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Hanvey S, Hackett P, Winch L, Lim E, Laney R, Welsh L. A multi-centre stereotactic radiosurgery planning study of multiple brain metastases using isocentric linear accelerators with 5 and 2.5 mm width multi-leaf collimators, CyberKnife and Gamma Knife. BJR Open 2024; 6:tzae003. [PMID: 38371494 PMCID: PMC10873585 DOI: 10.1093/bjro/tzae003] [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: 02/15/2024] [Revised: 02/15/2024] [Accepted: 02/15/2024] [Indexed: 02/20/2024] Open
Abstract
Objectives This study compared plans of high definition (HD), 2.5 mm width multi-leaf collimator (MLC), to standard, 5 mm width, isocentric linear accelerator (linacs), CyberKnife (CK), and Gamma Knife (GK) for stereotactic radiosurgery (SRS) techniques on multiple brain metastases. Methods Eleven patients undergoing SRS for multiple brain metastases were chosen. Targets and organs at risk (OARs) were delineated and optimized SRS plans were generated and compared. Results The linacs delivered similar conformity index (CI) values, but the gradient index (GI) for HD MLCs was significantly lower (P-value <.001). Half the OARs received significantly lower dose using HD MLCs. CK delivered a significantly lower CI than HD MLC linac (P-value <.001), but a significantly higher GI (P-value <.001). CI was significantly improved with the HD MLC linac compared to GK (P-value = 4.591 × 10-3), however, GK delivered a significantly lower GI (P-value <.001). OAR dose sparing was similar for the HD MLC TL, CK, and GK. Conclusions Comparing linacs for SRS, the preferred choice is HD MLCs. Similar results were achieved with the HD MLC linac, CK, or GK, with each delivering significant improvements in different aspects of plan quality. Advances in knowledge This article is the first to compare HD and standard width MLC linac plans using a combination of single isocentre volumetric modulated arc therapy and multi-isocentric dynamic conformal arc plans as required, which is a more clinically relevant assessment. Furthermore, it compares these plans with CK and GK, assessing the relative merits of each technique.
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Affiliation(s)
- Scott Hanvey
- University Hospitals Plymouth NHS Trust, Plymouth, PL6 8DH, United Kingdom
| | | | - Lucy Winch
- University Hospitals Bristol NHS Foundation Trust, Bristol, BS2 8ED, United Kingdom
| | - Elizabeth Lim
- University Hospitals Plymouth NHS Trust, Plymouth, PL6 8DH, United Kingdom
- University of Plymouth, Plymouth, PL4 8AA, United Kingdom
| | - Robin Laney
- University Hospitals Plymouth NHS Trust, Plymouth, PL6 8DH, United Kingdom
| | - Liam Welsh
- The Royal Marsden, London, SW3 6JJ, United Kingdom
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Role of the Neuroradiologist and Neurosurgeon in Contouring with the Clinical Oncologist for Stereotactic Radiosurgery. Clin Oncol (R Coll Radiol) 2022; 34:398-406. [DOI: 10.1016/j.clon.2022.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/04/2022] [Indexed: 11/24/2022]
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Pérez P, Torres PR, Bruna A, Brunetto M, Aon E, Franco D, Mattea F, Figueroa R, Santibáñez M, Valente M. Fricke gel xylenol orange dosimeter layers for stereotactic radiosurgery: A preliminary approach. Appl Radiat Isot 2021; 178:109936. [PMID: 34592691 DOI: 10.1016/j.apradiso.2021.109936] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 12/15/2022]
Abstract
Investigations regarding the feasibility, reliability, and accuracy of Fricke gel dosimeter layers for stereotactic radiosurgery are presented. A representative radiosurgery plan consisting of two targets has been investigated. Absorbed dose distributions measured using radiochromic films and gelatin Fricke Gel dosimetry in layers have been compared with dose distributions calculated by using a treatment planning system and Monte Carlo simulations. The different dose distributions have been compared by means of the gamma index demonstrating that gelatin Fricke gel dosimeter layers showed agreements of 100%, 100%, and 93%, with dose and distance tolerances of 2% and 2 mm, with respect to film dosimetry, treatment planning system and Monte Carlo simulations, respectively. The capability of the developed system for three-dimensional dose mapping was shown, obtaining promising results when compared with well-established dosimetry methods. The obtained results support the viability of Fricke gel dosimeter layers analyzed by optical methods for stereotactic radiosurgery.
