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Benidorm, Spain

Villalba S.R.,Hospital Clinica Benidorm | Sancho J.R.,Hospital Clinica Benidorm | Palacin A.O.,Hospital Clinica Benidorm | Calatayud J.P.,Hospital Clinica Benidorm | And 2 more authors.
Journal of Contemporary Brachytherapy

Purpose: To describe the potential clinical use of a new brachytherapy applicator for gynecological tumors, with special attention to locally advanced cervical carcinoma. This device allows the combination of intracavitary radiotherapy and MRI-compatible transperineal interstitial needles. The design of this template addresses the disadvantages of currently commercially available templates: the inability of the intracavitary component to reach deep into the cervix (MUPIT), and the MRI-incompatibility of these templates (MUPIT and Syed), which necessitates use of CT imaging for the dosimetry. Material and methods: The newly developed Benidorm Template applicator allows titanium needles in a template with straight and angled holes to provide different angles of divergence to be used with currently existing MRI-compatible intrauterine tubes. It can provide total coverage of the craniocaudal and lateral extension of the tumor (intrautherus, parametrial, and paravaginal). This method is mainly indicated in advanced cervical carcinoma with bulky parametrial invasion (medial or distal), with bulky primary disease that responds poorly to external beam radiotherapy extensive paravaginal involvement (tumor thickness greater than 0.5 cm) extending to the middle or lower third of the vagina, or for disease that has invaded the bladder or rectum (stage IVA). Results: Between April 2013 until December 2014, we treated 15 patients with locally advanced cervical carcinoma employing the Benidorm Template. The median dose at D90 for the CTV was 79.8 Gy (71.5-89.9 Gy), at D 2cc for the bladder it was 77.6 Gy (69.8-90.8 Gy), and at D 2cc for the rectum it was 71.9 Gy (58.3-83.7 Gy). Values expressed in EQD2, assuming α/β of 10 for CTV and 3 for OAR. Conclusions: This new applicator allows the use of MRI-based dosimetry, thus providing the advantages of MRI volume definition. As such, it facilitates determination of complete intracavitary and interstitial CTV coverage and the sparing of normal tissues. Source

Granero D.,Hospital General Universitario | Perez-Calatayud J.,Hospital Clinica Benidorm | Ballester F.,University of Valencia | Ouhib Z.,Lynn Cancer Institute of Boca Raton Regional Hospital
Physica Medica

Introduction and purpose: The Valencia applicators which are accessories of the microSelectron-HDR afterloader (Nucletron, Veenendaal, The Netherlands) are designed to treat skin lesions. These cup-shaped applicators are an alternative to superficial/orthovoltage x-ray treatment units. They limit the irradiation to the required area using tungsten-alloy shielding, and are equipped with a tungsten-alloy flattering filter allowing the treatment of skin tumors, the oral cavity, vaginal cuff, etc. The tungsten-alloy thickness to shield radiation is not the same in all parts of the applicators. This fact led us to question whether the leakage radiation differs depending on where it is measured, and whether this may be relevant in some clinical cases. The purpose of this work is to study from the radiation protection point of view the radiation leakage of the Valencia applicators, and provide a solution for current users and for the manufacturer. Methods and materials: Simulations based on the Monte Carlo (MC) method using the Geant4 code have been realized studying the dose rate distribution in air around the cup of the Valencia applicators. An experimental study with radiochromic film has also been done to measure the dose distribution in the back side of the applicators and to compare it with MC results. Results and conclusions: Radiation leakage of up to 170% of the prescribed dose has been found at the back surface of these applicators. Although this side is not usually directed to the patient, in some applications such as the treatment of a lesion on the nose, special care must be taken to avoid unexpected and unnecessary irradiation of the eyes. A possible solution could be to add additional shielding to the applicator in order to reduce this leakage or to put some shielding to protect the eyes. Additionally, a new concept design of the Valencia applicators using more shielding material in the applicator backside is proposed. © 2011 Associazione Italiana di Fisica Medica. Source

Richart J.,Hospital Clinica Benidorm | Pujades M.C.,Physics Section | Perez-Calatayud J.,Hospital Clinica Benidorm | Granero D.,Hospital General Universitario | And 3 more authors.
Physica Medica

