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García-Vázquez V, Calvo FA, Ledesma-Carbayo MJ, Sole CV, Calvo-Haro J, Desco M, Pascau J. Intraoperative computed tomography imaging for dose calculation in intraoperative electron radiation therapy: Initial clinical observations. PLoS One 2020; 15:e0227155. [PMID: 31923183 PMCID: PMC6953834 DOI: 10.1371/journal.pone.0227155] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Accepted: 12/12/2019] [Indexed: 12/20/2022] Open
Abstract
In intraoperative electron radiation therapy (IOERT) the energy of the electron beam is selected under the conventional assumption of water-equivalent tissues at the applicator end. However, the treatment field can deviate from the theoretic flat irradiation surface, thus altering dose profiles. This patient-based study explored the feasibility of acquiring intraoperative computed tomography (CT) studies for calculating three-dimensional dose distributions with two factors not included in the conventional assumption, namely the air gap from the applicator end to the irradiation surface and tissue heterogeneity. In addition, dose distributions under the conventional assumption and from preoperative CT studies (both also updated with intraoperative data) were calculated to explore whether there are other alternatives to intraoperative CT studies that can provide similar dose distributions. The IOERT protocol was modified to incorporate the acquisition of intraoperative CT studies before radiation delivery in six patients. Three studies were not valid to calculate dose distributions due to the presence of metal artefacts. For the remaining three cases, the average gamma pass rates between the doses calculated from intraoperative CT studies and those obtained assuming water-equivalent tissues or from preoperative CT studies were 73.4% and 74.0% respectively. The agreement increased when the air gap was included in the conventional assumption (98.1%) or in the preoperative CT images (98.4%). Therefore, this factor was the one mostly influencing the dose distributions of this study. Our experience has shown that intraoperative CT studies are not recommended when the procedure includes the use of shielding discs or surgical retractors unless metal artefacts are removed. IOERT dose distributions calculated under the conventional assumption or from preoperative CT studies may be inaccurate unless the air gap (which depends on the surface irregularities of the irradiated volume and on the applicator pose) is included in the calculations.
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Affiliation(s)
- Verónica García-Vázquez
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Comunidad de Madrid, Spain
- * E-mail: (VGV); (JP)
| | - Felipe A. Calvo
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Comunidad de Madrid, Spain
- Departamento de Oncología, Hospital General Universitario Gregorio Marañón, Madrid, Comunidad de Madrid, Spain
- Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Comunidad de Madrid, Spain
- Clínica Universidad de Navarra, Madrid, Comunidad de Madrid, Spain
| | - María J. Ledesma-Carbayo
- Biomedical Image Technologies Laboratory (BIT), Escuela Técnica Superior de Ingenieros de Telecomunicación, Universidad Politécnica de Madrid, Madrid, Comunidad de Madrid, Spain
- CIBER-BBN, Madrid, Comunidad de Madrid, Spain
| | - Claudio V. Sole
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Comunidad de Madrid, Spain
- Department of Radiation Oncology, Instituto de Radiomedicina, Santiago, Región Metropolitana de Santiago, Chile
| | - José Calvo-Haro
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Comunidad de Madrid, Spain
- Servicio de Cirugía Ortopédica y Traumatología, Hospital General Universitario Gregorio Marañón, Madrid, Comunidad de Madrid, Spain
- Departamento de Cirugía, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Comunidad de Madrid, Spain
| | - Manuel Desco
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Comunidad de Madrid, Spain
- Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid, Comunidad de Madrid, Spain
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Comunidad de Madrid, Spain
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Comunidad de Madrid, Spain
| | - Javier Pascau
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Comunidad de Madrid, Spain
- Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid, Comunidad de Madrid, Spain
- * E-mail: (VGV); (JP)
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Baghani HR, Heidarloo N, Aghamiri SMR, Mahdavi SR. Comparing the physical and dosimetric characteristics of cylindrical and beam shaper intraoperative radiotherapy applicators. Radiat Phys Chem Oxf Engl 1993 2019. [DOI: 10.1016/j.radphyschem.2019.01.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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3D Monte Carlo dosimetry of intraoperative electron radiation therapy (IOERT). Phys Med 2019; 57:207-214. [DOI: 10.1016/j.ejmp.2018.12.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 12/27/2018] [Accepted: 12/29/2018] [Indexed: 01/26/2023] Open
