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Dive into the research topics where Meritxell Arenas is active.

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Featured researches published by Meritxell Arenas.


Radiotherapy and Oncology | 2015

ESTRO consensus guideline on target volume delineation for elective radiation therapy of early stage breast cancer

Birgitte Vrou Offersen; Liesbeth Boersma; C. Kirkove; S. Hol; Marianne C. Aznar; Albert Biete Sola; Youlia M. Kirova; Jean-Philippe Pignol; Vincent Remouchamps; K. Verhoeven; Caroline Weltens; Meritxell Arenas; Dorota Gabrys; Neil Kopek; Mechthild Krause; Dan Lundstedt; Tanja Marinko; Angel Montero; John Yarnold; Philip Poortmans

BACKGROUND AND PURPOSE Delineation of clinical target volumes (CTVs) is a weak link in radiation therapy (RT), and large inter-observer variation is seen in breast cancer patients. Several guidelines have been proposed, but most result in larger CTVs than based on conventional simulator-based RT. The aim was to develop a delineation guideline obtained by consensus between a broad European group of radiation oncologists. MATERIAL AND METHODS During ESTRO teaching courses on breast cancer, teachers sought consensus on delineation of CTV through dialogue based on cases. One teacher delineated CTV on CT scans of 2 patients, followed by discussion and adaptation of the delineation. The consensus established between teachers was sent to other teams working in the same field, both locally and on a national level, for their input. This was followed by developing a broad consensus based on discussions. RESULTS Borders of the CTV encompassing a 5mm margin around the large veins, running through the regional lymph node levels were agreed, and for the breast/thoracic wall other vessels were pointed out to guide delineation, with comments on margins for patients with advanced breast cancer. CONCLUSION The ESTRO consensus on CTV for elective RT of breast cancer, endorsed by a broad base of the radiation oncology community, is presented to improve consistency.


International Journal of Radiation Oncology Biology Physics | 2002

Is vascular and lymphatic space invasion a main prognostic factor in uterine neoplasms with a sarcomatous component? A retrospective study of prognostic factors of 60 patients stratified by stages

Angeles Rovirosa; Carlos Ascaso; Jaume Ordi; Rosa Abellana; Meritxell Arenas; José-Antonio Lejarcegui; Jaume Pahisa; Luis M. Puig-Tintoré; Begoña Mellado; Beatrı́z Armenteros; Xavier Iglesias; Albert Biete

BACKGROUND Sarcomatous neoplasms of the uterine corpus are still a challenge in terms of obtaining prognostic factors and the most optimum complementary treatment to surgery. The most important prognostic factor is stage; relapses usually appear during the first 2 years, and most patients die within the first 3 years. We have performed a multivariate study of prognostic factors, stratifying patients by stage, to determine their impact on overall survival, disease-free survival, local relapse-free survival, and distant metastasis-free survival. Special emphasis has been given to vascular and lymphatic space invasion (VLSI). METHODS Sixty patients diagnosed with uterine neoplasms with a main sarcomatous component were treated at Hospital Clínic i Universitari of Barcelona between January 1975 and June 1999. Pathologic type: 32 carcinosarcomas, 14 leiomyosarcomas, 9 adenosarcomas, and 5 endometrial stromal sarcomas. TREATMENT 58/60 surgery, 35/60 postoperative radiotherapy, 2/60 exclusive chemotherapy, and 3/60 complementary chemotherapy. FIGO stages: 43 Stage I, 4 Stage II, 11 Stage III, and 2 Stage IV. Variables analyzed: age, stage, vascular and lymphatic space invasion, myometrial invasion, mitotic index, tumor size, unicentricity/multicentricity, necrosis, and radiotherapy. STATISTICS the S and Cox proportional risk models. The partial effect of each risk factor was calculated by hazard ratio (HR) with a confidence interval of 95%. RESULTS Early stages: Multivariate analysis showed that tumor size larger than 8 cm and VLSI had an impact on overall survival (HR = 4.01 and HR = 24.45, respectively). VLSI was present in 23% of the cases. Myometrial invasion greater than 50% had an impact on disease-free survival and local relapse-free survival (HR was 9.75 and 3.20, respectively). VLSI had an impact on distant metastasis-free survival (HR = 2.92). Advanced stages: VLSI was present in 89% of the cases. Only leiomyosarcoma type made the overall survival worse (HR = 10.54). CONCLUSIONS Vascular and lymphatic space invasion was a relevant prognostic factor in our series, with an impact on overall survival and distant metastasis-free survival in early stages. In advanced stages, VLSI had no impact on survival, but was present in 89% of cases. Myometrial invasion >50% had an impact on local relapse. Advanced stages had a more aggressive behavior, and there was a higher incidence of poor prognostic factors in these stages. Nevertheless, prospective studies are still needed on prognostic factors and on the best treatment option.


