keyword
MENU ▼
Read by QxMD icon Read
search

Radiation planning

keyword
https://www.readbyqxmd.com/read/28102956/experimental-verification-of-4d-monte-carlo-simulations-of-dose-delivery-to-a-moving-anatomy
#1
Sara Gholampourkashi, Miro Vujicic, Jason Belec, Joanna E Cygler, Emily Heath
PURPOSE: To evaluate a novel 4D Monte Carlo simulation tool by comparing calculations to physical measurements using a respiratory motion phantom. METHODS: We used a dynamic Quasar phantom in both stationary and breathing states (sinusoidal motion of amplitude of 1.8 cm and period of 3.3 s) for dose measurements on an Elekta Agility linear accelerator. Gafchromic EBT3 film and the RADPOS 4D dosimetry system were placed inside the lung insert of the phantom to measure dose profiles and point-dose values at the center of the spherical tumor inside the insert...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28102954/dosimetric-impact-of-lipiodol-in-stereotactic-body-radiation-therapy-on-liver-after-trans-arterial-chemoembolization
#2
Daisuke Kawahara, Shuichi Ozawa, Akito Saito, Teiji Nishio, Tomoki Kimura, Tatsuhiko Suzuki, Kazunari Hioki, Takeo Nakashima, Yoshimi Ohno, Yuji Murakami, Yasushi Nagata
PURPOSE: Stereotactic body radiation therapy (SBRT) combining trans-arterial chemoembolization (TACE) with Lipiodol is expected to improve local control. This study is aimed to estimate the dose enhancement in Lipiodol's proximity and to evaluate the dose calculation accuracy of the Acuros XB (AXB) algorithm and anisotropic analytical algorithm (AAA) in the Eclipse treatment planning system (TPS) (ver. 11, Varian Medical Systems, Palo Alto, USA), compared with that of the Monte Carlo (MC) calculation (using BEAMnrc/DOSXYZnrc code) for a virtual phantom and a treatment plan for liver SBRT after TACE...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28102946/a-portal-dosimetry-dose-prediction-method-based-on-collapsed-cone-algorithm-using-the-clinical-beam-model
#3
J Martínez Ortega, N Gómez González, P Castro Tejero, M Pinto Monedero, N B Tolani, L Núñez Martín, R Sánchez Montero
PURPOSE: Amorphous silicon electronical portal imaging devices (EPIDs) are widely used for dosimetric measurements in Radiation Therapy. The purpose of this work was to determine if a portal dose prediction method can be utilized for dose map calculations based on the linear accelerator model within a commercial treatment planning system (Pinnacle(3) v8.0 m). METHODS: The method was developed for a 6 MV photon beam on the Varian Clinac 21-EX, at a nominal dose rate of 400 MU/min...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28102944/a-simple-and-robust-trajectory-based-stereotactic-radiosurgery-treatment
#4
Byron Wilson, Karl Otto, Ermias Gete
INTRODUCTION: We present a Trajectory-based Volumetric Modulated Arc Therapy (TVMAT) technique for Stereotactic Radiosurgery (SRS) that takes advantage of a modern linacs ability to modulate dose rate and move the couch dynamically. In addition, we investigate the quality of the developed TVMAT method and the dosimetric accuracy of the technique. METHODS: The main feature of the TVMAT technique is a standard beam trajectory formed by dynamic motion of the treatment couch and the linac gantry...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28102943/comparison-of-five-cluster-validity-indices-performance-in-brain-18-f-fet-pet-image-segmentation-using-k-means
#5
Bedor Abualhaj, Guoyang Weng, Melissa Ong, Ali Asgar Attarwala, Flavia Molina, Karen Büsing, Gerhard Glatting
PURPOSE: Dynamic [(18) F]fluoro-ethyl-L-tyrosine positron emission tomography ([(18) F]FET-PET) is used to identify tumor lesions for radiotherapy treatment planning, to differentiate glioma recurrence from radiation necrosis and to classify gliomas grading. To segment different regions in the brain k-means cluster analysis can be used. The main disadvantage of k-means is that the number of clusters must be pre-defined. In this study, we therefore compared different cluster validity indices for automated and reproducible determination of the optimal number of clusters based on the dynamic PET data...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28102933/what-if-a-tumor-is-significantly-enlarged-just-before-stereotactic-body-radiation-therapy-a-case-report-and-review-of-the-literature
#6
Hung-Jen Chen, Ji-An Liang, Chih-Yi Chen, Yang-Hao Yu, Chun-Ru Chien
Stereotactic body radiation therapy (SBRT) plays an important role in early stage non-small cell lung cancer. Tumor growth before radiotherapy planning (RTP) or during SBRT has been reported in lung cancer patients; however, little is known of growth during the period in-between (i.e. after RTP but before SBRT). An 83-year-old man referred to our hospital and diagnosed with medically inoperable non-small cell lung cancer was noted to have significant tumor progression on day 1 of cone beam computed tomography just before the planned SBRT delivery...
