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Kazantsev P, Wesolowska P, Bokulic T, Falowska-Pietrzak O, Repnin K, Dimitriadis A, Swamidas J, Izewska J. The IAEA remote audit of small field dosimetry for testing the implementation of the TRS-483 code of practice. Med Phys 2024; 51:5632-5644. [PMID: 38700987 DOI: 10.1002/mp.17109] [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: 10/06/2023] [Revised: 03/27/2024] [Accepted: 04/02/2024] [Indexed: 05/05/2024] Open
Abstract
BACKGROUND The TRS‑483, an IAEA/AAPM International Code of Practice on dosimetry of small static photon fields, underwent testing via an IAEA coordinated research project (CRP). Alongside small field output factors (OFs) measurements using active dosimeters by CRP participants, the IAEA Dosimetry Laboratory received a mandate to formulate a remote small field dosimetry audit method using its passive dosimetry systems. PURPOSE This work aimed to develop a small field dosimetry audit methodology employing radiophotoluminescent dosimeters (RPLDs) and radiochromic films. The methodology was subsequently evaluated through a multicenter pilot study with CRP participants. METHODS The developments included designing and manufacturing a dosimeter holder set and the characterization of an RPLD system for measurements in small photon fields using the new holder. The audit included verification of small field OFs and lateral beam profiles for small fields. At first, treatment planning system (TPS) calculated OFs were checked against a reference data set that was available for conventional linacs. Second, calculated OFs were verified through the RPLD measurement of point doses in a machine-specific reference field, 4 cm × 4 cm, 2 cm × 2 cm, and 1 cm × 1 cm, corresponding size circular fields or nearest achievable field sizes. Lastly, profile checks in in-plane and cross-plane directions were done for the two smallest fields by comparing film measurements with TPS calculations at 20%, 50%, and 80% isodose levels. RESULTS RPLD correction factors for small field measurements were approximately unity. However, they influenced the dose determination's overall uncertainty in small fields, estimated at 2.30% (k = 1 level). Considering the previous experience in auditing reference beam output following the TRS-398 Code of Practice, the acceptance limit of 5% for the ratio of the dose determined by RPLD to the dose calculated by TPS, DRPLD/DTPS, was considered adequate. The multicenter pilot study included 15 participants from 14 countries (39 beams). Consistent with the previous findings, the results of the OF check against the reference data confirmed that TPSs tend to overestimate OFs for the smallest fields included in this exercise. All except three RPLD measurement results were within the acceptance limit, and the spread of results increased for smaller field sizes. The differences between the film measured and TPS calculated dose profiles were within 3 mm for most of the beams checked; deviated results revealed problems with TPS commissioning and calibration of the treatment unit collimation systems. CONCLUSION The newly developed small field dosimetry audit methodology proved effective and successfully complemented the CRP OF measurements by participants with RPLD audit results.
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Affiliation(s)
| | - Paulina Wesolowska
- International Atomic Energy Agency, Vienna, Austria
- The Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - Tomislav Bokulic
- International Atomic Energy Agency, Vienna, Austria
- University of Zagreb, Zagreb, Croatia
| | - Olga Falowska-Pietrzak
- International Atomic Energy Agency, Vienna, Austria
- Stockholm University, Stockholm, Sweden
| | - Kostiantyn Repnin
- International Atomic Energy Agency, Vienna, Austria
- Medical University of Vienna, Vienna, Austria
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Wesolowska P, Slusarczyk-Kacprzyk W, Fillmann M, Kazantsev P, Bulski W. Results of the IAEA supported national end-to-end audit of the IMRT technique in Poland. Phys Med 2023; 116:103168. [PMID: 37984129 DOI: 10.1016/j.ejmp.2023.103168] [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: 03/16/2023] [Revised: 10/09/2023] [Accepted: 11/05/2023] [Indexed: 11/22/2023] Open
Abstract
The dosimetry audit services were established in Poland in 1991, since then new audits have been introduced. The recently developed IAEA audit methodology for IMRT H&N treatments was tested nationally. Anthropomorphic SHANE phantom (CIRS) was used to perform measurements in 8 hospitals which voluntarily participated in the study. Each participant had to complete successfully pre-visit activities to take part in an onsite visit. During the visit, auditors together with the local staff, did a CT scan using local protocol, recalculated the plan and verified all the relevant parameters and performed measurements with an ionization chamber and films in SHANE. The adoption of IAEA methodology to the national circumstances was done with no major issues. Participants plans were verified and the results of ionization chamber were all within the 5 % tolerance limit for PTV (max 4,5%) and 7 % for OAR (max 5,3%). Film global gamma results (3 %, 3 mm, 90 % acceptance limit) were within 91,5-99,7% range. The IAEA established acceptance criteria which were achievable for most tests except for CTtoRED conversion curve. The locally performed study allowed establishing new limits. The audit gave interesting results and showed that the procedure is very thorough and capable to identify issues related with suboptimal treatment preparation and delivery. The new limits for CTtoRED conversion curve were adopted for national study. Such an audit gives an opportunity to verify the quality of locally implemented procedures and should be available for Polish hospitals on a daily basis.