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Affiliation(s)
- P Pérez
- Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes de Rayos X (LIIFAMIR(x)), Facultad de Matemática, Astronomía, Física y Computación, Universidad Nacional de Córdoba, Córdoba, Argentina; Instituto de Física Enrique Gaviola (IFEG), CONICET, Córdoba, Argentina.
| | - P Rico Torres
- Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes de Rayos X (LIIFAMIR(x)), Facultad de Matemática, Astronomía, Física y Computación, Universidad Nacional de Córdoba, Córdoba, Argentina; Instituto Venezolano de Investigaciones Científicas, Venezuela
| | - A Bruna
- FiMe - Física Médica SRL, Argentina
| | - M Brunetto
- Centro Médico Privado Deán Funes, Córdoba, Argentina
| | - E Aon
- Centro Médico Privado Deán Funes, Córdoba, Argentina
| | - D Franco
- Centro Médico Privado Deán Funes, Córdoba, Argentina
| | - F Mattea
- Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes de Rayos X (LIIFAMIR(x)), Facultad de Matemática, Astronomía, Física y Computación, Universidad Nacional de Córdoba, Córdoba, Argentina; Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina; Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada (IPQA), CONICET, Córdoba, Argentina
| | - R Figueroa
- Centro de excelencia de Física e Ingeniería en Salud (CFIS), Universidad de la Frontera, Temuco, Chile; Departamento de Ciencias Físicas, Universidad de la Frontera, Temuco, Chile
| | - M Santibáñez
- Departamento de Ciencias Físicas, Universidad de la Frontera, Temuco, Chile
| | - M Valente
- Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes de Rayos X (LIIFAMIR(x)), Facultad de Matemática, Astronomía, Física y Computación, Universidad Nacional de Córdoba, Córdoba, Argentina; Instituto de Física Enrique Gaviola (IFEG), CONICET, Córdoba, Argentina; Centro de excelencia de Física e Ingeniería en Salud (CFIS), Universidad de la Frontera, Temuco, Chile; Departamento de Ciencias Físicas, Universidad de la Frontera, Temuco, Chile.
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Gude Z, Adamson J, Kirkpatrick JP, Giles W. Hippocampal Avoidance in Multitarget Radiosurgery. Cureus 2021; 13:e15399. [PMID: 34249548 PMCID: PMC8253338 DOI: 10.7759/cureus.15399] [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] [Accepted: 05/22/2021] [Indexed: 11/16/2022] Open
Abstract
Brain metastases are a common complication for patients diagnosed with cancer. As stereotactic radiosurgery (SRS) becomes a more prevalent treatment option for patients with many brain metastases, further research is required to better characterize the ability of SRS to treat large numbers of metastases (≥4) and the impact on normal brain tissue and, ultimately, neurocognition and quality of life (QOL). This study serves first as an evaluation of the feasibility of hippocampal avoidance for SRS patients, specifically receiving single-isocenter multitarget treatments (SIMT) planned with volumetric modulated arc therapy (VMAT). Second, this study analyzes the effects of standard-definition (SD) multileaf collimators (MLCs) (5 mm width) on plan quality and hippocampal avoidance. The 40 patients enrolled in this Institutional Review Board (IRB)-approved study had between four and 10 brain metastases and were treated with SIMT using VMAT. From the initial 40 patients, eight hippocampi across seven patients had hippocampal doses exceeding the maximum biologically effective dose (BED) constraint given by RTOG 0933. With the addition of upper constraints in the optimization objectives and one arc angle adjustment in one patient plan, four out of seven patient plans were able to meet the maximum hippocampal BED constraint, avoiding five out of eight total hippocampi at risk. High-definition (HD) MLCs allowed for an average decrease of 29% ± 23% (p = 0.007) in the maximum BED delivered to all eight hippocampi at risk. The ability to meet dose constraints depended on the distance between the hippocampus and the nearest planning target volume (PTV). Meeting the maximum hippocampal BED constraint in re-optimized plans was equally likely with the use of SD-MLCs (five out of eight hippocampi at risk were avoided) but resulted in increased dose to normal tissue volumes (23.67% ± 16.3% increase in V50%[cc] of normal brain tissue, i.e., brain volume subtracted by the total PTV) when compared to the HD-MLC re-optimized plans. Comparing the effects of SD-MLCs on plans not optimized for hippocampal avoidance resulted in increases of 48.2% ± 32.2% (p = 0.0056), 31.5% ± 16.3% (p = 0.024), and 16.7% ± 8.5% (p = 0.022) in V20%[cc], V50%[cc], and V75%[cc], respectively, compared to the use of HD-MLCs. The conformity index changed significantly neither when plans were optimized for hippocampal avoidance nor when SD-MLC leaves were used for treatment. In plans not optimized for hippocampal avoidance, mean hippocampal dose increased with the use of SD-MLCs by 38.0% ± 37.5% (p = 0.01). However, the use of SD-MLCs did not result in an increased number of hippocampi at risk.