November 18, 2016: Thoracic Cancer
https://www.readbyqxmd.com/read/28102349/development-of-patient-specific-phantoms-for-verification-of-stereotactic-body-radiation-therapy-planning-in-patients-with-metallic-screw-fixation
#7
Dongryul Oh, Chae-Seon Hong, Sang Gyu Ju, Minkyu Kim, Bum Yong Koo, SungBack Choi, Hee Chul Park, Doo Ho Choi, Hongryull Pyo
A new technique for manufacturing a patient-specific dosimetric phantom using three-dimensional printing (PSDP_3DP) was developed, and its geometrical and dosimetric accuracy was analyzed. External body contours and structures of the spine and metallic fixation screws (MFS) were delineated from CT images of a patient with MFS who underwent stereotactic body radiation therapy for spine metastasis. Contours were converted into a STereoLithography file format using in-house program. A hollow, four-section PSDP was designed and manufactured using three types of 3DP to allow filling with a muscle-equivalent liquid and insertion of dosimeters...
January 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28100416/a-retrospective-analysis-of-the-clinical-effects-of-neoadjuvant-combination-therapy-with-full-dose-gemcitabine-and-radiation-therapy-in-patients-with-biliary-tract-cancer
#8
S Kobayashi, A Tomokuni, K Gotoh, H Takahashi, H Akita, S Marubashi, T Yamada, T Teshima, K Fukui, Y Fujiwara, M Sakon
PURPOSE: This study aims to evaluate survival and the objective response to neoadjuvant combination therapy with gemcitabine and radiation therapy in patients with biliary tract cancer. METHODS: The chemoradiation therapy regimen consisted of 3 cycles of full-dose gemcitabine (1000 mg/m(2) at days 1, 8, and 15, every 4 weeks) with 50-60 Gy radiation. We compared 27 patients who received neoadjuvant chemoradiation therapy and 79 patients who were treated without neoadjuvant therapy...
January 11, 2017: European Journal of Surgical Oncology
https://www.readbyqxmd.com/read/28096917/assessment-of-histopathological-features-of-needle-biopsy-in-recurrent-prostate-cancer-following-salvage-high-intensity-focused-ultrasound
#9
Michele Billia, Khurram M Siddiqui, Susanne Chan, Fan Li, Ali Al-Zahrani, Jose A Gomez, Joseph L Chin
INTRODUCTION: Local recurrence of prostate cancer (PCa) following radiotherapy may be treated with curative intent using salvage high-intensity focused ultrasound (s-HIFU). The interpretation of needle core biopsy specimens following s-HIFU is a daunting task, even for experienced pathologists. We describe various histopathological features encountered in biopsy specimens following whole-gland s-HIFU in one of the largest descriptive studies to date. METHODS: Fifty-five patients with biopsy-proven localized radio-recurrent PCa underwent s-HIFU and transrectal ultrasound (TRUS)-guided prostatic needle biopsies at 180 days post-treatment...
November 2016: Canadian Urological Association Journal, Journal de L'Association des Urologues du Canada
https://www.readbyqxmd.com/read/28095159/validation-and-modification-of-a-prediction-model-for-acute-cardiac-events-in-patients-with-breast-cancer-treated-with-radiotherapy-based-on-three-dimensional-dose-distributions-to-cardiac-substructures
#10
Veerle A B van den Bogaard, Bastiaan D P Ta, Arjen van der Schaaf, Angelique B Bouma, Astrid M H Middag, Enja J Bantema-Joppe, Lisanne V van Dijk, Femke B J van Dijk-Peters, Laurens A W Marteijn, Gertruida H de Bock, Johannes G M Burgerhof, Jourik A Gietema, Johannes A Langendijk, John H Maduro, Anne P G Crijns
Purpose A relationship between mean heart dose (MHD) and acute coronary event (ACE) rate was reported in a study of patients with breast cancer (BC). The main objective of our cohort study was to validate this relationship and investigate if other dose-distribution parameters are better predictors for ACEs than MHD. Patients and Methods The cohort consisted of 910 consecutive female patients with BC treated with radiotherapy (RT) after breast-conserving surgery. The primary end point was cumulative incidence of ACEs within 9 years of follow-up...
