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Proton beam therapy

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https://www.readbyqxmd.com/read/28304223/metastatic-clival-chordoma-a-case-report-of-multiple-extraneural-metastases-following-resection-and-proton-beam-radiotherapy-in-a-5-year-old-boy
#1
Martin J Rutkowski, Harjus S Birk, Matthew D Wood, Arie Perry, Theodore Nicolaides, Christopher P Ames, Nalin Gupta
The authors report the case of a 5-year-old boy in whom extraneural metastases developed 5 years after he underwent an occipitocervical fusion and transoral approach to treat a clival chordoma without local recurrence. Following primary resection, the patient's postoperative course was complicated by recurrent meningitis secondary to CSF leak, which responded to antibiotics, and communicating hydrocephalus, for which a ventriculoperitoneal shunt was placed. The patient then underwent postoperative proton beam radiotherapy...
March 17, 2017: Journal of Neurosurgery. Pediatrics
https://www.readbyqxmd.com/read/28300385/a-benchmarking-method-to-evaluate-the-accuracy-of-a-commercial-proton-monte-carlo-pencil-beam-scanning-treatment-planning-system
#2
Liyong Lin, Sheng Huang, Minglei Kang, Petri Hiltunen, Reynald Vanderstraeten, Jari Lindberg, Sami Siljamaki, Todd Wareing, Ian Davis, Allen Barnett, John McGhee, Charles B Simone, Timothy D Solberg, James E McDonough, Christopher Ainsley
AcurosPT is a Monte Carlo algorithm in the Eclipse 13.7 treatment planning system, which is designed to provide rapid and accurate dose calculations for proton therapy. Computational run-time in minimized by simplifying or eliminating less significant physics processes. In this article, the accuracy of AcurosPT was benchmarked against both measurement and an independent MC calculation, TOPAS. Such a method can be applied to any new MC calculation for the detection of potential inaccuracies. To validate multiple Coulomb scattering (MCS) which affects primary beam broadening, single spot profiles in a Solidwater(®) phantom were compared for beams of five selected proton energies between AcurosPT, measurement and TOPAS...
March 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28297453/spot-scanning-proton-therapy-minimizes-neutron-dose-in-the-setting-of-radiation-therapy-administered-during-pregnancy
#3
Xin Wang, Falk Poenisch, Narayan Sahoo, Ronald X Zhu, MingFwu Lii, Michael T Gillin, Jing Li, David Grosshans
This is a real case study to minimize the neutron dose equivalent (H) to a fetus using spot scanning proton beams with favorable beam energies and angles. Minimum neutron dose exposure to the fetus was achieved with iterative planning under the guidance of neutron H measurement. Two highly conformal treatment plans, each with three spot scanning beams, were planned to treat a 25-year-old pregnant female with aggressive recurrent chordoma of the base of skull who elected not to proceed with termination. Each plan was scheduled for delivery every other day for robust target coverage...
September 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28295434/the-potential-of-dual-energy-ct-to-reduce-proton-beam-range-uncertainties
#4
Esther Bär, Arthur Lalonde, Gary Royle, Hsiao-Ming Lu, Hugo Bouchard
PURPOSE: Dual-energy CT (DECT) promises improvements in estimating stopping power ratios (SPRs) for proton therapy treatment planning. Although several comparable mathematical formalisms have been proposed in literature, the optimal techniques to characterize human tissue SPRs with DECT in a clinical environment are not fully established. The aim of this work is to compare the most robust DECT methods against conventional single-energy CT (SECT) in conditions reproducing a clinical environment, where CT artifacts and noise play a major role on the accuracy of these techniques...
March 15, 2017: Medical Physics
https://www.readbyqxmd.com/read/28294362/systematic-out-of-field-secondary-neutron-spectrometry-and-dosimetry-in-pencil-beam-scanning-proton-therapy
#5
Sebastian Trinkl, Vladimir Mares, Franz Siegfried Englbrecht, Jan Jakob Wilkens, Marek Wielunski, Katia Parodi, Werner Rühm, Martin Hillbrand
BACKGROUND AND PURPOSE: Systematic investigation of the energy and angular dependence of secondary neutron fluence energy distributions and ambient dose equivalents values (H*(10)) inside a pencil beam scanning proton therapy treatment room using a gantry. MATERIAL AND METHODS: Neutron fluence energy distributions were measured with an extended-range Bonner sphere spectrometer featuring ³He proportional counters, at four positions at 0°, 45°, 90° and 135° with respect to beam direction and at a distance of 2 m from the isocenter...
