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Author Oliver, S.; Vijande, J.; Tejedor-Aguilar, N.; Miro, R.; Rovira-Escutia, J.J.; Ballester, F.; Juste, B.; Carmona, V.; Felici, G.; Verdu, G.; Sanchis, E.; Conde, A.; Perez-Calatayud, J. doi  openurl
  Title Monte Carlo flattening filter design to high energy intraoperative electron beam homogenization Type Journal Article
  Year 2023 Publication Radiation Physics and Chemistry Abbreviated Journal Radiat. Phys. Chem.  
  Volume 212 Issue Pages 111102 - 6pp  
  Keywords Intraoperative radiotherapy; Electron portable LinAc; Flattening filter; Dosimetry; Monte Carlo  
  Abstract Intraoperative radiotherapy using mobile linear accelerators is used for a wide variety of malignancies. However, when large fields are used in combination with high energies, a deterioration of the flatness dose profile is measured with respect to smaller fields and lower energies. Indeed, for the LIAC HWL of Sordina, this deterioration is observed for the 12 MeV beam combined with 10 cm (or larger) diameter applicator. Aimed to solve this problem, a flattening filter has been designed and validated evaluating the feasibility of its usage at the upper part of the applicator. The design of the filter was based on Monte Carlo simulations because of its accuracy in modeling components of clinical devices, among other purposes. The LIAC 10 cm diameter applicator was modeled and simulated independently by two different research groups using two different MC codes, reproducing the heterogeneity of the 12 MeV energy beam. Then, an iterative process of filter design was carried out. Finally, the MC designed conical filter with the optimal size and height to obtain the desired flattened beam was built in-house using a 3D printer. During the experimental validation of the applicator-filter, percentage depth dose, beam profiles, absolute and peripheral dose measurements were performed to demonstrate the effectiveness of the filter addition in the applicator. These measurements conclude that the beam has been flattened, from 5.9% with the standard configuration to 1.6% for the configuration with the filter, without significant increase of the peripheral dose. Consequently, the new filter-applicator LIAC configuration can be used also in a conventional surgery room. A reduction of 16% of the output dose and a reduction of 1.1 mm in the D50 of the percentage depth dose was measured with respect to the original configuration. This work is a proof-of-concept that demonstrates that it is possible to add a filter able to flatten the beam delivered by the Sordina LIAC HWL. Future studies will focus on more refined technical solutions fully compatible with the integrity of the applicator, including its sterilization, to be safely introduced in the clinical practice.  
  Address [Oliver, S.; Miro, R.; Juste, B.; Verdu, G.] Univ Polite cn Vale ncia, Inst Segur Ind Radiofis & Medioambiental ISIRYM, Cami Vera S-N, Valencia 46022, Spain, Email: gverdu@iqn.upv.es  
  Corporate Author Thesis  
  Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0969-806x ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001026194900001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5578  
Permanent link to this record
 

 
Author Perez-Calatayud, J.; Ballester, F.; Tedgren, C.; DeWerd, L.A.; Papagiannis, P.; Rivard, M.J.; Siebert, F.A.; Vijande, J. doi  openurl
  Title GEC-ESTRO ACROP recommendations on calibration and traceability of HE HDR-PDR photon-emitting brachytherapy sources at the hospital level Type Journal Article
  Year 2022 Publication Radiotherapy and Oncology Abbreviated Journal Radiother. Oncol.  
  Volume 176 Issue Pages 108-117  
  Keywords Brachytherapy; High energy; Calibration; Dosimetry; HDR-PDR  
  Abstract The vast majority of radiotherapy departments in Europe using brachytherapy (BT) perform temporary implants of high-or pulsed-dose rate (HDR-PDR) sources with photon energies higher than 50 keV. Such techniques are successfully applied to diverse pathologies and clinical scenarios. These recommen-dations are the result of Working Package 21 (WP-21) initiated within the BRAchytherapy PHYsics Quality Assurance System (BRAPHYQS) GEC-ESTRO working group with a focus on HDR-PDR source cal-ibration. They provide guidance on the calibration of such sources, including practical aspects and issues not specifically accounted for in well-accepted societal recommendations, complementing the BRAPHYQS WP-18 Report dedicated to low energy BT photon emitting sources (seeds). The aim of this report is to provide a European-wide standard in HDR-PDR BT source calibration at the hospital level to maintain high quality patient treatments.  
  Address [Perez-Calatayud, Jose] La Fe Hosp, Radiotherapy Dept, Valencia, Spain, Email: javier.vijande@uv.es  
  Corporate Author Thesis  
  Publisher Elsevier Ireland Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0167-8140 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000880438000006 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5466  
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Author Vijande, J.; Tedgren, A.C.; Ballester, F.; Baltas, D.; Papagiannis, P.; Rivard, M.J.; Siebert, F.A.; De Werd, L.; Perez-Calatayud, J. doi  openurl
  Title Source strength determination in iridium-192 and cobalt-60 brachytherapy: A European survey on the level of agreement between clinical measurements and manufacturer certificates Type Journal Article
  Year 2021 Publication Physics and Imaging in Radiation Oncology Abbreviated Journal Phys. Imag. Radiat. Oncol.  
