3,539 results match your criteria dosimetric parameters

Optimization of collimator angles in dual-arc volumetric modulated arc therapy planning for whole-brain radiotherapy with hippocampus and inner ear sparing.

Sci Rep 2021 Sep 24;11(1):19035. Epub 2021 Sep 24.

Department of Radiation Oncology and Therapy, The First Hospital of Jilin University, Changchun, 130021, China.

To optimize the collimator angles in dual-arc volumetric modulated arc therapy (VMAT) plans for whole-brain radiotherapy with hippocampus and inner ear sparing (HIS-WBRT). Two sets of dual-arc VMAT plans were generated for 13 small-cell lung cancer patients: (1) The collimator angles of arcs 1 and 2 (θ/θ) were 350°/10°, 350°/30°, 350°/45°, 350°/60°, and 350°/80°, i.e. Read More

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September 2021

Correlations between bone marrow radiation dose and hematologic toxicity in locally advanced cervical cancer patients receiving chemoradiation with cisplatin: a systematic review.

Radiother Oncol 2021 Sep 21. Epub 2021 Sep 21.

Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Dr. Molewaterplein 40, 3015 GD, Rotterdam, The Netherlands. Electronic address:

Patients with locally advanced cervical cancer (LACC) treated with chemoradiation often experience hematologic toxicity (HT), as chemoradiation can induce bone marrow (BM) suppression. Studies on the relationship between BM dosimetric parameters and clinically significant HT might provide relevant indices for developing BM-sparing (BMS) radiotherapy techniques. This systematic review studied the relationship between bone marrow dose and HT in LACC-patients treated with primary cisplatin-based chemoradiation. Read More

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September 2021

A Nomogram for the Determination of the Necessity of Concurrent Chemotherapy in Patients With Stage II-IVa Nasopharyngeal Carcinoma.

Front Oncol 2021 6;11:640077. Epub 2021 Sep 6.

Department of Radiation Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu, China.

Background: The efficiency of concurrent chemotherapy (CC) remains controversial for stage II-IVa nasopharyngeal carcinoma (NPC) patients treated with induction chemotherapy (IC) followed by intensity-modulated radiotherapy (IMRT). Therefore, we aimed to propose a nomogram to identify patients who would benefit from CC.

Methods: A total of 434 NPC patients (stage II-IVa) treated with IC followed by IMRT between January 2010 and December 2015 were included. Read More

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September 2021

Dosimetric effect of intensity-modulated radiation therapy for postoperative non-small cell lung cancer with and without air cavity in the planning target volume.

Med Dosim 2021 Sep 19. Epub 2021 Sep 19.

Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China. Electronic address:

To evaluate the dosimetric effect of intensity-modulated radiation therapy (IMRT) for postoperative non-small cell lung cancer (NSCLC), with and without the air cavity in the planning target volume (PTV). Two kinds of IMRT plans were made for 21 postoperative NSCLC patients. In Plan-0: PTV included the tracheal air cavity, and in Plan-1: the air cavity was subtracted from the PTV. Read More

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September 2021

AI-based quantification of planned radiotherapy dose to cardiac structures and coronary arteries in breast cancer patients.

Int J Radiat Oncol Biol Phys 2021 Sep 18. Epub 2021 Sep 18.

Image Sciences Institute, University Medical Center Utrecht, Utrecht, the Netherlands; Department of Biomedical Engineering and Physics, Amsterdam University Medical Centers - Location AMC, University of Amsterdam, Amsterdam, the Netherlands; Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers - Location AMC, University of Amsterdam, Amsterdam, the Netherlands; Amsterdam Cardiovascular Sciences, Amsterdam UMC - location AMC.

Purpose: To develop and evaluate an automatic deep learning method for segmentation of cardiac chambers and large arteries, and localization of the three main coronary arteries in radiotherapy planning CT. To determine the planned radiotherapy dose to cardiac structures for breast cancer therapy.

Materials And Methods: Eighteen contrast-enhanced cardiac scans acquired with a dual-layer-detector CT scanner were included for method development. Read More

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September 2021

The feasibility of a dose painting procedure to treat prostate cancer based on mpMR images and hierarchical clustering.

Radiat Oncol 2021 Sep 20;16(1):182. Epub 2021 Sep 20.

Department of Aerospace Engineering, Iowa State University, Ames, IA, 50011, USA.

Background: We aimed to assess the feasibility of a dose painting (DP) procedure, known as simultaneous integrated boost intensity modulated radiation Therapy (SIB-IMRT), for treating prostate cancer with dominant intraprostatic lesions (DILs) based on multi-parametric magnetic resonance (mpMR) images and hierarchical clustering with a machine learning technique.

