1,677 results match your criteria ptv dosimetric

Assessment of HDR brachytherapy-replicating prostate radiotherapy planning for tomotherapy, cyberknife and VMAT.

Med Dosim 2021 Sep 19. Epub 2021 Sep 19.

Sir Charles Gairdner Hospital, Perth, Australia; 5D Clinics, Perth, Australia; University of Western Australia, Perth, Australia. Electronic address:

A dosimetric study was undertaken to assess the ability of Cyberknife (CK), Volumetric Modulated Arc Therapy (VMAT), and TomoTherapy (Tomo) to generate treatment plans that mimic the dosimetry of high dose-rate brachytherapy (HDR BT) for prostate cancer. The project aimed to assess the potential of using stereotactic body radiotherapy (SBRT) for boost treatment of high-risk prostate cancer patients where HDR BT in combination with conformal external beam radiotherapy (EBRT) is the standard of care. The datasets of 6 prostate patients previously treated with HDR BT were collated. 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

New fractionations in breast cancer: a dosimetric study of 3D-CRT versus VMAT.

J Med Radiat Sci 2021 Sep 22. Epub 2021 Sep 22.

Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Roma, Italy.

Introduction: Adjuvant radiation therapy (RT) following primary surgery in women affected by early breast cancer (EBC) plays a central role in reducing local recurrences and overall mortality. The FAST-FORWARD trial recently demonstrated that 1-week hypofractionated adjuvant RT is not inferior to the standard schedule in terms of local relapse, cosmetic outcomes and toxicity. The aim of this in silico study was to evaluate the dosimetric aspects of a 1-week RT course, administered through volumetric modulated arc therapy (VMAT), compared with traditional three-dimensional conformal radiation therapy (3D-CRT) with tangential fields. 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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Abdominal synthetic CT reconstruction with intensity projection prior for MRI-only adaptive radiotherapy.

Phys Med Biol 2021 Sep 16. Epub 2021 Sep 16.

Medical Artificial Intelligence and Automation (MAIA) Laboratory, Department of Radiation Oncology, The University of Texas Southwestern Medical Center, Dallas, Texas, UNITED STATES.

Objective: Owing to the superior soft tissue contrast of MRI, MRI-guided adaptive radiotherapy (ART) is well-suited to managing interfractional changes in anatomy. An MRI-only workflow is desirable, but producing synthetic CT (sCT) data through paired data-driven deep learning (DL) for abdominal dose calculations remains a challenge due to the highly variable presence of intestinal gas. We present the preliminary dosimetric evaluation of our novel approach to sCT reconstruction that is well suited to handling intestinal gas in abdominal MRI-only ART. Read More

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September 2021

Initial analysis of the dosimetric benefit and clinical resource cost of CBCT-based online adaptive radiotherapy for patients with cancers of the cervix or rectum.

J Appl Clin Med Phys 2021 Sep 16. Epub 2021 Sep 16.

Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.

Purpose: This provides a benchmark of dosimetric benefit and clinical cost of cone-beam CT-based online adaptive radiotherapy (ART) technology for cervical and rectal cancer patients.

Methods: An emulator of a CBCT-based online ART system was used to simulate more than 300 treatments for 13 cervical and 15 rectal cancer patients. CBCT images were used to generate adaptive replans. Read More

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September 2021

A comparative study on hypofractionated whole-breast irradiation with sequential or simultaneous integrated boost on different positions after breast-conserving surgery.

Sci Rep 2021 Sep 9;11(1):18017. Epub 2021 Sep 9.

Department of Radiation Oncology, Shandong Cancer Hospital and Institute (Shandong Cancer Hospital), Shandong First Medical University and Shandong Academy of Medical Sciences, 440 Jiyan Road, Jinan, 250117, China.

This study explored the dosimetric difference between hypofractionated whole-breast irradiation (HFWBI) with sequential boost (SEB) and simultaneous integrated boost (SIB) based on supine and prone positions to identify the superior boost mode and superior position. Thirty breast cancer patients eligible for HFWBI after breast-conserving surgery were enrolled. All patients underwent 3DCT simulation scanning in both supine and prone positions. Read More

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September 2021

Deterioration of Intended Target Volume Radiation Dose Due to Anatomical Changes in Patients with Head-and-Neck Cancer.

