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Hong Qi Tan, Zhaohong Mi, Andrew A Bettiol
We present a simple and universal approach to calculate the total ionization cross section (TICS) for electron impact ionization in DNA bases and other biomaterials in the condensed phase. Evaluating the electron impact TICS plays a vital role in ion-beam radiobiology simulation at the cellular level, as secondary electrons are the main cause of DNA damage in particle cancer therapy. Our method is based on extending the dielectric formalism. The calculated results agree well with experimental data and show a good comparison with other theoretical calculations...
March 2018: Physical Review. E
Valentina Pinzi, Ilaria Bisogno, Francesco Prada, Emilio Ciusani, Laura Fariselli
PURPOSE: Meningiomas account for one third of primary intracranial tumors, nevertheless information on meningioma cell lines and in vivo models is scant. Although radiotherapy is one of the most relevant therapeutic options for the treatment patients with meningioma, radiobiological research to understand tumor responses to this treatment is far from being thoroughly understood. The aim of this report is to provide a comprehensive picture of the current literature on this field, so as to foster s research in this regard...
May 18, 2018: International Journal of Radiation Biology
Poushali Bhattacharya, Neena G Shetake, Badri N Pandey, Amit Kumar
PURPOSE: One of the most important implications of 'Radiation Biology' research is to improve cancer radiotherapy with minimum side effects. In this regard, combination of chemotherapy with radiation has significantly improved tumor control as well as overall survival in a variety of cancers. However, this has been achieved at the cost of significant normal tissue toxicity, due to the lack of specificity of chemotherapy. Membrane-localized receptor tyrosine kinases (RTKs) have been found to play a driving role in various hallmarks of cancer...
May 18, 2018: International Journal of Radiation Biology
Paul Reid, Puthenparampil Wilson, Yanrui Li, Loredana G Marcu, Alexander H Staudacher, Michael P Brown, Eva Bezak
Head and neck cancers (HNCs) are aggressive epithelial tumours frequently treated using radiation. HNC biology shows distinctions dependent on the oncologic involvement of the human papilloma virus (HPV). Clinically, HPV positive HNCs respond better to radiotherapy but few in vitro data demonstrate radiobiological differences explaining differences in clinical outcomes. This pilot study examined radiobiological responses to irradiation and subsequent regeneration in two HNC cell lines (HPV positive and negative)...
May 17, 2018: Scientific Reports
C M van Leeuwen, A L Oei, J Crezee, A Bel, N A P Franken, L J A Stalpers, H P Kok
BACKGROUND: Prediction of radiobiological response is a major challenge in radiotherapy. Of several radiobiological models, the linear-quadratic (LQ) model has been best validated by experimental and clinical data. Clinically, the LQ model is mainly used to estimate equivalent radiotherapy schedules (e.g. calculate the equivalent dose in 2 Gy fractions, EQD2 ), but increasingly also to predict tumour control probability (TCP) and normal tissue complication probability (NTCP) using logistic models...
May 16, 2018: Radiation Oncology
Giulia Marvaso, Giulia Riva, Delia Ciardo, Sara Gandini, Cristiana Fodor, Dario Zerini, Sarah Pia Colangione, Giorgia Timon, Stefania Comi, Raffaella Cambria, Federica Cattani, Ottavio De Cobelli, Roberto Orecchia, Barbara A Jereczek-Fossa
Ultra-hypofractionated radiotherapy (RT) is given over a shorter time with larger doses with respect to conventional fractionation in patients with localized prostate cancer (PCa). The use of hypofractionation is supported both from the radiobiological point of view (the low α/β-ratio in PCa and dose escalation) and from the rising number of clinical evidences. The aim of this study is to review our data regarding oncological outcomes, namely biochemical progression-free survival (b-PFS) and clinical progression-free survival (c-PFS), acute and long-term toxicities in patients treated with a ultra-hypofractionated RT...
May 10, 2018: Medical Oncology
E Fiorina, V Ferrero, F Pennazio, G Baroni, G Battistoni, N Belcari, P Cerello, N Camarlinghi, M Ciocca, A Del Guerra, M Donetti, A Ferrari, S Giordanengo, G Giraudo, A Mairani, M Morrocchi, C Peroni, A Rivetti, M D Da Rocha Rolo, S Rossi, V Rosso, P Sala, G Sportelli, S Tampellini, F Valvo, R Wheadon, M G Bisogni
Hadrontherapy is a method for treating cancer with very targeted dose distributions and enhanced radiobiological effects. To fully exploit these advantages, in vivo range monitoring systems are required. These devices measure, preferably during the treatment, the secondary radiation generated by the beam-tissue interactions. However, since correlation of the secondary radiation distribution with the dose is not straightforward, Monte Carlo (MC) simulations are very important for treatment quality assessment...
