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Walker LS, Byrne JP. Clinical impact of DVH uncertainties. Med Dosim 2024:S0958-3947(24)00031-1. [PMID: 38987038 DOI: 10.1016/j.meddos.2024.06.002] [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: 10/26/2022] [Revised: 03/26/2024] [Accepted: 06/11/2024] [Indexed: 07/12/2024]
Abstract
Dose-volume histograms (DVH), along with dose and volume metrics, are central to radiotherapy planning. As such, errors have the potential to significantly impact the selection of appropriate treatment plans. Dose distributions that pass tests in one TPS may fail the same tests when transferred to another, even if using identical structures and dose grid information. This work shows the design and implementation of methods for assessing the accuracy of dose and volume computations performed by treatment planning systems (TPS), and other analytical tools. We demonstrate examples where differences in calculations between systems can change the assessment of a plan's clinical acceptability. Our work also provides a more detailed DVH analysis of single targets than earlier published studies. This is relevant for SRS plans and small structure dose assessments. Very small structures are a particular problem because of their coarse digital representation, and the impact of this is thoroughly examined. Reference DVH curves were derived mathematically, based on Gaussian dose distributions centered on spherical structures. The structures and dose distributions were generated synthetically, and imported into RayStation, MasterPlan, and ProKnow. Corresponding DVHs were analytically derived and taken as ground truth references, for comparison with the commercial DVH calculations. Two commonly used dose metrics PCI and MGI were used to determine the limit of calculation accuracy for small structures. In addition, to measure the DVH differences between a larger range of commercial DVH calculators, the D95 metric from a set of real clinical plans was compared across both the 3 DVH calculators under test, and across a further six TPSs from other hospitals. We show that even slight deviations between the results of DVH calculators can lead to plan check failures, and we illustrate this with the commonly used D95 planning metric. We present clinical data across eight planning systems that highlight instances where plan checks would pass in one software and fail in another due to DVH calculation differences. For the smallest volumes tested, errors of up to 20% were observed in the DVHs. RayStation was tested down to a 3 mm radius sphere (≈0.1 cc) and this showed close to 10% error, reducing to 1% for 10 mm radius (≈4.0 cc) and 0.1% for 20 mm radius (≈33 cc). In clinical plans, the variation in D95 was up to 9% for the smallest volumes, and typically around 2% in the range 0.5 cc-20 cc, and 1% in 20 cc-70 cc, falling to <0.1% for large volumes. Paddick Conformity Index (PCI) and Modified Gradient Index (MGI) are commonly used plan quality indicators for very small volumes. For volumes ≈0.1 cc we observed errors of up to 40% in PCI, and up to 75% in MGI. Our study extends the range of tested DVH calculators in published work, and shows their performance over a wider range of volume sizes. We provide quantitative evidence of the critical need to test the accuracy of DVH calculators in the TPS before clinical use. This work is particularly relevant for both stereotactic plan evaluation and for assessment of small volume doses in published dose constraint recommendations. We demonstrate that significant errors can occur in DVHs for volumes less than 1 cc, even if the volumes themselves are calculated accurately. Even for large structures, deviations between the outputs of DVH calculators can lead to indicated or reported plan check failures if they do not include appropriate tolerances. We urge caution in the use of DVH metrics for these very small volumes and recommend that appropriate DVH uncertainty tolerances are set in organ dose constraints when using them to evaluate clinical plans.
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Affiliation(s)
- L S Walker
- Radiotherapy Physics, Northern Centre for Cancer Care, Newcastle Upon Tyne NHS Foundation Trust, Newcastle Upon Tyne, Tyne and Wear, UK.
