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Radiation, proton therapy

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https://www.readbyqxmd.com/read/28410691/quantification-of-the-uncertainties-of-a-biological-model-and-their-impact-on-variable-rbe-proton-treatment-plan-optimization
#1
A F Resch, G Landry, F Kamp, G Cabal, C Belka, J J Wilkens, K Parodi, G Dedes
PURPOSE: In proton radiation therapy, a relative biological effectiveness (RBE) equal to 1.1 is currently assumed, although biological experiments show that it is not constant. The purpose of this study was to quantify the uncertainties of a published biological model and explore their impact on variable RBE treatment plan (TP) optimization. METHODS: Two patient cases with a high and a low (α/β)x tumor were investigated. Firstly, intensity modulated proton therapy TPs assuming constant RBE were derived, and subsequently the variable RBE weighted dose (RWD), including the uncertainty originating in the fit to the experimental data and the uncertainty of the (α/β)x, were calculated...
April 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28399342/uveal-melanoma-treatment-and-prognostication
#2
Mehmet Dogrusöz, Martine J Jager, Bertil Damato
Approximately 90% of uveal melanoma develop in the choroid, with the remainder arising in the ciliary body or the iris. The treatment of uveal melanoma is aimed at conserving the eye and useful vision, and, if possible, preventing metastatic disease. Enucleation is now reserved for tumors that are large and/or involve the optic disc, having largely been replaced by various forms of radiotherapy (plaque brachy-therapy, proton beam or stereotactic radiotherapy) and laser therapy. Whereas iridectomy and iridocyclectomy are widely performed, transscleral exoresection of choroidal tumors is performed only in a few centers because it requires special skills and hypotensive anesthesia...
March 2017: Asia-Pacific Journal of Ophthalmology
https://www.readbyqxmd.com/read/28392312/out-of-field-doses-in-radiotherapy-input-to-epidemiological-studies-and-dose-risk-models
#3
Roger Harrison
Out-of-field doses in radiotherapy have been increasingly studied in recent years because of the generally improved survival of patients who have received radiotherapy as part of their treatment for cancer and their subsequent risk of a second malignancy. This short article attempts to identify some current problems, challenges and opportunities for dosimetry developments in this field. Out-of-field doses and derived risk estimates contribute to general knowledge about radiation effects on humans as well as contributing to risk-benefit considerations for the individual patient...
April 6, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28385372/enrollment-of-elderly-patients-with-locally-advanced-non-small-cell-lung-cancer-in-multi-institutional-trials-of-proton-beam-radiation-therapy
#4
Vivek Verma, Jean-Claude M Rwigema, Sebastian Adeberg, Charles B Simone
No abstract text is available yet for this article.
March 16, 2017: Clinical Lung Cancer
https://www.readbyqxmd.com/read/28380636/the-role-of-image-guided-intensity-modulated-proton-therapy-in-glioma
#5
David R Grosshans, Radhe Mohan, Vinai Gondi, Helen A Shih, Anita Mahajan, Paul D Brown
Gliomas represent a broad spectrum of disease with life-expectancy outcomes ranging from months to decades. As our understanding of the molecular profiles of gliomas expands rapidly, practitioners are now better able to identify patients with favorable versus nonfavorable prognoses. Radiation therapy plays a key role in glioma treatment, improving disease control and oftentimes survival. However, for survivors, either long-term or short-term, radiation-induced cognitive impairments may negatively impact their quality of life...
April 1, 2017: Neuro-oncology
https://www.readbyqxmd.com/read/28379849/sparsity-constrained-split-feasibility-for-dose-volume-constraints-in-inverse-planning-of-intensity-modulated-photon-or-proton-therapy
#6
Scott Penfold, Rafał Zalas, Margherita Casiraghi, Mark Brooke, Yair Censor, Reinhard Schulte
A split feasibility formulation for the inverse problem of intensity-modulated radiation therapy treatment planning with dose-volume constraints included in the planning algorithm is presented. It involves a new type of sparsity constraint that enables the inclusion of a percentage-violation constraint in the model problem and its handling by continuous (as opposed to integer) methods. We propose an iterative algorithmic framework for solving such a problem by applying the feasibility-seeking CQ-algorithm of Byrne combined with the automatic relaxation method that uses cyclic projections...
