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Krista C J Wink, Erik Roelofs, Charles B Simone, David Dechambre, Alina Santiago, Judith van der Stoep, Wim Dries, Julia Smits, Stephen Avery, Filippo Ammazzalorso, Nicolas Jansen, Urszula Jelen, Timothy Solberg, Dirk de Ruysscher, Esther G C Troost
PURPOSE: To compare dose to organs at risk (OARs) and dose-escalation possibility for 24 stage I non-small cell lung cancer (NSCLC) patients in a ROCOCO (Radiation Oncology Collaborative Comparison) trial. METHODS: For each patient, 3 photon plans [Intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT) and CyberKnife], a double scattered proton (DSP) and an intensity-modulated carbon-ion (IMIT) therapy plan were created. Dose prescription was 60 Gy (equivalent) in 8 fractions...
March 12, 2018: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
Krzysztof Slosarek, Barbara Bekman, Jacek Wendykier, Aleksandra Grządziel, Antonella Fogliata, Luca Cozzi
BACKGROUND: To appraise the dosimetric features and the quality of the treatment plan for radiosurgery of multiple brain metastases optimized with a novel automated engine and to compare with plans optimized for robotic-based delivery. METHODS: A set of 15 patients with multiple brain metastases was selected for this in silico study. The technique under investigation is the recently introduced HyperArc. For all patients, three treatment plans were computed and compared: i: a HyperArc; ii: a standard VMAT; iii) a CyberKnife...
March 15, 2018: Radiation Oncology
Atallah Baydoun, Neha Vapiwala, Lee E Ponsky, Musaddiq Awan, Ali Kassaee, David Sutton, Tarun K Podder, Yuxia Zhang, Donald Dobbins, Raymond F Muzic, Bryan Traughber, Mitchell Machtay, Rodney Ellis
PURPOSE: We conducted this dosimetric analysis to evaluate the feasibility of a multi-center stereotactic body radiation therapy (SBRT) trial for renal cell carcinoma (RCC) using different SBRT platforms. MATERIALS/METHODS: The computed tomography (CT) simulation images of 10 patients with unilateral RCC previously treated on a Phase 1 trial at Institution 1 were anonymized and shared with Institution 2 after IRB approval. Treatment planning was generated through five different platforms aiming a total dose of 48 Gy in three fractions...
March 14, 2018: Journal of Applied Clinical Medical Physics
Keisuke Usui, Keisuke Sasai, Koichi Ogawa
This study aimed to verify the validity of generating treatment plans for volumetric arc therapy (VMAT) for prostate cancer using magnetic resonance (MR) imaging with a dose calculation algorithm in Acuros XB (Eclipse version 13.6; Varian Medical Systems, Palo Alto, CA, USA) based on deterministically solving the linear Boltzmann transport equations. Four different classes were applied to prostate MR images: MRW (all water equivalent); MRW+B (water and bone); MRS+B (soft tissue and bone); and MRS+B+G (soft tissue, bone, and rectal gas)...
March 14, 2018: Radiological Physics and Technology
David M Edmunds, Lone Gothard, Komel Khabra, Anna Kirby, Poonam Madhale, Helen McNair, David Roberts, K K Tang, Richard Symonds-Tayler, Fatemeh Tahavori, Kevin Wells, Ellen Donovan
Voluntary inspiration breath hold (VIBH) for left breast cancer patients has been shown to be a safe and effective method of reducing radiation dose to the heart. Currently, VIBH protocol compliance is monitored visually. In this work, we establish whether it is possible to gate the delivery of radiation from an Elekta linac using the Microsoft Kinect version 2 (Kinect v2) depth sensor to measure a patient breathing signal. This would allow contactless monitoring during VMAT treatment, as an alternative to equipment-assisted methods such as active breathing control (ABC)...