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Affiliation(s)
- Paulina Wesolowska
- Department of Medical Physics, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland.
| | | | - Marta Fillmann
- Department of Medical Physics, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - Pavel Kazantsev
- Dosimetry Laboratory, Dosimetry and Medical Radiation Physics Section, Division of Human Health, International Atomic Energy Agency, Vienna, Austria
| | - Wojciech Bulski
- Department of Medical Physics, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland
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Saez J, Bar-Deroma R, Bogaert E, Cayez R, Chow T, Clark CH, Esposito M, Feygelman V, Monti AF, Garcia-Miguel J, Gershkevitsh E, Goossens J, Herrero C, Hussein M, Khamphan C, Kierkels RGJ, Lechner W, Lemire M, Nevelsky A, Nguyen D, Paganini L, Pasler M, Fernando Pérez Azorín J, Ramos Garcia LI, Russo S, Shakeshaft J, Vieillevigne L, Hernandez V. Universal evaluation of MLC models in treatment planning systems based on a common set of dynamic tests. Radiother Oncol 2023; 186:109775. [PMID: 37385376 DOI: 10.1016/j.radonc.2023.109775] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 06/19/2023] [Accepted: 06/23/2023] [Indexed: 07/01/2023]
Abstract
PURPOSE To demonstrate the feasibility of characterising MLCs and MLC models implemented in TPSs using a common set of dynamic beams. MATERIALS AND METHODS A set of tests containing synchronous (SG) and asynchronous sweeping gaps (aSG) was distributed among twenty-five participating centres. Doses were measured with a Farmer-type ion chamber and computed in TPSs, which provided a dosimetric characterisation of the leaf tip, tongue-and-groove, and MLC transmission of each MLC, as well as an assessment of the MLC model in each TPS. Five MLC types and four TPSs were evaluated, covering the most frequent combinations used in radiotherapy departments. RESULTS Measured differences within each MLC type were minimal, while large differences were found between MLC models implemented in clinical TPSs. This resulted in some concerning discrepancies, especially for the HD120 and Agility MLCs, for which differences between measured and calculated doses for some MLC-TPS combinations exceeded 10%. These large differences were particularly evident for small gap sizes (5 and 10 mm), as well as for larger gaps in the presence of tongue-and-groove effects. A much better agreement was found for the Millennium120 and Halcyon MLCs, differences being within ± 5% and ± 2.5%, respectively. CONCLUSIONS The feasibility of using a common set of tests to assess MLC models in TPSs was demonstrated. Measurements within MLC types were very similar, but TPS dose calculations showed large variations. Standardisation of the MLC configuration in TPSs is necessary. The proposed procedure can be readily applied in radiotherapy departments and can be a valuable tool in IMRT and credentialing audits.
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Affiliation(s)
- Jordi Saez
- Hospital Clínic de Barcelona, Department of Radiation Oncology, Barcelona, Spain.