Purpose: Dynamic delivery of intensity modulated beams (dIMRT) requires not only accurate verification of leaf positioning but also a control on the speed of motion. The latter is a parameter that has a major impact on the dose delivered to the patient. Time consumed in quality assurance (QA) procedures is an issue of relevance in any radiotherapy department. Electronic portal imaging dosimetry (EPID) can be very efficient for routine tests. The purpose of this work is to investigate the ability of our EPID for detecting small errors in leaf positioning, and to present our daily QA procedures for dIMRT based on EPID. Methods and materials: A Varian 2100 CD Clinac equipped with an 80 leaf Millennium MLC and with amorphous silicon based EPID (aS500, Varian) is used. The daily QA program consists in performing: Stability check of the EPID signal, Garden fence test, Sweeping slit test, and Leaf speed test. Results and discussion: The EPID system exhibits good long term reproducibility. The mean portal dose at the centre of a 10 × 10 cm2 static field was 1.002 ± 0.004 (range 1.013-0.995) for the period evaluated of 47 weeks. Garden fence test shows that leaf position errors of up to 0.2 mm can be detected. With the Sweeping slit test we are able to detect small deviations on the gap width and errors of individual leaves of 0.5 and 0.2 mm. With the Leaf speed test problems due to motor fatigue or friction between leaves can be detected. Conclusions: This set of tests takes no longer than 5 min in the linac treatment room. With EPID dosimetry, a consistent daily QA program can be applied, giving complete information about positioning/speed MLC. © 2011 Associazione Italiana di Fisica Medica. Source

Vijande J.,University of Valencia | Granero D.,Hospital General Universitario | Perez-Calatayud J.,Hospital Clinica Benidorm | Perez-Calatayud J.,Polytechnic University of Valencia | Ballester F.,University of Valencia
Applied Radiation and Isotopes

The 137Cs medium dose rate (MDR) CSM40 source model (Eckert & Ziegler BEBIG, Germany) is in clinical use but no dosimetric dataset has been published. This study aims to obtain dosimetric data for the CSM40 source for its use in clinical practice as required by the American Association of Physicists in Medicine (AAPM) and the European Society for Radiotherapy and Oncology (ESTRO). Penelope2008 and Geant4 Monte Carlo codes were used to characterize this source dosimetrically. It was located in an unbounded water phantom with composition and mass density as recommended by AAPM and ESTRO. Due to the low photon energies of 137Cs, absorbed dose was approximated by collisional kerma. Additional simulations were performed to obtain the air-kerma strength, sK. Mass-energy absorption coefficients in water and air were consistently derived and used to calculate collisional kerma. Results performed with both radiation transport codes showed agreement typically within 0.05%. Dose rate constant, radial dose function and anisotropy function are provided for the CSM40 and compared with published data for other commercially available 137Cs sources. An uncertainty analysis has been performed. The data provided by this study can be used as input data and verification in the treatment planning systems. © 2013 Elsevier Ltd. Source

Lopez Torrecilla J.,Hospital General Universitario | Zapatero A.,Hospital Universitario Of La Princesa | Herruzo I.,Hospital Universitario Carlos Haya | Calvo F.A.,Hospital Universitario Gregorio Maranon | And 21 more authors.
Clinical and Translational Oncology

Aim: The purpose of the study was to describe infrastructures, treatment modalities, and workload in radiation oncology (RO) in Spain, referred particularly to prostate cancer (PC). Methods: An epidemiologic, cross-sectional study was performed during 2008-2009. A study-specific questionnaire was sent to the 108 RO-registered departments. Results: One hundred and two departments answered the survey, and six were contacted by telephone. Centers operated 236 treatment units: 23 (9.7 %) cobalt machines, 37 (15.7 %) mono-energetic linear accelerators, and 176 (74.6 %) multi-energy linear accelerators. Sixty-one (56.4 %) and 33 (30.5 %) departments, respectively, reported intensity-modulated radiation therapy (IMRT) and image-guided RT (IGRT) capabilities; three-dimensional-conformal RT was used in 75.8 % of patients. Virtual simulators were present in 95 departments (88.0 %), 35 use conventional simulators. Fifty-one departments (47.2 %) have brachytherapy units, 38 (35.2 %) perform prostatic implants. Departments saw a mean of 24.9 new patients/week; the number of patients treated annually was 102,054, corresponding to 88.4 % of patients with a RT indication. In 56.5 % of the hospitals, multidisciplinary teams were available to treat PC. Conclusions: Results provide an accurate picture of current situation of RO in Spain, showing a trend toward the progressive introduction of new technologies (IMRT, IGRT, brachytherapy). © 2013 Federación de Sociedades Españolas de Oncología (FESEO). Source

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