| | - J P Byrne
- Radiotherapy Physics, Northern Centre for Cancer Care, Newcastle Upon Tyne NHS Foundation Trust, Newcastle Upon Tyne, Tyne and Wear, UK
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Penoncello GP, Voss MM, Gao Y, Sensoy L, Cao M, Pepin MD, Herchko SM, Benedict SH, DeWees TA, Rong Y. Multicenter Multivendor Evaluation of Dose Volume Histogram Creation Consistencies for 8 Commercial Radiation Therapy Dosimetric Systems. Pract Radiat Oncol 2024; 14:e236-e248. [PMID: 37914082 DOI: 10.1016/j.prro.2023.09.009] [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: 07/13/2023] [Revised: 09/11/2023] [Accepted: 09/26/2023] [Indexed: 11/03/2023]
Abstract
PURPOSE To evaluate dose volume histogram (DVH) construction differences across 8 major commercial treatment planning systems (TPS) and dose reporting systems for clinically treated plans of various anatomic sites and target sizes. METHODS AND MATERIALS Dose files from 10 selected clinically treated plans with a hypofractionation, stereotactic radiation therapy prescription or sharp dose gradients such as head and neck plans ranging from prescription doses of 18 Gy in 1 fraction to 70 Gy in 35 fractions, each calculated at 0.25 and 0.125 cm grid size, were created and anonymized in Eclipse TPS, and exported to 7 other major TPS (Pinnacle, RayStation, and Elements) and dose reporting systems (MIM, Mobius, ProKnow, and Velocity) systems for comparison. Dose-volume constraint points of clinical importance for each plan were collected from each evaluated system (D0.03 cc [Gy], volume, and the mean dose were used for structures without specified constraints). Each reported constraint type and structure volume was normalized to the value from Eclipse for a pairwise comparison. A Wilcoxon rank-sum test was used for statistical significance and a multivariable regression model was evaluated adjusting for plan, grid size, and distance to target center. RESULTS For all DVH points relative to Eclipse, all systems reported median values within 1.0% difference of each other; however, they were all different from Eclipse. Considering mean values, Pinnacle, RayStation, and Elements averaged at 1.038, 1.046, and 1.024, respectively, while MIM, Mobius, ProKnow, and Velocity reported 1.026, 1.050, 1.033, and 1.022, respectively relative to Eclipse. Smaller dose grid size improved agreement between the systems marginally without statistical significance. For structure volumes relative to Eclipse, larger differences are seen across all systems with a range in median values up to 3.0% difference and mean up to 10.1% difference. CONCLUSIONS Large variations were observed between all systems. Eclipse generally reported, at statistically significant levels, lower values than all other evaluated systems. The nonsignificant change resulting from lowering the dose grid resolution indicates that this resolution may be less important than other aspects of calculating DVH curves, such as the 3-dimensional modeling of the structure.
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Affiliation(s)
- Gregory P Penoncello
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona; Department of Radiation Oncology, University of Colorado, Aurora, Colorado
| | - Molly M Voss
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Scottsdale, Arizona
| | - Yu Gao
- Department of Radiation Oncology, Stanford University, Palo Alto, California
| | - Levent Sensoy
- Department of Radiation Oncology, University of Miami, Miami, Florida
| | - Minsong Cao
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California
| | - Mark D Pepin
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Steven M Herchko
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida
| | - Stanley H Benedict
- Department of Radiation Oncology, University of California Davis, Sacramento, California
| | - Todd A DeWees
- Department of Computational and Quantitative Medicine, City of Hope, Duarte, California; Department of Radiation Oncology, City of Hope, Duarte, California.
| | - Yi Rong
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona.