Methods: The mpMR images of 120 patients were used to create hierarchical clustering and draw a dendrogram. Three clusters were selected for performing agglomerative clustering. Read More

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September 2021

Dosimetric Comparison, Treatment Efficiency Estimation, and Biological Evaluation of Popular Stereotactic Radiosurgery Options in Treating Single Small Brain Metastasis.

Front Oncol 2021 5;11:716152. Epub 2021 Aug 5.

Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China.

Objectives: This study aimed to show the advantages of each stereotactic radiosurgery (SRS) treatment option for single small brain metastasis among Gamma Knife (GK), Cone-based VMAT (Cone-VMAT), and MLC-based CRT (MLC-CRT) plans.

Materials And Methods: GK, Cone-VMAT, and MLC-CRT SRS plans were retrospectively generated for 11 patients with single small brain metastasis whose volume of gross tumor volume (GTV) ranged from 0.18 to 0. Read More

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Prediction of Radiation Pneumonitis Using Genome-Scale Flux Analysis of RNA-Seq Derived From Peripheral Blood.

Front Med (Lausanne) 2021 31;8:715961. Epub 2021 Aug 31.

Cancer Center, Renmin Hospital of Wuhan University, Wuhan, China.

Radiation pneumonitis (RP) frequently occurs during a treatment course of chest radiotherapy, which significantly reduces the clinical outcome and efficacy of radiotherapy. The ability to easily predict RP before radiotherapy would allow this disease to be avoided. This study recruited 48 lung cancer patients requiring chest radiotherapy. Read More

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Dosimetric analysis of three-dimensional conformal radiotherapy, intensity-modulated radiotherapy-step and shoot, helical tomotherapy, and volumetric modulated arc therapy in prostate cancer radiotherapy.

J Cancer Res Ther 2021 Jul-Sep;17(4):893-900

Radiation Oncology Department, Rumah Sakit Cipto Mangunkusumo, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia.

Introduction: There is limited study comparing dosimetry parameters in detail. In regard to prostate cancer, there are four different techniques, namely three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy-step and shoot (IMRT-SS), IMRT-helical tomotherapy (HT), and volumetric-modulated arc therapy (VMAT).

Materials And Methods: Experimental study with intervention on ten prostate cancer patients' computed tomography planning data. Read More

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September 2021

Benefit of Deep Inspiratory Breath Hold for Right Breast Cancer When Regional Lymph Nodes Are Irradiated.

Pract Radiat Oncol 2021 Sep 8. Epub 2021 Sep 8.

Department of Therapeutic Radiology, Yale School of Medicine, New Haven, CT. Electronic address:

Background: While DIBH is routinely utilized for left-sided breast cancers, its benefits for right-sided breast cancer (rBC) have yet to be established. We compared free-breathing (FB) and DIBH treatment plans for a cohort of rBC undergoing RNI to determine its potential benefits.

Methods: rBC patients considered for RNI (IMNs, supraclavicular field, +/- axilla) from 10/2017-5/2020 were included in this analysis. Read More

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September 2021

Multi-criteria optimization for planning volumetric-modulated arc therapy for prostate cancer.

PLoS One 2021 10;16(9):e0257216. Epub 2021 Sep 10.

Department of Radiation Oncology, Yeungnam University College of Medicine, Daegu, Republic of Korea.

We aimed to compare the volumetric-modulated arc therapy (VMAT) plans with or without multi-criteria optimization (MCO) on commercial treatment-planning systems (Eclipse, Varian Medical System, Palo Alto, CA, USA) for patients with prostate cancer. We selected 25 plans of patients with prostate cancer who were previously treated on the basis of a VMAT plan. All plans were imported into the Eclipse Treatment Planning System version 15. Read More

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September 2021

Comparison of combinations of irradiation techniques and jaw conditions in intensity-modulated radiotherapy for lung cancer.

J Appl Clin Med Phys 2021 Sep 10. Epub 2021 Sep 10.

Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China.

Purpose: To assist in the selection of a suitable combination of an irradiation technique and jaw condition in intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc radiotherapy (VMAT) for lung cancer treatment plans.

Materials And Methods: Thirty patients with lung cancer who underwent radiotherapy were enrolled retrospectively. They were categorized as having central lung cancer, peripheral lung cancer with mediastinal lymph node metastasis (peripheral E lung cancer), and peripheral lung cancer without mediastinal lymph node metastasis (peripheral N lung cancer). Read More

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September 2021

Pre-treatment sTNFR1 and HGF levels predict toxicity and overall survival after Y radioembolization: potential novel application of biomarkers for personalized management of hepatotoxicity.

