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Piyali Chatterjee, Arup K Ghosh, Monoj Samanta, Tapas Chakraborty
Intermolecular proton transfer (IMPT) in a C-H∙∙∙O hydrogen bonded dimer of an α,β-unsaturated aldehyde, methacrolein (MC), upon non-resonant multi-photon ionization by 532 nm laser pulses (10 ns), has been investigated using time-of-flight (TOF) mass spectrometry under supersonic cooling condition. The mass peaks corresponding to both the protonated molecular ion [(MC)H+ ] and intact dimer cation [(MC)2 ].+ show up in the mass spectra, and the peak intensity of the former increases proportionately with the latter with the betterment of the jet cooling conditions...
June 7, 2018: Journal of Physical Chemistry. A
Daniel R Gomez, Heng Li, Joe Y Chang
In the setting of early-stage non-small cell lung cancer (NSCLC), defining the optimal clinical context for proton beam therapy (PBT) is challenging due to the increasing evidence demonstrating high rates of local control and good tolerance of stereotactic ablative body radiation (SABR). Given the relatively small percentage of lung and other critical structures treated with SABR, dosimetric studies comparing the two techniques have typically concluded that there are modest advantages to PBT, typically by reducing the low dose volumes, such as volume of lung receiving 5 Gy...
April 2018: Translational Lung Cancer Research
Thyrza Zeralda Jagt, Sebastiaan Breedveld, Rens van Haveren, Ben J M Heijmen, Mischa S Hoogeman
Proton therapy plans are very sensitive to anatomical changes such as density changes along the pencil-beam paths and changes in organ shape and location. Previously, we developed a restoration method which compensates for density changes along the pencil-beam paths but is unable to adapt for anatomical changes. This study's purpose is to develop and evaluate an automated method for adaptation of IMPT plans in near real-time to the anatomy of the day.
 We developed an automated treatment plan adaptation method using (1) a restoration of spot positions (Bragg peaks) by adapting the energies to the new water equivalent path lengths; and (2) a spot addition to fully cover the target of the day, followed by a fast Reference Point Method optimization of the spot weights resulting in a Pareto optimal plan for the daily anatomy...
June 6, 2018: Physics in Medicine and Biology
Jan Unkelbach, Harald Paganetti
Accurate prediction of tumor control and toxicities in radiation therapy faces many uncertainties. Besides interpatient variability in the response to radiation, there are also dosimetric uncertainties, that is, differences between the dose displayed in a treatment planning system and the dose actually delivered to the patient. These uncertainties originate from several sources including imperfect knowledge of the patient geometry, approximation in the physics of radiation interaction with tissues, and uncertainties in the biological effectiveness of radiation...
April 2018: Seminars in Radiation Oncology
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
Qijie Huang, Salma K Jabbour, Zhiyan Xiao, Ning Yue, Xiao Wang, Hongbin Cao, Yu Kuang, Yin Zhang, Ke Nie
BACKGROUND: The principle aim of this study is to incorporate 4DCT ventilation imaging into functional treatment planning that preserves high-functioning lung with both double scattering and scanning beam techniques in proton therapy. METHODS: Eight patients with locally advanced non-small-cell lung cancer were included in this study. Deformable image registration was performed for each patient on their planning 4DCTs and the resultant displacement vector field with Jacobian analysis was used to identify the high-, medium- and low-functional lung regions...
April 25, 2018: Radiation Oncology
Kinga Bernatowicz, Xavier Geets, Ana Barragan, Guillaume Janssens, Kevin Souris, Edmond Sterpin
Intensity-modulated proton therapy (IMPT) offers excellent dose conformity and healthy tissue sparing, but it can be substantially compromised in the presence of anatomical changes. A major dosimetric effect is caused by density changes, which alter the planned proton range in the patient. Three different methods, which automatically restore an IMPT plan dose on a daily CT image were implemented and compared: (1) simple dose restoration (DR) using optimization objectives of the initial plan, (2) voxel-wise dose restoration (vDR), and (3) isodose volume dose restoration (iDR)...
April 20, 2018: Physics in Medicine and Biology
Garrett L Jensen, Pierre Blanchard, G Brandon Gunn, Adam S Garden, C David Fuller, Erich M Sturgis, Maura L Gillison, Jack Phan, William H Morrison, David I Rosenthal, Steven J Frank
Introduction: Peripheral blood count components are accessible and evidently predictive in other cancers but have not been explored in oropharyngeal carcinoma. We examine if there is an association between the use of intensity-modulated radiotherapy (IMRT) or intensity-modulated proton therapy (IMPT) and lymphopenia, as well as if there is an association between baseline neutrophilia, baseline leukocytosis and lymphocyte nadir in oropharyngeal cancer. Materials and Methods: Analysis started with 150 patients from a previous case to case study design, which retrospectively identified adults with oropharyngeal carcinoma, 100 treated with IMRT in 2010-2012 and 50 treated with IMPT in 2011-2014...