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Samanci Y, Askeroglu MO, Düzkalir AH, Peker S. Assessing the impact of distortion correction on Gamma Knife radiosurgery for multiple metastasis: Volumetric and dosimetric analysis. BRAIN & SPINE 2024; 4:102791. [PMID: 38584868 PMCID: PMC10995810 DOI: 10.1016/j.bas.2024.102791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 03/11/2024] [Accepted: 03/19/2024] [Indexed: 04/09/2024]
Abstract
Introduction Magnetic resonance imaging (MRI) is a robust neuroimaging technique and is the preferred method for stereotactic radiosurgery (SRS) planning. However, MRI data always contain distortions caused by hardware and patient factors. Research question Can these distortions potentially compromise the effectiveness and safety of SRS treatments? Material and methods Twenty-six MR datasets with multiple metastatic brain tumors (METs) used for Gamma Knife radiosurgery (GKRS) were retrospectively evaluated. A commercially available software was used for distortion correction. Geometrical agreement between corrected and uncorrected tumor volumes was evaluated using MacDonald criteria, Euclidian distance, and Dice similarity coefficient (DSC). SRS plans were generated using uncorrected tumor volumes, which were assessed to determine their coverage of the corrected tumor volumes. Results The median target volume was 0.38 cm3 (range,0.01-12.38 cm3). A maximum displacement of METs of up to 2.87 mm and a median displacement of 0.55 mm (range,0.1-2.87 mm) were noted. The median DSC between uncorrected and corrected MRI was 0.92, and the most concerning case had a DSC of 0.46. Although all plans met the optimization criterion of at least 98% of the uncorrected tumor volume (median 99.55%, range 98.1-100%) receiving at least 100% of the prescription dose, the percent of the corrected tumor volume receiving the total prescription dose was a median of 95.45% (range,23.1-99.5%). Discussion and conclusion MRI distortion, though visually subtle, has significant implications for SRS planning. Regular utilization of corrected MRI is recommended for SRS planning as distortion is sometimes enough to cause a volumetric miss of SRS targets.
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Affiliation(s)
- Yavuz Samanci
- Department of Neurosurgery, Koc University School of Medicine, Istanbul, Turkey
- Gamma Knife Center, Department of Neurosurgery, Koc University Hospital, Istanbul, Turkey
| | - M. Orbay Askeroglu
- Gamma Knife Center, Department of Neurosurgery, Koc University Hospital, Istanbul, Turkey
| | - Ali Haluk Düzkalir
- Gamma Knife Center, Department of Neurosurgery, Koc University Hospital, Istanbul, Turkey
- Department of Neurosurgery, Koc University Hospital, Istanbul, Turkey
| | - Selcuk Peker
- Department of Neurosurgery, Koc University School of Medicine, Istanbul, Turkey
- Gamma Knife Center, Department of Neurosurgery, Koc University Hospital, Istanbul, Turkey
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Oshiro Y, Mizumoto M, Kato Y, Tsuchida Y, Tsuboi K, Sakae T, Sakurai H. Single isocenter dynamic conformal arcs-based radiosurgery for brain metastases: Dosimetric comparison with Cyberknife and clinical investigation. Tech Innov Patient Support Radiat Oncol 2024; 29:100235. [PMID: 38299171 PMCID: PMC10827586 DOI: 10.1016/j.tipsro.2024.100235] [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: 10/22/2023] [Revised: 12/14/2023] [Accepted: 01/09/2024] [Indexed: 02/02/2024] Open
Abstract
Purpose To compare the dosimetric quality of automatic multiple brain metastases planning (MBM) with that of Cyberknife (CK) based on the clinical tumor condition, such as the tumor number, size, and location. Methods 76 treatment plans for 46 patients treated with CK were recalculated with the MBM treatment planning system. Conformity index (CI), homogeneity index (HI), gradient index (GI), lesion underdosage volume factor (LUF), healthy tissue overdose volume factor (HTOF), geometric conformity index (g) and mean dose to normal organs were compared between CK and MBM for tumor number, size, shape and distance from the brainstem or chiasm. Results The results showed that the mean brain dose was significantly smaller in MBM than CK. CI did not differ between MBM and CK; however, HI was significantly more ideal in CK (p = 0.000), and GI was significantly smaller in MBM (P = 0.000). LUF was larger in CK (p = 0.000) and HTOF and g was larger in MBM (p = 0.003, and 0.012). For single metastases, CK had significantly better HTOF (p = 0.000) and g (p = 0.002), but there were no differences for multiple tumors. Brain dose in MBM was significantly lower and CI was higher for tumors < 30 mm (p = 0.000 and 0.000), whereas HTOF and g for tumors < 10 mm were significantly smaller in CK (p = 0.041 and p = 0.016). Among oval tumors, brain dose, GI and LUF were smaller in MBM, but HTOF and g were smaller in CK. There were no particular trends for tumors close to the brainstem, but HTOF tended to be smaller in CK (0.03 vs. 0.29, p = 0.068) for tumors inside the brainstem. Conclusions MBM can reduce the brain dose while achieving a dose distribution quality equivalent to that with CK.