April 5, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28370020/development-of-the-open-source-dose-calculation-and-optimization-toolkit-matrad
#7
Hans-Peter Wieser, Eduardo Cisternas, Niklas Wahl, Silke Ulrich, Alexander Stadler, Henning Mescher, Lucas-Raphael Müller, Thomas Klinge, Hubert Gabrys, Lucas Burigo, Mark Bangert, Andrea Mairani, Swantje Ecker, Benjamin Ackermann, Malte Ellerbrock, Katia Parodi, Oliver Jäkel
PURPOSE: We report on the development of the open-source cross-platform radiation treatment planning toolkit matRad and its comparison against validated treatment planning systems. The toolkit enables three-dimensional intensity-modulated radiation therapy treatment planning for photons, scanned protons and scanned carbon ions. METHODS: matRad is entirely written in Matlab and is freely available online. It re-implements well-established algorithms employing a modular and sequential software design to model the entire treatment planning workflow...
April 1, 2017: Medical Physics
https://www.readbyqxmd.com/read/28366554/comparative-study-of-the-calculated-risk-of-radiation-induced-cancer-after-photon-and-proton-beam-based-radiosurgery-of-liver-metastases
#8
Gracinda Mondlane, Michael Gubanski, Pehr A Lind, Ana Ureba, Albert Siegbahn
INTRODUCTION: The potential of proton therapy to improve the sparing of the healthy tissue has been demonstrated in several studies. However, even small doses delivered to the organs at risk (OAR) may induce long-term detriments after radiotherapy. In this study, we investigated the possibility to reduce the risk of radiation-induced secondary cancers with intensity modulated proton therapy (IMPT), when used for radiosurgery of liver metastases. MATERIAL AND METHODS: Ten patients, previously treated for liver metastases with photon-beam based stereotactic body radiation therapy (SBRT) were retrospectively planned for radiosurgery with IMPT...
March 30, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28366501/analysis-of-repeated-proton-beam-therapy-for-patients-with-hepatocellular-carcinoma
#9
Yoshiko Oshiro, Masashi Mizumoto, Toshiyuki Okumura, Kuniaki Fukuda, Nobuyoshi Fukumitsu, Masato Abei, Hitoshi Ishikawa, Daichi Takizawa, Hideyuki Sakurai
PURPOSE: To evaluate the feasibility and efficacy of repeated proton beam therapy (PBT) and to analyze the dose-volume relationship. PATIENTS AND METHODS: A retrospective analysis was performed in 83 patients who received definitive repeated PBT. Proton beams were delivered with expiratory gating. The numbers of treatment courses were 2, 3, and 4 in 68, 12, and 3 patients, respectively. MIM software was used for dose analysis. RESULTS: The planned median total dose was 70...
March 30, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/28365895/does-proton-therapy-have-a-future-in-cns-tumors
#10
REVIEW
Stephanie E Combs
Proton therapy is characterized by certain physical properties leading to a reduction in integral dose. As proton therapy becomes more widely available, the ongoing discussion on the real indications for proton therapy becomes more important. In the present article, data on proton therapy for tumors of the central nervous system (CNS) is summarized and discussed in view of modern photon treatments. Still today, no randomized controlled trials are available confirming any clinical benefit of protons in CNS tumors...
March 2017: Current Treatment Options in Neurology
https://www.readbyqxmd.com/read/28365241/adjuvant-ab-interno-tumor-treatment-after-proton-beam-irradiation
#11
Ira Seibel, Aline I Riechardt, Jens Heufelder, Dino Cordini, Antonia M Joussen
PURPOSE: This study was performed to show long-term outcomes concerning globe preservation in uveal melanoma patients after proton beam therapy with the main focus on outcomes according to different adjuvant ab interno surgical procedures. DESIGN: Retrospective cohort study METHODS: All patients treated with primary proton beam therapy for choroidal or ciliary body melanoma between June 1998 and June 2015 were included. RESULTS: A total of 2499 patients underwent primary proton beam therapy, with local tumor control and globe preservation rates of 95...