J Nucl Med 2021 Sep 9. Epub 2021 Sep 9.

Department of Radiology, University of Michigan.

Liver function may be negatively affected by radiation for treatment of hepatic malignancy. Pretreatment blood cytokine levels are biomarkers for prediction of toxicity and survival after external beam radiation therapy. We hypothesized that cytokines may also predict outcomes after radioembolization, enabling a biomarker-driven personalized approach to treatment. Read More

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September 2021

Modeling early radiation DNA damage occurring during [Lu]Lu-DOTA-[Tyr]octreotate radionuclide therapy.

J Nucl Med 2021 Sep 9. Epub 2021 Sep 9.

IRSN, Institut de Radioprotection et de Sûreté Nucléaire, France.

: The aim of this study is to build a simulation framework to evaluate the number of DNA double strand breaks (DSBs) induced by targeted radionuclide therapy (TRT). This work represents the first step towards exploring underlying biological mechanisms and influence of physical/chemical parameters to enable a better response prediction in patients. We used this tool to characterize early DSB induction by [Lu]Lu-DOTA-[Tyr]octreotate (Lu-DOTATATE), a commonly used TRT for neuroendocrine tumors. Read More

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September 2021

Hybrid Tomo-Helical and Tomo-Direct radiotherapy for localized prostate cancer.

J Appl Clin Med Phys 2021 Sep 8. Epub 2021 Sep 8.

Department of Radiation Oncology, Faculty of Medicine, Akdeniz University, Antalya, Turkey.

Purpose: The aim of the study is to present a new planning approach to provide better planning target volume (PTV) coverage and reduce bladder and rectum dose with hybrid Tomo-Helical (TH)/Tomo-Direct (TD) radiotherapy (RT) for localized prostate cancer (LPC).

Methods: Twenty-five LPC patients were included in this retrospective study. TH plans, TD plans, and hybrid TH/TD plans were created. Read More

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September 2021

Effective Organs-at-Risk Dose Sparing in Volumetric Modulated Arc Therapy Using a Half-Beam Technique in Whole Pelvic Irradiation.

Front Oncol 2021 18;11:611469. Epub 2021 Aug 18.

Department of Radiation Oncology, Ajou University School of Medicine, Suwon, South Korea.

Background: Although there are some controversies regarding whole pelvic radiation therapy (WPRT) due to its gastrointestinal and hematologic toxicities, it is considered for patients with gynecological, rectal, and prostate cancer. To effectively spare organs-at-risk (OAR) doses using multi-leaf collimator (MLC)'s optimal segments, potential dosimetric benefits in volumetric modulated arc therapy (VMAT) using a half-beam technique (HF) were investigated for WPRT.

Methods: While the size of a fully opened field (FF) was decided to entirely include a planning target volume in all beam's eye view across arc angles, the HF was designed to use half the FF from the isocenter for dose optimization. Read More

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Radiotherapy dose-volume parameters predict facial lymphedema after concurrent chemoradiation for nasopharyngeal carcinoma.

Radiat Oncol 2021 Sep 6;16(1):172. Epub 2021 Sep 6.

Department of Radiation Oncology, Pusan National University Yangsan Hospital and Pusan National University School of Medicine, Yangsan, 50612, Republic of Korea.

Background: To investigate risk factors for developing radiation-associated facial lymphedema (FL) in nasopharyngeal carcinoma (NPC) patients after concurrent chemoradiation (CCRT).

Methods: Clinical data from 87 patients who underwent definitive CCRT for NPC in 2010-2018 was retrospectively evaluated. FL severity was graded using MD Anderson Cancer Center head and neck lymphedema rating scale. Read More

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September 2021

Dosimetric evaluation for temporomandibular joint cone beam computed tomography exams using different field of view.

Biomed Phys Eng Express 2021 Sep 17;7(6). Epub 2021 Sep 17.

Division of Oral Radiology, Faculdade São Leopoldo Mandic, Instituto de Pesquisas São Leopoldo Mandic, Campinas, São Paulo (SP), 13045-755, Brazil.

To optimize the absorbed organ dose in relation to the field of view for temporomandibular joint examinations in four cone beam computed tomography devices.An anthropomorphic adult head and neck phantom, and 192 LiF dosimeters (TLD-100) were used. The dosimeters were placed in the region corresponding to the lens, parotid glands, submandibular glands, and thyroid. Read More

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September 2021

Advanced dose calculation algorithm in superficial brachytherapy - the impact of tissue inhomogeneity on treatment plan dosimetry.