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Affiliation(s)
- Yoshiko Oshiro
- Department of Radiation Oncology, Tsukuba Medical Center Hospital, Amakubo 1-3-1, Tsukuba, Ibaraki, 305-8558, Japan
| | - Masashi Mizumoto
- Department of Neurosurgery, Tsukuba Central Hospital, Amakubo 1-3-1, Tsukuba, Ibaraki, 305-8558, Japan
- Department of Radiation Therapy, University of Tsukuba, Amakubo 1-3-1, Tsukuba, Ibaraki, 305-8558, Japan
| | - Yuichi Kato
- Department of Radiation Oncology, Tsukuba Medical Center Hospital, Amakubo 1-3-1, Tsukuba, Ibaraki, 305-8558, Japan
| | - Yukihiro Tsuchida
- Department of Neurosurgery, Tsukuba Central Hospital, Amakubo 1-3-1, Tsukuba, Ibaraki, 305-8558, Japan
| | - Koji Tsuboi
- Department of Neurosurgery, Tsukuba Central Hospital, Amakubo 1-3-1, Tsukuba, Ibaraki, 305-8558, Japan
| | - Takeji Sakae
- Department of Radiation Therapy, University of Tsukuba, Amakubo 1-3-1, Tsukuba, Ibaraki, 305-8558, Japan
| | - Hideyuki Sakurai
- Department of Radiation Therapy, University of Tsukuba, Amakubo 1-3-1, Tsukuba, Ibaraki, 305-8558, Japan
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Huang Y, Liang E, Schaff EM, Zhao B, Snyder KC, Chetty IJ, Shah MM, Siddiqui SM. Impact of MRI resolution for Linac-based stereotactic radiosurgery. Front Oncol 2023; 13:1090582. [PMID: 36761944 PMCID: PMC9902927 DOI: 10.3389/fonc.2023.1090582] [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: 11/05/2022] [Accepted: 01/09/2023] [Indexed: 01/26/2023] Open
Abstract
Objective Magnetic resonance imaging (MRI) is a standard imaging modality in intracranial stereotactic radiosurgery (SRS) for defining target volumes. However, wide disparities in MRI resolution exist, which could directly impact accuracy of target delineation. Here, sequences with various MRI resolution were acquired on phantoms to evaluate the effect on volume definition and dosimetric consequence for cranial SRS. Materials/Methods Four T1-weighted MR sequences with increasing 3D resolution were compared, including two Spin Echo (SE) 2D acquisitions with 5mm and 3mm slice thickness (SE5mm, SE3mm) and two gradient echo 3D acquisitions (TFE, BRAVO). The voxel sizes were 0.4×0.4×5.0, 0.5×0.5×3.0, 0.9×0.9×1.25, and 0.4×0.4×0.5 mm3, respectively. Four phantoms with simulated lesions of different shape and volume (range, 0.53-25.0 cm3) were imaged, resulting in 16 total sets of MRIs. Four radiation oncologists provided contours on individual MR image set. All observer contours were compared with ground truth, defined on CT image according to the absolute dimensions of the target structure, using Dice similarity coefficient (DSC), Hausdorff distance (HD), mean distance-to-agreement (MDA), and the ratio between reconstructed and true volume (Ratiovol ). For dosimetric consequence, SRS plans targeting observer volumes were created. The true Paddick conformity index ( C I p a d d i c k t r u e ), calculated with true target volume, was correlated with quality of observer volume. Results All measures of observer contours improved as increasingly higher MRI resolution was provided from SE5mm to BRAVO. The improvement in DSC, HD and MDA was statistically significant (p<0.01). Dosimetrically, C I p a d d i c k t r u e strongly correlated with DSC of the planning observer volume (Pearson's r=0.94, p<0.00001). Conclusions Significant improvement in target definition and reduced inter-observer variation was observed as the MRI resolution improved, which also improved the quality of SRS plans. Results imply that high resolution 3D MR sequences should be used to minimize potential errors in target definition, and multi-slice 2D sequences should be avoided.