January 17, 2017: Journal of Clinical Oncology: Official Journal of the American Society of Clinical Oncology
https://www.readbyqxmd.com/read/28094849/the-collimator-monitoring-fill-factor-of-a-two-dimensional-detector-array-a-measure-of-its-ability-to-detect-collimation-errors
#11
Tenzin Sonam Stelljes, Hui Khee Looe, Dietrich Harder, Björn Poppe
PURPOSE: Two-dimensional detector arrays are routinely used for constancy checks and treatment plan verification in photon-beam radiotherapy. In addition to the spatial resolution of the dose profiles, the "coverage" of the radiation field with respect to the detection of any beam collimation deficiency appears as the second characteristic feature of a detector array. The here proposed "collimator monitoring fill factor" (CM fill factor) has been conceived to serve as a quantitative characteristic of this "coverage"...
January 17, 2017: Medical Physics
https://www.readbyqxmd.com/read/28094211/likelihood-of-unacceptable-normal-tissue-doses-in-breast-cancer-patients-undergoing-regional-nodal-irradiation-in-routine-clinical-practice
#12
Jose Bazan, Dominic DiCostanzo, Karla Kuhn, Lonika Majithia, Allison Quick, Nilendu Gupta, Julia White
PURPOSE: As indications for regional nodal irradiation (RNI) for breast cancer have expanded, so too has scrutiny over potential late toxicity from radiotherapy. This emphasizes the need for careful radiation treatment planning to maximize the therapeutic ratio. We sought to evaluate how often unacceptable doses (UDs) to organs at risk (OARs) occur and the associated factors for patients receiving RNI in daily practice. METHODS AND MATERIALS: Treatment records of patients who received RNI from February 2012 to May 2015 were studied...
October 19, 2016: Practical Radiation Oncology
https://www.readbyqxmd.com/read/28089762/long-terms-results-of-a-trial-of-concurrent-chemotherapy-and-escalating-doses-of-radiation-for-unresectable-non-small-cell-lung-cancer-ncctg-n0028-alliance
#13
Steven E Schild, Shauna L Hillman, Angelina D Tan, Helen J Ross, William L McGinnis, Yolanda A Garces, David L Graham, Alex A Adjei, James R Jett
INTRODUCTION OR HYPOTHESIS: This phase I/II trial was originally designed to determine the maximally tolerated dose(MTD) of thoracic radiotherapy(TRT) as part of a combined modality approach. This report includes the long-term outcome of patients treated on this study. The phase II portion was never completed as RTOG-0617 opened before it was concluded. METHODS: The MTD was defined as 74Gy in 37 fractions in this study. Twenty-five patients with unresectable non-small cell lung cancer(NSCLC) were treated with 2Gy daily fractions and concurrent weekly carboplatin and paclitaxel...
January 12, 2017: Journal of Thoracic Oncology
https://www.readbyqxmd.com/read/28089602/particle-swarm-optimizer-for-weighting-factor-selection-in-intensity-modulated-radiation-therapy-optimization-algorithms
#14
Jie Yang, Pengcheng Zhang, Liyuan Zhang, Huazhong Shu, Baosheng Li, Zhiguo Gui
In inverse treatment planning of intensity-modulated radiation therapy (IMRT), the objective function is typically the sum of the weighted sub-scores, where the weights indicate the importance of the sub-scores. To obtain a high-quality treatment plan, the planner manually adjusts the objective weights using a trial-and-error procedure until an acceptable plan is reached. In this work, a new particle swarm optimization (PSO) method which can adjust the weighting factors automatically was investigated to overcome the requirement of manual adjustment, thereby reducing the workload of the human planner and contributing to the development of a fully automated planning process...
January 12, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28089528/hydrogel-spacer-distribution-within-the-perirectal-space-in-patients-undergoing-radiotherapy-for-prostate-cancer-impact-of-spacer-symmetry-on-rectal-dose-reduction-and-the-clinical-consequences-of-hydrogel-infiltration-into-the-rectal-wall
#15
Benjamin W Fischer-Valuck, Anupama Chundury, Hiram Gay, Walter Bosch, Jeff Michalski
PURPOSE: Hydrogel prostate-rectum spacers, biomaterials placed between the prostate and rectum, continue to gain interest as a method to reduce or limit rectal dose during dose escalated prostate cancer radiation therapy. Because the spacer is initially injected into the perirectal space as a liquid, the final distribution can vary. The purpose of this study was to evaluate hydrogel spacer (SpaceOAR system) implantation and distribution from a recent prospective randomized control trial and correlate spacer symmetry with rectal dose reduction as well as rectal wall infiltration (RWI) to acute and late toxicity...
