PURPOSE: STereotactic Arrhythmia Radioablation (STAR) showed promising results in patients with refractory ventricular tachycardia. However, clinical data are scarce and heterogeneous. The STOPSTORM.eu consortium was established to investigate and harmonize STAR in Europe. The primary goal of this benchmark study was to investigate current treatment planning practice within the STOPSTORM project as a baseline for future harmonization. METHODS AND MATERIALS: Planning target volumes (PTVs) overlapping extracardiac organs-at-risk and/or cardiac substructures were generated for 3 STAR cases. Participating centers were asked to create single-fraction treatment plans with 25 Gy dose prescriptions based on in-house clinical practice. All treatment plans were reviewed by an expert panel and quantitative crowd knowledge-based analysis was performed with independent software using descriptive statistics for International Commission on Radiation Units and Measurements report 91 relevant parameters and crowd dose-volume histograms. Thereafter, treatment planning consensus statements were established using a dual-stage voting process. RESULTS: Twenty centers submitted 67 treatment plans for this study. In most plans (75%) intensity modulated arc therapy with 6 MV flattening filter free beams was used. Dose prescription was mainly based on PTV D95% (49%) or D96%-100% (19%). Many participants preferred to spare close extracardiac organs-at-risk (75%) and cardiac substructures (50%) by PTV coverage reduction. PTV D0.035cm3 ranged from 25.5 to 34.6 Gy, demonstrating a large variety of dose inhomogeneity. Estimated treatment times without motion compensation or setup ranged from 2 to 80 minutes. For the consensus statements, a strong agreement was reached for beam technique planning, dose calculation, prescription methods, and trade-offs between target and extracardiac critical structures. No agreement was reached on cardiac substructure dose limitations and on desired dose inhomogeneity in the target. CONCLUSIONS: This STOPSTORM multicenter treatment planning benchmark study not only showed strong agreement on several aspects of STAR treatment planning, but also revealed disagreement on others. To standardize and harmonize STAR in the future, consensus statements were established; however, clinical data are urgently needed for actionable guidelines for treatment planning.

• MeSH
• benchmarking * MeSH
• celková dávka radioterapie MeSH
• komorová tachykardie chirurgie   radioterapie   MeSH
• konsensus * MeSH
• kritické orgány * účinky záření   MeSH
• lidé MeSH
• plánování radioterapie pomocí počítače * normy   metody   MeSH
• radiochirurgie * normy   metody   MeSH
• radioterapie s modulovanou intenzitou metody   normy   MeSH
• srdce účinky záření   MeSH
• srdeční arytmie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• Geografické názvy
• Evropa MeSH

In the Czech Republic, a more advanced version of postal audit in radiotherapy (RT) is available. It covers dose measurements with thermoluminescent dosemeters (TLD) in more complex conditions of irradiation, when dose distribution is affected by heterogeneities in the irradiated volume. Relative deviation between doses measured with TLDs and doses stated by RT centre should not exceed 3%. During 2015-2017, all Czech RT centres equipped with modern linear accelerators were subjected to this more advanced TLD audit. A total of 70% of participants complied with the limit of 3% in the first round of this audit.

• MeSH
• částice - urychlovače normy   MeSH
• celková dávka radioterapie MeSH
• fotony MeSH
• lidé MeSH
• plánování radioterapie pomocí počítače metody   normy   MeSH
• řízení kvality MeSH
• termoluminiscenční dozimetrie normy   MeSH
• zajištění kvality zdravotní péče normy   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

The most important dosimetry quantity that is determined at radiotherapy centers is the absorbed dose to water for external beams. Fixed tolerances for absorbed doses measured under reference conditions with an ionization chamber for high-energy photon and electron beams are usually 2 and 3%, respectively, regardless of uncertainties of the input variables and other conditions during evaluation. In reality, this agreement should be evaluated considering the uncertainties of the input variables because they affect the size of the random deviations of the measurements from their true values. The aim of this work was to develop a new approach to evaluate the agreement between measured and reported values based on statistical interference rather than to use fixed tolerance levels. The proposed method considers different scenarios that can occur during the evaluation of agreement. Because the method is described in general, it can be used in all similar situations when partial uncertainties can be established.

