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  • 1.
    Dasu, Alexandru
    et al.
    The Skandion Clinic, Uppsala, Sweden.
    Flejmer, Anna M.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology. The Skandion Clinic, Uppsala, Sweden.
    Edvardsson, Anneli
    Medical Radiation Physics, Department of Clinical Sciences Lund, Lund University, Lund, Sweden.
    Witt Nyström, Petra
    The Skandion Clinic, Uppsala, Sweden.
    Normal tissue sparing potential of scanned proton beams with and without respiratory gating for the treatment of internal mammary nodes in breast cancer radiotherapy2018In: Physica medica (Testo stampato), ISSN 1120-1797, E-ISSN 1724-191X, Vol. 52, p. 81-85Article in journal (Refereed)
    Abstract [en]

    Proton therapy has shown potential for reducing doses to normal tissues in breast cancer radiotherapy. However data on the impact of protons when including internal mammary nodes (IMN) in the target for breast radiotherapy is comparatively scarce. This study aimed to evaluate normal tissue doses when including the IMN in regional RT with scanned proton beams, with and without respiratory gating. The study cohort was composed of ten left-sided breast patients CT-scanned during enhanced inspiration gating (EIG) and free-breathing (FB). Proton plans were designed for the target including or excluding the IMN. Targets and organs-at-risk were delineated according to RTOG guidelines. Comparison was performed between dosimetric parameters characterizing target coverage and OAR radiation burden. Statistical significance of differences was tested using a paired, two-tailed Student’s t-test. Inclusion of the IMN in the target volume led to a small increase of the cardiopulmonary burden. The largest differences were seen for the ipsilateral lung where the mean dose increased from 6.1 to 6.6 Gy (RBE) (P < 0.0001) in FB plans and from 6.9 to 7.4 Gy (RBE) (P = 0.003) in EIG plans. Target coverage parameters were very little affected by the inclusion of IMN into the treatment target. Radiotherapy with scanned proton beams has the potential of maintaining low cardiovascular burden when including the IMN into the target, irrespective of whether respiratory gating is used or not.

  • 2.
    Dasu, Alexandru
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. The Skandion Clinic, Uppsala, Sweden.
    Toma-Dasu, Iuliana
    Stockholm University, Sweden; Karolinska Institutet, Sweden .
    Models for the risk of secondary cancers from radiation therapy2017In: Physica medica (Testo stampato), ISSN 1120-1797, E-ISSN 1724-191X, Vol. 42, p. 232-238Article in journal (Refereed)
    Abstract [en]

    The interest in the induction of secondary tumours following radiotherapy has greatly increased as developments in detecting and treating the primary tumours have improved the life expectancy of cancer patients. However, most of the knowledge on the current levels of risk comes from patients treated many decades ago. As developments of irradiation techniques take place at a much faster pace than the progression of the carcinogenesis process, the earlier results could not be easily extrapolated to modern treatments. Indeed, the patterns of irradiation from historically-used orthovoltage radiotherapy and from contemporary techniques like conformal radiotherapy with megavoltage radiation, intensity modulated radiation therapy with photons or with particles are quite different. Furthermore, the increased interest in individualised treatment options raises the question of evaluating and ranking the different treatment plan options from the point of view of the risk for cancer induction, in parallel with the quantification of other long-term effects. It is therefore inevitable that models for risk assessment will have to be used to complement the knowledge from epidemiological studies and to make predictions for newer forms of treatment for which clinical evidence is not yet available. This work reviews the mathematical models that could be used to predict the risk of secondary cancers from radiotherapy-relevant dose levels, as well as the approaches and factors that have to be taken into account when including these models in the clinical evaluation process. These include the effects of heterogeneous irradiation, secondary particles production, imaging techniques, interpatient variability and other confounding factors.

