: 12/02/2022] Open
Abstract
Purpose To automate the generation of region‐of‐interest (ROI) apertures for use with megavoltage imaging for online positional corrections during cranial stereotactic radiosurgery. Materials and methods Digitally reconstructed radiographs (DRRs) were created for a 3D‐printed skull phantom at 5 degree gantry angle increments for a three‐arc beam arrangement. At each angle, 3000 random rectangular apertures were generated, and 100 shifts on a grid were applied to the anatomy within the frame. For all shifts, the mutual information (MI) between the shifted and unshifted DRR was calculated to derive an average MI gradient. The top 10% of apertures that minimized registration errors were overlaid and discretely thresholded to generate imaging plans. Imaging was acquired with the skull while implementing simulated patient motion on a linac. Control point‐specific couch motions were derived to align the skull to its planned positioning. Results Apertures with a range of repositioning errors less than 0.1 mm possessed a 42% larger average MI gradient when compared with apertures with a range greater than 1 mm. Dose calculations with Monte Carlo exhibited an 84% reduction in the dose received by 50% of the skull with the 50% thresholded plan when compared to a constant 22 × 22 cm2 imaging plan. For all different imaging plans (with and without motion), the calculated median 3D‐errors with respect to the tracking of a metal‐BB fiducial positioned at isocenter in the skull were sub‐mm except for the 80% thresholded plan. Conclusions Sub‐mm positional errors are achievable with couch motions derived from control point–specific ROI imaging. Smaller apertures that conform to an anatomical ROI can be utilized to minimize the imaging dose incurred at the expense of larger errors.
Collapse
Affiliation(s)
- Cody Church
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
| | - David Parsons
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Alasdair Syme
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Radiation Oncology, Dalhousie University, Halifax, Nova Scotia, Canada
| |
Collapse
|
13
|
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
|
14
|
Reitz D, Muecke J, da Silva Mendes V, Landry G, Reiner M, Niyazi M, Belka C, Freislederer P, Corradini S. Intrafractional monitoring of patients using four different immobilization mask systems for cranial radiotherapy. Phys Imaging Radiat Oncol 2022; 23:134-139. [PMID: 35958289 PMCID: PMC9361321 DOI: 10.1016/j.phro.2022.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 07/16/2022] [Accepted: 07/18/2022] [Indexed: 11/11/2022] Open
Abstract
Background and purpose Patients receiving cranial radiotherapy are immobilized with a thermoplastic mask to restrict patient motion. Depending on the target volume margins and treatment dose, different mask systems are used. Intrafractional movements can be monitored using stereoscopic X-ray imaging. The aim of the present work was to compare the magnitudes of intrafractional deviation for different mask systems. Material and methods Four different head mask systems (open face mask, open mask, stereotactic mask, double mask) used in the treatment of 40 patients were investigated. In total 487 treatment fractions and 3708 X-ray images were collected. Deviations were calculated by comparison of the acquired X-ray images with digitally reconstructed radiographs. The results of intrafractional X-ray deviations for translational and rotational axes were compared between the different mask systems. Results Deviations were below 0.6 mm for translations and below 0.6° for rotations for all mask systems. Along the lateral and longitudinal directions the stereotactic mask was superior, while along the vertical direction the double mask showed the lowest deviations. For low rotational deviations the double mask is the best amongst all other mask systems. Conclusion As expected, the lowest movement was shown using cranial stereotactic mask systems. The results have shown deviations lower than 0.6 mm and 0.6° using any of the four thermoplastic mask systems.