May 7, 2018: Physica Medica: PM
Marco Durante, Jürgen Debus
Protons are the most common charged particles used in oncology. Acceleration of heavier ions requires larger accelerators and is more expensive, yet heavy nuclei share the same advantageous dose-depth profile characteristics of protons and have potential additional advantages. These advantages are related to the physical characteristics of the beam, owing to reduced lateral scattering and sharper lateral penumbra. In addition, heavy ions produce an increased biological response. In fact, in the target region heavy ions behave as densely ionizing radiation, which produce distinct biological effects compared to sparsely ionizing x-rays and protons...
April 2018: Seminars in Radiation Oncology
Sven van den Bosch, Wouter V Vogel, Cornelis P Raaijmakers, Tim Dijkema, Chris H J Terhaard, Abrahim Al-Mamgani, Johannes H A M Kaanders
Diagnostic imaging continues to evolve, and now has unprecedented accuracy for detecting small nodal metastasis. This influences the tumor load in elective target volumes and subsequently has consequences for the radiotherapy dose required to control disease in these volumes. Small metastases that used to remain subclinical and were included in elective volumes, will nowadays be detected and included in high-dose volumes. Consequentially, high-dose volumes will more often contain low-volume disease. These target volume transformations lead to changes in the tumor burden in elective and "gross" tumor volumes with implications for the radiotherapy dose prescribed to these volumes...
May 3, 2018: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
Yoshiyuki Katsuta, Noriyuki Kadoya, Yukio Fujita, Eiji Shimizu, Kazuhiro Majima, Haruo Matsushita, Ken Takeda, Keiichi Jingu
PURPOSE: The log file-based method cannot display dosimetric changes due to linac component miscalibration because of the insensitivity of log files to linac component miscalibration. The purpose of this study was to supply dosimetric changes in log file-based patient dose calculations for double-arc volumetric-modulated arc therapy (VMAT) in head-and-neck cases. METHODS AND MATERIALS: Fifteen head-and-neck cases participated in this study. For each case, treatment planning system (TPS) doses were produced by double-arc and single-arc VMAT...
April 2018: Physica Medica: PM
Drosoula Giantsoudi, Judith Adams, Shannon MacDonald, Harald Paganetti
PURPOSE: To investigate the effect of differences in linear energy transfer (LET) and thus the relative biological effectiveness (RBE) between passively scattered proton therapy (PS) and pencil-beam scanning intensity-modulated proton therapy (IMPT). METHODS: IMPT treatment plans were generated for six ependymoma patients, originally treated with PS, using the original plan's computed tomography image sets and beam directions, and its dose-volume values as optimization constraints...
May 4, 2018: Acta Oncologica
Rong Wang, Tingyang Zhou, Wei Liu, Li Zuo
Cancer cells subjected to ionizing radiation may release signals which can influence nearby non-irradiated cells, termed bystander effects. The transmission of bystander effects among cancer cells involves the activation of inflammatory cytokines, death ligands, and reactive oxygen/nitrogen species. In addition to bystander effects, two other forms of non-target effects (NTEs) have been identified in radiotherapy, as one is called cohort effects and the other is called abscopal effects. Cohort effects represent the phenomenon where irradiated cells can produce signals that reduce the survival of neighboring cells within an irradiated volume...
April 6, 2018: Oncotarget
Luigi Minafra, Valentina Bravatà, Francesco P Cammarata, Giorgio Russo, Maria C Gilardi, Giusi I Forte
BACKGROUND/AIM: In breast cancer (BC) care, radiation therapy (RT) is an efficient treatment to control localized tumor. Radiobiological research is needed to understand molecular differences that affect radiosensitivity of different tumor subtypes and the response variability. The aim of this study was to analyze gene expression profiling (GEP) in primary BC cells following irradiation with doses of 9 Gy and 23 Gy delivered by intraoperative electron radiation therapy (IOERT) in order to define gene signatures of response to high doses of ionizing radiation...