• MeSH
• celková dávka radioterapie MeSH
• kalibrace MeSH
• lidé MeSH
• nádory radioterapie   MeSH
• nejistota MeSH
• plánování radioterapie pomocí počítače metody   normy   MeSH
• radioterapie s modulovanou intenzitou metody   normy   MeSH
• statistické modely * MeSH
• vysokoenergetická radioterapie normy   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE: To demonstrate an efficient method for training and validation of a knowledge-based planning (KBP) system as a radiation therapy clinical trial plan quality-control system. METHODS AND MATERIALS: We analyzed 86 patients with stage IB through IVA cervical cancer treated with intensity modulated radiation therapy at 2 institutions according to the standards of the INTERTECC (International Evaluation of Radiotherapy Technology Effectiveness in Cervical Cancer, National Clinical Trials Network identifier: 01554397) protocol. The protocol used a planning target volume and 2 primary organs at risk: pelvic bone marrow (PBM) and bowel. Secondary organs at risk were rectum and bladder. Initial unfiltered dose-volume histogram (DVH) estimation models were trained using all 86 plans. Refined training sets were created by removing sub-optimal plans from the unfiltered sample, and DVH estimation models… and DVH estimation models were constructed by identifying 30 of 86 plans emphasizing PBM sparing (comparing protocol-specified dosimetric cutpoints V10 (percentage volume of PBM receiving at least 10 Gy dose) and V20 (percentage volume of PBM receiving at least 20 Gy dose) with unfiltered predictions) and another 30 of 86 plans emphasizing bowel sparing (comparing V40 (absolute volume of bowel receiving at least 40 Gy dose) and V45 (absolute volume of bowel receiving at least 45 Gy dose), 9 in common with the PBM set). To obtain deliverable KBP plans, refined models must inform patient-specific optimization objectives and/or priorities (an auto-planning "routine"). Four candidate routines emphasizing different tradeoffs were composed, and a script was developed to automatically re-plan multiple patients with each routine. After selection of the routine that best met protocol objectives in the 51-patient training sample (KBPFINAL), protocol-specific DVH metrics and normal tissue complication probability were compared for original versus KBPFINAL plans across the 35-patient validation set. Paired t tests were used to test differences between planning sets. RESULTS: KBPFINAL plans outperformed manual planning across the validation set in all protocol-specific DVH cutpoints. The mean normal tissue complication probability for gastrointestinal toxicity was lower for KBPFINAL versus validation-set plans (48.7% vs 53.8%, P<.001). Similarly, the estimated mean white blood cell count nadir was higher (2.77 vs 2.49 k/mL, P<.001) with KBPFINAL plans, indicating lowered probability of hematologic toxicity. CONCLUSIONS: This work demonstrates that a KBP system can be efficiently trained and refined for use in radiation therapy clinical trials with minimal effort. This patient-specific plan quality control resulted in improvements on protocol-specific dosimetric endpoints.

• MeSH
• klinické zkoušky jako téma normy   MeSH
• kostní dřeň MeSH
• kritické orgány * MeSH
• léčba šetřící orgány metody   normy   MeSH
• lidé MeSH
• močový měchýř MeSH
• nádory děložního čípku patologie   radioterapie   MeSH
• pánevní kosti MeSH
• plánování radioterapie pomocí počítače metody   normy   MeSH
• radioterapie s modulovanou intenzitou metody   normy   MeSH
• rektum MeSH
• řízení kvality * MeSH
• střeva MeSH
• tumor burden MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• validační studie MeSH

UNLABELLED: The International Atomic Energy Agency (IAEA) has a long tradition of supporting development of methodologies for national networks providing quality audits in radiotherapy. A series of co-ordinated research projects (CRPs) has been conducted by the IAEA since 1995 assisting national external audit groups developing national audit programs. The CRP 'Development of Quality Audits for Radiotherapy Dosimetry for Complex Treatment Techniques' was conducted in 2009-2012 as an extension of previously developed audit programs. MATERIAL AND METHODS: The CRP work described in this paper focused on developing and testing two steps of dosimetry audit: verification of heterogeneity corrections, and treatment planning system (TPS) modeling of small MLC fields, which are important for the initial stages of complex radiation treatments, such as IMRT. The project involved development of a new solid slab phantom with heterogeneities containing special measurement inserts for thermoluminescent dosimeters (TLD) and radiochromic films. The phantom and the audit methodology has been developed at the IAEA and tested in multi-center studies involving the CRP participants. RESULTS: The results of multi-center testing of methodology for two steps of dosimetry audit show that the design of audit procedures is adequate and the methodology is feasible for meeting the audit objectives. A total of 97% TLD results in heterogeneity situations obtained in the study were within 3% and all results within 5% agreement with the TPS predicted doses. In contrast, only 64% small beam profiles were within 3 mm agreement between the TPS calculated and film measured doses. Film dosimetry results have highlighted some limitations in TPS modeling of small beam profiles in the direction of MLC leave movements. DISCUSSION: Through multi-center testing, any challenges or difficulties in the proposed audit methodology were identified, and the methodology improved. Using the experience of these studies, the participants could incorporate the auditing procedures in their national programs.