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García-Vázquez V, Sesé-Lucio B, Calvo FA, Vaquero JJ, Desco M, Pascau J. Surface scanning for 3D dose calculation in intraoperative electron radiation therapy. Radiat Oncol 2018; 13:243. [PMID: 30526626 PMCID: PMC6286593 DOI: 10.1186/s13014-018-1181-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 11/12/2018] [Indexed: 02/03/2023] Open
Abstract
Background Dose calculations in intraoperative electron radiation therapy (IOERT) rely on the conventional assumption of water-equivalent tissues at the applicator end, which defines a flat irradiation surface. However, the shape of the irradiation surface modifies the dose distribution. Our study explores, for the first time, the use of surface scanning methods for three-dimensional dose calculation of IOERT. Methods Two different three-dimensional scanning technologies were evaluated in a simulated IOERT scenario: a tracked conoscopic holography sensor (ConoProbe) and a structured-light three-dimensional scanner (Artec). Dose distributions obtained from computed tomography studies of the surgical field (gold standard) were compared with those calculated under the conventional assumption or from pseudo-computed tomography studies based on surfaces. Results In the simulated IOERT scenario, the conventional assumption led to an average gamma pass rate of 39.9% for dose values greater than 10% (two configurations, with and without blood in the surgical field). Results improved when considering surfaces in the dose calculation (88.5% for ConoProbe and 92.9% for Artec). Conclusions More accurate three-dimensional dose distributions were obtained when considering surfaces in the dose calculation of the simulated surgical field. The structured-light three-dimensional scanner provided the best results in terms of dose distributions. The findings obtained in this specific experimental setup warrant further research on surface scanning in the IOERT context owing to the clinical interest of improving the documentation of the actual IOERT scenario.
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Affiliation(s)
- Verónica García-Vázquez
- Instituto de Investigación Sanitaria Gregorio Marañón. Calle Doctor Esquerdo, 46, 28007, Madrid, Spain.
| | - Begoña Sesé-Lucio
- Instituto de Investigación Sanitaria Gregorio Marañón. Calle Doctor Esquerdo, 46, 28007, Madrid, Spain
| | - Felipe A Calvo
- Instituto de Investigación Sanitaria Gregorio Marañón. Calle Doctor Esquerdo, 46, 28007, Madrid, Spain.,Departamento de Oncología, Hospital General Universitario Gregorio Marañón, Madrid, Spain.,Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain.,Clínica Universidad de Navarra, Madrid, Spain
| | - Juan J Vaquero
- Instituto de Investigación Sanitaria Gregorio Marañón. Calle Doctor Esquerdo, 46, 28007, Madrid, Spain.,Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid, Spain
| | - Manuel Desco
- Instituto de Investigación Sanitaria Gregorio Marañón. Calle Doctor Esquerdo, 46, 28007, Madrid, Spain.,Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid, Spain.,Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain.,Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Javier Pascau
- Instituto de Investigación Sanitaria Gregorio Marañón. Calle Doctor Esquerdo, 46, 28007, Madrid, Spain.,Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid, Spain.,Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain
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Heidarloo N, Baghani HR, Aghamiri SMR, Mahdavi SR, Akbari ME. Commissioning of beam shaper applicator for conformal intraoperative electron radiotherapy. Appl Radiat Isot 2017; 123:69-81. [DOI: 10.1016/j.apradiso.2017.02.039] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Revised: 02/04/2017] [Accepted: 02/23/2017] [Indexed: 11/27/2022]
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Abstract
Literature was reviewed to assess the physical aspects governing the present and emerging technologies used in intraoperative radiation therapy (IORT). Three major technologies were identified: treatment with electrons, treatment with external generators of kV X-rays and electronic brachytherapy. Although also used in IORT, literature on brachytherapy with radioactive sources is not systematically reviewed since an extensive own body of specialized literature and reviews exists in this field. A comparison with radioactive sources is made in the use of balloon catheters for partial breast irradiation where these are applied in almost an identical applicator technique as used with kV X-ray sources. The physical constraints of adaption of the dose distribution to the extended target in breast IORT are compared. Concerning further physical issues, the literature on radiation protection, commissioning, calibration, quality assurance (QA) and in-vivo dosimetry of the three technologies was reviewed. Several issues were found in the calibration and the use of dosimetry detectors and phantoms for low energy X-rays which require further investigation. The uncertainties in the different steps of dose determination were estimated, leading to an estimated total uncertainty of around 10-15% for IORT procedures. The dose inhomogeneity caused by the prescription of electrons at 90% and by the steep dose gradient of kV X-rays causes additional deviations from prescription dose which must be considered in the assessment of dose response in IORT.
