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Contouring radiotherapy

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https://www.readbyqxmd.com/read/28327466/regional-deep-hyperthermia-impact-of-observer-variability-in-ct-based-manual-tissue-segmentation-on-a-simulated-temperature-distribution
#1
Bassim Aklan, Josefin Hartmann, Diana Zink, Hadi Siavooshhaghighi, Ricarda Merten, Florian Putz, Oliver Ott, Rainer Fietkau, Christoph Bert
The aim of this study was to systematically investigate the influence of inter- and intra-observer segmentation variation of tumor and organs at risk on the simulated temperature coverage of the target. CT scans of six patients with tumors in the pelvic region acquired for radiotherapy treatment planning were used for the hyperthermia treatment planning. To study the effect of inter-observer variation, three observers manually segmented in the CT images of each patient the following structures: fat, muscle, bone and bladder...
March 22, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28318880/highly-conformal-craniospinal-radiotherapy-techniques-can-underdose-the-cranial-clinical-target-volume-if-leptomeningeal-extension-through-skull-base-exit-foramina-is-not-contoured
#2
D J Noble, T Ajithkumar, J Lambert, I Gleeson, M V Williams, S J Jefferies
AIMS: Craniospinal irradiation (CSI) remains a crucial treatment for patients with medulloblastoma. There is uncertainty about how to manage meningeal surfaces and cerebrospinal fluid (CSF) that follows cranial nerves exiting skull base foramina. The purpose of this study was to assess plan quality and dose coverage of posterior cranial fossa foramina with both photon and proton therapy. MATERIALS AND METHODS: We analysed the radiotherapy plans of seven patients treated with CSI for medulloblastoma and primitive neuro-ectodermal tumours and three with ependymoma (total n = 10)...
March 15, 2017: Clinical Oncology: a Journal of the Royal College of Radiologists
https://www.readbyqxmd.com/read/28301492/variability-in-target-delineation-of-cervical-carcinoma-a-korean-radiation-oncology-group-study-krog-15-06
#3
Ji Hyeon Joo, Young Seok Kim, Byung Chul Cho, Chi Young Jeong, Won Park, Hak Jae Kim, Won Sup Yoon, Mee Sun Yoon, Ji-Yoon Kim, Jin Hwa Choi, Youngmin Choi, Joo-Young Kim
PURPOSE: To determine inter-observer variability in target volume definition of cervical cancer in radical and adjuvant radiotherapy (RT) settings. METHODS: Eight physicians contoured CTVs of 2 patients underwent definitive and postoperative RT. Each volume was analyzed using the individual/median volume ratio and generalized conformity index (CIgen). And center of mass (COM) of each contour was calculated. Expert agreement was quantified using an expectation maximization algorithm for Simultaneous Truth and Performance Level Estimation (STAPLE)...
2017: PloS One
https://www.readbyqxmd.com/read/28300381/comparison-of-ct-images-with-average-intensity-projection-free-breathing-and-mid-ventilation-for-dose-calculation-in-lung-cancer
#4
Chirasak Khamfongkhruea, Sangutid Thongsawad, Chirapha Tannanonta, Sasikarn Chamchod
The purpose of this study was to compare three computed tomography (CT) images under different conditions-average intensity projection (AIP), free breathing (FB), mid-ventilation (MidV)-used for radiotherapy contouring and planning in lung cancer patients. Two image sets derived from four-dimensional CT (4DCT) acquisition (AIP and MidV) and three-dimensional CT with FB were generated and used to plan for 29 lung cancer patients. Organs at risk (OARs) were delineated for each image. AIP images were calculated with 3D conformal radiotherapy (3DCRT) and intensity-modulated radiation therapy (IMRT)...
March 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28297341/assessment-of-monte-carlo-algorithm-for-compliance-with-rtog-0915-dosimetric-criteria-in-peripheral-lung-cancer-patients-treated-with-stereotactic-body-radiotherapy
#5
Damodar Pokhrel, Sumit Sood, Rajeev Badkul, Hongyu Jiang, Christopher McClinton, Christopher Lominska, Parvesh Kumar, Fen Wang
The purpose of the study was to evaluate Monte Carlo-generated dose distributions with the X-ray Voxel Monte Carlo (XVMC) algorithm in the treatment of peripheral lung cancer patients using stereotactic body radiotherapy (SBRT) with non-protocol dose-volume normalization and to assess plan outcomes utilizing RTOG 0915 dosimetric compliance criteria. The Radiation Therapy Oncology Group (RTOG) protocols for non-small cell lung cancer (NSCLC) currently require radiation dose to be calculated using tissue density heterogeneity corrections...