  • 3.
    de las Heras Gala, Hugo
    et al.
    Helmholtz Zentrum München, Munich, Germany.
    Torresin, Alberto
    ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy.
    Dasu, Alexandru
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. The Skandion Clinic, Uppsala, Sweden.
    Rampado, Osvaldo
    A.O.U. Città della Salute e della Scienza, Torino, Italy.
    Delis, Harry
    International Atomic Energy Agency, Vienna, Austria.
    Hernández Girón, Irene
    Leiden University Medical Center, Leiden, The Netherlands.
    Theodorakou, Chrysoula
    The Christie NHS Foundation Trust, Manchester, UK.
    Andersson, Jonas
    University of Umeå, Umeå, Sweden.
    Holroyd, John
    Dental X-ray Protection Services, PHE, UK.
    Nilsson, Mats
    Skane University Hospital, Malmö, Sweden.
    Edyvean, Sue
    Public Health England (PHE), Chilton, Didcot, Oxfordshire, UK.
    Gershan, Vesna
    Faculty of Natural Sciences and Mathematics, Skopje, Macedonia.
    Hadid-Beurrier, Lama
    Hôpital Jean-Verdier, Paris, France.
    Hoog, Christopher
    Centre Antoine Lacassagne, Nice, France.
    Delpon, Gregory
    Centre René Gauducheau, Nantes, France.
    Sancho Kolster, Ismael
    Institut Català d’Oncologia, L’Hospitalet de Llobregat, Spain.
    Peterlin, Primož
    Institute of Oncology Ljubljana, Slovenia.
    Garayoa Roca, Julia
    Fundación Jiménez Díaz, Madrid, Spain.
    Caprile, Paola
    Pontificia Universidad Católica de Chile, Santiago, Chile.
    Zervides, Costas
    University of Nicosia, Medical School, Nicosia, Cyprus.
    Quality control in cone-beam computed tomography (CBCT) EFOMP-ESTRO-IAEA protocol (summary report)2017In: Physica medica (Testo stampato), ISSN 1120-1797, E-ISSN 1724-191X, Vol. 39, p. 67-72Article in journal (Refereed)
    Abstract [en]

    The aim of the guideline presented in this article is to unify the test parameters for image quality evaluation and radiation output in all types of cone-beam computed tomography (CBCT) systems. The applications of CBCT spread over dental and interventional radiology, guided surgery and radiotherapy. The chosen tests provide the means to objectively evaluate the performance and monitor the constancy of the imaging chain. Experience from all involved associations has been collected to achieve a consensus that is rigorous and helpful for the practice.

    The guideline recommends to assess image quality in terms of uniformity, geometrical precision, voxel density values (or Hounsfield units where available), noise, low contrast resolution and spatial resolution measurements. These tests usually require the use of a phantom and evaluation software. Radiation output can be determined with a kerma-area product meter attached to the tube case. Alternatively, a solid state dosimeter attached to the flat panel and a simple geometric relationship can be used to calculate the dose to the isocentre. Summary tables including action levels and recommended frequencies for each test, as well as relevant references, are provided.

    If the radiation output or image quality deviates from expected values, or exceeds documented action levels for a given system, a more in depth system analysis (using conventional tests) and corrective maintenance work may be required.

  • 4.
    Flejmer, Anna M.
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Chehrazi, Behnaz
    Department of Physics, Stockholm University, Stockholm, Sweden.
    Josefsson, Dan
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Radiation Physics.
    Toma-Dasu, Iuliana
    Medical Radiation Physics, Stockholm University and Karolinska Institutet, Stockholm, Sweden.
    Dasu, Alexandru
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. The Skandion Clinic, Uppsala, Sweden .
    Impact of physiological breathing motion for breast cancer radiotherapy with proton beam scanning: An in silico study2017In: Physica medica (Testo stampato), ISSN 1120-1797, E-ISSN 1724-191X, Vol. 39, p. 88-94Article in journal (Refereed)
    Abstract [en]