October 17, 2016: Practical Radiation Oncology
https://www.readbyqxmd.com/read/28089483/patterns-of-failure-after-radiotherapy-for-pediatric-patients-with-intracranial-ependymoma
#16
Fatima Tensaouti, Anne Ducassou, Léonor Chaltiel, Stéphanie Bolle, Xavier Muracciole, Bernard Coche-Dequeant, Claire Alapetite, Valérie Bernier, Line Claude, Stéphane Supiot, Aymeri Huchet, Christine Kerr, Elisabeth le Prisé, Anne Laprie
PURPOSE: To investigate the patterns of failure after radiotherapy for pediatric intracranial ependymoma and their correlation with dose parameters. METHODS: Between 2000 and 2013, 206 patients were treated in France. MRI scans at relapse were registered to the original planning CTs for topographic analysis of failure patterns. To compare relapse patients (RP) with non relapse patients (NRP), several dose parameters were derived from dose volume histograms. RESULTS: Over a median follow-up of 53...
January 12, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/28089481/recommendations-for-mri-based-contouring-of-gross-tumor-volume-and-organs-at-risk-for-radiation-therapy-of-pancreatic-cancer
#17
H D Heerkens, W A Hall, X A Li, P Knechtges, E Dalah, E S Paulson, C A T van den Berg, G J Meijer, E J Koay, C H Crane, K Aitken, M van Vulpen, B A Erickson
PURPOSE: Local recurrence is a common and morbid event in patients with unresectable pancreatic adenocarcinoma. A more conformal and targeted radiation dose to the macroscopic tumor in nonmetastatic pancreatic cancer is likely to reduce acute toxicity and improve local control. Optimal soft tissue contrast is required to facilitate delineation of a target and creation of a planning target volume with margin reduction and motion management. Magnetic resonance imaging (MRI) offers considerable advantages in optimizing soft tissue delineation and is an ideal modality for imaging and delineating a gross tumor volume (GTV) within the pancreas, particularly as it relates to conformal radiation planning...
October 17, 2016: Practical Radiation Oncology
https://www.readbyqxmd.com/read/28089480/deep-inspiration-breath-hold-produces-a-clinically-meaningful-reduction-in-ipsilateral-lung-dose-during-locoregional-radiation-therapy-for-some-women-with-right-sided-breast-cancer
#18
Jessica L Conway, Leigh Conroy, Lindsay Harper, Marie Scheifele, Haocheng Li, Wendy L Smith, Tannis Graham, Tien Phan, Ivo A Olivotto
PURPOSE: The goal of the work described here was to determine whether deep inspiration breath-hold (DIBH) produces a clinically meaningful reduction in pulmonary dose compared with free breathing (FB) during locoregional radiation for right-sided breast cancer. METHODS AND MATERIALS: Four-field, modified-wide tangent plans with full nodal coverage were developed for 30 consecutive patients on paired DIBH and FB CT scans. Nodes were contoured according to European Society for Radiotherapy and Oncology guidelines...
October 19, 2016: Practical Radiation Oncology
https://www.readbyqxmd.com/read/28089479/estimation-of-radiation-induced-secondary-cancer-risks-for-early-stage-non-small-cell-lung-cancer-patients-after-stereotactic-body-radiation-therapy
#19
Chunhui Han, Timothy E Schultheiss, Jeffrey Y C Wong
PURPOSE: In this study, we evaluated radiation-induced secondary lung cancer risks for the lung and the breast from stereotactic body radiation therapy treatment of early-stage non-small cell lung cancer with different radiation therapy treatment modalities. METHODS AND MATERIALS: Ten patients (5 men and 5 women) with early-stage non-small cell lung cancer who received definitive stereotactic body radiation therapy treatments were retrospectively selected. For each patient, two 3-dimensional conformal radiation therapy (3D-CRT) plans using 6- and 10-MV photons, respectively; a helical tomotherapy (HT) plan; and 2 volumetric modulated arc therapy (VMAT) plans using 1 and 2 arcs, respectively, were generated...
October 19, 2016: Practical Radiation Oncology
https://www.readbyqxmd.com/read/28089106/-edge-on-moskin-detector-for-stereotactic-beam-measurement-and-verification
#20
Wei Loong Jong, Ngie Min Ung, Ath Vannyat, Zulaikha Jamalludin, Anatoly Rosenfeld, Jeannie Hsiu Ding Wong
Dosimetry in small radiation field is challenging and complicated because of dose volume averaging and beam perturbations in a detector. We evaluated the suitability of the "Edge-on" MOSkin (MOSFET) detector in small radiation field measurement. We also tested the feasibility for dosimetric verification in stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT). "Edge-on" MOSkin detector was calibrated and the reproducibility and linearity were determined. Lateral dose profiles and output factors were measured using the "Edge-on" MOSkin detector, ionization chamber, SRS diode and EBT2 film...
January 6, 2017: Physica Medica: PM
keyword
keyword
20542
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"