May 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28296324/the-feasibility-of-atlas-based-automatic-segmentation-of-mri-for-h-n-radiotherapy-planning
#6
Kieran Wardman, Robin J D Prestwich, Mark J Gooding, Richard J Speight
Atlas-based autosegmentation is an established tool for segmenting structures for CT-planned head and neck radiotherapy. MRI is being increasingly integrated into the planning process. The aim of this study is to assess the feasibility of MRI-based, atlas-based autosegmentation for organs at risk (OAR) and lymph node levels, and to compare the segmentation accuracy with CT-based autosegmentation. Fourteen patients with locally advanced head and neck cancer in a prospective imaging study underwent a T1-weighted MRI and a PET-CT (with dedicated contrast-enhanced CT) in an immobilization mask...
July 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28296320/a-comparative-study-based-on-image-quality-and-clinical-task-performance-for-ct-reconstruction-algorithms-in-radiotherapy
#7
Hua Li, Steven Dolly, Hsin-Chen Chen, Mark A Anastasio, Daniel A Low, Harold H Li, Jeff M Michalski, Wade L Thorstad, Hiram Gay, Sasa Mutic
CT image reconstruction is typically evaluated based on the ability to reduce the radiation dose to as-low-as-reasonably-achievable (ALARA) while maintaining acceptable image quality. However, the determination of common image quality metrics, such as noise, contrast, and contrast-to-noise ratio, is often insufficient for describing clinical radiotherapy task performance. In this study we designed and implemented a new comparative analysis method associating image quality, radiation dose, and patient size with radiotherapy task performance, with the purpose of guiding the clinical radiotherapy usage of CT reconstruction algorithms...
July 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28296186/changes-in-periprostatic-adipose-tissue-induced-by-5%C3%AE-reductase-inhibitors
#8
D Taussky, M Barkati, S Campeau, K Zerouali, A Nadiri, F Saad, G Delouya
There is increasing interest in periprostatic fat and its influence on prostate cancer aggressiveness. In vitro data suggest that adipose stromal/stem cells (ASCs) can increase production of cytokines and growth factors resulting in invasive growth and metastasis in prostate cancer. The objective of the study was to determine the interaction between 5α-reductase inhibitors (5ARIs) and periprostatic adipose tissue (PPAT) and factors of prostate cancer aggressiveness. In this retrospective study, we identified 61 patients treated with 5ARIs for a period of ≥12 months before undergoing radiation therapy (brachytherapy or external beam radiotherapy)...
March 10, 2017: Andrology
https://www.readbyqxmd.com/read/28291932/online-dosimetric-evaluation-of-larynx-sbrt-a-pilot-study-to-assess-the-necessity-of-adaptive-replanning
#9
Weihua Mao, Timothy Rozario, Weiguo Lu, Xuejun Gu, Yulong Yan, Xun Jia, Baran Sumer, David L Schwartz
PURPOSE: We have initiated a multi-institutional phase I trial of 5-fraction stereotactic body radiotherapy (SBRT) for Stage III-IVa laryngeal cancer. We conducted this pilot dosimetric study to confirm potential utility of online adaptive replanning to preserve treatment quality. METHODS: We evaluated ten cases: five patients enrolled onto the current trial and five patients enrolled onto a separate phase I SBRT trial for early-stage glottic larynx cancer. Baseline SBRT treatment plans were generated per protocol...
January 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28291931/investigation-of-dosimetric-variations-of-liver-radiotherapy-using-deformable-registration-of-planning-ct-and-cone-beam-ct
#10
Pu Huang, Gang Yu, Jinhu Chen, Changsheng Ma, Shaohua Qin, Yong Yin, Yueqiang Liang, Hongsheng Li, Dengwang Li
Many patients with technically unresectable or medically inoperable hepatocellular carcinoma (HCC) had hepatic anatomy variations as a result of interfraction deformation during fractionated radiotherapy. We conducted this retrospective study to investigate interfractional normal liver dosimetric consequences via reconstructing weekly dose in HCC patients. Twenty-three patients with HCC received conventional fractionated three-dimensional conformal radiation therapy (3DCRT) were enrolled in this retrospective investigation...