March 11, 2017: Medical Physics
https://www.readbyqxmd.com/read/28291917/rectal-dose-to-prostate-cancer-patients-treated-with-proton-therapy-with-or-without-rectal-spacer
#6
Heeteak Chung, Jerimy Polf, Shahed Badiyan, Matthew Biagioli, Daniel Fernandez, Kujtim Latifi, Richard Wilder, Minesh Mehta, Michael Chuong
The purpose of this study was to evaluate whether a spacer inserted in the prerectal space could reduce modeled rectal dose and toxicity rates for patients with prostate cancer treated in silico with pencil beam scanning (PBS) proton therapy. A total of 20 patients were included in this study who received photon therapy (12 with rectal spacer (DuraSeal™ gel) and 8 without). Two PBS treatment plans were retrospectively created for each patient using the following beam arrangements: (1) lateral-opposed (LAT) fields and (2) left and right anterior oblique (LAO/RAO) fields...
January 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28288384/bulk-production-and-evaluation-of-high-specific-activity-186g-re-for-cancer-therapy-using-enriched-186-wo3-targets-in-a-proton-beam
#7
Tara Mastren, Valery Radchenko, Hong T Bach, Ethan R Balkin, Eva R Birnbaum, Mark Brugh, Jonathan W Engle, Matthew D Gott, James Guthrie, Heather M Hennkens, Kevin D John, Alan R Ketring, Marina Kuchuk, Joel R Maassen, Cleo M Naranjo, F Meiring Nortier, Tim E Phelps, Silvia S Jurisson, D Scott Wilbur, Michael E Fassbender
INTRODUCTION: Rhenium-186g (t1/2 = 3.72 d) is a β(-) emitting isotope suitable for theranostic applications. Current production methods rely on reactor production by way of the reaction (185)Re(n,γ)(186g)Re, which results in low specific activities limiting its use for cancer therapy. Production via charged particle activation of enriched (186)W results in a (186g)Re product with a higher specific activity, allowing it to be used more broadly for targeted radiotherapy applications. This targets the unmet clinical need for more efficient radiotherapeutics...
March 3, 2017: Nuclear Medicine and Biology
https://www.readbyqxmd.com/read/28283192/supine-craniospinal-irradiation-in-pediatric-patients-by-proton-pencil-beam-scanning
#8
Paolo Farace, Nicola Bizzocchi, Roberto Righetto, Francesco Fellin, Francesco Fracchiolla, Stefano Lorentini, Lamberto Widesott, Carlo Algranati, Barbara Rombi, Sabina Vennarini, Maurizio Amichetti, Marco Schwarz
BACKGROUND AND PURPOSE: Proton therapy is the emerging treatment modality for craniospinal irradiation (CSI) in pediatric patients. Herein, special methods adopted for CSI at proton Therapy Center of Trento by pencil beam scanning (PBS) are comprehensively described. MATERIALS AND METHODS: Twelve pediatric patients were treated by proton PBS using two/three isocenters. Special methods refer to: (i) patient positioning in supine position on immobilization devices crossed by the beams; (ii) planning field-junctions via the ancillary-beam technique; (iii) achieving lens-sparing by three-beams whole-brain-irradiation; (iv) applying a movable-snout and beam-splitting technique to reduce the lateral penumbra...
March 7, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/28281862/model-based-approach-for-quantitative-estimates-of-skin-heart-and-lung-toxicity-risk-for-left-side-photon-and-proton-irradiation-after-breast-conserving-surgery
#9
Francesco Tommasino, Marco Durante, Vittoria D'Avino, Raffaele Liuzzi, Manuel Conson, Paolo Farace, Giuseppe Palma, Marco Schwarz, Laura Cella, Roberto Pacelli
BACKGROUND: Proton beam therapy represents a promising modality for left-side breast cancer (BC) treatment, but concerns have been raised about skin toxicity and poor cosmesis. The aim of this study is to apply skin normal tissue complication probability (NTCP) model for intensity modulated proton therapy (IMPT) optimization in left-side BC. MATERIAL AND METHODS: Ten left-side BC patients undergoing photon irradiation after breast-conserving surgery were randomly selected from our clinical database...
March 10, 2017: Acta Oncologica
https://www.readbyqxmd.com/read/28281357/comparison-of-gastric-cancer-radiotherapy-performed-with-volumetric-modulated-arc-therapy-or-single-field-uniform-dose-proton-therapy
#10
Gracinda Mondlane, Michael Gubanski, Pehr A Lind, Ana Ureba, Albert Siegbahn
BACKGROUND: Proton-beam therapy of large abdominal cancers has been questioned due to the large variations in tissue density in the abdomen. The aim of this study was to evaluate the importance of these variations for the dose distributions produced in adjuvant radiotherapy of gastric cancer (GC), implemented with photon-based volumetric modulated arc therapy (VMAT) or with proton-beam single-field uniform-dose (SFUD) method. MATERIAL AND METHODS: Eight GC patients were included in this study...