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Grishchuk D, Dimitriadis A, Sahgal A, De Salles A, Fariselli L, Kotecha R, Levivier M, Ma L, Pollock BE, Regis J, Sheehan J, Suh J, Yomo S, Paddick I. ISRS Technical Guidelines for Stereotactic Radiosurgery: Treatment of Small Brain Metastases (≤1 cm in Diameter). Pract Radiat Oncol 2022; 13:183-194. [PMID: 36435388 DOI: 10.1016/j.prro.2022.10.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/10/2022] [Accepted: 10/12/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE The objective of this literature review was to develop International Stereotactic Radiosurgery Society (ISRS) consensus technical guidelines for the treatment of small, ≤1 cm in maximal diameter, intracranial metastases with stereotactic radiosurgery. Although different stereotactic radiosurgery technologies are available, most of them have similar treatment workflows and common technical challenges that are described. METHODS AND MATERIALS A systematic review of the literature published between 2009 and 2020 was performed in Pubmed using the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) methodology. The search terms were limited to those related to radiosurgery of brain metastases and to publications in the English language. RESULTS From 484 collected abstract 37 articles were included into the detailed review and bibliographic analysis. An additional 44 papers were identified as relevant from a search of the references. The 81 papers, including additional 7 international guidelines, were deemed relevant to at least one of five areas that were considered paramount for this report. These areas of technical focus have been employed to structure these guidelines: imaging specifications, target volume delineation and localization practices, use of margins, treatment planning techniques, and patient positioning. CONCLUSION This systematic review has demonstrated that Stereotactic Radiosurgery (SRS) for small (1 cm) brain metastases can be safely performed on both Gamma Knife (GK) and CyberKnife (CK) as well as on modern LINACs, specifically tailored for radiosurgical procedures, However, considerable expertise and resources are required for a program based on the latest evidence for best practice.
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Affiliation(s)
- Diana Grishchuk
- National Hospital for Neurology and Neurosurgery, London, United Kingdom.
| | - Alexis Dimitriadis
- National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Arjun Sahgal
- Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Ontario, Canada
| | - Antonio De Salles
- Department of Neurosurgery, University of California, Los Angeles, California
| | - Laura Fariselli
- Radiotherapy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta Milano, Unita di Radiotherapia, Milan, Italy
| | - Rupesh Kotecha
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, Florida
| | - Marc Levivier
- Neurosurgery Service and Gamma Knife Center, Center Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Lijun Ma
- Department of Radiation Oncology, University of California San Francisco, San Francisco, California
| | - Bruce E Pollock
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota
| | - Jean Regis
- Department of Functional Neurosurgery, La Timone Hospital, Aix-Marseille University, Marseille, France
| | - Jason Sheehan
- Department of Neurologic Surgery, University of Virginia, Charlottesville, Virginia
| | - John Suh
- Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio
| | - Shoji Yomo
- Division of Radiation Oncology, Aizawa Comprehensive Cancer Center, Aizawa Hospital, Matsumoto, Japan
| | - Ian Paddick
- National Hospital for Neurology and Neurosurgery, London, United Kingdom
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Diez P, Hanna GG, Aitken KL, van As N, Carver A, Colaco RJ, Conibear J, Dunne EM, Eaton DJ, Franks KN, Good JS, Harrow S, Hatfield P, Hawkins MA, Jain S, McDonald F, Patel R, Rackley T, Sanghera P, Tree A, Murray L. UK 2022 Consensus on Normal Tissue Dose-Volume Constraints for Oligometastatic, Primary Lung and Hepatocellular Carcinoma Stereotactic Ablative Radiotherapy. Clin Oncol (R Coll Radiol) 2022; 34:288-300. [PMID: 35272913 DOI: 10.1016/j.clon.2022.02.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/21/2022] [Accepted: 02/14/2022] [Indexed: 12/25/2022]
Abstract
The use of stereotactic ablative radiotherapy (SABR) in the UK has expanded over the past decade, in part as the result of several UK clinical trials and a recent NHS England Commissioning through Evaluation programme. A UK SABR Consortium consensus for normal tissue constraints for SABR was published in 2017, based on the existing literature at the time. The published literature regarding SABR has increased in volume over the past 5 years and multiple UK centres are currently working to develop new SABR services. A review and update of the previous consensus is therefore appropriate and timely. It is hoped that this document will provide a useful resource to facilitate safe and consistent SABR practice.