December 2017: Clinical and Translational Radiation Oncology
Chenbin Liu, Steven E Schild, Joe Y Chang, Zhongxing Liao, Shawn Korte, Jiajian Shen, Xiaoning Ding, Yanle Hu, Yixiu Kang, Sameer R Keole, Terence T Sio, William W Wong, Narayan Sahoo, Martin Bues, Wei Liu
PURPOSE: To investigate how spot size and spacing affect plan quality, robustness, and interplay effects of robustly optimized intensity modulated proton therapy (IMPT) for lung cancer. METHODS AND MATERIALS: Two robustly optimized IMPT plans were created for 10 lung cancer patients: first by a large-spot machine with in-air energy-dependent large spot size at isocenter (σ: 6-15 mm) and spacing (1.3 σ), and second by a small-spot machine with in-air energy-dependent small spot size (σ: 2-6 mm) and spacing (5 mm)...
June 1, 2018: International Journal of Radiation Oncology, Biology, Physics
Xiaoqiang Li, Peyman Kabolizadeh, Di Yan, An Qin, Jun Zhou, Ye Hong, Thomas Guerrero, Inga Grills, Craig Stevens, Xuanfeng Ding
BACKGROUND: To evaluate spot-scanning proton arc therapy (SPArc) and multi-field robust optimized intensity modulated proton therapy (RO-IMPT) in treating stage III non-small-cell lung cancer (NSCLC) patients. METHODS: Two groups of stage IIIA or IIIB NSCLC patients (group 1: eight patients with tumor motion less than 5 mm; group 2: six patients with tumor motion equal to or more than 5 mm) were re-planned with SPArc and RO-IMPT. Both plans were generated using robust optimization to achieve an optimal coverage with 99% of internal target volume (ITV) receiving 66 Gy (RBE) in 33 fractions...
February 27, 2018: Radiation Oncology
Sung-Min Rhee, Nam Yun Chung, Hyeon Jang Jeong, Joo Han Oh
BACKGROUND: Subacromial pain pumps are used for analgesia after arthroscopic rotator cuff surgery. However, there is controversy about myotoxic or tendinotoxic effects of local anesthetics. HYPOTHESIS: Ropivacaine administered via a subacromial pain pump would have no adverse effect on rotator cuff tendon healing, fatty degeneration, strength, or functional outcomes after arthroscopic repair. STUDY DESIGN: Cohort study; Level of evidence, 3...
April 2018: American Journal of Sports Medicine
Lee C Goddard, N Patrik Brodin, William R Bodner, Madhur K Garg, Wolfgang A Tomé
OBJECTIVE: To investigate whether photon or proton-based stereotactic body radiation therapy (SBRT is the preferred modality for high dose hypofractionation prostate cancer treatment. Achievable dose distributions were compared when uncertainties in target positioning and range uncertainties were appropriately accounted for. METHODS: 10 patients with prostate cancer previously treated at our institution (Montefiore Medical Center) with photon SBRT using volumetric modulated arc therapy (VMAT) were identified...
May 2018: British Journal of Radiology
Wenbo Gu, Daniel O'Connor, Dan Nguyen, Victoria Y Yu, Dan Ruan, Lei Dong, Ke Sheng
PURPOSE: Intensity-Modulated Proton Therapy (IMPT) is the state-of-the-art method of delivering proton radiotherapy. Previous research has been mainly focused on optimization of scanning spots with manually selected beam angles. Due to the computational complexity, the potential benefit of simultaneously optimizing beam orientations and spot pattern could not be realized. In this study, we developed a novel integrated beam orientation optimization (BOO) and scanning-spot optimization algorithm for intensity-modulated proton therapy (IMPT)...
April 2018: Medical Physics
Jan Unkelbach, Mark Bangert, Karen De Amorim Bernstein, Nicolaus Andratschke, Matthias Guckenberger
PURPOSE: Proton treatment slots are a limited resource. Therefore, we consider combined proton-photon treatments in which most fractions are delivered with photons and only a few with protons. We demonstrate how both modalities can be combined to optimally capitalize on the proton's ability to reduce normal tissue dose. METHODS: An optimal combined treatment must account for fractionation effects. We therefore perform simultaneous optimization of intensity-modulated proton (IMPT) and photon (IMRT) plans based on their cumulative biologically effective dose (BED)...
January 19, 2018: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
Nirav K Patel, Morad Chughtai, Anton Khlopas, Chukwuweike Gwam, Nipun Sodhi, Assem A Sultan, Tanner McGinn, Anil Bhave, Jaydev B Mistry, Ronald E Delanois, Michael A Mont
INTRODUCTION: Knee stiffness following total knee arthroplasty (TKA) is a common complication, especially in obese patients. The initial, non-operative treatments for this complication includes splinting and physical therapy. If these measures fail, manipulation under anesthesia (MUA) or surgical exploration can be considered to restore range of motion (ROM). However, it is generally desirable to avoid these procedures. For these reasons, newer physical therapy protocols have been developed...