March 10, 2017: Acta Oncologica
https://www.readbyqxmd.com/read/28273345/feasibility-study-of-using-fall-off-gradients-of-early-and-late-pet-scans-for-proton-range-verification
#11
Jongmin Cho, Kira Grogg, Chul Hee Min, Xuping Zhu, Harald Paganetti, Hyun Cheol Lee, Georges El Fakhri
PURPOSE: While positron emission tomography (PET) allows for the imaging of tissues activated by proton beams in terms of monitoring the therapy administered, most endogenous tissue elements are activated by relatively high energy protons. Therefore, a relatively large distance off-set exists between the dose fall-off and activity fall-off. However, (16) O(p,2p,2n)(13) N has a relatively low energy threshold which peaks around 12 MeV and also a residual proton range that is approximately 1 to 2 mm...
March 8, 2017: Medical Physics
https://www.readbyqxmd.com/read/28270731/guideline-for-radiotherapy-with-curative-intent-in-patients-with-early-stage-medically-inoperable-non-small-cell-lung-cancer
#12
C B Falkson, E T Vella, E Yu, M El-Mallah, R Mackenzie, P M Ellis, Y C Ung
OBJECTIVES: For this guideline, we investigated the effectiveness of radiotherapy with curative intent in medically inoperable patients with early-stage non-small-cell lung cancer (nsclc). METHODS: The guideline was developed by Cancer Care Ontario's Program in Evidence-Based Care and by the Lung Cancer Disease Site Group through a systematic review of mainly retrospective studies, expert consensus, and formal internal and external reviews. RECOMMENDATIONS: ■ Stereotactic body radiation therapy (sbrt) with curative intent is an option that should be considered for patients with early-stage, node-negative, medically inoperable nsclc...
February 2017: Current Oncology
https://www.readbyqxmd.com/read/28267208/progression-free-survival-of-children-with-localized-ependymoma-treated-with-intensity-modulated-radiation-therapy-or-proton-beam-radiation-therapy
#13
Mariko Sato, Jillian R Gunther, Anita Mahajan, Eunji Jo, Arnold C Paulino, Adekunle M Adesina, Jeremy Y Jones, Leena M Ketonen, Jack M Su, M Fatih Okcu, Soumen Khatua, Robert C Dauser, William E Whitehead, Jeffrey Weinberg, Murali M Chintagumpala
BACKGROUND: The treatment for childhood intracranial ependymoma includes maximal surgical resection followed by involved-field radiotherapy, commonly in the form of intensity-modulated radiation therapy (IMRT). Proton-beam radiation therapy (PRT) is used at some centers in an effort to decrease long-term toxicity. Although protons have the theoretical advantage of a minimal exit dose to the surrounding uninvolved brain tissue, it is unknown whether they have the same efficacy as photons in preventing local recurrence...
March 7, 2017: Cancer
https://www.readbyqxmd.com/read/28258888/using-proton-beam-therapy-in-the-elderly-population-a-snapshot-of-current-perception-and-practice
#14
Juliette Thariat, Terence Sio, Pierre Blanchard, Samir Patel, Yusuke Demizu, Federico Ampil, Sebastien Guihard, Robert C Miller, Ulf Karlsson, Marco Krengli, Huan Giap, Nam Nguyen
PURPOSE: With limited proton therapy (PT) resources, several centers have designed their own decision-making systems for PT slot prioritization. The pediatric population is well recognized for deriving benefits from PT; however, elderly patients are not a focus for PT. When should PT be considered for use in the elderly population? METHODS AND MATERIALS: We performed a pilot survey of 25 international academic radiation oncologists (ROs) who also spend significant amounts of clinical time caring for elderly patients...
January 6, 2017: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/28252445/comparing-the-dosimetric-impact-of-interfractional-anatomical-changes-in-photon-proton-and-carbon-ion-radiotherapy-for-pancreatic-cancer-patients
#15
Antonetta Christina Houweling, Koen Crama, Jorrit Visser, Kyohei Fukata, Coen Rasch, Tatsuya Ohno, Arjan Bel, Astrid van der Horst
Radiotherapy using charged particles is characterized by a low dose to the surrounding healthy organs, while delivering a high dose to the tumor. However, interfractional anatomical changes can greatly affect the robustness of particle therapy. Therefore, we compared the dosimetric impact of interfractional anatomical changes (i.e. body contour differences and gastrointestinal gas volume changes) in photon, proton and carbon ion therapy for pancreatic cancer patients. In this retrospective planning study, photon, proton and carbon ion treatment plans were created for 9 patients...