Strahlentherapie Und Onkologie | 2012

Anti-inflammatory effects of low-dose radiotherapy: Indications, dose and radiobiological mechanisms involved

Meritxell Arenas; S. Sabater; Hernández; A. Rovirosa; P.C. Lara; A. Biete; Julián Panés

Low-dose radiotherapy (LD-RT) has been used for several benign diseases, including arthrodegenerative and inflammatory pathologies. Despite its effectiveness in clinical practice, little is known about the mechanisms through which LD-RT modulates the various phases of the inflammatory response and about the optimal dose fractionation. The objective of this review is to deepen knowledge about the most effective LD-RT treatment schedule and radiobiological mechanisms underlying the anti-inflammatory effects of LD-RT in various in vitro experiments, in vivo studies, and clinical studies.ZusammenfassungNiedrigdosierte Strahlentherapie (LD-RT) wird für die Behandlung verschiedener gutartiger Erkrankungen, einschließlich für arthrodegenerative und entzündliche Erkrankungen verwendet. Obwohl diese in der Praxis effektiv sind, wissen wir noch sehr wenig über die zugrundeliegenden Mechanismen der entzündungshemmenden Wirkung und die optimale Dosisfraktionierung. Das Ziel des Artikels ist es, unser Wissen über LD-RT und die zugrundeliegenden entzündungshemmenden Effekte in verschiedenen In-vitro-Versuchen und In-vivo-Studien sowie in klinischen Studien zu vertiefen.


International Journal of Radiation Oncology Biology Physics | 2000

Acoustic analysis after radiotherapy in T1 vocal cord carcinoma: a new approach to the analysis of voice quality

Angeles Rovirosa; Eugenio Martínez-Celdrán; Alicia Ortega; Carlos Ascaso; Rosa Abellana; Mercedes Velasco; Montserrat Bonet; Carmen Herrera; Francesc Casas; Rosa Marı́a Francisco; Meritxell Arenas; Victor Hernandez; A. Sanchez-Reyes; Concha León; Jordi Traserra; Albert Biete

PURPOSE The study of acoustic voice parameters (fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio) in extended vowel production, oral reading of a standard paragraph, spontaneous speech and a song in irradiated patients for Tis-T1 vocal cord carcinoma. METHODS AND MATERIALS Eighteen male patients irradiated for Tis-T1 vocal cord carcinoma and a control group of 31 nonirradiated subjects of the same age were included in a study of acoustic voice analysis. The control group had been rigorously selected for voice quality and the irradiated group had previous history of smoking in two-thirds of the cases and a vocal cord biopsy. Radiotherapy patients were treated with a 6MV Linac receiving a total dose of 66 Gy, 2 Gy/day, with median treatment areas of 28 cm(2). Acoustic voice analysis was performed 1 year after radiotherapy, the voice of patients in extended vowel production, oral reading of a standard paragraph, spontaneous speech, and in a song was tape registered and analyzed by a Kay Elemetrics Computerized Speech Lab (model CSL# 4300). Fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio were obtained in each case. Mann Whitney analysis was used for statistical tests. RESULTS The irradiated group presented higher values of fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio. Mann-Whitney analysis showed significant differences for fundamental frequency and jitter in vowel production, oral reading, spontaneous speech, and song. Shimmer only showed differences in vowel production and harmonics-to-noise ratio in oral reading and song. CONCLUSIONS In our study only fundamental frequency and jitter showed significant increased values to the control group in all the acoustic situations. Sustained vowel production showed the worst values of the acoustic parameters in comparison with the other acoustic situations. This study seems to suggest that more work should be done in this field.


Strahlentherapie Und Onkologie | 2012

Anti-inflammatory effects of low-dose radiotherapy

Meritxell Arenas; S. Sabater; V. Hernández; A. Rovirosa; P.C. Lara; A. Biete; Julián Panés

Low-dose radiotherapy (LD-RT) has been used for several benign diseases, including arthrodegenerative and inflammatory pathologies. Despite its effectiveness in clinical practice, little is known about the mechanisms through which LD-RT modulates the various phases of the inflammatory response and about the optimal dose fractionation. The objective of this review is to deepen knowledge about the most effective LD-RT treatment schedule and radiobiological mechanisms underlying the anti-inflammatory effects of LD-RT in various in vitro experiments, in vivo studies, and clinical studies.ZusammenfassungNiedrigdosierte Strahlentherapie (LD-RT) wird für die Behandlung verschiedener gutartiger Erkrankungen, einschließlich für arthrodegenerative und entzündliche Erkrankungen verwendet. Obwohl diese in der Praxis effektiv sind, wissen wir noch sehr wenig über die zugrundeliegenden Mechanismen der entzündungshemmenden Wirkung und die optimale Dosisfraktionierung. Das Ziel des Artikels ist es, unser Wissen über LD-RT und die zugrundeliegenden entzündungshemmenden Effekte in verschiedenen In-vitro-Versuchen und In-vivo-Studien sowie in klinischen Studien zu vertiefen.