Collapse
|
15
|
Eder MM, Reiner M, Heinz C, Garny S, Freislederer P, Landry G, Niyazi M, Belka C, Riboldi M. Single-isocenter stereotactic radiosurgery for multiple brain metastases: Impact of patient misalignments on target coverage in non-coplanar treatments. Z Med Phys 2022; 32:296-311. [PMID: 35504799 PMCID: PMC9948862 DOI: 10.1016/j.zemedi.2022.02.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 02/10/2022] [Accepted: 02/14/2022] [Indexed: 10/18/2022]
Abstract
Frameless single-isocenter non-coplanar stereotactic radiosurgery (SRS) for patients with multiple brain metastases is a treatment at high geometrical complexity. The goal of this study is to analyze the dosimetric impact of non-coplanar image guidance with stereoscopic X-ray imaging. Such an analysis is meant to provide insights on the adequacy of safety margins, and to evaluate the benefit of imaging at non-coplanar configurations. The ExacTrac® (ET) system (Brainlab AG, Munich, Germany) was used for stereoscopic X-ray imaging in frameless single-isocenter non-coplanar SRS for multiple brain metastases. Sub-millimeter precision was found for the ET-based pre-treatment setup, whereas a degradation was noted for non-coplanar treatment angles. Misalignments without intra-fractional positioning corrections were reconstructed in 6 degrees of freedom (DoF) to resemble the situation without non-coplanar image guidance. Dose recalculation in 20 SRS patients with applied positioning corrections did not reveal any significant differences in D98% for 75 planning target volumes (PTVs) and gross tumor volumes (GTVs). For recalculation without applied positioning corrections, significant differences (p<0.05) were reported in D98% for both PTVs and GTVs, with stronger effects for small PTV volumes. A worst-case analysis at increasing translational and rotational misalignment revealed that dosimetric changes are a complex function of the combination thereof. This study highlighted the important role of positioning correction with ET at non-coplanar configurations in frameless single-isocenter non-coplanar SRS for patients with multiple brain metastases. Uncorrected patient misalignments at non-coplanar couch angles were linked to a significant loss of PTV coverage, with effects varying according to the combination of single DoF and PTV geometrical properties.
Collapse
Affiliation(s)
- Michael Martin Eder
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany; Department of Medical Physics, Ludwig-Maximilians University, Garching, Germany.
| | - Michael Reiner
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany.
| | - Christian Heinz
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany.
| | - Sylvia Garny
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany.
| | - Philipp Freislederer
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany.
| | - Guillaume Landry
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany; Department of Medical Physics, Ludwig-Maximilians University, Garching, Germany.
| | - Maximilian Niyazi
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany; German Cancer Consortium (DKTK), Partner Site Munich, Munich, Germany.
| | - Claus Belka
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany; German Cancer Consortium (DKTK), Partner Site Munich, Munich, Germany.
| | - Marco Riboldi
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany.
| |
Collapse
|
16
|
Ohira S, Komiyama R, Kanayama N, Ueda Y, Inui S, Miyazaki M, Koizumi M, Konishi K. Intra‐fractional motion error during HyperArc stereotactic radiosurgery on patients with brain metastases: Comparison of open and full‐face clamshell‐style immobilization devices. J Appl Clin Med Phys 2022; 23:e13536. [PMID: 35049125 PMCID: PMC8992945 DOI: 10.1002/acm2.13536] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 11/14/2021] [Accepted: 01/06/2022] [Indexed: 11/23/2022] Open
Abstract
Purpose To compare the intrafractional motion error (IME) during stereotactic irradiation (STI) in patients with brain metastases immobilized using open‐ (Encompass) and full‐face (DSPS) clamshell‐style immobilization devices. Methods Encompass (38 patients) and DSPS (38 patients) were used for patient immobilization, and HyperArc plans with three to four non‐coplanar beams were generated to deliver 25 to 35 Gy in three to five fractions. Cone‐beam computed tomography (CBCT) was performed on patients before and after the treatment. Moreover, the difference in patient position between the two CBCT images was considered as the IME. The margins to compensate for IME were calculated using the van Herk margin formula. Results For Encompass, the mean values of IME in the translational setup were 0.1, 0.2, and 0.0 mm in the anterior–posterior, superior–inferior, and left–right directions, respectively, and the mean values of IME about rotational axes were −0.1, 0.0, and 0.0° for the Pitch, Roll, and Yaw rotations, respectively. For DSPS, the mean values of IME in the translational setup were 0.2, 0.2, and 0.0 mm in the anterior–posterior, superior–inferior, and left–right directions, respectively, and the mean values of IME about rotational axes were −0.1, −0.1, and 0.0° for the Pitch, Roll, and Yaw rotations, respectively. No statistically significant difference was observed between the IME of the two immobilization systems except in the anterior–posterior direction (p = 0.02). Moreover, no statistically significant correlation was observed between three‐dimensional IME and treatment time. The margin compensation for IME was less than 1 mm for both immobilization devices. Conclusions The IME during STI using open‐ and full‐face clamshell‐style immobilization devices is approximately equal considering the adequate accuracy in patient positioning.