J Contemp Brachytherapy 2021 Aug 28;13(4):441-446. Epub 2021 May 28.

Treatment Planning Department, Maria Sklodowska-Curie National Research Institute of Oncology Gliwice Branch, Poland.

Purpose: Given tissue inhomogeneity and lack of backscatter media, superficial brachytherapy necessitates more accurate dosimetry than TG-43 formalism. However, the introduction of modern model-based dose calculation algorithms into clinical practice should be carefully evaluated. The aim of this work was to compare dose distributions calculated with TG-43 and advanced collapsed cone engine (ACE) algorithms for individual multi-catheter moulds, and investigate the impact of target size and the lack of bolus to differences between plans. Read More

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Role of non-absorbable oral antibiotics in bowel preparation for intracavitary brachytherapy: effects of rifaximin on rectal dosimetric parameters during vaginal cuff brachytherapy.

J Contemp Brachytherapy 2021 Aug 24;13(4):426-432. Epub 2021 Aug 24.

Department of Clinical Oncology, Golestan Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

Purpose: Brachytherapy is a major tool for dose escalation in gynecological cancer treatment. Control of rectal repletion is particularly challenging; it can impact dose received by this organ at risk and there are reported toxicities. The use of methods, such as enema and bowel preparation, to reduce rectal volume is a difficult process for patients, and its repeatability requires patients' cooperation. Read More

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Comparison of Radiation Pneumonitis in Lung Cancer Patients Treated with HT versus IMRT and Circulating Lymphocyte Subsets as Predicting Risk Factors.

J Inflamm Res 2021 28;14:4205-4215. Epub 2021 Aug 28.

Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Chongqing University Cancer Hospital, Chongqing, People's Republic of China.

Purpose: We sought to compare the symptomatic radiation pneumonitis (RP) in lung cancer patients treated with helical tomotherapy (HT) versus intensity-modulated radiotherapy (IMRT), and examine the predictive value of circulating lymphocyte subsets affecting the occurrence of RP.

Patients And Methods: Circulating lymphocyte subsets, clinical characteristics, dosimetric parameters and pulmonary function were collected from 130 lung cancer patients treated with HT (n = 53) or IMRT (n = 77) from 2016 through 2020. Symptomatic RP was compared between groups. Read More

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Comparison of Dose Distribution Between VMAT-SBRT and Scanning Carbon-ion Radiotherapy for Early-stage NSCLC.

Anticancer Res 2021 Sep;41(9):4571-4575

Department of Radiation Oncology, Kanagawa Cancer Center, Yokohama, Japan.

Background/aim: The purpose of this study was to compare the dose distribution between scanning carbon-ion radiotherapy (sCIRT) and volumetric-modulated arc therapy with stereotactic body radiation therapy (VMAT-SBRT) for stage I non-small cell lung cancer (NSCLC).

Patients And Methods: Fifteen patients with early-stage NSCLC who underwent sCIRT at Kanagawa Cancer Center between 2018-2020 were enrolled. Dose-volume histogram parameters of the planned target volume and normal organs for sCIRT and VMAT-SBRT were evaluated. Read More

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September 2021

A novel TPS toolkit to assess correlation between transit fluence dosimetry and DVH metrics for adaptive head and neck radiotherapy.

Phys Eng Sci Med 2021 Aug 31. Epub 2021 Aug 31.

Department of Physics, The University of Adelaide, Adelaide, SA, 5005, Australia.

Inter-fractional anatomical variations in head and neck (H&N) cancer patients can lead to clinically significant dosimetric changes. Adaptive re-planning should thus commence to negate any potential over-dosage to organs-at-risk (OAR), as well as potential under-dosage to target lesions. The aim of this study is to explore the correlation between transit fluence, as measured at an electronic portal imaging device (EPID), and dose volume histogram (DVH) metrics to target and OAR structures in a simulated environment. Read More

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The impact of organ-at-risk contour variations on automatically generated treatment plans for NSCLC.

Radiother Oncol 2021 Aug 27;163:136-142. Epub 2021 Aug 27.

Department of Radiation Oncology (Maastro), GROW School for Oncology, Maastricht University Medical Centre+, Maastricht, The Netherlands.

Background And Purpose: Quality of automatic contouring is generally assessed by comparison with manual delineations, but the effect of contour differences on the resulting dose distribution remains unknown. This study evaluated dosimetric differences between treatment plans optimized using various organ-at-risk (OAR) contouring methods.

Materials And Methods: OARs of twenty lung cancer patients were manually and automatically contoured, after which user-adjustments were made. Read More

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Study of relationship between dose, LET and the risk of brain necrosis after proton therapy for skull base tumors.