Reports of Practical Oncology & Radiotherapy | 2012

Radiation techniques used in patients with breast cancer: Results of a survey in Spain

M. Algara; Meritxell Arenas; Dolores De las Peñas Eloisa Bayo; Julia Muñoz; José Antonio Carceller; Juan Salinas; Ferran Moreno; Francisco Martínez; Ezequiel González; A. Montero

AIM To evaluate the resources and techniques used in the irradiation of patients with breast cancer after lumpectomy or mastectomy and the status of implementation of new techniques and therapeutic schedules in our country. BACKGROUND The demand for cancer care has increased among the Spanish population, as long as cancer treatment innovations have proliferated. Radiation therapy in breast cancer has evolved exponentially in recent years with the implementation of three-dimensional conformal radiotherapy, intensity modulated radiotherapy, image guided radiotherapy and hypofractionation. MATERIAL AND METHODS An original survey questionnaire was sent to institutions participating in the SEOR-Mama group (GEORM). In total, the standards of practice in 969 patients with breast cancer after surgery were evaluated. RESULTS The response rate was 70% (28/40 centers). In 98.5% of cases 3D conformal treatment was used. All the institutions employed CT-based planning treatment. Boost was performed in 56.4% of patients: electrons in 59.8%, photons in 23.7% and HDR brachytherapy in 8.8%. Fractionation was standard in 93.1% of patients. Supine position was the most frequent. Only 3 centers used prone position. The common organs of risk delimited were: homolateral lung (80.8%) and heart (80.8%). In 84% histograms were used. An 80.8% of the centers used isocentric technique. In 62.5% asymmetric fields were employed. CTV was delimited in 46.2%, PTV in 65% and both in 38.5%. A 65% of the centers checked with portal films. IMRT and hypofractionation were used in 1% and in 5.5% respectively. CONCLUSION In most of centers, 3D conformal treatment and CT-based planning treatment were used. IMRT and hypofractionation are currently poorly implemented in Spain.


Radiotherapy and Oncology | 2016

Analysing the integration of MR images acquired in a non-radiotherapy treatment position into the radiotherapy workflow using deformable and rigid registration

S. Sabater; María del Rosario Pastor-Juan; Roberto Berenguer; Ignacio Andres; Marimar Sevillano; Elena Lozano-Setien; Esther Jimenez-Jimenez; Angeles Rovirosa; Ricardo Sánchez-Prieto; Meritxell Arenas

AIM Our aim was to analyse the feasibility of integrating an MRI acquired in a non-radiotherapy set-up into the prostate cancer radiotherapy workflow. MATERIAL AND METHODS The MRIs of 15 prostate cancer patients, acquired with a flat table-top (MRI-flat), and with a curved tabletop (MRI-curve) were analysed. MRIs were rigidly (RIR) and non-rigidly registered (DIR) with CT images. The prostate and rectum were contoured in each image set and translated to the CT, and IMRT plans were computed taking into account structural changes after RIR and DIR (P-flatRIR, P-curveRIR and P-curveDIR). In addition the P-curveDIR was overlaid with RIR structures. Spatial overlap parameters and dose-volume histogram metrics were generated. RESULTS No significant differences were observed among P-flatRIR and P-curveRIR or P-flatRIR and P-curveDIR. Median gamma-values: P-curveRIR, 95.3%; P-curveDIR, 96%, translated-P-curveDIR, 95%. DVH metrics for translated-P-curveDIR were: Dmin, 64.5Gy; Dmean, 70.06Gy; V95%, 100%. No statistically significant differences were found in the dosimetric MRI-flatDIR values. CONCLUSIONS The dosimetric reproduction of treatment position image following image registration of non-radiotherapy set-up images suggests that it is feasible to integrate these images into the radiotherapy workflow.


The Breast | 2014

Accelerated hypofractionated breast radiotherapy: FAQs (frequently asked questions) and facts.