March 29, 2017: American Journal of Ophthalmology
https://www.readbyqxmd.com/read/28350950/spine-oncology-metastatic-spine-tumors
#12
David Choi, Mark Bilsky, Michael Fehlings, Charles Fisher, Ziya Gokaslan
Surgery for spinal metastases remains the mainstay treatment for pain, instability, and neurological deterioration due to tumor infiltration of the spine. However, several new therapies are emerging which may improve outcomes further, and in some cases even replace the need for surgery. We now have a better understanding of which factors influence survival and quality of life after surgery, and this underpins the development and application of new treatments, and assessment of outcome.Depending on genetic subtyping of tumors, novel immunotherapies and chemotherapies may be very effective in prolonging quality of life...
March 1, 2017: Neurosurgery
https://www.readbyqxmd.com/read/28341320/gallbladder-toxicity-and-high-dose-ablative-intent-radiation-for-liver-tumors-should-we-constrain-the-dose
#13
Shyam K Tanguturi, Andrzej Niemierko, Jennifer Y Wo, Khanhnhat N Nguyen, Hugh Prichard, Andrew X Zhu, John A Wolfgang, Theodore S Hong
PURPOSE: Little is known about the risk of gallbladder toxicity from hypofractionated (HFXRT) and stereotactic body radiation therapy (SBRT). We report on gallbladder toxicity and attribution to treatment in a prospective series of patients with primary and metastatic liver tumors receiving ablative-intent HFXRT and SBRT with protons. METHODS AND MATERIALS: We evaluated 93 patients with intact gallbladders enrolled in either of 2 trials investigating proton HFXRT and SBRT for primary and metastatic liver tumors from 2009 to 2014...
February 9, 2017: Practical Radiation Oncology
https://www.readbyqxmd.com/read/28341315/initial-clinical-experience-of-postmastectomy-intensity-modulated-proton-therapy-in-patients-with-breast-expanders-with-metallic-ports
#14
Robert W Mutter, Nicholas B Remmes, Mohamed Mh Kahila, Kathy A Hoeft, Deanna H Pafundi, Yan Zhang, Kimberly S Corbin, Sean S Park, Elizabeth S Yan, Valerie Lemaine, Judy C Boughey, Chris J Beltran
PURPOSE: The feasibility of proton postmastectomy radiation therapy in patients reconstructed with expanders has not been previously reported, limiting treatment options. We analyzed the dosimetric impact of the metallic port contained within expanders on intensity modulated proton therapy (IMPT) and report our techniques and quality control for treating patients in this setting. METHODS AND MATERIALS: Twelve patients with the same expander model underwent 2-field IMPT as part of a prospective registry...
December 16, 2016: Practical Radiation Oncology
https://www.readbyqxmd.com/read/28341297/geant4-models-for-the-secondary-radiation-flux-in-the-collimation-system-of-a-300mev-proton-microbeam
#15
Yanxin Dou, David N Jamieson, Jianli Liu, Anlong Li, Liyi Li
In Harbin, we are developing a 300MeV proton microbeam for many applications in space science including upset studies in microelectronic devices, radiation hardness of materials for satellites and radiation effects in human tissues. There are also applications of this facility proposed for proton therapy. The microbeam system will employ a purpose-built proton synchrotron to provide the beam. However there are many challenges to be addressed in the design, construction and operation of this facility. Here we address two important design aspects for which we apply GEANT4 modeling...