| | - Raquel Bar-Deroma
- Rambam Health Care Campus, Department of Radiotherapy, Division of Oncology, Haifa, Israel
| | - Evelien Bogaert
- Ghent University Hospital and Ghent University, Department of Radiation Oncology, Ghent, Belgium
| | - Romain Cayez
- Oscar Lambret Center, Department of Medical Physics, Lille, France
| | - Tom Chow
- Juravinski Hospital and Cancer Centre at Hamilton Health Sciences, Department of Medical Physics, Ontario, Canada
| | - Catharine H Clark
- National Physical Laboratory, Metrology for Medical Physics Centre, London TW11 0PX, UK; Radiotherapy Physics, University College London Hospital, 250 Euston Rd, London NW1 2PG, UK; Dept Medical Physics and Bioengineering, University College London, Malet Place, London WC1 6BT, UK
| | - Marco Esposito
- AUSL Toscana Centro, Medical Physics Unit, Florence, Italy; The Abdus Salam International Center for Theoretical, Trieste, Italy
| | | | - Angelo F Monti
- ASST GOM Niguarda, Department of Medical Physics, Milano, Italy
| | - Julia Garcia-Miguel
- Consorci Sanitari de Terrassa, Department of Radiation Oncology, Terrassa, Spain
| | - Eduard Gershkevitsh
- North Estonia Medical Centre, Department of Medical Physics, Tallinn, Estonia
| | - Jo Goossens
- Iridium Netwerk, Department of Medical Physics, Antwerp, Belgium
| | - Carmen Herrero
- Centro Médico de Asturias-IMOMA, Department of Medical Physics, Oviedo, Spain
| | - Mohammad Hussein
- National Physical Laboratory, Metrology for Medical Physics Centre, London TW11 0PX, UK
| | - Catherine Khamphan
- Institut du Cancer - Avignon Provence, Department of Medical Physics, Avignon, France
| | - Roel G J Kierkels
- Radiotherapiegroep, Department of Medical Physics, Arnhem/Deventer, the Netherlands
| | - Wolfgang Lechner
- Medical University of Vienna, Department of Radiation Oncology, Vienna, Austria
| | - Matthieu Lemire
- CIUSSS de l'Est-de-l'Île-de-Montréal, Service de Radio-Physique, Montréal, Canada
| | - Alexander Nevelsky
- Rambam Health Care Campus, Department of Radiotherapy, Division of Oncology, Haifa, Israel
| | | | - Lucia Paganini
- Humanitas Clinical and Research Center, Radiotherapy and Radiosurgery Department, Rozzano, Italy
| | - Marlies Pasler
- Lake Constance Radiation Oncology Center, Department of Radiation Oncology, Singen, Friedrichshafen, Germany; Radiotherapy Hirslanden, St. Gallen, Switzerland
| | - José Fernando Pérez Azorín
- Medical Physics and Radiation Protection Department, Gurutzeta-Cruces University Hospital, Barakaldo, Spain; Biocruces Health Research Institute, Barakaldo, Spain
| | | | | | - John Shakeshaft
- Gold Coast University Hospital, ICON Cancer Centre, Gold Coast, Australia
| | - Laure Vieillevigne
- Institut Claudius Regaud-Institut Universitaire du Cancer de Toulouse, Department of Medical Physics, Toulouse, France
| | - Victor Hernandez
- Hospital Sant Joan de Reus, Department of Medical Physics, Reus, Spain; Universitat Rovira i Virgili, Tarragona, Spain
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Mehrens H, Molineu A, Hernandez N, Court L, Howell R, Jaffray D, Peterson CB, Pollard-Larkin J, Kry SF. Characterizing the interplay of treatment parameters and complexity and their impact on performance on an IROC IMRT phantom using machine learning. Radiother Oncol 2023; 182:109577. [PMID: 36841341 PMCID: PMC10121814 DOI: 10.1016/j.radonc.2023.109577] [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: 11/30/2022] [Revised: 02/06/2023] [Accepted: 02/12/2023] [Indexed: 02/26/2023]
Abstract
AIM OF THE STUDY To elucidate the important factors and their interplay that drive performance on IMRT phantoms from the Imaging and Radiation Oncology Core (IROC). METHODS IROC's IMRT head and neck phantom contains two targets and an organ at risk. Point and 2D dose are measured by TLDs and film, respectively. 1,542 irradiations between 2012-2020 were retrospectively analyzed based on output parameters, complexity metrics, and treatment parameters. Univariate analysis compared parameters based on pass/fail, and random forest modeling was used to predict output parameters and determine the underlying importance of the variables. RESULTS The average phantom pass rate was 92% and has not significantly improved over time. The step-and-shoot irradiation technique had significantly lower pass rates that significantly affected other treatment parameters' pass rates. The complexity of plans has significantly increased with time, and all aperture-based complexity metrics (except MCS) were associated with the probability of failure. Random forest-based prediction of failure had an accuracy of 98% on held-out test data not used in model training. While complexity metrics were the most important contributors, the specific metric depended on the set of treatment parameters used during the irradiation. CONCLUSION With the prevalence of errors in radiotherapy, understanding which parameters affect treatment delivery is vital to improve patient treatment. Complexity metrics were strongly predictive of irradiation failure; however, they are dependent on the specific treatment parameters. In addition, the use of one complexity metric is insufficient to monitor all aspects of the treatment plan.
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Affiliation(s)
- Hunter Mehrens
- IROC Houston Quality Assurance Center, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; The University of Texas MD Anderson Cancer Center UT Health Houston Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Andrea Molineu
- IROC Houston Quality Assurance Center, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Nadia Hernandez
- IROC Houston Quality Assurance Center, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Laurence Court
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; The University of Texas MD Anderson Cancer Center UT Health Houston Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Rebecca Howell
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; The University of Texas MD Anderson Cancer Center UT Health Houston Graduate School of Biomedical Sciences, Houston, TX, USA
| | - David Jaffray
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Christine B Peterson
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; The University of Texas MD Anderson Cancer Center UT Health Houston Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Julianne Pollard-Larkin
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; The University of Texas MD Anderson Cancer Center UT Health Houston Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Stephen F Kry
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; The University of Texas MD Anderson Cancer Center UT Health Houston Graduate School of Biomedical Sciences, Houston, TX, USA.