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Affiliation(s)
- P Diez
- Radiotherapy Physics, National Radiotherapy Trials Quality Assurance Group (RTTQA), Mount Vernon Cancer Centre, Northwood, UK
| | - G G Hanna
- Belfast Health and Social Care Trust, Belfast, UK; Queen's University Belfast, Belfast, UK
| | - K L Aitken
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust, Sutton, Surrey, UK; Institute of Cancer Research, London, UK
| | - N van As
- Institute of Cancer Research, London, UK; Department of Radiotherapy, Royal Marsden NHS Foundation Trust, Chelsea, London, UK
| | - A Carver
- Department of Medical Physics, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Medical Centre, Edgbaston, Birmingham, UK
| | - R J Colaco
- Department of Clinical Oncology, The Christie Hospital NHS Foundation Trust, Manchester, UK
| | - J Conibear
- Radiotherapy Department, Barts Cancer Centre, London, UK
| | - E M Dunne
- Department of Clinical Oncology, Guys and St Thomas' NHS Foundation Trust, London, UK
| | - D J Eaton
- Radiotherapy Physics, National Radiotherapy Trials Quality Assurance Group (RTTQA), Mount Vernon Cancer Centre, Northwood, UK; Department of Medical Physics, Guys and St Thomas' NHS Foundation Trust, London, UK; School of Biomedical Engineering & Imaging Sciences, King's College London, London, UK
| | - K N Franks
- Department of Clinical Oncology, Leeds Cancer Centre, St James's University Hospitals, Leeds, UK
| | - J S Good
- Department of Clinical Oncology, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital Birmingham, Edgbaston, Birmingham, UK
| | - S Harrow
- Department of Clinical Oncology, Edinburgh Cancer Centre, Western General Hospital, Edinburgh, UK
| | - P Hatfield
- Department of Clinical Oncology, Leeds Cancer Centre, St James's University Hospitals, Leeds, UK
| | - M A Hawkins
- Department of Medical Physics and Biomechanical Engineering, University College London, London, UK; Department of Clinical Oncology, University College London Hospitals NHS Foundation Trust, London, UK
| | - S Jain
- Belfast Health and Social Care Trust, Belfast, UK; Queen's University Belfast, Belfast, UK
| | - F McDonald
- Institute of Cancer Research, London, UK; Department of Radiotherapy, Royal Marsden NHS Foundation Trust, Chelsea, London, UK
| | - R Patel
- Radiotherapy Physics, National Radiotherapy Trials Quality Assurance Group (RTTQA), Mount Vernon Cancer Centre, Northwood, UK
| | - T Rackley
- Department of Clinical Oncology, Velindre Cancer Centre, Cardiff, UK
| | - P Sanghera
- Department of Clinical Oncology, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital Birmingham, Edgbaston, Birmingham, UK
| | - A Tree
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust, Sutton, Surrey, UK; Institute of Cancer Research, London, UK
| | - L Murray
- Department of Clinical Oncology, Leeds Cancer Centre, St James's University Hospitals, Leeds, UK; Leeds Institute of Medical Research at St James's, University of Leeds, Leeds, UK.