December 2016: Physica Medica: PM
https://www.readbyqxmd.com/read/28339108/very-high-energy-electron-vhee-beams-in-radiation-therapy-treatment-plan-comparison-between-vhee-vmat-and-ppbs
#16
Emil Schüler, Kjell Eriksson, Elin Hynning, Steven L Hancock, Susan M Hiniker, Magdalena Bazalova-Carter, Tony Wong, Quynh-Thu Le, Billy W Loo, Peter G Maxim
PURPOSE: The aim of this study was to evaluate the performance of very high energy electron beams (VHEE) beams in comparison to clinically derived treatment plans generated with volumetric modulated arc therapy (VMAT) and proton pencil beam scanning (PPBS) technology. We developed a custom optimization script that could be applied automatically across modalities to eliminate operator bias during IMRT optimization. METHODS: Four clinical cases were selected (prostate cancer, lung cancer, pediatric brain tumor, and head and neck cancer (HNC))...
March 24, 2017: Medical Physics
https://www.readbyqxmd.com/read/28338373/risk-of-major-cardiac-events-following-adjuvant-proton-versus-photon-radiation-therapy-for-patients-with-thymic-malignancies
#17
Jennifer Vogel, Liyong Lin, Charles B Simone, Abigail T Berman
BACKGROUND: While often managed with surgery alone, patients with thymic malignancies with high-risk features may benefit from adjuvant radiation therapy but are at risk for late toxicities. Previously, the risk of major cardiac events (MCEs) was reported to increase by 7% per one Gray (Gy) to the heart. In this study, we compare dose to organs at risk (OARs) with intensity-modulated (IMRT) versus proton beam therapy (PBT). We hypothesize a decrease risk of predicted MCEs with PBT. MATERIAL AND METHODS: Patients requiring adjuvant therapy for thymic malignancies were treated with double scattered proton beam therapy (DS-PBT)...
March 24, 2017: Acta Oncologica
https://www.readbyqxmd.com/read/28333688/treatment-planning-of-intensity-modulated-composite-particle-therapy-with-dose-and-linear-energy-transfer-optimization
#18
Taku Inaniwa, Nobuyuki Kanematsu, Koji Noda, Tadashi Kamada
The biological effect of charged-particle beams depends on both dose and radiation quality. The radiation quality of charged-particle beams has been most commonly represented by the linear energy transfer (LET) in radiation biology studies. We investigated a new therapeutic technique using two or more ion species in one treatment session, which we call an Intensity Modulated composite PArtiCle Therapy (IMPACT), for optimizing the physical dose and dose-averaged LET distributions in a patient as its proof of principle...
March 23, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28321635/relative-biological-effectiveness-in-a-proton-spread-out-bragg-peak-formed-by-pencil-beam-scanning-mode
#19
Anna Michaelidesová, Jana Vachelová, Monika Puchalska, Kateřina Pachnerová Brabcová, Vladimír Vondráček, Lembit Sihver, Marie Davídková
In recent years, there is an increased interest in using scanning modes in proton therapy, due to the more conformal dose distributions, thanks to the spot-weighted dose delivery. The dose rate in each spot is however much higher than the dose rate when using passive irradiation modes, which could affect the cell response. The purpose of this work was to investigate how the relative biological effectiveness changes along the spread-out Bragg peak created by protons delivered by the pencil beam scanning mode...
March 20, 2017: Australasian Physical & Engineering Sciences in Medicine
https://www.readbyqxmd.com/read/28302921/deciphering-the-acute-cellular-phosphoproteome-response-to-irradiation-with-x-rays-protons-and-carbon-ions
#20
Martin Winter, Ivana Dokic, Julian Schlegel, Uwe Warnken, Jürgen Debus, Amir Abdollahi, Martina Schnölzer
Radiotherapy is a cornerstone of cancer therapy. The recently established particle therapy with raster-scanning protons and carbon ions landmarks a new era in the field of high-precision cancer medicine. However, molecular mechanisms governing radiation induced intracellular signaling remain elusive. Here, we present the first comprehensive proteomic and phosphoproteomic study applying stable isotope labeling by amino acids in cell culture (SILAC) in combination with high-resolution mass spectrometry to decipher cellular response to irradiation with X-rays, protons and carbon ions...
March 16, 2017: Molecular & Cellular Proteomics: MCP
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