  Volume 19 Issue Pages 108-111  
  Keywords RAKR; Calibration; HDR; PDR; Brachytherapy  
  Abstract Background and purpose: Brachytherapy treatment outcomes depend on the accuracy of the delivered dose distribution, which is proportional to the reference air-kerma rate (RAKR). Current societal recommendations require the medical physicist to compare the measured RAKR values to the manufacturer source calibration certificate. The purpose of this work was to report agreement observed in current clinical practice in the European Union. Materials and methods: A European survey was performed for high- and pulsed-dose-rate (HDR and PDR) highenergy sources (Ir-192 and Co-60), to quantify observed RAKR differences. Medical physicists at eighteen hospitals from eight European countries were contacted, providing 1,032 data points from 2001 to 2020. Results: Over the survey period, 77% of the Ir-192 measurements used a well chamber instead of the older Krieger phantom method. Mean differences with the manufacturer calibration certificate were 0.01% +/- 1.15% for Ir-192 and -0.1% +/- 1.3% for Co-60. Over 95% of RAKR measurements in the clinic were within 3% of the manufacturer calibration certificate. Conclusions: This study showed that the agreement level was generally better than that reflected in prior societal recommendations positing 5%. Future recommendations on high-energy HDR and PDR source calibrations in the clinic may consider tightened agreements levels.  
  Address [Vijande, Javier; Ballester, Facundo] Univ Valencia UV, Dept Fis Atom Mol & Nucl, Burjassot, Spain, Email: Javier.vijande@uv.es  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000694711800017 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4969  
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Author Hueso-Gonzalez, F.; Ballester, F.; Perez-Calatayud, J.; Siebert, F.A.; Vijande, J. doi  openurl
  Title Towards clinical application of RayStretch for heterogeneity corrections in LDR permanent I-125 prostate brachytherapy Type Journal Article
  Year 2017 Publication Brachytherapy Abbreviated Journal Brachytherapy  
  Volume 16 Issue 3 Pages 616-623  
  Keywords Brachytherapy; Low-dose rate; Heterogeneities; Prostate; Calcifications; Dosimetry  
  Abstract PURPOSE: RayStretch is a simple algorithm proposed for heterogeneity corrections in low-dose-rate brachytherapy. It is built on top of TG-43 consensus data, and it has been validated with Monte Carlo (MC) simulations. In this study, we take a real clinical prostate implant with 71 1251 seeds as reference and we apply RayStretch to analyze its performance in worst-case scenarios. METHODS AND MATERIALS: To do so, we design two cases where large calcifications are located in the prostate lobules. RayStretch resilience under various calcification density values is also explored. Comparisons against MC calculations are performed. RESULTS: Dose volume histogram related parameters like prostate D-90, rectum D-2cc, or urethra D-10 obtained with RayStretch agree within a few percent with the detailed MC results for all cases considered. CONCLUSIONS: The robustness and compatibility of RayStretch with commercial treatment planning systems indicate its applicability in clinical practice for dosimetric corrections in prostate calcifications. Its use during intraoperative ultrasound planning is foreseen.  
  Address [Hueso-Gonzalez, Fernando] Target Systemelekt GmbH, Wuppertal, Germany, Email: javier.vijande@uv.es  
  Corporate Author Thesis  
  Publisher Elsevier Science Inc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1538-4721 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000402231600019 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3151  
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Author Vijande, J.; Ballester, F.; Ouhib, Z.; Granero, D.; Pujades-Claumarchirant, M.C.; Perez-Calatayud, J. doi  openurl
  Title Dosimetry comparison between TG-43 and Monte Carlo calculations using the Freiburg flap for skin high-dose-rate brachytherapy Type Journal Article
  Year 2012 Publication Brachytherapy Abbreviated Journal Brachytherapy  
  Volume 11 Issue 6 Pages 528-535  
  Keywords Ir-192; Brachytherapy; Dosimetry; Penelope2008; Freiburg flap  
  Abstract PURPOSE: The purpose of this work was to evaluate whether the delivered dose to the skin surface and at the prescription depth when using a Freiburg flap applicator is in agreement with the one predicted by the treatment planning system (TPS) using the TG-43 dose-calculation formalism. METHODS AND MATERIALS: Monte Carlo (MC) simulations and radiochromic film measurements have been performed to obtain dose distributions with the source located at the center of one of the spheres and between two spheres. Primary and scatter dose contributions were evaluated to understand the role played by the scatter component. A standard treatment plan was generated using MC- and TG-43-based TPS applying the superposition principle. RESULTS: The MC model has been validated by performing additional simulations in the same conditions but transforming air and Freiburg flap materials into water to match TG-43 parameters. Both dose distributions differ less than 1%. Scatter defect compared with TG-43 data is up to 15% when the source is located at the center of the sphere and up to 25% when the source is between two spheres. Maximum deviations between TPS- and MC-based distributions are of 5%. CONCLUSIONS: The deviations in the TG-43-based dose distributions for a standard treatment plan with respect to the MC dose distribution calculated taking into account the composition and shape of the applicator and the surrounding air are lower than 5%. Therefore, this study supports the validity of the TPS used in clinical practice. (C) 2012 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.  
  Address [Vijande, Javier; Ballester, Facundo] Univ Valencia, Dept Atom Mol & Nucl Phys, E-46100 Burjassot, Spain, Email: javier.vijande@uv.es  
  Corporate Author Thesis  
  Publisher Elsevier Science Inc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1538-4721 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000310863700018 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1227  
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