January 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28291927/single-fraction-radiosurgery-stereotactic-body-radiation-therapy-sbrt-for-spine-metastasis-a-dosimetric-comparison-of-multiple-delivery-platforms
#11
Adrian Nalichowski, Isaac Kaufman, John Gallo, Todd Bossenberger, Tim Solberg, Ezequiel Ramirez, Yulong Yan, Julie Fredrick, Tewfik Bichay, Alan Mayville, Jay Burmeister
There are numerous commercial radiotherapy systems capable of delivering single fraction spine radiosurgery/SBRT. We aim to compare the capabilities of several of these systems to deliver this treatment when following standardized criteria from a national protocol. Four distinct target lesions representing various case presentations of spine metastases were contoured in both the thoracic and lumbar spine of an anthropomorphic SBRT phantom. Single fraction radiosurgery/SBRT plans were designed for each target with each of our treatment platforms...
January 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28291918/organ-motion-in-pediatric-high-risk-neuroblastoma-patients-using-four-dimensional-computed-tomography
#12
Sneha Kannan, Boon-Keng Kevin Teo, Timothy Solberg, Christine Hill-Kayser
PURPOSE/OBJECTIVE(S): High-risk neuroblastoma (HR-NBL) requires multimodality treatment, including external beam radiation of the primary tumor site following resection. Radiotherapy planning must take into account motion of the target and adjacent normal anatomy, both of which are poorly understood in the pediatric population, and which may differ significantly from those in adults. METHODS/MATERIALS: We examined 4DCT scans of 15 consecutive pediatric patients treated for HR-NBL, most with tumors in the abdominal cavity...
January 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28291912/improving-the-efficiency-of-breast-radiotherapy-treatment-planning-using-a-semi-automated-approach
#13
Robert A Mitchell, Philip Wai, Ruth Colgan, Anna M Kirby, Ellen M Donovan
OBJECTIVES: To reduce treatment planning times while maintaining plan quality through the introduction of semi-automated planning techniques for breast radiotherapy. METHODS: Automatic critical structure delineation was examined using the Smart Probabilistic Image Contouring Engine (SPICE) commercial autosegmentation software (Philips Radiation Oncology Systems, Fitchburg, WI) for a cohort of ten patients. Semiautomated planning was investigated by employing scripting in the treatment planning system to automate segment creation for breast step-and-shoot planning and create objectives for segment weight optimization; considerations were made for three different multileaf collimator (MLC) configurations...
January 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28281859/geometrical-uncertainty-of-heart-position-in-deep-inspiration-breath-hold-radiotherapy-of-left-sided-breast-cancer-patients
#14
Tuomas Koivumäki, Juuso Tujunen, Tuomas Virén, Janne Heikkilä, Jan Seppälä
BACKGROUND: This study aimed to determine the geometrical uncertainty of the position of the heart with daily cone beam computed tomography (CBCT) during deep-inspiration breath-hold (DIBH) treatment of the left breast. MATERIAL AND METHODS: A visually guided optical respiratory monitoring system was used in DIBH treatment of 15 breast cancer patients. Heart position was determined in relation to the planning target volume (PTV) in 225 fractions in which daily low-dose CBCT images were compared with planning CT images...
March 10, 2017: Acta Oncologica
https://www.readbyqxmd.com/read/28273341/still-equivalent-for-dose-calculation-in-the-monte-carlo-era-a-comparison-of-free-breathing-and-average-intensity-projection-ct-datasets-for-lung-sbrt-using-three-generations-of-dose-calculation-algorithms
#15
Kristina Zvolanek, Rongtao Ma, Christina Zhou, Xiaoying Liang, Shuo Wang, Vivek Verma, Xiaofeng Zhu, Qinghui Zhang, Joseph Driewer, Chi Lin, Weining Zhen, Andrew Wahl, Su-Min Zhou, Dandan Zheng
PURPOSE: Inhomogeneity dose modeling and respiratory motion description are two critical technical challenges for lung stereotactic body radiotherapy, an important treatment modality for small size primary and secondary lung tumors. Recent studies revealed lung density-dependent target dose differences between Monte Carlo (Type-C) algorithm and earlier algorithms. Therefore, this study aimed to investigate the equivalence of the two most popular CT datasets for treatment planning, free breathing (FB) and average intensity projection (AIP) CTs, using Type-C algorithms, and comparing with two older generation algorithms (Type-A and Type-B)...