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Geurts MW, Jacqmin DJ, Jones LE, Kry SF, Mihailidis DN, Ohrt JD, Ritter T, Smilowitz JB, Wingreen NE. AAPM MEDICAL PHYSICS PRACTICE GUIDELINE 5.b: Commissioning and QA of treatment planning dose calculations-Megavoltage photon and electron beams. J Appl Clin Med Phys 2022; 23:e13641. [PMID: 35950259 PMCID: PMC9512346 DOI: 10.1002/acm2.13641] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 04/04/2022] [Accepted: 04/06/2022] [Indexed: 11/23/2022] Open
Abstract
The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnostic and therapeutic radiology requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guidelines and technical standards by those entities not providing these services is not authorized. The following terms are used in the AAPM practice guidelines:
Must and Must Not: Used to indicate that adherence to the recommendation is considered necessary to conform to this practice guideline. While must is the term to be used in the guidelines, if an entity that adopts the guideline has shall as the preferred term, the AAPM considers that must and shall have the same meaning. Should and Should Not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances.
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Mehrens H, Nguyen T, Edward S, Hartzell S, Glenn M, Branco D, Hernandez N, Alvarez P, Molineu A, Taylor P, Kry S. The current status and shortcomings of stereotactic radiosurgery. Neurooncol Adv 2022; 4:vdac058. [PMID: 35664554 PMCID: PMC9154323 DOI: 10.1093/noajnl/vdac058] [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] [Indexed: 11/13/2022] Open
Abstract
Background Stereotactic radiosurgery (SRS) is a common treatment for intracranial lesions. This work explores the state of SRS treatment delivery to characterize current treatment accuracy based on treatment parameters. Methods NCI clinical trials involving SRS rely on an end-to-end treatment delivery on a patient surrogate (credentialing phantom) from the Imaging and Radiation Oncology Core (IROC) to test their treatment accuracy. The results of 1072 SRS phantom irradiations between 2012 and 2020 were retrospectively analyzed. Univariate analysis and random forest models were used to associate irradiation conditions with phantom performance. The following categories were evaluated in terms of how they predicted outcomes: year of irradiation, TPS algorithm, machine model, energy, and delivered field size. Results Overall, only 84.6% of irradiations have met the IROC/NCI acceptability criteria. Pass rate has remained constant over time, while dose calculation accuracy has slightly improved. Dose calculation algorithm (P < .001), collimator (P = .024), and field size (P < .001) were statistically significant predictors of pass/fail. Specifically, pencil beam algorithms and cone collimators were more likely to be associated with failing phantom results. Random forest modeling identified the size of the field as the most important factor for passing or failing followed by algorithm. Conclusion Constant throughout this retrospective study, approximately 15% of institutions fail to meet IROC/NCI standards for SRS treatment. In current clinical practice, this is particularly associated with smaller fields that yielded less accurate results. There is ongoing need to improve small field dosimetry, beam modeling, and QA to ensure high treatment quality, patient safety, and optimal clinical trials.