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Affiliation(s)
- Frank W Hensley
- Department of Radiation Oncology, University Hospital of Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
- , Present address: Birkenweg 35, 69221, Dossenheim, Germany.
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Esposito A, Sakellaris T, Limede P, Costa F, Cunha LT, Dias AG, Lencart J, Sarmento S, Rosa CC. Effects of shielding on pelvic and abdominal IORT dose distributions. Phys Med 2016; 32:1397-1404. [PMID: 27780674 DOI: 10.1016/j.ejmp.2016.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/04/2016] [Accepted: 10/05/2016] [Indexed: 10/20/2022] Open
Abstract
PURPOSE To study the impact of shielding elements in the proximity of Intra-Operative Radiation Therapy (IORT) irradiation fields, and to generate graphical and quantitative information to assist radiation oncologists in the design of optimal shielding during pelvic and abdominal IORT. METHOD An IORT system was modeled with BEAMnrc and EGS++ Monte Carlo codes. The model was validated in reference conditions by gamma index analysis against an experimental data set of different beam energies, applicator diameters, and bevel angles. The reliability of the IORT model was further tested considering shielding layers inserted in the radiation beam. Further simulations were performed introducing a bone-like layer embedded in the water phantom. The dose distributions were calculated as 3D dose maps. RESULTS The analysis of the resulting 2D dose maps parallel to the clinical axis shows that the bevel angle of the applicator and its position relative to the shielding have a major influence on the dose distribution. When insufficient shielding is used, a hotspot nearby the shield appears near the surface. At greater depths, lateral scatter limits the dose reduction attainable with shielding, although the presence of bone-like structures in the phantom reduces the impact of this effect. CONCLUSIONS Dose distributions in shielded IORT procedures are affected by distinct contributions when considering the regions near the shielding and deeper in tissue: insufficient shielding may lead to residual dose and hotspots, and the scattering effects may enlarge the beam in depth. These effects must be carefully considered when planning an IORT treatment with shielding.
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Affiliation(s)
| | | | | | - Filipa Costa
- Medical Physics, Radiobiology and Radiation Protection Group, IPO Porto Research Centre (CI-IPOP), Portuguese Oncology Institute of Porto (IPO Porto), Porto, Portugal
| | - Luis T Cunha
- Medical Physics, Radiobiology and Radiation Protection Group, IPO Porto Research Centre (CI-IPOP), Portuguese Oncology Institute of Porto (IPO Porto), Porto, Portugal; Medical Physics Department, Portuguese Oncology Institute of Porto (IPO Porto), Porto, Portugal
| | - Anabela Gregório Dias
- Medical Physics, Radiobiology and Radiation Protection Group, IPO Porto Research Centre (CI-IPOP), Portuguese Oncology Institute of Porto (IPO Porto), Porto, Portugal; Medical Physics Department, Portuguese Oncology Institute of Porto (IPO Porto), Porto, Portugal
| | - Joana Lencart
- Medical Physics, Radiobiology and Radiation Protection Group, IPO Porto Research Centre (CI-IPOP), Portuguese Oncology Institute of Porto (IPO Porto), Porto, Portugal; Medical Physics Department, Portuguese Oncology Institute of Porto (IPO Porto), Porto, Portugal
| | - Sandra Sarmento
- Medical Physics, Radiobiology and Radiation Protection Group, IPO Porto Research Centre (CI-IPOP), Portuguese Oncology Institute of Porto (IPO Porto), Porto, Portugal; Medical Physics Department, Portuguese Oncology Institute of Porto (IPO Porto), Porto, Portugal
| | - Carla Carmelo Rosa
- INESC TEC - INESC Technology and Science, Porto, Portugal; Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal.
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Assessment of clinically relevant dose distributions in pelvic IOERT using Gafchromic EBT3 films. Phys Med 2015; 31:692-701. [DOI: 10.1016/j.ejmp.2015.05.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 05/06/2015] [Accepted: 05/20/2015] [Indexed: 11/21/2022] Open
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Glatting G, Clausen S, Wenz F. Intraoperative radiation therapy. Z Med Phys 2014; 24:1-2. [PMID: 24472599 DOI: 10.1016/j.zemedi.2013.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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