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Affiliation(s)
| | - Justus Adamson
- Radiation Oncology, Duke University Medical Center, Durham, USA
| | | | - William Giles
- Radiation Oncology, Duke University Medical Center, Durham, USA
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Calvo‐Ortega J, Greer PB, Hermida‐López M, Moragues‐Femenía S, Laosa‐Bello C, Casals‐Farran J. Validation of virtual water phantom software for pre-treatment verification of single-isocenter multiple-target stereotactic radiosurgery. J Appl Clin Med Phys 2021; 22:241-252. [PMID: 34028955 PMCID: PMC8200437 DOI: 10.1002/acm2.13269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 02/05/2021] [Accepted: 04/13/2021] [Indexed: 11/09/2022] Open
Abstract
The aim of this study was to benchmark the accuracy of the VIrtual Phantom Epid dose Reconstruction (VIPER) software for pre-treatment dosimetric verification of multiple-target stereotactic radiosurgery (SRS). VIPER is an EPID-based method to reconstruct a 3D dose distribution in a virtual phantom from in-air portal images. Validation of the VIPER dose calculation was assessed using several MLC-defined fields for a 6 MV photon beam. Central axis percent depth doses (PDDs) and output factors were measured with an ionization chamber in a water tank, while dose planes at a depth of 10 cm in a solid flat phantom were acquired with radiochromic films. The accuracy of VIPER for multiple-target SRS plan verification was benchmarked against Monte Carlo simulations. Eighteen multiple-target SRS plans designed with the Eclipse treatment planning system were mapped to a cylindrical water phantom. For each plan, the 3D dose distribution reconstructed by VIPER within the phantom was compared with the Monte Carlo simulation, using a 3D gamma analysis. Dose differences (VIPER vs. measurements) generally within 2% were found for the MLC-defined fields, while film dosimetry revealed gamma passing rates (GPRs) ≥95% for a 3%/1 mm criteria. For the 18 multiple-target SRS plans, average 3D GPRs greater than 93% and 98% for the 3%/2 mm and 5%/2 mm criteria, respectively. Our results validate the use of VIPER as a dosimetric verification tool for pre-treatment QA of single-isocenter multiple-target SRS plans. The method requires no setup time on the linac and results in an accurate 3D characterization of the delivered dose.
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Affiliation(s)
- Juan‐Francisco Calvo‐Ortega
- Servicio de Oncología RadioterápicaHospital QuirónsaludBarcelonaSpain
- Servicio de Oncología RadioterápicaHospital Universitari DexeusBarcelonaSpain
| | - Peter B. Greer
- Department of Radiation OncologyCalvary Mater Newcastle HospitalNewcastleNSW2298Australia
- School of Mathematical and Physical SciencesUniversity of NewcastleNewcastleNSW2300Australia
| | | | - Sandra Moragues‐Femenía
- Servicio de Oncología RadioterápicaHospital QuirónsaludBarcelonaSpain
- Servicio de Oncología RadioterápicaHospital Universitari DexeusBarcelonaSpain
| | - Coral Laosa‐Bello
- Servicio de Oncología RadioterápicaHospital QuirónsaludBarcelonaSpain
- Servicio de Oncología RadioterápicaHospital Universitari DexeusBarcelonaSpain
| | - Joan Casals‐Farran
- Servicio de Oncología RadioterápicaHospital QuirónsaludBarcelonaSpain
- Servicio de Oncología RadioterápicaHospital Universitari DexeusBarcelonaSpain
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