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Affiliation(s)
- Hunter Mehrens
- Department of Outreach Physics, UT MD Anderson Cancer Center, Houston, TX
- Imaging and Radiation Oncology Core
| | - Trang Nguyen
- Department of Outreach Physics, UT MD Anderson Cancer Center, Houston, TX
- Imaging and Radiation Oncology Core
| | - Sharbacha Edward
- Department of Outreach Physics, UT MD Anderson Cancer Center, Houston, TX
- Imaging and Radiation Oncology Core
| | - Shannon Hartzell
- Department of Outreach Physics, UT MD Anderson Cancer Center, Houston, TX
- Imaging and Radiation Oncology Core
| | - Mallory Glenn
- Department of Outreach Physics, UT MD Anderson Cancer Center, Houston, TX
- Imaging and Radiation Oncology Core
| | - Daniela Branco
- Department of Outreach Physics, UT MD Anderson Cancer Center, Houston, TX
- Imaging and Radiation Oncology Core
| | - Nadia Hernandez
- Department of Outreach Physics, UT MD Anderson Cancer Center, Houston, TX
- Imaging and Radiation Oncology Core
| | - Paola Alvarez
- Department of Outreach Physics, UT MD Anderson Cancer Center, Houston, TX
- Imaging and Radiation Oncology Core
| | - Andrea Molineu
- Department of Outreach Physics, UT MD Anderson Cancer Center, Houston, TX
- Imaging and Radiation Oncology Core
| | - Paige Taylor
- Department of Outreach Physics, UT MD Anderson Cancer Center, Houston, TX
- Imaging and Radiation Oncology Core
| | - Stephen Kry
- Department of Outreach Physics, UT MD Anderson Cancer Center, Houston, TX
- Imaging and Radiation Oncology Core
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Glenn MC, Brooks F, Peterson CB, Howell RM, Followill DS, Pollard-Larkin JM, Kry SF. Photon beam modeling variations predict errors in IMRT dosimetry audits. Radiother Oncol 2021; 166:8-14. [PMID: 34748857 PMCID: PMC8863621 DOI: 10.1016/j.radonc.2021.10.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 11/16/2022]
Abstract
Background & purpose: To evaluate treatment planning system (TPS) beam modeling parameters as contributing factors to IMRT audit performance. Materials & methods: We retrospectively analyzed IROC Houston phantom audit performance and concurrent beam modeling survey responses from 337 irradiations performed between August 2017 and November 2019. Irradiation results were grouped based on the reporting of typical or atypical beam modeling parameter survey responses (<10th or >90th percentile values), and compared for passing versus failing (>7% error) or “poor” (>5% error) irradiation status. Additionally, we assessed the impact on the planned dose distribution from variations in modeling parameter value. Finally, we estimated the overall impact of beam modeling parameter variance on dose calculations, based on reported community variations. Results: Use of atypical modeling parameters were more frequently seen with failing phantom audit results (p = 0.01). Most pronounced was for Eclipse AAA users, where phantom irradiations with atypical values of dosimetric leaf gap (DLG) showed a greater incidence of both poor-performing (p = 0.048) and failing phantom audits (p = 0.014); and in general, DLG value was correlated with dose calculation accuracy (r = 0.397, p < 0.001). Manipulating TPS parameters induced systematic changes in planned dose distributions which were consistent with prior observations of how failures manifest. Dose change estimations based on these dose calculations agreed well with true dosimetric errors identified. Conclusion: Atypical TPS beam modeling parameters are associated with failing phantom audits. This is identified as an important factor contributing to the observed failing phantom results, and highlights the need for accurate beam modeling.
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Affiliation(s)
- Mallory C Glenn
- Department of Radiation Oncology, University of Washington, Seattle, United States
| | - Fre'Etta Brooks
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, United States; The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, United States
| | - Christine B Peterson
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, United States; Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, United States
| | - Rebecca M Howell
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, United States; The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, United States
| | - David S Followill
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, United States; The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, United States
| | - Julianne M Pollard-Larkin
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, United States; The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, United States
| | - Stephen F Kry
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, United States; The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, United States.
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Edward SS, C Glenn M, Peterson CB, Balter PA, Pollard-Larkin JM, Howell RM, S Followill D, Kry SF. Dose calculation errors as a component of failing IROC lung and spine phantom irradiations. Med Phys 2020; 47:4502-4508. [PMID: 32452027 DOI: 10.1002/mp.14258] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 04/19/2020] [Accepted: 05/11/2020] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Between July 2013 and August 2019, 22% of the imaging and radiation oncology core (IROC) spine, and 15% of the moving lung phantom irradiations have failed to meet established acceptability criteria. The spine phantom simulates a highly modulated stereotactic body radiation therapy (SBRT) case, whereas the lung phantom represents a low-to-none modulation moving target case. In this study, we assessed the contribution of dose calculation errors to these phantom results and evaluated their effects on failure rates. METHODS We evaluated dose calculation errors by comparing the calculation accuracy of various institutions' treatment planning systems (TPSs) vs IROC-Houston's previously established independent dose recalculation system (DRS). Each calculation was compared with the measured dose actually delivered to the phantom; cases in which the recalculation was more accurate were interpreted as a deficiency in the institution's TPS. A total of 258 phantom irradiation plans (172 lung and 86 spine) were recomputed. RESULTS Overall, the DRS performed better than the TPSs in 47% of the spine phantom cases. However, the DRS was more accurate in 93% of failing spine phantom cases (with an average improvement of 2.35%), indicating a deficiency in the institution's treatment planning system. Deficiencies in dose calculation accounted for 60% of the overall discrepancy between measured and planned doses among spine phantoms. In contrast, lung phantom DRS calculations were more accurate in only 35% and 42% of all and failing lung phantom cases respectively, indicating that dose calculation errors were not substantially present. These errors accounted for only 30% of the overall discrepancy between measured and planned doses. CONCLUSIONS Dose calculation errors are common and substantial in IROC spine phantom irradiations, highlighting a major failure mode in this phantom and in clinical treatment management of these cases. In contrast, dose calculation accuracy had only a minimal contribution to failing lung phantom results, indicating that other failure modes drive problems with this phantom and similar clinical treatments.