A. Montero; Xavier Sanz; R. Hernanz; Dolores Cabrera; Meritxell Arenas; Eloisa Bayo; Ferran Moreno; Manel Algara

The demand for breast cancer care has increased as cancer treatment innovations have proliferated. Adjuvant radiotherapy to the breast is considered to be part of the standard treatment in breast cancer. The role of radiotherapy in terms of reducing loco-regional recurrence and increased survival after conservative surgery, and also after a mastectomy in selected cases, has been previously shown in several randomized trials. Patterns of radiotherapy commonly used for breast cancer comprise a period of approximately five weeks, frequently with the addition of an additional 1-1.5 weeks of a radiation boost to the primary tumour area. In last years, there has been a renewed interest in hypofractionated and accelerated radiotherapy schedules that reduce the overall treatment time to barely three weeks, leading to an improvement in quality of life for patients and also optimizing workload of radiation oncology departments. However, despite the existing evidence supporting the use of hypofractionated treatment regimens, their widespread is still far from complete. Many questions have generated resistance among clinical oncologists for their regular use. The aim of this review is to answer those questions that may arise with the use of moderate hypofractionation in breast cancer.


Brachytherapy | 2015

Dosimetric analysis of rectal filling on rectal doses during vaginal cuff brachytherapy

S. Sabater; Meritxell Arenas; Roberto Berenguer; Santiago Machin-Hamalainen; Ignacio Andres; Mª.M. Sevillano; Esther Jimenez-Jimenez; Ana Martos; Veronica Lopez-Honrubia; Jesus Fernandez-Lopez

PURPOSE Several studies have analyzed the effect of bladder filling during vaginal cuff brachytherapy (VCB), but the effect of rectum filling has not been studied. We sought to evaluate the effects of rectal volume on rectal doses during postoperative VCB. METHODS AND MATERIALS Brachytherapy planning CT scans (334 sets) obtained from 92 consecutive patients treated with VCB were resegmented (bladder and rectum) and replanned retrospectively using the same parameters to homogenize data and improve analysis. Rectal volume and a set of values derived from dose-volume histograms (DVHs) were extracted (maximal dose [Dmax], D0.1cc, D1cc, and D2cc). Univariate and multivariate analyses were carried out to evaluate the association between rectal volume and DVH metrics after adjusting for other clinical factors. RESULTS A positive significant correlation was observed between rectal volume correlated and Dmax, D0.1cc, D1cc, and D2cc. Multiple linear regression models found that rectal volume, cylinder angle position, and cylinder diameter variables correlated significantly with the different DVH parameters analyzed. These variables explained the 14.5% and 18% of variance on regression models. CONCLUSIONS Larger rectal volumes are associated with higher rectal dose parameters during VCB fractions. Prospective studies are needed to investigate whether these data are linked to differences in rectal toxicity.


Radiotherapy and Oncology | 2015

Can we shorten the overall treatment time in postoperative brachytherapy of endometrial carcinoma? Comparison of two brachytherapy schedules

Angeles Rovirosa; Carlos Ascaso; Meritxell Arenas; S. Sabater; A. Herreros; Albert Camarasa; I. Ríos; Katarzyna Holub; Jaume Pahisa; Albert Biete

PURPOSE To analyze vaginal-cuff relapses (VCR) and toxicity of two brachytherapy (BT) schedules in postoperative endometrial carcinoma and to correlate vaginal toxicity with vaginal-surface-EQD2Gy3 dose (VS-EQD2Gy3). METHODS/MATERIALS 319 patients (p) I-IIIC-Figo-stage were treated with 2 BT schedules. One schedule included 166p (Group-1) to whom 3 fractions (Fr) of 4-6Gy per week (w) of BT were administered after external beam radiotherapy (EBI) (125p) and 6Fr/2w of 4-6Gy in exclusive-BT (41p). The second schedule included 153p (Group-2) with BT administered daily with 2Fr/w of 5-6Gy after EBI (94p) and 5-6Gy/4Fr/w in exclusive-BT (59p). Doses were prescribed at 5mm from the vaginal surface. Toxicity was evaluated using RTOG scores for the rectum and bladder and objective LENT-SOMA scores for the vagina. STATISTICS Chi-square, Fisher and Students-t tests. RESULTS Mean follow-up (months): Group-1: 66.55 (7.73-115.40), Group-2: 41.49 (3.13-87.90). VCR: Group-1: 3p (1.88%); Group-2: 2p (1.3%). No differences were found between the two schedules comparing rectal (p=0.170), bladder (p=0.125) and vagina (p=0.680) late toxicities and comparing vagina EBI+BTp vs. exclusive-BTp (p=0.667). Significant differences in VS-EQD23Gy were observed considering EBI+BT (Groups 1+2) vs. exclusive-BT (Groups 1+2) (p<0.0001); nevertheless, no association was found between VS-EQD23Gy and vaginal complications. CONCLUSIONS No differences were found between the two schedules. No association was found between vaginal toxicity and VS-EQD23Gy. Consequently, treatment with the least number of fractions is preferable.

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Albert Biete

University of Barcelona

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A. Rovirosa

University of Barcelona

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A. Herreros

University of Barcelona

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Jaume Pahisa

University of Barcelona

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I. Ríos

University of Barcelona

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A. Biete

University of Barcelona

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