Cancers (Basel) 2021 Aug 24;13(17). Epub 2021 Aug 24.

Department of Radiation Oncology, Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands.

Delivered radiation dose can differ from intended dose. This study quantifies dose deterioration in targets, identifies predictive factors, and compares dosimetric to clinical patient selection for adaptive radiotherapy in head-and-neck cancer patients. One hundred and eighty-eight consecutive head-and-neck cancer patients treated up to 70 Gy were analyzed. Read More

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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

Predicting the effect of indirect cell kill in the treatment of multiple brain metastases via single-isocenter/multitarget volumetric modulated arc therapy stereotactic radiosurgery.

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

Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky, USA.

Purpose: Due to spatial uncertainty, patient setup errors are of major concern for radiosurgery of multiple brain metastases (m-bm) when using single-isocenter/multitarget (SIMT) volumetric modulated arc therapy (VMAT) techniques. However, recent clinical outcome studies show high rates of tumor local control for SIMT-VMAT. In addition to direct cell kill (DCK), another possible explanation includes the effects of indirect cell kill (ICK) via devascularization for a single dose of 15 Gy or more and by inducing a radiation immune intratumor response. Read More

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September 2021

Evaluation of VMAT Planning Strategies for Prostate Patients with Bilateral Hip Prosthesis.

Technol Cancer Res Treat 2021 Jan-Dec;20:15330338211038490

7005Beaumont Health, Troy, MI, USA.

In this study, we investigate linac volumetric-modulated arc therapy (VMAT) planning strategies for bilateral hip prostheses prostate patients with respect to plan quality and deliverability, while limiting entrance dose to the prostheses. Three VMAT plans were retrospectively created for 20 patients: (1) partial arcs (PA), (2) 2 full arcs optimized with 500 cGy max prostheses dose (MD), and (3) 2 full arcs optimized with max dose-volume histogram (DVH) constraint of 500 cGy to 10% prostheses volume (MDVH). PA techniques contained 6 PA with beam angles that avoid entering each prosthesis. Read More

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September 2021

A dosimetric and radiobiological evaluation of VMAT following mastectomy for patients with left-sided breast cancer.

Radiat Oncol 2021 Sep 6;16(1):171. Epub 2021 Sep 6.

Department of Radiation Oncology, Jiangxi Cancer Hospital of Nanchang University, Nanchang, Jiangxi, 330029, People's Republic of China.

Background: To compare the dosimetric, normal tissue complication probability (NTCP), secondary cancer complication probabilities (SCCP), and excess absolute risk (EAR) differences of volumetric modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT) for left-sided breast cancer after mastectomy.

Methods And Materials: Thirty patients with left-sided breast cancer treated with post-mastectomy radiation therapy (PMRT) were randomly enrolled in this study. Both IMRT and VMAT treatment plans were created for each patient. Read More

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September 2021

Fully automated planning and delivery of hippocampal-sparing whole brain irradiation.

Med Dosim 2021 Sep 1. Epub 2021 Sep 1.

Department of Radiation Oncology, Loyola University Medical Center, Maywood, IL, 60153 USA.

The goal of this study is to fully automate the treatment planning and delivery process of hippocampal-sparing whole brain irradiation (HS-WBRT) by combining a RapidPlan (RP) knowledge-based planning model and HyperArc (HA) technology. Additionally, this study compares the dosimetric performance of RapidPlan-HyperArc (RP-HA) treatment plans with RP plans and volumetric modulated arc therapy (VMAT) plans. Ten patients previously treated with HS-WBRT using conventional VMAT were re-planned using RP-HA technique and RP model for HS-WBRT. Read More

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September 2021

Phase I Trial of Stereotactic MRI-guided Online Adaptive Radiation Therapy (SMART) for the Treatment of Oligometastatic Ovarian Cancer.

Int J Radiat Oncol Biol Phys 2021 Aug 30. Epub 2021 Aug 30.

Department of Radiation Oncology, Rutgers University, New Brunswick, NJ.