March 2, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28244411/joint-estimation-of-cardiac-toxicity-and-recurrence-risks-after-comprehensive-nodal-photon-versus-proton-therapy-for-breast-cancer
#16
Line B Stick, Jen Yu, Maja V Maraldo, Marianne C Aznar, Anders N Pedersen, Søren M Bentzen, Ivan R Vogelius
PURPOSE: The study aims to perform joint estimation of the risk of recurrence caused by inadequate radiation dose coverage of lymph node targets and the risk of cardiac toxicity caused by radiation exposure to the heart. Delivered photon plans are compared with realistic proton plans, thereby providing evidence-based estimates of the heterogeneity of treatment effects in consecutive cases for the 2 radiation treatment modalities. METHODS AND MATERIALS: Forty-one patients referred for postlumpectomy comprehensive nodal photon irradiation for left-sided breast cancer were included...
March 15, 2017: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/28240218/an-anthropomorphic-breathing-phantom-of-the-thorax-for-testing-new-motion-mitigation-techniques-for-pencil-beam-scanning-proton-therapy
#17
R L Perrin, M Zakova, M Peroni, K Bernatowicz, C Bikis, A K Knopf, S Safai, P Fernandez-Carmona, N Tscharner, D C Weber, T C Parkel, A J Lomax
Motion-induced range changes and incorrectly placed dose spots strongly affect the quality of pencil-beam-scanned (PBS) proton therapy, especially in thoracic tumour sites, where density changes are large. Thus motion-mitigation techniques are necessary, which must be validated in a realistic patient-like geometry. We report on the development and characterisation of a dynamic, anthropomorphic, thorax phantom that can realistically mimic thoracic motions and anatomical features for verifications of proton and photon 4D treatments...
March 21, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28237409/water-equivalent-thickness-of-immobilization-devices-in-proton-therapy-planning-modelling-at-treatment-planning-and-validation-by-measurements-with-a-multi-layer-ionization-chamber
#18
Francesco Fellin, Roberto Righetto, Giovanni Fava, Diego Trevisan, Dante Amelio, Paolo Farace
PURPOSE: To investigate the range errors made in treatment planning due to the presence of the immobilization devices along the proton beam path. METHODS: The measured water equivalent thickness (WET) of selected devices was measured by a high-energy spot and a multi-layer ionization chamber and compared with that predicted by treatment planning system (TPS). Two treatment couches, two thermoplastic masks (both un-stretched and stretched) and one headrest were selected...
February 22, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28236644/theoretical-dosimetric-evaluation-of-carbon-and-oxygen-minibeam-radiation-therapy
#19
Wilfredo González, Cécile Peucelle, Yolanda Prezado
PURPOSE: Charged particles have several advantages over x-rays radiations, both in terms of physics and radiobiology. The combination of these advantages with those of minibeam radiation therapy (MBRT) could help enhancing the therapeutic index for some cancers with poor prognosis. Among the different ions explored for therapy, carbon ions are considered to provide the optimum physical and biological characteristics. Oxygen could be advantageous due to a reduced oxygen enhancement ratio along with a still moderate biological entrance dose...
February 25, 2017: Medical Physics
https://www.readbyqxmd.com/read/28228150/a-comparative-study-of-dose-distribution-of-pbt-3d-crt-and-imrt-for-pediatric-brain-tumors
#20
Daichi Takizawa, Masashi Mizumoto, Tetsuya Yamamoto, Yoshiko Oshiro, Hiroko Fukushima, Takashi Fukushima, Toshiyuki Terunuma, Toshiyuki Okumura, Koji Tsuboi, Hideyuki Sakurai
INTRODUCTION: It was reported that proton beam therapy (PBT) reduced the normal brain dose compared with X-ray therapy for pediatric brain tumors. We considered whether there was not the condition that PBT was more disadvantageous than intensity modulated photon radiotherapy (IMRT) and 3D conventional radiotherapy (3D-CRT) for treatment of pediatric brain tumors about the dose reduction for the normal brain when the tumor location or tumor size were different. METHODS: The subjects were 12 patients treated with PBT at our institute, including 6 cases of ependymoma treated by local irradiation and 6 cases of germinoma treated by irradiation of all four cerebral ventricles...
February 22, 2017: Radiation Oncology
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