March 13, 2018: Journal of Applied Clinical Medical Physics
Yuji Nakaguchi, Takeshi Oono, Masato Maruyama, Yoshinobu Shimohigashi, Yudai Kai, Yuya Nakamura
In this study, we evaluated the basic performance of the three-dimensional dose verification system COMPASS (IBA Dosimetry). This system is capable of reconstructing 3D dose distributions on the patient anatomy based on the fluence measured using a new transmission detector (Dolphin, IBA Dosimetry) during treatment. The stability of the absolute dose and geometric calibrations of the COMPASS system with the Dolphin detector were investigated for fundamental validation. Furthermore, multileaf collimator (MLC) test patterns and a complicated volumetric modulated arc therapy (VMAT) plan were used to evaluate the accuracy of the reconstructed dose distributions determined by the COMPASS...
March 12, 2018: Radiological Physics and Technology
Xin Zhang, Yi Rong, Steven Morrill, Jian Fang, Ganesh Narayanasamy, Edvaldo Galhardo, Sanjay Maraboyina, Christopher Croft, Fen Xia, Jose Penagaricano
Robust optimization generates scenario-based plans by a minimax optimization method to find optimal scenario for the trade-off between target coverage robustness and organ-at-risk (OAR) sparing. In this study, 20 lung cancer patients with tumors located at various anatomical regions within the lungs were selected and robust optimization photon treatment plans including intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) plans were generated. The plan robustness was analyzed using perturbed doses with setup error boundary of ±3 mm in anterior/posterior (AP), ±3 mm in left/right (LR), and ±5 mm in inferior/superior (IS) directions from isocenter...
March 10, 2018: Journal of Applied Clinical Medical Physics
Hendrik Ballhausen, Minglun Li, Ute Ganswindt, Claus Belka
PURPOSE: To evaluate the impact of shorter treatment times on intra-fractional motion of the prostate during external beam radiotherapy. METHODS: 53 h of intra-fractional motion of the prostate were recorded in real-time by 4D ultrasound (4DUS) during 720 fractions in 28 patients, 14 of which whom treated with step-and-shoot intensity-modulated radiotherapy (IMRT) and 14 of whom were treated with volumetric arc therapy (VMAT). RESULTS: The average VMAT fraction was recorded for 2 min 43 s and was substantially shorter than the average step-and-shoot IMRT fraction at 6 min 13 s...
March 9, 2018: Strahlentherapie und Onkologie: Organ der Deutschen Röntgengesellschaft ... [et Al]
Michael Chao, Huong Ho, Yee Chan, Alwin Tan, Trung Pham, Damien Bolton, Andrew Troy, Catherine Temelcos, Shomik Sengupta, Kevin McMillan, Chee Wee Cham, Madalena Liu, Wei Ding, Brindha Subramanian, Jason Wasiak, Daryl Lim Joon, Sandra Spencer, Nathan Lawrenstchuk
OBJECTIVE: The purpose of this study was to report on the dosimetric benefits and late toxicity outcomes following injection of a hydrogel spacer (HS) between the prostate and rectum for patients treated with prostate radiotherapy. METHODS: A total of 76 patients with a clinical stage of T1-T3a prostate cancer underwent general anaesthesia for fiducial marker insertion plus injection of the HS into the peri-rectal space prior to intensity modulated radiation therapy (IMRT) or volumetric modulated radiation therapy (VMAT)...
March 9, 2018: BJU International
Manindra Bhushan, Girigesh Yadav, Deepak Tripathi, Lalit Kumar, Vimal Kishore, Abhinav Dewan, Gourav Kumar, Inderjit Kaur Wahi, Munish Gairola
PURPOSE: To evaluate the feasibility of flattening filter free beam (FFFB) for the treatment of gastric tumors and to review their benefits over 6MV flatten beam (6MV_FFB). METHODS: Fifteen patients with histologically proven gastric carcinoma were selected. CT scans with slice thickness of 0.3 cm were acquired and planning target volume (PTV) and organ at risk (OAR) were delineated. Plans were made retrospectively for each patient for the prescription dose of 45 Gy/25 fractions to the PTV...