Objective: SBRT is increasingly used to treat a variety of oligometastatic histologies, but few data exist for ovarian cancer. Ablative SBRT dosing is challenging in sites like the abdomen, pelvis, and central thorax due to proximity and motion of organs-at-risk. A novel radiation delivery method, stereotactic magnetic-resonance-guided online-adaptive radiotherapy (SMART), may improve SBRT's therapeutic index through enhanced soft-tissue visualization, real-time non-ionizing imaging, and ability to adapt to the anatomy-of-the-day, with the goal of producing systemic-therapy-free intervals. Read More

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Dosimetric comparison of intensity modulated radiotherapy and intensity modulated proton therapy in the treatment of recurrent nasopharyngeal carcinoma.

Med Dosim 2021 Aug 29. Epub 2021 Aug 29.

Department of Medical Physics, Pamela Youde Nethersole Eastern Hospital, Hong Kong.

Background And Purpose: To compare the dosimetric performance of Intensity Modulated Proton Therapy (IMPT) and Intensity Modulated Radiotherapy (IMRT) in terms of target volume coverage and sparing of neurological organs-at-risk (OARs) in salvaging recurrent nasopharyngeal carcinoma (rNPC). The maximum dose to the internal carotid artery (ICA) and nasopharyngeal (NP) mucosa, which are associated with potential carotid blowout and massive epistaxis, were also evaluated.

Materials And Methods: IMRT and IMPT treatment plans were created for twenty patients with locally advanced rNPC. Read More

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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 study of Hounsfield number correction effect in areas influenced by contrast product in lungs case.

Rep Pract Oncol Radiother 2021 12;26(4):590-597. Epub 2021 Aug 12.

HASSAN II Oncology Center, University Hospital Mohammed VI, Oujda, Morocco.

Background: The aim of the study was dosimetric effect quantification of exclusive computed tomography (CT) use with an intravenous (IV) contrast agent (CA ), on dose distribution of 3D-CRT treatment plans for lung cancer. Furthermore, dosimetric advantage investigation of manually contrast-enhanced region overriding, especially the heart.

Materials And Methods: Ten patients with lung cancer were considered. Read More

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Dosimetric impact of Acuros XB on cervix radiotherapy using RapidArc technique: a dosimetric study.

Rep Pract Oncol Radiother 2021 12;26(4):582-589. Epub 2021 Aug 12.

Medical Physics Division and Radiation Oncology Department, Rajiv Gandhi Cancer Institute and Research Center, New Delhi, India.

Background: Acuros XB (AXB) may predict better rectal toxicities and treatment outcomes in cervix carcinoma. The aim of the study was to quantify the potential impact of AXB computations on the cervix radiotherapy using the RapidArc (RA ) technique as compared to anisotropic analytical algorithm (AA) computations.

Materials And Methods: A cohort of 30 patients previously cared for cervix carcinoma (stages II-IIIB) was selected for the present analysis. Read More

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Evaluation of volumetric modulated arc therapy (VMAT) - based total body irradiation (TBI) in pediatric patients.

Rep Pract Oncol Radiother 2021 12;26(4):518-527. Epub 2021 Aug 12.

Department of Radiation Oncology, M.K. Dedeman Oncology Hospital, School of Medicine, Erciyes University, Kayseri, Turkey.

Background: The dosimetric characterization of volumetric modulated arc therapy (VMAT)-based total-body irradiation (TBI) in pediatric patients is evaluated.

Materials And Methods: Twenty-two patients between the ages of 2 and 12 years were enrolled for VMAT-based TBI from 2018 to 2020. Three isocenters were irradiated over three overlapping arcs. Read More

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Dosimetric Comparison Between Helical Tomotherapy and Volumetric Modulated Arc Therapy in Patients With Malignant Pleural Mesothelioma.

Clin Oncol (R Coll Radiol) 2021 Aug 21. Epub 2021 Aug 21.

Department of Radiation Oncology, University Hospital Bonn, University of Bonn, Bonn, Germany.

Aims: To carry out a dosimetric comparison and constraints feasibility proof of adjuvant radiotherapy through helical tomotherapy or volumetric modulated arc therapy (VMAT) for malignant pleural mesothelioma patients after pleurectomy/decortication.

Materials And Methods: Retrospective calculations were carried out on previously acquired simulations. A whole-pleura volume with 50. 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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Stereotactic body radiotherapy using a hydrogel spacer for localized prostate cancer: A dosimetric comparison between tomotherapy with the newly-developed tumor-tracking system and cyberknife.