    This study investigates the impact of breathing motion on proton breast treatment plans. Twelve patients with CT datasets acquired during breath-hold-at-inhalation (BHI), breath-hold-at-exhalation (BHE) and in free-breathing (FB) were included in the study. Proton plans were designed for the left breast for BHI and subsequently recalculated for BHE or designed for FB and recalculated for the extreme breath-hold phases. The plans were compared from the point of view of their target coverage and doses to organs-at-risk. The median amplitude of breathing motion determined from the positions of the sternum was 4.7 mm (range 0.5-14.6 mm). Breathing motion led to a degradation of the dose coverage of the target (heterogeneity index increased from 4-7% to 8-11%), but the degraded values of the dosimetric parameters of interest fulfilled the clinical criteria for plan acceptance. Exhalation decreased the lung burden [average dose 3.1-4.5 Gy (RBE)], while inhalation increased it [average dose 5.8-6.8 Gy (RBE)]. The individual values depended on the field arrangement. Smaller differences were seen for the heart [average dose 0.1-0.2 Gy (RBE)] and the LAD [1.9-4.6 Gy (RBE)]. Weak correlations were generally found between changes in dosimetric parameters and respiratory motion. The differences between dosimetric parameters for various breathing phases were small and their expected clinical impact is consequently quite small. The results indicated that the dosimetric parameters of the plans corresponding to the extreme breathing phases are little affected by breathing motion, thus suggesting that this motion might have little impact for the chosen beam orientations with scanned proton beams.

  • 5.
    Lazzeroni, Marta
    et al.
    Medical Radiation Physics, Department of Oncology and Pathology, Karolinska Institutet, Sweden.
    Uhrdin, Johan
    RaySearch Laboratories AB, Stockholm, Sweden.
    Carvalho, Sara
    Department of Radiation Oncology, GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands.
    van Elmpt, Wouter
    Department of Radiation Oncology, GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands.
    Lambin, Philippe
    Department of Radiation Oncology, GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands.
    Dasu, Alexandru
    The Skandion Clinic, Uppsala, Sweden.
    Wersäll, Peter
    Medical Radiation Physics, Department of Oncology and Pathology, Karolinska Institutet, Sweden; Medical Radiation Physics, Department of Physics, Stockholm University, Sweden.
    Toma-Dasu, Iuliana
    Medical Radiation Physics, Department of Oncology and Pathology, Karolinska Institutet, Sweden; Medical Radiation Physics, Department of Physics, Stockholm University, Sweden.
    Evaluation of third treatment week as temporal window for assessing responsiveness on repeated FDG-PET scans in Non-Small Cell Lung Cancer patients2018In: Physica medica (Testo stampato), ISSN 1120-1797, E-ISSN 1724-191X, Vol. 46, p. 45-51Article in journal (Refereed)
    Abstract [en]

    Purpose

    Early assessment of tumour response to treatment with repeated FDG-PET-CT imaging has potential for treatment adaptation but it is unclear what the optimal time window for this evaluation is. Previous studies indicate that changes in SUVmean and the effective radiosensitivity (αeff, accounting for uptake variations and accumulated dose until the second FDG-PET-CT scan) are predictive of 2-year overall survival (OS) when imaging is performed before radiotherapy and during the second week. This study aims to investigate if multiple FDG-PET-derived quantities determined during the third treatment week have stronger predictive power.

    Methods

    Twenty-eight lung cancer patients were imaged with FDG-PET-CT before radiotherapy (PET1) and during the third week (PET2). SUVmean, SUVmax, SUVpeak, MTV41%–50% (Metabolic Tumour Volume), TLG41%–50% (Total Lesion Glycolysis) in PET1 and PET2 and their change (), as well as average αeff (α¯eff) and the negative fraction of αeff values (fαeff<0) were determined. Correlations were sought between FDG-PET-derived quantities and OS with ROC analysis.