May 2018: Anticancer Research
Soumyajit Roy, Iulian Badragan, Sheikh Nisar Ahmed, Michael Sia, Jorawur Singh, Gaurav Bahl
PURPOSE: The purpose of this article was to generate an algorithm to calculate radiobiological endpoints and composite indices and use them to compare volumetric modulated arc therapy (VMAT) and 3-dimensional conformal radiation therapy (3D-CRT) techniques in patients with locally advanced non-small cell lung cancer. METHODS AND MATERIALS: The study included 25 patients with locally advanced non-small cell lung cancer treated with 3D-CRT at our center between January 1, 2010, and December 31, 2014...
March 1, 2018: Practical Radiation Oncology
Manjit Dosanjh, Bleddyn Jones, Jörg Pawelke, Martin Pruschy, Brita Singers Sørensen
Particle therapy (PT) as cancer treatment, using protons or heavier ions, can provide a more favorable dose distribution compared to X-rays. While the physical characteristics of particle radiation have been the aim of intense research, less focus has been placed on the actual biological responses arising from particle irradiation. One of the biggest challenges for proton radiobiology is the RBE, with an increasing concern that the clinically-applied generic RBE-value of 1.1 is an approximation, as RBE is a complex quantity, depending on both biological and physical parameters, such as dose, LET, cellular and tissue radiobiological characteristics, as well as the endpoints being studied...
April 24, 2018: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
M Dos Santos, V Paget, M Ben Kacem, F Trompier, M Benadjaoud, A François, O Guipaud, M Benderitter, F Milliat
PURPOSE: The main objective of radiobiology is to establish links between doses and radiation-induced biological effects. In this context, well-defined dosimetry protocols are crucial to the determination of experimental protocols. This work proposes a new dosimetry protocol for cell irradiation in a SARRP and shows the importance of the modification of some parameters defined in dosimetry protocol for physical dose and biological outcomes. MATERIALS AND METHODS: Once all parameters of the configuration were defined, dosimetry measurements with ionization chambers and EBT3 films were performed to evaluate the dose rate and the attenuation due to the cell culture medium...
April 27, 2018: International Journal of Radiation Biology
Jose Asuncion Ramos-Mendez, Joseph Perl, Jan Schuemann, Aimee Louise McNamara, Harald Paganetti, Bruce A Faddegon
Simulation of water radiolysis and the subsequent chemistry provides important information on the effect of ionizing radiation on biological material. The Geant4 Monte Carlo toolkit has added chemical processes via the Geant4-DNA project. The TOPAS tool simplifies the modeling of complex radiotherapy applications with Geant4 without requiring advanced computational skills, extending the pool of users. Thus, a new extension to TOPAS, TOPAS-nBio, is under development to facilitate the configuration of track-structure simulations as well as water radiolysis simulations with Geant4-DNA for radiobiological studies...
April 26, 2018: Physics in Medicine and Biology
George Sgouros, Robert Hobbs, Anders Josefsson
Radiopharmaceutical therapy is a cancer treatment modality by which radiation is delivered directly to targeted tumor cells or to their microenvironment. This makes it possible to deliver highly potent alpha-particle radiation. The short-range and highly potent nature of alpha-particles requires a dosimetry methodology that considers microscale distributions of the alpha-emitting agent. The high energy deposition density along an alpha-particle track causes a spectrum of DNA lesions. The majority of these are irreparable DNA double-stranded breaks...
April 26, 2018: Current Radiopharmaceuticals
V Y Kuperman
PURPOSE: to evaluate how protracted delivery of radiation affects radiobiological properties of hypofractionated radiotherapy. METHODS: the utilized approach is based on the concept of biologically effective dose (BED). The linear-quadratic model replete with a protraction factor is used to describe changes in biologically effective dose in normal tissue (BEDnt ) caused by varying number of fractions under the condition of fixed BED in the treatment target (BEDtar )...
April 25, 2018: Medical Physics
Ines-Ana Jurkovic, Esengul Kocak-Uzel, Abdallah Sherif Radwan Mohamed, Eleftherios Lavdas, Sotirios Stathakis, Nikos Papanikolaou, David C Fuller, Panayiotis Mavroidis
Introduction: This study evaluates treatment plans aiming at determining the expected impact of daily patient setup corrections on the delivered dose distribution and plan parameters in head-and-neck radiotherapy. Materials and Methods: In this study, 10 head-and-neck cancer patients are evaluated. For the evaluation of daily changes of the patient internal anatomy, image-guided radiation therapy based on computed tomography (CT)-on-rails was used. The daily-acquired CT-on-rails images were deformedly registered to the CT scan that was used during treatment planning...
January 2018: Journal of Medical Physics
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