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Affiliation(s)
- Sharbacha S Edward
- The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA.,IROC Houston Quality Assurance Center, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Mallory C Glenn
- The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA.,IROC Houston Quality Assurance Center, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Christine B Peterson
- The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA.,Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Peter A Balter
- The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA.,Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Julianne M Pollard-Larkin
- The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA.,Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Rebecca M Howell
- The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA.,Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - David S Followill
- The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA.,IROC Houston Quality Assurance Center, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Stephen F Kry
- The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA.,IROC Houston Quality Assurance Center, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
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9
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Edward SS, Alvarez PE, Taylor PA, Molineu HA, Peterson CB, Followill DS, Kry SF. Differences in the Patterns of Failure Between IROC Lung and Spine Phantom Irradiations. Pract Radiat Oncol 2020; 10:372-381. [PMID: 32413413 DOI: 10.1016/j.prro.2020.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 03/16/2020] [Accepted: 04/17/2020] [Indexed: 11/25/2022]
Abstract
PURPOSE Our purpose was to investigate and classify the reasons why institutions fail the Imaging and Radiation Oncology Core (IROC) stereotactic body radiation therapy (SBRT) spine and moving lung phantoms, which are used to credential institutions for clinical trial participation. METHODS AND MATERIALS All IROC moving lung and SBRT spine phantom irradiation failures recorded from January 2012 to December 2018 were evaluated in this study. A failure was a case where the institution did not meet the established IROC criteria for agreement between planned and delivered dose. We analyzed the reports for all failing irradiations, including point dose disagreement, dose profiles, and gamma analyses. Classes of failure patterns were created and used to categorize each instance. RESULTS There were 158 failing cases analyzed: 116 of 1052 total lung irradiations and 42 of 263 total spine irradiations. Seven categories were required to describe the lung phantom failures, whereas 4 were required for the spine. Types of errors present in both phantom groups included systematic dose and localization errors. Fifty percent of lung failures were due to a superior-inferior localization error, that is, error in the direction of major motion. Systematic dose errors, however, contributed to only 22% of lung failures. In contrast, the majority (60%) of spine phantom failures were due to systematic dose errors, with localization errors (in any direction) accounting for only 14% of failures. CONCLUSIONS There were 2 distinct patterns of failure between the IROC moving lung and SBRT spine phantoms. The majority of the lung phantom failures were due to localization errors, whereas the spine phantom failures were largely attributed to systematic dose errors. Both of these errors are clinically relevant and could manifest as errors in patient cases. These findings highlight the value of independent end-to-end dosimetry audits and can help guide the community in improving the quality of radiation therapy by focusing attention on where errors manifest in the community.
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Affiliation(s)
- Sharbacha S Edward
- UT Health Graduate School of Biomedical Sciences, Houston, Texas; IROC Houston Quality Assurance Center, Houston, Texas; Department of Radiation Physics, Houston, Texas
| | - Paola E Alvarez
- IROC Houston Quality Assurance Center, Houston, Texas; Department of Radiation Physics, Houston, Texas
| | - Paige A Taylor
- UT Health Graduate School of Biomedical Sciences, Houston, Texas; IROC Houston Quality Assurance Center, Houston, Texas; Department of Radiation Physics, Houston, Texas
| | - H Andrea Molineu
- IROC Houston Quality Assurance Center, Houston, Texas; Department of Radiation Physics, Houston, Texas
| | - Christine B Peterson
- UT Health Graduate School of Biomedical Sciences, Houston, Texas; Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - David S Followill
- UT Health Graduate School of Biomedical Sciences, Houston, Texas; IROC Houston Quality Assurance Center, Houston, Texas; Department of Radiation Physics, Houston, Texas
| | - Stephen F Kry
- UT Health Graduate School of Biomedical Sciences, Houston, Texas; IROC Houston Quality Assurance Center, Houston, Texas; Department of Radiation Physics, Houston, Texas.