    Results

    Neither SUVmean, SUVmax, SUVpeak in PET1 and PET2 (AUC = 0.5–0.6), nor their changes (AUC = 0.5–0.6) were significant for outcome prediction purposes. Lack of correlation with OS was also found for α¯eff (AUC = 0.5) and fαeff<0 (AUC = 0.5). Threshold-based quantities (MTV41%–50%, TLG41%–50%) and their changes had AUC = 0.5–0.7.

    P-values were in all cases ≫0.05.

    Conclusions

    The poor OS predictive power of the quantities determined from repeated FDG-PET-CT images indicates that the third week of treatment might not be suitable for treatment response assessment. Comparatively, the second week during the treatment appears to be a better time window.

  • 6.
    Quast, Ulrich
    et al.
    Ex University Hospital, Germany.
    Kaulich, Theodor W.
    University Hospital, Germany.
    Alvarez-Romero, Jose T.
    ININ, Mexico.
    Carlsson Tedgren, Åsa
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Radiation Physics. Karolinska University Hospital, Sweden.
    Enger, Shirin A.
    McGill University, Canada.
    Medich, David C.
    Worcester Polytech Institute, MA 01609 USA.
    Mourtada, Firas
    Helen F Graham Cancer Centre and Research Institute, DE 19713 USA.
    Perez-Calatayud, Jose
    University Hospital La Fe, Spain; Clin Benidorm, Spain.
    Rivard, Mark J.
    Tufts University, MA 02111 USA.
    Abu Zakaria, G.
    University of Cologne, Germany; Gono University, Bangladesh.
    A brachytherapy photon radiation quality index Q(BT) for probe-type dosimetry2016In: Physica medica (Testo stampato), ISSN 1120-1797, E-ISSN 1724-191X, Vol. 32, no 6, p. 741-748Article in journal (Refereed)
    Abstract [en]

    Introduction: In photon brachytherapy (BT), experimental dosimetry is needed to verify treatment plans if planning algorithms neglect varying attenuation, absorption or scattering conditions. The detectors response is energy dependent, including the detector material to water dose ratio and the intrinsic mechanisms. The local mean photon energy E(r) must be known or another equivalent energy quality parameter used. We propose the brachytherapy photon radiation quality index Q(BT) ((E) over bar), to characterize the photon radiation quality in view of measurements of distributions of the absorbed dose to water, D-w, around BT sources. Materials and methods: While the external photon beam radiotherapy (EBRT) radiation quality index Q(EBRT) ((E) over bar) = TPR1020((E) over bar) is not applicable to BT, the authors have applied a novel energy dependent parameter, called brachytherapy photon radiation quality index, defined as Q(BT) ((E) over bar) = D-prim(r = 2 cm; theta(0) = 90 degrees)/D-prim(r(0) = 1 cm; theta(0) = 90 degrees), utilizing precise primary absorbed dose data, D-prim, from source reference databases, without additional MC-calculations. Results and discussion: For BT photon sources used clinically, Q(BT) ((E) over bar) enables to determine the effective mean linear attenuation coefficient (mu) over bar (E) and thus the effective energy of the primary photons E-prim(eff)(r(0), theta(0)) at the TG-43 reference position P-ref (r(0) = 1 cm; theta(0) = 90 degrees) being close to the mean total photon energy (E) over bar (tot)(r(0), theta(0)). If one has calibrated detectors, published (E) over bar (tot)(r) and the BT radiation quality correction factor k(Q, Q0)(BT) ((E) over bar, r, theta) for different BT radiation qualities Q and Q(0), the detectors response can be determined and D-w(r, theta) measured in the vicinity of BT photon sources. Conclusions: This novel brachytherapy photon radiation quality index Q(BT) characterizes sufficiently accurate and precise the primary photon` s penetration probability and scattering potential. (C) 2016 Published by Elsevier Ltd on behalf of Associazione Italiana di Fisica Medica.