J Appl Clin Med Phys 2021 Aug 20. Epub 2021 Aug 20.

Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan.

Purpose: With a new tumor-tracking system (Synchrony®) for tomotherapy (Radixact®), the internal and set-up margins can be tightened, like cyberknife (CyberKnife®), in the planning of stereotactic body radiotherapy (SBRT) for prostate cancer. Recently, the usefulness of placing a hydrogel spacer between the prostate and rectum has been established in prostate radiotherapy. We evaluated the characteristics of tomotherapy plans with the tumor-tracking system and compared them with cyberknife SBRT plans for localized prostate cancer using a hydrogel spacer. 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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[Study on the assignment method of intensity modulated radiotherapy plan for nasopharyngeal carcinoma based on MR images].

Zhonghua Zhong Liu Za Zhi 2021 Aug;43(8):850-855

Department of Radiation Physics, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan 250117, China.

To discuss the influence of different computed tomography (CT) value assignment methods on dose calculation of intensity modulated radiotherapy (IMRT) plan which designed for nasopharyngeal carcinoma (NPC) and the value assignment methods of IMRT plan for NPC based on magnetic resonance (MR) images. Simulation CT and MR image of 32 NPC patients in Shandong Cancer Hospital from March 2018 to November 2018 were selected for this study. Populate CT values were obtained by contouring and analyzing the simulation CT of patients' tissue, including bone, air, brain, eyeball, optic-nerve, lens, parotid, masseter, skin. Read More

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Toward MR-integrated proton therapy: modeling the potential benefits for liver tumors.

Phys Med Biol 2021 Sep 23;66(19). Epub 2021 Sep 23.

Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America.

Magnetic resonance imaging (MRI)-integrated proton therapy (MRiPT) is envisioned to improve treatment quality for many cancer patients. However, given the availability of alternative image-guided strategies, its clinical need is yet to be justified. This study aims to compare the expected clinical outcomes of MRiPT with standard of practice cone-beam CT (CBCT)-guided PT, and other MR-guided methods, i. Read More

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September 2021

Geometric and Dosimetric Changes in Tumor and Lung Tissue During Radiotherapy for Lung Cancer With Atelectasis.

Front Oncol 2021 22;11:690278. Epub 2021 Jul 22.

Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China.

Background And Purpose: This article retrospectively characterized the geometric and dosimetric changes in target and normal tissues during radiotherapy for lung cancer patients with atelectasis.

Materials And Methods: A total of 270 cone beam computed tomography (CBCT) scans of 18 lung patients with atelectasis were collected. The degree and time of resolution or expansion of the atelectasis were recorded. Read More

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Dosimetric study of a hybrid plan technique for external beam radiotherapy in patients with cervical cancer.

Radiat Environ Biophys 2021 Aug 6. Epub 2021 Aug 6.

División de Oncología y Uronefrología, Departamento de Radioterapia, Unidad Médica de Alta Especialidad, Hospital de Especialidades del Centro Médico Nacional "Ignacio García Téllez", Instituto Mexicano del Seguro Social, CP 97150, Mérida, Yucatán, México.

The aim of this study was to investigate the effect of a hybrid technique which results from combining intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) for the treatment of cervical cancer patients. Plans made with the hybrid technique and pure IMRT and VMAT were retrospectively compared in 20 patients with cervical cancer at different stages. All plans were made using the same contours based on the original computed tomography (CT) scans. Read More

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Evaluation of Auto-Planning for Left-Side Breast Cancer After Breast-Conserving Surgery Based on Geometrical Relationship.

Technol Cancer Res Treat 2021 Jan-Dec;20:15330338211033050

Department of Radiation Oncology, Yunnan Cancer Hospital, the Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China.

Purpose: This study aimed to evaluate (1) the performance of the Auto-Planning module embedded in the Pinnacle treatment planning system (TPS) with 30 left-side breast cancer plans and (2) the dose-distance correlations between dose-based patients and overlap volume histogram-based (OVH) patients.

Method: A total of 30 patients with left-side breast cancer after breast-conserving surgery were enrolled in this study. The clinical manual-planning (MP) and the Auto-Planning (AP) plans were generated by Monaco and by the Auto-Planning module in Pinnacle respectively. Read More

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