• MeSH
• dozimetry MeSH
• fantomy radiodiagnostické MeSH
• lidé MeSH
• mezinárodní agentury MeSH
• plánování radioterapie pomocí počítače metody   normy   MeSH
• radiometrie přístrojové vybavení   metody   normy   MeSH
• řízení kvality MeSH
• termoluminiscenční dozimetrie přístrojové vybavení   metody   normy   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH

PURPOSE: The purpose of this article was to highlight the importance of data management systems in radiotherapy. METHODS: We performed a database search to review the errors or potential errors in radiotherapy planning and delivery which could be prevented in case of using the DICOM communication system. RESULTS: We registered the following rates of errors: 1) Errors caused by manual rewriting of treatment plan 30%; 2) Errors caused by wrong assignment of the verification system 15%; 3) Errors during the manual rewriting of treatment data to the verification system 15%; 4) Patient identification 5%; 5) Field verification 15% 6) Wedge orientation 10%. CONCLUSION: DICOM communication system may significantly improve the quality assurance in radiotherapy.

• MeSH
• bezpečnost pacientů normy   MeSH
• chybná zdravotní péče prevence a kontrola   MeSH
• lidé MeSH
• nemocnice univerzitní normy   MeSH
• plánování radioterapie pomocí počítače normy   MeSH
• radiační onkologie normy   MeSH
• radiologické informační systémy normy   MeSH
• radiologické oddělení nemocnice normy   MeSH
• ukazatele kvality zdravotní péče normy   MeSH
• výsledek terapie MeSH
• výsledky a postupy - zhodnocení (zdravotní péče) normy   MeSH
• zajištění kvality zdravotní péče normy   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

PURPOSE: Magnetic resonance imaging (MRI)-assisted radiation treatment planning enables enhanced target contouring. The purpose of this study is to analyze the feasibility and accuracy of computed tomography (CT) and MRI data fusion for MRI-based treatment planning in an institution where an MRI scanner is not available in the radiotherapy department. METHODS AND MATERIALS: The registration inaccuracy of applicators and soft tissue was assessed in 42 applications with CT/MRI data fusion. The absolute positional difference of the center of the applicators was measured in four different planes from the top of the tandem to the cervix. Any inaccuracy of registration of soft tissue in relation to the position of applicators was determined and dose-volume parameters for MRI preplans and for CT/MRI fusion plans with or without target and organs at risk (OAR) adaptation were evaluated. RESULTS: We performed 6,132 measurements in 42 CT/MRI image fusions. Median absolute difference of the center of tandem on CT and MRI was 1.1 mm. Median distance between the center of the right ovoid on CT and MRI was 1.7 and 1.9 mm in the laterolateral and anteroposterior direction, respectively. Corresponding values for the left ovoid were 1.6 and 1.8 mm. Rotation of applicators was 3.1°. Median absolute difference in position of applicators in relation to soft tissue was 1.93, 1.50, 1.05, and 0.84 mm in the respective transverse planes, and 1.17, 1.28, 1.27, and 1.17 mm in selected angular directions. The dosimetric parameters for organs at risk on CT/MRI fusion plans without OAR adaptation were significantly impaired whereas the target coverage was not influenced. Planning without target adaptation led to overdosing of the target volume, especially high-risk clinical target volume--D₉₀ 88.2 vs. 83.1 (p < 0.05). CONCLUSIONS: MRI-based preplanning with consecutive CT/MRI data fusion can be safe and feasible, with an acceptable inaccuracy of soft tissue registration.