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Isono M, Tatsumi D. [19. Install of Radiation Treatment Delivery Systems Using Reference Beam Data]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2020; 76:735-739. [PMID: 32684566 DOI: 10.6009/jjrt.2020_jjrt_76.7.735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Affiliation(s)
- Masaru Isono
- Osaka International Cancer Institute, Department of Radiation Oncology
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11
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Glenn MC, Peterson CB, Followill DS, Howell RM, Pollard-Larkin JM, Kry SF. Reference dataset of users' photon beam modeling parameters for the Eclipse, Pinnacle, and RayStation treatment planning systems. Med Phys 2019; 47:282-288. [PMID: 31667870 DOI: 10.1002/mp.13892] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/30/2019] [Accepted: 10/23/2019] [Indexed: 11/10/2022] Open
Abstract
PURPOSE The aim of this work was to provide a novel description of how the radiotherapy community configures treatment planning system (TPS) radiation beam models for clinically used treatment machines. Here we describe the results of a survey of self-reported TPS beam modeling parameter values across different C-arm linear accelerators, beam energies, and multileaf collimator (MLC) configurations. ACQUISITION AND VALIDATION METHODS Beam modeling data were acquired via electronic survey implemented through the Imaging and Radiation Oncology Core (IROC) Houston Quality Assurance Center's online facility questionnaire. The survey was open to participation from January 2018 through January 2019 for all institutions monitored by IROC. After quality control, 2818 beam models were collected from 642 institutions. This survey, designed for Eclipse, Pinnacle, and RayStation, instructed physicists to report parameter values used to model the radiation source and MLC for each treatment machine and beam energy used clinically for intensity-modulated radiation therapy. Parameters collected included the effective source/spot size, MLC transmission, dosimetric leaf gap, tongue and groove effect, and other nondosimetric parameters specific to each TPS. To facilitate survey participation, instructions were provided on how to identify requested beam modeling parameters within each TPS environment. DATA FORMAT AND USAGE NOTES Numeric values of the beam modeling parameters are compiled and tabulated according to TPS and calculation algorithm, linear accelerator model class, beam energy, and MLC configuration. Values are also presented as distributions, ranging from the 2.5th to the 97.5th percentile. POTENTIAL APPLICATIONS These data provide an independent guide describing how the radiotherapy community mathematically represents its clinical radiation beams. These distributions may be used by the community for comparison during the commissioning or verification of their TPS beam models. Ultimately, we hope that the current work will allow institutions to spot potentially suspicious parameter values and help ensure more accurate radiotherapy delivery.
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Affiliation(s)
- Mallory C Glenn
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,The University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
| | - Christine B Peterson
- The University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, TX, 77030, USA.,Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - David S Followill
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,The University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
| | - Rebecca M Howell
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,The University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
| | - Julianne M Pollard-Larkin
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,The University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
| | - Stephen F Kry
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,The University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
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12
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Zhang Y, Le AH, Tian Z, Iqbal Z, Chiu T, Gu X, Pugachev A, Reynolds R, Park YK, Lin MH, Stojadinovic S. Modeling Elekta VersaHD using the Varian Eclipse treatment planning system for photon beams: A single-institution experience. J Appl Clin Med Phys 2019; 20:33-42. [PMID: 31471950 PMCID: PMC6806469 DOI: 10.1002/acm2.12709] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 07/30/2019] [Accepted: 08/01/2019] [Indexed: 11/08/2022] Open
Abstract
The aim of this study was to report a single‐institution experience and commissioning data for Elekta VersaHD linear accelerators (LINACs) for photon beams in the Eclipse treatment planning system (TPS). Two VersaHD LINACs equipped with 160‐leaf collimators were commissioned. For each energy, the percent‐depth‐dose (PDD) curves, beam profiles, output factors, leaf transmission factors and dosimetric leaf gaps (DLGs) were acquired in accordance with the AAPM task group reports No. 45 and No. 106 and the vendor‐supplied documents. The measured data were imported into Eclipse TPS to build a VersaHD beam model. The model was validated by creating treatment plans spanning over the full‐spectrum of treatment sites and techniques used in our clinic. The quality assurance measurements were performed using MatriXX, ionization chamber, and radiochromic film. The DLG values were iteratively adjusted to optimize the agreement between planned and measured doses. Mobius, an independent LINAC logfile‐based quality assurance tool, was also commissioned both for routine intensity‐modulated radiation therapy (IMRT) QA and as a secondary check for the Eclipse VersaHD model. The Eclipse‐generated VersaHD model was in excellent agreement with the measured PDD curves and beam profiles. The measured leaf transmission factors were less than 0.5% for all energies. The model validation study yielded absolute point dose agreement between ionization chamber measurements and Eclipse within ±4% for all cases. The comparison between Mobius and Eclipse, and between Mobius and ionization chamber measurements lead to absolute point dose agreement within ±5%. The corresponding 3D dose distributions evaluated with 3%global/2mm gamma criteria resulted in larger than 90% passing rates for all plans. The Eclipse TPS can model VersaHD LINACs with clinically acceptable accuracy. The model validation study and comparisons with Mobius demonstrated that the modeling of VersaHD in Eclipse necessitates further improvement to provide dosimetric accuracy on par with Varian LINACs.
