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https://www.readbyqxmd.com/read/28107554/inclusion-of-a-variable-rbe-into-proton-and-photon-plan-comparison-for-various-fractionation-schedules-in-prostate-radiation-therapy
#1
Jakob Ödén, Kjell Eriksson, Iuliana Toma-Dasu
PURPOSE: A constant relative biological effectiveness (RBE) of 1.1 is currently used in proton radiation therapy to account for the increased biological effectiveness compared to photon therapy. However, there is increasing evidence that proton RBE vary with the linear energy transfer (LET), the dose per fraction and the type of the tissue. Therefore, this study aims to evaluate the impact of disregarding variations in RBE when comparing proton and photon dose plans for prostate treatments for various fractionation schedules using published RBE models and several α/β assumptions...
January 20, 2017: Medical Physics
https://www.readbyqxmd.com/read/28105886/interobserver-delineation-uncertainty-in-involved-node-radiation-therapy-inrt-for-early-stage-hodgkin-lymphoma-on-behalf-of-the-radiotherapy-committee-of-the-eortc-lymphoma-group
#2
Marianne C Aznar, Theodore Girinsky, Anne Kiil Berthelsen, Berthe Aleman, Max Beijert, Martin Hutchings, Yolande Lievens, Paul Meijnders, Peter Meidahl Petersen, Deborah Schut, Maja V Maraldo, Richard van der Maazen, Lena Specht
BACKGROUND AND PURPOSE: In early-stage classical Hodgkin lymphoma (HL) the target volume nowadays consists of the volume of the originally involved nodes. Delineation of this volume on a post-chemotherapy CT-scan is challenging. We report on the interobserver variability in target volume definition and its impact on resulting treatment plans. MATERIALS AND METHODS: Two representative cases were selected (1: male, stage IB, localization: left axilla; 2: female, stage IIB, localizations: mediastinum and bilateral neck)...
January 20, 2017: Acta Oncologica
https://www.readbyqxmd.com/read/28105468/simulating-the-effect-of-spectroscopic-mri-as-a-metric-for-radiation-therapy-planning-in-patients-with-glioblastoma
#3
J Scott Cordova, Shravan Kandula, Saumya Gurbani, Jim Zhong, Mital Tejani, Oluwatosin Kayode, Kirtesh Patel, Roshan Prabhu, Eduard Schreibmann, Ian Crocker, Chad A Holder, Hyunsuk Shim, Hui-Kuo Shu
Due to glioblastoma's infiltrative nature, an optimal radiation therapy (RT) plan requires targeting infiltration not identified by anatomical magnetic resonance imaging (MRI). Here, high-resolution, whole-brain spectroscopic MRI (sMRI) is used to describe tumor infiltration alongside anatomical MRI and simulate the degree to which it modifies RT target planning. In 11 patients with glioblastoma, data from preRT sMRI scans were processed to give high-resolution, whole-brain metabolite maps normalized by contralateral white matter...
December 2016: Tomography: a Journal for Imaging Research
https://www.readbyqxmd.com/read/28105389/chemophototherapy-an-emerging-treatment-option-for-solid-tumors
#4
REVIEW
Dandan Luo, Kevin A Carter, Dyego Miranda, Jonathan F Lovell
Near infrared (NIR) light penetrates human tissues with limited depth, thereby providing a method to safely deliver non-ionizing radiation to well-defined target tissue volumes. Light-based therapies including photodynamic therapy (PDT) and laser-induced thermal therapy have been validated clinically for curative and palliative treatment of solid tumors. However, these monotherapies can suffer from incomplete tumor killing and have not displaced existing ablative modalities. The combination of phototherapy and chemotherapy (chemophototherapy, CPT), when carefully planned, has been shown to be an effective tumor treatment option preclinically and clinically...
January 2017: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
https://www.readbyqxmd.com/read/28103970/-a-phase-i-ii-study-of-chemotherapy-concurrent-with-twice-daily-radiotherapy-%C3%A2-schedules-by-intensity-modulated-radiation-therapy-using-simultaneous-integrated-boost-for-limited-stage-small-cell-lung-cancer
#5
Jing You, Huiming Yu, Maxiaowei Song, Chen Shi, Xiaohang Wang, Ye Zheng, Rong Yu, Anhui Shi, Guangying Zhu
BACKGROUND: Twice-daily radiation concurrent with chemotherapy is one of the standard methods for limited-stage small cell lung cancer. The study was to evaluate the feasibility of chemotherapy concurrent with dose-escalating twice-daily radiotherapy by simultaneous integrated boost intensity-modulated radiation therapy (SIB-IMRT) approach in patients with limited-stage small cell lung cancer. METHODS: Patients with limited-stage small cell lung cancer were included, treated with twice-daily radiotherapy by SIB-IMRT concurrent with chemotherapy of etoposide plus cisplatin...
January 20, 2017: Zhongguo Fei Ai za Zhi, Chinese Journal of Lung Cancer
https://www.readbyqxmd.com/read/28102956/experimental-verification-of-4d-monte-carlo-simulations-of-dose-delivery-to-a-moving-anatomy
#6
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
#7
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
#8
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
#9
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/28102933/what-if-a-tumor-is-significantly-enlarged-just-before-stereotactic-body-radiation-therapy-a-case-report-and-review-of-the-literature
#10
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
#11
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
#12
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
#13
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/28094211/likelihood-of-unacceptable-normal-tissue-doses-in-breast-cancer-patients-undergoing-regional-nodal-irradiation-in-routine-clinical-practice
#14
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
#15
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
#16
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
#17
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/28089481/recommendations-for-mri-based-contouring-of-gross-tumor-volume-and-organs-at-risk-for-radiation-therapy-of-pancreatic-cancer
#18
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
#19
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
#20
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
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