• MeSH
• brachyterapie metody   MeSH
• celková dávka radioterapie MeSH
• cisplatina terapeutické užití   MeSH
• konformní radioterapie metody   MeSH
• kritické orgány diagnostické zobrazování   účinky záření   MeSH
• lidé MeSH
• magnetická rezonanční tomografie metody   normy   MeSH
• nádory děložního čípku diagnostické zobrazování   farmakoterapie   patologie   radioterapie   MeSH
• plánování radioterapie pomocí počítače metody   normy   MeSH
• počítačová rentgenová tomografie metody   normy   MeSH
• radiační poranění prevence a kontrola   MeSH
• radiosenzibilizující látky terapeutické užití   MeSH
• radioterapie s modulovanou intenzitou metody   MeSH
• studie proveditelnosti MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cisplatina MeSH
• radiosenzibilizující látky MeSH

INTRODUCTION: The Czech thermoluminescent dosimeters (TLD) quality assurance network was established in 1997. Its aim is to pursue a regular independent quality audit in Czech radiotherapy centres and to support state supervision. MATERIALS AND METHODS: The audit is realised via mailed TL dosimetry. The TLD system consists of encapsulated LiF:Mg,Ti powder (type MT-N) read with Harshaw manual reader model 4000. Basic mode of the TLD audit covers measurements under reference conditions, specifically beam calibration checks for all clinically used photon and electron beams. Advanced mode consists of measurements under both reference and non-reference conditions using a solid multipurpose phantom ('Leuven phantom') for photon beams. The radiotherapy centres are instructed to deliver to the TLD on central beam axis absorbed dose of 2 Gy calculated with their treatment planning system for a particular treatment set-up. The TLD measured doses are compared with the calculated ones. Deviations of +/-3% are considered acceptable for both basic and advanced mode of the audit. RESULTS: There are 34 radiotherapy centres in the Czech Republic. They undergo the basic mode of the TLD audit regularly every 2 years. If a centre shows a deviation outside the acceptance level, it is audited more often. Presently, most of the checked beams comply with the acceptance level. The advanced TLD audit has been implemented as a pilot study for the present. The results were mostly within the acceptance limit for the measurements on-axis, whereas for off-axis points they fell beyond the limit more frequently, especially for set-ups with inhomogeneities, oblique incidence and wedges. CONCLUSIONS: The results prove the importance of the national TLD quality assurance network. It has contributed to the improvement of clinical dosimetry in the Czech Republic. In addition, it helps the regulatory authority to monitor effectively and regularly radiotherapy centres.

• MeSH
• fantomy radiodiagnostické MeSH
• lidé MeSH
• nádory radioterapie   MeSH
• plánování radioterapie pomocí počítače normy   MeSH
• revize kvality lékařské péče * MeSH
• termoluminiscenční dozimetrie přístrojové vybavení   normy   MeSH
• zajištění kvality zdravotní péče * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

OBJECTIVE: To evaluate geometric and dosimetric inaccuracies in the irradiation of the rat brain with the Leksell Gamma Knife. MATERIALS AND METHODS: Altogether three types of dosimeters were employed for these measurements: (a) a thermoluminescent dosimeter, (b) a semiconductor detector and (c) a polymer gel dosimeter. The thermoluminescent dosimeter and the semiconductor detector were calibrated using an ion chamber and then implanted in the brain of a rat cadaver and used for absolute dose determination. A special glass phantom mimicking exactly the shape of the rat body filled with the polymer gel was used for measurements of the relative dose distribution and evaluation of geometric inaccuracies during the stereotactic irradiation in the rat brain. RESULTS: Both thermoluminescent and semiconductor detectors, due to their size, measured mean doses. The observed results demonstrated that the Leksell GammaPlan can be employed for the calculation of absorbed doses in irradiation of experimental animals. In our case, it was necessary to apply a correction factor of 1.078 for the absolute absorbed dose to obtain reliable results. A comparison of calculated dose profiles using the treatment planning system in all three axes with those measured by the polymer gel dosimeter demonstrated a very good geometric agreement with the mean deviation in profile position of 0.5 mm. CONCLUSION: The results indicate that this technique can effectively check the geometric and dosimetric accuracy of stereotactic irradiation in the rat brain. The Leksell GammaPlan can be employed for the calculation of absorbed doses, but the correction factor of 1.078 had to be applied for the absolute dose calculations in our irradiation geometry.

• MeSH
• dávka záření MeSH
• gely MeSH
• kalibrace MeSH
• krysa rodu Rattus MeSH
• mozek chirurgie   MeSH
• plánování radioterapie pomocí počítače metody   normy   MeSH
• polymery MeSH
• radiochirurgie přístrojové vybavení   metody   normy   MeSH
• reprodukovatelnost výsledků MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• gely MeSH
• polymery MeSH