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Affiliation(s)
- You Zhang
- UT Southwestern Medical Center, Dallas, TX, USA
| | - Anh H Le
- Roswell Park Cancer Institute, Buffalo, NK, USA
| | - Zhen Tian
- Winship Cancer Institute of Emory University, Atlanta, GA, USA
| | | | | | - Xuejun Gu
- UT Southwestern Medical Center, Dallas, TX, USA
| | | | | | - Yang K Park
- UT Southwestern Medical Center, Dallas, TX, USA
| | - Mu-Han Lin
- UT Southwestern Medical Center, Dallas, TX, USA
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13
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Kry SF, Glenn MC, Peterson CB, Branco D, Mehrens H, Steinmann A, Followill DS. Independent recalculation outperforms traditional measurement-based IMRT QA methods in detecting unacceptable plans. Med Phys 2019; 46:3700-3708. [PMID: 31152568 DOI: 10.1002/mp.13638] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 05/28/2019] [Accepted: 05/29/2019] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To evaluate the performance of an independent recalculation and compare it against current measurement-based patient specific intensity-modulated radiation therapy (IMRT) quality assurance (QA) in predicting unacceptable phantom results as measured by the Imaging and Radiation Oncology Core (IROC). METHODS When institutions irradiate the IROC head and neck IMRT phantom, they are also asked to submit their internal IMRT QA results. Separately from this, IROC has previously created reference beam models on the Mobius3D platform to independently recalculate phantom results based on the institution's DICOM plan data. The ability of the institutions' IMRT QA to predict the IROC phantom result was compared against the independent recalculation for 339 phantom results collected since 2012. This was done to determine the ability of these systems to detect failing phantom results (i.e., large errors) as well as poor phantom results (i.e., modest errors). Sensitivity and specificity were evaluated using common clinical thresholds, and receiver operator characteristic (ROC) curves were used to compare across different thresholds. RESULTS Overall, based on common clinical criteria, the independent recalculation was 12 times more sensitive at detecting unacceptable (failing) IROC phantom results than clinical measurement-based IMRT QA. The recalculation was superior, in head-to-head comparison, to the EPID, ArcCheck, and MapCheck devices. The superiority of the recalculation vs these array-based measurements persisted under ROC analysis as the recalculation curve had a greater area under it and was always above that for these measurement devices. For detecting modest errors (poor phantom results rather than failing phantom results), neither the recalculation nor measurement-based IMRT QA performed well. CONCLUSIONS A simple recalculation outperformed current measurement-based IMRT QA methods at detecting unacceptable plans. These findings highlight the value of an independent recalculation, and raise further questions about the current standard of measurement-based IMRT QA.
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Affiliation(s)
- Stephen F Kry
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX, 7030, USA.,Graduate School of Biomedical Sciences, The University of Texas Houston Health Science Center, Houston, TX, USA
| | - Mallory C Glenn
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX, 7030, USA.,Graduate School of Biomedical Sciences, The University of Texas Houston Health Science Center, Houston, TX, USA
| | - Christine B Peterson
- Graduate School of Biomedical Sciences, The University of Texas Houston Health Science Center, Houston, TX, USA.,Department of Biostatistics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX, 7030, USA
| | - Daniela Branco
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX, 7030, USA.,Graduate School of Biomedical Sciences, The University of Texas Houston Health Science Center, Houston, TX, USA
| | - Hunter Mehrens
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX, 7030, USA
| | - Angela Steinmann
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX, 7030, USA.,Graduate School of Biomedical Sciences, The University of Texas Houston Health Science Center, Houston, TX, USA
| | - David S Followill
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX, 7030, USA.,Graduate School of Biomedical Sciences, The University of Texas Houston Health Science Center, Houston, TX, USA
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Isono M. [6. Acquisition of Beam Data in Radiation Treatment System and Determination of Baseline Data]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2019; 75:80-88. [PMID: 30662036 DOI: 10.6009/jjrt.2019_jsrt_75.1.80] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Affiliation(s)
- Masaru Isono
- Osaka International Cancer Institute, Department of Radiation Oncology
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15
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Akino Y, Mizuno H, Tanaka Y, Isono M, Masai N, Yamamoto T. Inter-institutional variability of small-field-dosimetry beams among HD120™ multileaf collimators: a multi-institutional analysis. ACTA ACUST UNITED AC 2018; 63:205018. [DOI: 10.1088/1361-6560/aae450] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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