March 8, 2017: Medical Physics
https://www.readbyqxmd.com/read/28273332/comparison-between-model-predicted-tumor-oxygenation-dynamics-and-vascular-flow-related-doppler-indices
#16
Antonella Belfatto, Ailyn M Vidal Urbinati, Delia Ciardo, Dorella Franchi, Federica Cattani, Roberta Lazzari, Barbara A Jereczek-Fossa, Roberto Orecchia, Guido Baroni, Pietro Cerveri
PURPOSE: Mathematical modeling is a powerful and flexible method to investigate complex phenomena. It discloses the possibility of reproducing expensive as well as invasive experiments in a safe environment with limited costs. This makes it suitable to mimic tumor evolution and response to radiotherapy although the reliability of the results remains an issue. Complexity reduction is therefore a critical aspect in order to be able to compare model outcomes to clinical data. Among the factors affecting treatment efficacy, tumor oxygenation is known to play a key role in radiotherapy response...
March 8, 2017: Medical Physics
https://www.readbyqxmd.com/read/28258633/a-longitudinal-evaluation-of-early-anatomical-changes-of-parotid-gland-in-intensity-modulated-radiotherapy-of-nasopharyngeal-carcinoma-patients-with-parapharyngeal-space-involvement
#17
Yingting Zhang, Chengguang Lin, Jianhua Wu, Xiaobo Jiang, Shara W Y Lee, Shing-Yau Tam, Vincent W C Wu
INTRODUCTION: Radiotherapy of nasopharyngeal carcinoma patients with parapharyngeal space (PPS) involvement may deliver high dose to the parotid gland. This study evaluated parotid gland changes during and up to 3 months after radiotherapy. METHODS: Kilovoltage computed tomography (CT) scans of head and neck region of 39 nasopharyngeal carcinoma patients with PPS involvement were performed at pre-radiotherapy, 10th, 20th and 30th fractions and 3 months after treatment...
March 4, 2017: Journal of Medical Radiation Sciences
https://www.readbyqxmd.com/read/28255809/unplanned-irradiation-of-internal-mammary-lymph-nodes-in-breast-cancer
#18
Gul Kanyilmaz, Meryem Aktan, Mehmet Koc, Hikmettin Demir, Lütfi Saltuk Demir
AIMS: To evaluate the incidental dose to the internal mammary chain (IMC) in patients treated with three-dimensional conformal radiotherapy, to estimate the predictors affecting the magnitude of IMC receiving dose and to determine the predictive role of clinical parameters on survival. MATERIALS AND METHODS: Between 2009 and 2015, 348 patients undergoing RT for breast cancer were retrospectively analyzed. All patients underwent our department's routine procedure for breast cancer...
March 3, 2017: La Radiologia Medica
https://www.readbyqxmd.com/read/28254869/phase-ii-study-of-a-radiotherapy-total-dose-increase-in-hypoxic-lesions-identified-by-f-miso-pet-ct-in-patients-with-non-small-cell-lung-carcinoma-rtep5-study
#19
Pierre Vera, Sébastien Thureau, Philippe Chaumet-Riffaud, Romain Modzelewski, Pierre Bohn, Maximilien Vermandel, Sébastien Hapdey, Amandine Pallardy, Marc-André Mahé, Marie Lacombe, Pierre Boisselier, Sophie Guillemard, Pierre Olivier, Véronique Beckendorf, Naji Salem, Nathalie Charrier, Enrique Chajon, Anne Devillers, Nicolas Aide, Serge Danhier, Fabrice Denis, Jean-Pierre Muratet, Etienne Martin, Alina Berriolo-Riedinger, Helène Kolesnikov-Gauthier, Eric Dansin, Carole Massabeau, Fredéric Courbon, Marie-Pierre Farcy-Jacquet, Pierre-Olivier Kotzki, Claire Houzard, Francoise Mornex, Laurent Vervueren, Amaury Paumier, Philippe Fernandez, Mathieu Salaun, Bernard Dubray
A multicenter phase II study investigated a selective radiotherapy (RT) dose increase to tumor areas with significant F-miso uptake in patients with non-small cell lung carcinoma (NSCLC). Methods: Eligible patients had locally advanced NSCLC, no contra-indication to concomitant chemo-radiotherapy (CCRT). The F-miso uptake on PET/CT was assessed by experts. If there was no uptake, 66 Gy was delivered. In F-miso-positive patients, the contours of the hypoxic area were transferred to the radiation oncologist. It was necessary for the radiotherapy dose to be as high as possible while fulfilling dose-limiting constraints for the spinal cord and lungs...
March 2, 2017: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
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
#20
Antonetta C Houweling, Koen Crama, Jorrit Visser, Kyohei Fukata, Coen R N 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
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