March 8, 2018: Journal of Gastrointestinal Cancer
Jong Min Park, So-Yeon Park, Hong-Gyun Wu, Jung-In Kim
PURPOSE: To investigate the changes in quality of the volumetric modulated arc therapy (VMAT) plans with couch-shift between arcs by half of a multi-leaf collimator (MLC) leaf width. METHODS: A total of 22 patients with head-and-neck cancer were retrospectively selected. Since the smallest MLC leaf width was 5 mm in this study, the couch was shifted by 2.5 mm in the longitudinal-direction between arcs to increase the resolution of fluence map. A total of three types of VMAT plans were generated for each patient; the three types of plans were a two-full-arc plan without couch-shift (NS plan), a two-half-arc-pair plan with couch-shift (HAS plan), and a two-full-arc pair plan with couch-shift (FAS plan)...
February 2018: Physica Medica: PM
Audrey H Zhuang, Arthur J Olch
The dosimetric consequences of errors in patient setup or beam delivery and anatomical changes are not readily known. A new product, PerFRACTION (Sun Nuclear Corporation), is designed to identify these errors by comparing the exit dose image measured on an electronic portal imaging device (EPID) from each field of each fraction to those from baseline fraction images. This work investigates the sensitivity of PerFRACTION to detect the deviation caused by these errors in a variety of realistic scenarios. Integrated EPID images were acquired in clinical mode and saved in ARIA...
March 6, 2018: Journal of Applied Clinical Medical Physics
Ruggero Ruggieri, Stefania Naccarato, Rosario Mazzola, Francesco Ricchetti, Stefanie Corradini, Alba Fiorentino, Filippo Alongi
BACKGROUND: Linac-based stereotactic radiosurgery or fractionated stereotactic radiotherapy (SRS/FSRT) of multiple brain lesions using volumetric modulated arc therapy (VMAT) is typically performed by a multiple-isocenter approach, i.e. one isocenter per lesion, which is time-demanding for the need of independent setup verifications of each isocenter. Here, we present our initial experience with a new dedicated mono-isocenter technique with multiple non-coplanar arcs (HyperArc™, Varian Inc...
March 5, 2018: Radiation Oncology
Masahide Saito, Naoki Sano, Yuki Shibata, Kengo Kuriyama, Takafumi Komiyama, Kan Marino, Shinichi Aoki, Kazunari Ashizawa, Kazuya Yoshizawa, Hiroshi Onishi
The purpose of this study was to compare the MLC error sensitivity of various measurement devices for VMAT pre-treatment quality assurance (QA). This study used four QA devices (Scandidos Delta4, PTW 2D-array, iRT systems IQM, and PTW Farmer chamber). Nine retrospective VMAT plans were used and nine MLC error plans were generated for all nine original VMAT plans. The IQM and Farmer chamber were evaluated using the cumulative signal difference between the baseline and error-induced measurements. In addition, to investigate the sensitivity of the Delta4 device and the 2D-array, global gamma analysis (1%/1, 2%/2, and 3%/3 mm), dose difference (1%, 2%, and 3%) were used between the baseline and error-induced measurements...
March 3, 2018: Journal of Applied Clinical Medical Physics
Mingfang Guo, Erliang Huang, Xianfeng Liu, Ying Tang
BACKGROUND: The aim of this study was to compare the dosimetric parameters, clinical complications, and efficacy of volumetric modulated arc therapy (VMAT) and fixed-field intensity-modulated radiotherapy (f-IMRT) in radical radiotherapy for cervical cancer without lymphadenectasis. METHODS: 84 cervical cancer patients undergoing treatment with VMAT and f-IMRT were selected. Dose-volume histograms were used to evaluate the dose distribution in the planning target volume (PTV) and organs at risk...