Collapse
Affiliation(s)
- Shingo Ohira
- Department of Radiation Oncology Osaka International Cancer Institute Osaka Japan
- Department of Medical Physics and Engineering Osaka University Graduate School of Medicine Suita Japan
| | - Riho Komiyama
- Department of Radiation Oncology Osaka International Cancer Institute Osaka Japan
| | - Naoyuki Kanayama
- Department of Radiation Oncology Osaka International Cancer Institute Osaka Japan
| | - Yoshihiro Ueda
- Department of Radiation Oncology Osaka International Cancer Institute Osaka Japan
| | - Shoki Inui
- Department of Radiation Oncology Osaka International Cancer Institute Osaka Japan
| | - Masayoshi Miyazaki
- Department of Radiation Oncology Osaka International Cancer Institute Osaka Japan
| | - Masahiko Koizumi
- Department of Medical Physics and Engineering Osaka University Graduate School of Medicine Suita Japan
| | - Koji Konishi
- Department of Radiation Oncology Osaka International Cancer Institute Osaka Japan
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Miura H, Hioki K, Ozawa S, Kanemoto K, Nakao M, Doi Y, Kenjo M, Nagata Y. Uncertainty in the positioning of patients receiving treatment for brain metastases and wearing surgical mask underneath thermoplastic mask during COVID-19 crisis. J Appl Clin Med Phys 2021; 22:274-280. [PMID: 34028970 PMCID: PMC8200509 DOI: 10.1002/acm2.13279] [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: 12/17/2020] [Revised: 04/15/2021] [Accepted: 04/20/2021] [Indexed: 12/26/2022] Open
Abstract
Thermoplastic masks, used along with surgical masks, enable immobilization methods to reduce the risk of infection in patients undergoing intracranial stereotactic radiosurgery and stereotactic radiotherapy (SRS/SRT) during the COVID‐19 crisis. The purpose of this study was to investigate the feasibility of thermoplastic mask immobilization with a surgical mask using an ExacTrac system. Twelve patients each with brain metastases were immobilized using a thermoplastic mask and a surgical mask and only a thermoplastic mask. Two x‐ray images were acquired to correct (XC) and verify (XV) the patient’s position at a couch angle of 0°. Subsequently, the XC and XV images were acquired at each planned couch angle for non‐coplanar beams. When the position errors were detected after couch rotation for non‐coplanar beams, the errors were corrected at each planned couch angle until a clinically acceptable tolerance was attained. The position errors in the translational and rotational directions (vertical, lateral, longitudinal, pitch, roll, and yaw) were retrospectively investigated using data from the ExacTrac system database. A standard deviation of XC translational and rotational position errors with and without a surgical mask in the lateral (1.52 vs 2.07 mm), longitudinal (1.59 vs 1.87 mm), vertical (1.00 vs 1.73 mm), pitch (0.99 vs 0.79°), roll (1.24 vs 0.68°), and yaw (1.58 vs 0.90°) directions were observed at a couch angle of 0°. Most of patient positioning errors were less than 1.0 mm or 1.0° after the couch was rotated to the planned angle for non‐coplanar beams. The overall absolute values of the translational and rotational XV position errors with and without the surgical mask were less than 0.5 mm and 0.5°, respectively. This study showed that a thermoplastic mask with a surgical mask is a feasible immobilization technique for brain SRS/SRT patients using the ExacTrac system.
Collapse
Affiliation(s)
- Hideharu Miura
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, 732-0057, Japan.,Department of Radiation Oncology, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, 739-8511, Japan
| | - Kazunari Hioki
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, 732-0057, Japan
| | - Shuichi Ozawa
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, 732-0057, Japan.,Department of Radiation Oncology, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, 739-8511, Japan
| | - Kenji Kanemoto
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, 732-0057, Japan
| | - Minoru Nakao
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, 732-0057, Japan.,Department of Radiation Oncology, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, 739-8511, Japan
| | - Yoshiko Doi
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, 732-0057, Japan.,Department of Radiation Oncology, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, 739-8511, Japan
| | - Masahiko Kenjo
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, 732-0057, Japan.,Department of Radiation Oncology, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, 739-8511, Japan
| | - Yasushi Nagata
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, 732-0057, Japan.,Department of Radiation Oncology, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, 739-8511, Japan
| |
Collapse
|