  • 7.
    Siiskonen, T.
    et al.
    STUK Radiat and Nucl Safety Author, Finland.
    Ciraj-Bjelac, O.
    Univ Belgrade, Serbia.
    Dabin, J.
    Belgian Nucl Res Ctr SCK CEN, Belgium.
    Diklic, A.
    Univ Hosp Rijelca, Croatia.
    Domienik-Andrzejewska, J.
    NIOM, Poland.
    Farah, J.
    Paris Sud Univ Hosp, France.
    Fernandez, J. M.
    San Carlos Hosp and Complutense Univ, Spain.
    Gallagher, A.
    St James Hosp, Ireland.
    Hourdakis, C. J.
    EEAE Greek Atom Energy Commiss, Greece.
    Jurkovic, S.
    Univ Hosp Rijelca, Croatia; Univ Rijeka, Croatia.
    Jarvinen, H.
    STUK Radiat and Nucl Safety Author, Finland.
    Jarvinen, J.
    Turku Univ Hosp, Finland; Univ Turku, Finland.
    Knezevic, Z.
    RBI, Croatia.
    Koukorava, C.
    EEAE Greek Atom Energy Commiss, Greece.
    Maccia, C.
    CAATS, France.
    Majer, M.
    RBI, Croatia.
    Malchair, F.
    CAATS, France; ZEPHYRA, Belgium; Ctr Hosp Univ Liege CHULg, Belgium.
    Riccardi, L.
    Veneto Inst Oncol IOV IRCCS, Italy.
    Rizk, C.
    Natl Council Sci Res, Lebanon; St Joseph Univ, Lebanon.
    Sanchez, R.
    San Carlos Hosp and Complutense Univ, Spain.
    Sandborg, Michael
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV). Region Östergötland, Center for Diagnostics, Medical radiation physics.
    Merce, M. Sans
    Univ Hosp Geneva HUG, Switzerland; Univ Hosp Lausanne CHUV, Switzerland.
    Segota, D.
    Univ Hosp Rijelca, Croatia.
    Sierpowska, J.
    Cent Hosp Northern Karelia, Finland.
    Simantirakis, G.
    EEAE Greek Atom Energy Commiss, Greece.
    Sukupova, L.
    Inst Clin and Expt Med, Czech Republic.
    Thrapsanioti, Z.
    EEAE Greek Atom Energy Commiss, Greece.
    Vano, E.
    San Carlos Hosp and Complutense Univ, Spain.
    Establishing the European diagnostic reference levels for interventional cardiology2018In: Physica medica (Testo stampato), ISSN 1120-1797, E-ISSN 1724-191X, Vol. 54, p. 42-48Article in journal (Refereed)
    Abstract [en]

    Interventional cardiac procedures may be associated with high patient doses and therefore require special attention to protect the patients from radiation injuries such as skin erythema, cardiovascular tissue reactions or radiation-induced cancer. In this study, patient exposure data is collected from 13 countries (37 clinics and nearly 50 interventional rooms) and for 10 different procedures. Dose data was collected from a total of 14,922 interventional cardiology procedures. Based on these data European diagnostic reference levels (DRL) for air kerma-area product are suggested for coronary angiography (CA, DRL = 35 Gy cm(2)), percutaneous coronary intervention (PCI, 85 Gy cm(2)), transcatheter aortic valve implantation (TAVI, 130 Gy cm(2)), electrophysiological procedures (12 Gy cm(2)) and pacemaker implantations Pacemaker implantations were further divided into single-chamber (2.5 Gy cm(2)) and dual chamber (3.5 Gy cm(2)) procedures and implantations of cardiac resynchronization therapy pacemaker (18 Gy cm(2)). Results show that relatively new techniques such as TAVI and treatment of chronic total occlusion (CTO) often produce relatively high doses, and thus emphasises the need for use of an optimization tool such as DRL to assist in reducing patient exposure. The generic DRL presented here facilitate comparison of patient exposure in interventional cardiology.

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