Radiother Oncol 2021 Aug 27;163:143-149. Epub 2021 Aug 27.

Institute of Nuclear Physics Polish Academy of Sciences, 31342 Krakow, Poland.

Purpose: We investigated the relationship between RBE-weighted dose (DRBE) calculated with constant (cRBE) and variable RBE (vRBE), dose-averaged linear energy transfer (LETd) and the risk of radiographic changes in skull base patients treated with protons.

Methods: Clinical treatment plans of 45 patients were recalculated with Monte Carlo tool FRED. Radiographic changes (i. Read More

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Dosimetric impact of contrast-enhanced 4d computed tomography for stereotactic body radiation therapy of hepatocelluar carcinoma.

Rep Pract Oncol Radiother 2021 12;26(4):598-604. Epub 2021 Aug 12.

Govt. Cancer Hospital, NSCB Medical College, Jabalpur, Madhya Pradesh, India.

Background: A purpose of the study was to investigate the dosimetric impact of contrast media on dose calculation using average 4D contrast-enhanced computed tomography (4D-CECT) and delayed 4D-CT (d4D-CT) images caused by CT simulation contrast agents for stereotactic body radiation therapy (SBRT) of liver cases.

Materials And Methods: Fifteen patients of liver SBRT treated using the volumetric modulated arc therapy (VMAT) technique were selected retrospectively. 4D-CECT, and d4D-CT were acquired with the Anzai gating system and GE CT. Read More

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A simulation study of ionizing radiation acoustic imaging (iRAI) as a real-time dosimetric technique for ultra-high dose rate radiotherapy (UHDR-RT).

Med Phys 2021 Aug 25. Epub 2021 Aug 25.

Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA.

Purpose: Electron-based ultra-high dose rate radiation therapy (UHDR-RT), also known as Flash-RT, has shown the ability to improve the therapeutic index in comparison to conventional radiotherapy (CONV-RT) through increased sparing of normal tissue. However, the extremely high dose rates in UHDR-RT have raised the need for accurate real-time dosimetry tools. This work aims to demonstrate the potential of the emerging technology of Ionized Radiation Acoustic Imaging (iRAI) through simulation studies and investigate its characteristics as a promising relative in vivo dosimetric tool for UHDR-RT. Read More

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A Planning Comparison of IMRT vs. Pencil Beam Scanning for Deep Inspiration Breath Hold Lung Cancers.

Med Dosim 2021 Aug 20. Epub 2021 Aug 20.

Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.

Deep inspiration breath hold (DIBH) has dosimetric advantages for lung cancer patients treated with external beam therapy, but is difficult for many patients to perform. Proton therapy permits sparing of the downstream organs at risk (OAR). We compared conventionally fractionated proton (p) and photon(x) plans on both free breathing (FB) and DIBH planning CTs to determine the effect of DIBH with proton therapy. Read More

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Generating pseudo-computerized tomography (P-CT) scan images from magnetic resonance imaging (MRI) images using machine learning algorithms based on fuzzy theory for radiotherapy treatment planning.

Med Phys 2021 Aug 21. Epub 2021 Aug 21.

Department of Radiation Oncology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Purpose: The substitution of computerized tomography (CT) with magnetic resonance imaging (MRI) has been investigated for external radiotherapy treatment planning. The present study aims to use pseudo-CT (P-CT) images created by MRI images to calculate the dose distribution for facilitating the treatment planning process.

Methods: In this work, following image segmentation with a fuzzy clustering algorithm, an adaptive neuro-fuzzy algorithm was utilized to design the Hounsfield unit (HU) conversion model based on the features vector of MRI images. Read More

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Dosimetric comparison and biological evaluation of fixed-jaw intensity-modulated radiation therapy for T-shaped esophageal cancer.

Radiat Oncol 2021 Aug 19;16(1):158. Epub 2021 Aug 19.

Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University, No. 241 West Huaihai Road, Xuhui District, Shanghai, 200030, China.

Background: To evaluate the dosimetric and biological benefits of the fixed-jaw (FJ) intensity-modulated radiation therapy (IMRT) technique for patients with T-shaped esophageal cancer.

Methods: FJ IMRT plans were generated for thirty-five patients and compared with jaw tracking (JT) IMRT, static jaw (SJ) IMRT and JT volumetric modulated arc therapy (VMAT). Dosimetric parameters, tumor control probability (TCP) and normal tissue complication probability (NTCP), monitor units (MUs), delivery time and gamma passing rate, as a measure of dosimetric verification, were compared. Read More

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