2018: Oncology Research and Treatment
A Ranger, A Dunlop, K Hutchinson, H Convery, M K Maclennan, H Chantler, N Twyman, C Rose, D McQuaid, R A Amos, C Griffin, N M deSouza, E Donovan, E Harris, C E Coles, A Kirby
AIMS: Radiotherapy target volumes in early breast cancer treatment increasingly include the internal mammary chain (IMC). In order to maximise survival benefits of IMC radiotherapy, doses to the heart and lung should be minimised. This dosimetry study compared the ability of three-dimensional conformal radiotherapy, arc therapy and proton beam therapy (PBT) techniques with and without breath-hold to achieve target volume constraints while minimising dose to organs at risk (OARs). MATERIALS AND METHODS: In 14 patients' datasets, seven IMC radiotherapy techniques were compared: wide tangent (WT) three-dimensional conformal radiotherapy, volumetric-modulated arc therapy (VMAT) and PBT, each in voluntary deep inspiratory breath-hold (vDIBH) and free breathing (FB), and tomotherapy in FB only...
February 23, 2018: Clinical Oncology: a Journal of the Royal College of Radiologists
Dwi Seno Kuncoro Sihono, Michael Ehmann, Sigrun Heitmann, Sandra von Swietochowski, Mario Grimm, Judit Boda-Heggemann, Frank Lohr, Frederik Wenz, Hansjörg Wertz
PURPOSE/OBJECTIVE: To determine intrafraction prostate motion during volumetric modulated arc therapy (VMAT) using transperineal ultrasound (US) real-time tracking. METHODS AND MATERIALS: 770 US monitoring sessions in 38 prostate cancer patients' VMAT treatment series were retrospectively evaluated. Intrafraction motion assessment of the prostate was based on continuous position monitoring with a 4-dimensional US system along the 3 directions: left-right (LR), anterior-posterior (AP), and inferior-superior (SI)...
January 31, 2018: International Journal of Radiation Oncology, Biology, Physics
Åse Ballangrud, Li Cheng Kuo, Laura Happersett, Seng Boh Lim, Kathryn Beal, Yoshiya Yamada, Margie Hunt, James Mechalakos
BACKGROUND AND PURPOSE: This study summarizes the cranial stereotactic radiosurgery (SRS) volumetric modulated arc therapy (VMAT) procedure at our institution. MATERIALS AND METHODS: Volumetric modulated arc therapy plans were generated for 40 patients with 188 lesions (range 2-8, median 5) in Eclipse and treated on a TrueBeam STx. Limitations of the custom beam model outside the central 2.5 mm leaves necessitated more than one isocenter pending the spatial distribution of lesions...
February 23, 2018: Journal of Applied Clinical Medical Physics
Tuomas Koivumäki, Antonella Fogliata, Michele Zeverino, Eeva Boman, Joanna Sierpowska, Raphaël Moeckli, Véronique Vallet, Luca Cozzi, Janne Heikkilä, Anssi Väänänen, Kristiina Vuolukka, Saara Sillanmäki, Jan Seppälä
PURPOSE: The dosimetric differences between four radiation therapy techniques for left sided whole breast irradiation were evaluated side by side in the same patient population. METHODS: Radiotherapy treatment plans were retrospectively created with Accuray TomoDirect (TD), Elekta Volumetric Modulated Arc Therapy (E-VMAT), Varian RapidArc (RA) and Field-in-field (FinF) technique for 20 patients, who had received left breast irradiation during deep-inspiration breath-hold...
January 2018: Physica Medica: PM
Tatsuya Kamima, Hiromi Baba, Ryo Takahashi, Mikiko Yamashita, Yasuharu Sugawara, Daisuke Kawai, Toshijiro Yamamoto, Aya Satou, Hidenobu Tachibana
PURPOSE: No multi-institutional studies of computer-based independent dose calculation have addressed the discrepancies among radiotherapy treatment planning systems (TPSs) and the verification programs for intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT). We conducted a multi-institutional study to investigate whether ±5% is a reasonable action level for independent dose calculation for IMRT/VMAT. METHODS: In total, 477 IMRT/VMAT plans for prostate or head and neck (H&N) malignancies were retrospectively analyzed using a modified Clarkson-based commercial verification program...
January 2018: Physica Medica: PM
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