December 22, 2017: Surgical Technology International
Ulrike Kaiser, Christian Kopkow, Stefanie Deckert, Katrin Neustadt, Lena Jacobi, Paul Cameron, Valerio De Angelis, Christian Apfelbacher, Bernhard Arnold, Judy Birch, Anna Bjarnegård, Sandra Christiansen, Amanda C de C Williams, Gudrun Gossrau, Andrea Heinks, Michael Hüppe, Henri Kiers, Ursula Kleinert, Paolo Martelletti, Lance McCracken, Nelleke de Meij, Bernd Nagel, Jo Nijs, Heike Norda, Jasvinder A Singh, Ellen Spengler, Caroline B Terwee, Peter Tugwell, Johan W S Vlaeyen, Heike Wandrey, Edmund Neugebauer, Rainer Sabatowski, Jochen Schmitt
Interdisciplinary multimodal pain therapy (IMPT) is a biopsychosocial treatment approach for patients with chronic pain that comprises at least psychological and physiotherapeutic interventions. Core outcome sets (COSs) are currently developed in different medical fields to standardize and improve the selection of outcome domains, and measurement instruments in clinical trials, to make trial results meaningful, to pool trial results, and to allow indirect comparison between interventions. The objective of this study was to develop a COS of patient-relevant outcome domains for chronic pain in IMPT clinical trials...
April 2018: Pain
Melenda D Jeter, Daniel Gomez, Quynh-Nhu Nguyen, Ritsuko Komaki, Xiaodong Zhang, Xiaorong Zhu, Michael O'Reilly, Frank V Fossella, Ting Xu, Xiong Wei, Hui Wang, Wenjuan Yang, Anne Tsao, Radhe Mohan, Zhongxing Liao
PURPOSE: To establish, in the phase 1 portion of a prospective phase 1/2 study, the maximum tolerated dose of image guided intensity modulated radiation therapy (IMRT) or proton therapy (IMPT), both with a simultaneous integrated boost (SIB), for patients with stage II to IIIB non-small cell lung cancer receiving concurrent chemoradiation therapy. METHODS AND MATERIALS: Patients had pathologically proven non-small cell lung cancer, either unresectable stage II to IIIB disease or recurrent disease after surgical resection, and could tolerate concurrent chemoradiation...
March 1, 2018: International Journal of Radiation Oncology, Biology, Physics
Pablo Botas, Clemens Grassberger, Gregory Sharp, Harald Paganetti
The purpose of this study was to investigate internal tumor volume density overwrite strategies to minimize intensity modulated proton therapy (IMPT) plan degradation of mobile lung tumors. Four planning paradigms were compared for nine lung cancer patients. Internal gross tumor volume (IGTV) and internal clinical target volume (ICTV) structures were defined encompassing their respective volumes in every 4DCT phase. The paradigms use different planning CT (pCT) created from the average intensity projection (AIP) of the 4DCT, overwriting the density within the IGTV to account for movement...
January 30, 2018: Physics in Medicine and Biology
Jae Phan, Sweet Ping Ng, Courtney Pollard, Jack Phan
Adenoid cystic carcinoma (ACC) is generally treated with surgical resection followed by postoperative radiotherapy. In cases where surgical management is precluded due to the location of the tumor and/or patient factors, radiation therapy can be offered to achieve local control. Here, we present a case of unresectable Stage T4N0 ACC of the nasopharynx with skull base and intracranial extension treated with intensity modulated proton therapy (IMPT), which achieved good local control with no significant late toxicity...
September 15, 2017: Curēus
Keisuke Yasui, Toshiyuki Toshito, Chihiro Omachi, Kensuke Hayashi, Kenichiro Tanaka, Kumiko Asai, Akira Shimomura, Rie Muramatsu, Naoki Hayashi
In this study, we evaluate dosimetric advantages of using patient-specific aperture system with intensity-modulated proton therapy (IMPT) for head and neck tumors at the shallow depth. We used four types of patient-specific aperture system (PSAS) to irradiate shallow regions less than 4 g/cm2 with a sharp lateral penumbra. Ten head and neck IMPT plans with or without aperture were optimized separately with the same 95% prescription dose and same dose constraint for organs at risk (OARs). The plans were compared using dose volume histograms (DVHs), dose distributions, and some dose indexes such as volume receiving 50% of the prescribed dose (V50 ), mean or maximum dose (Dmean and Dmax ) to the OARs...
January 2018: Journal of Applied Clinical Medical Physics
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