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Eaton DJ. Why all radiotherapy planning studies are wrong but some are useful. Med Dosim 2021; 46:209-211. [PMID: 33423882 DOI: 10.1016/j.meddos.2020.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 12/14/2020] [Indexed: 01/20/2023]
Abstract
Dosimetry comparison studies of radiotherapy treatment planning are common, but often their limitations are not fully acknowledged. Useful data for the community may be produced, which is reproducible and reliable for implementation by others. However, this will only be achieved by clear and detailed reporting, and by consideration of delivered doses and clinical significance.
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Affiliation(s)
- David J Eaton
- Radiotherapy Physics, Guy's and St Thomas' Hospitals, London, UK.
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Growcott S, Dembrey T, Patel R, Eaton D, Cameron A. Inter-Observer Variability in Target Volume Delineations of Benign and Metastatic Brain Tumours for Stereotactic Radiosurgery: Results of a National Quality Assurance Programme. Clin Oncol (R Coll Radiol) 2020; 32:13-25. [DOI: 10.1016/j.clon.2019.06.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 05/21/2019] [Indexed: 11/28/2022]
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Cho YB, Alasti H, Kong V, Catton C, Berlin A, Chung P, Bayley A, Jaffray D. Impact of high dose volumetric CT on PTV margin reduction in VMAT prostate radiotherapy. ACTA ACUST UNITED AC 2019; 64:065017. [DOI: 10.1088/1361-6560/ab050f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Eaton DJ, Lee J, Patel R, Millin AE, Paddick I, Walker C. Stereotactic radiosurgery for benign brain tumors: Results of multicenter benchmark planning studies. Pract Radiat Oncol 2018; 8:e295-e304. [PMID: 29884596 DOI: 10.1016/j.prro.2018.02.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 01/30/2018] [Accepted: 02/13/2018] [Indexed: 12/25/2022]
Abstract
PURPOSE Stereotactic radiosurgery (SRS) is strongly indicated for treatment of surgically inaccessible benign brain tumors. Various treatment platforms are available, but few comparisons have included multiple centers. As part of a national commissioning program, benchmark planning cases were completed by all clinical centers in the region. METHODS AND MATERIALS Four benign cases were provided, with images and structures predelineated, including intracanalicular vestibular schwannoma (VS), larger VS, skull base meningioma, and secreting pituitary adenoma. Centers were asked to follow their local practice, and plans were reviewed centrally using metrics for target coverage, selectivity, gradient falloff, and normal tissue sparing. RESULTS Sixty-eight plans were submitted using 18 different treatment platforms. Fourteen plans were subsequently revised following feedback, and review of 5 plans led to a restriction of service on 2 platforms (2 centers). Prescription doses were consistent for VS and meningioma submissions, but a wide range of doses were used for the pituitary case. All centers prioritized coverage, with the prescription isodose covering ≥95% of 78/82 target volumes. Lower values may be expected next to air cavities when using advanced algorithms, and in general may be acceptable for some benign lesions. Selectivity was much more variable, and in some cases this was combined with high gradient index and/or >1 mm margin, resulting in large volumes of normal tissue being irradiated. Normal tissue doses were more variable across linear accelerator (LINAC)-based plans than with Gamma Knife or CyberKnife, and dose spillage seemed independent of prescription isodose (inhomogeneity). This may reflect the variety of LINAC-based approaches represented or the necessary tradeoff between different objectives. CONCLUSIONS These benchmarking exercises have highlighted areas of different clinical practice and priorities and potential for improvement. The subsequent sharing of plan data and margin philosophies between the neurosurgery and oncology communities allowed for meaningful comparison between centers and their peers.
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Affiliation(s)
- David J Eaton
- National Radiotherapy Trials Quality Assurance group, Mount Vernon Hospital, Northwood, United Kingdom.
| | - Jonathan Lee
- National Radiotherapy Trials Quality Assurance group, Mount Vernon Hospital, Northwood, United Kingdom
| | - Rushil Patel
- National Radiotherapy Trials Quality Assurance group, Mount Vernon Hospital, Northwood, United Kingdom
| | | | - Ian Paddick
- Medical Physics Ltd, Reading, United Kingdom; Cromwell Hospital, London, United Kingdom
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