Evaluation of the effect of user-guided deformable image registration of thoracic images on registration accuracy among users
In this study, 4-dimensional computed tomographic images of 10 thoracic cancer patients were used. The dataset for these patients was provided by DIR-Lab (www.dir-lab.com) and included a coordinate list of anatomical landmarks (300 bronchial bifurcations). (Source: Medical Dosimetry)
Source: Medical Dosimetry - January 30, 2020 Category: Radiology Authors: Yujiro Nakajima, Noriyuki Kadoya, Takayuki Kanai, Masahide Saito, Satoshi Kito, Shimpei Hashimoto, Katsuyuki Karasawa, Keiichi Jingu Source Type: research
The comparison of VMAT test results for Clinac 2300C/D and TrueBeam accelerators
This study aimed to compare long-term VMAT performance QA on 3 accelerators: TrueBeam (TB) and 2 Clinacs (V4 and V5). All VMAT test plans were provided by Varian. (Source: Medical Dosimetry)
Source: Medical Dosimetry - January 29, 2020 Category: Radiology Authors: Agata Latala, Edyta Fujak, Agnieszka Walewska, Pawe ł Kukołowicz Source Type: research
Optimizing planning CT using past CT images for prostate cancer volumetric modulated arc therapy
This study aimed to evaluate a new method to optimize planning computed tomography (CT) using three-dimensional (3D) displacement error between the planning and diagnosed past CT scans. Thirty-two patients undergoing volumetric modulated arc therapy for prostate cancer were evaluated for a 3D displacement error between bone- and prostate-matching spatial coordinates using multiple acquisition planning CT (MPCT) scans. Each MPCT image and a past CT image were used to perform rigid image registration (RIR) and deformable image registration (DIR), and the 3D displacement error was calculated. (Source: Medical Dosimetry)
Source: Medical Dosimetry - January 29, 2020 Category: Radiology Authors: Yoshinori Tanabe, Takayuki Ishida, Hidetoshi Eto, Tatsuhiro Sera, Yuki Emoto Source Type: research
Dosimetric comparison of iPlan Ⓡ Pencil Beam (PB) and Monte Carlo (MC) algorithms in stereotactic radiosurgery/radiotherapy (SRS/SRT) plans of intracranial arteriovenous malformations
This study is a retrospective dosimetric comparison of iPlan Ⓡ Monte Carlo (MC) and Pencil Beam (PB) algorithms in SRS/SRT plans of cranial arteriovenous malformations (AVMs). PB plans of 60 AVM patients who were already treated using 6 MV photons from a linear accelerator were selected and divided into 2 groups. (Source: Medical Dosimetry)
Source: Medical Dosimetry - January 26, 2020 Category: Radiology Authors: Sharika Venugopal Menon, Raghukumar Paramu, Saju Bhasi, Zhenia Gopalakrishnan, Sarin Bhaskaran, Raghuram Kesavan Nair Source Type: research
A comparison of dose and set-up accuracy between flexed and extended neck positions in Helical Tomotherapy of nasopharyngeal carcinoma
This study investigated the dosimetric and set-up accuracy differences between these 2 set-up positions. Twenty NPC patients treated with HT from each set-up position were retrospectively recruited. HT plans were computed using the same target prescription and organs at risks (OARs) constraints for both set-up positions. The doses parameters of the target volumes and OARs were assessed. (Source: Medical Dosimetry)
Source: Medical Dosimetry - January 21, 2020 Category: Radiology Authors: Jason CP Lam, Vincent WC Wu, George Chiu, Pauline SW Kong, CM Wong Source Type: research
Dosimetric comparison between volumetric-modulated arc therapy and a hybrid volumetric-modulated arc therapy and segmented field-in-field technique for post-mastectomy chest wall and regional lymph node irradiation
(Source: Medical Dosimetry)
Source: Medical Dosimetry - January 16, 2020 Category: Radiology Source Type: research
Optimization of autogenerated chest-wall radiation treatment plans developed for postmastectomy breast cancer patients in underserved clinics
Over the past decade, several strides have been made to improve the management of breast cancer in developing countries; however, there are still obstacles present. In the area of radiation therapy, these hurdles include limited access to radiotherapy treatment and scarcity of oncology specialists. In an effort to reduce inequities in cancer care while improving patient outcomes, our research is focused on developing automated postmastectomy radiation therapy (PMRT) plans for breast cancer patients in these underserved communities that can be further improved upon through treatment planning system (TPS) specific optimizati...
Source: Medical Dosimetry - January 15, 2020 Category: Radiology Authors: Temiloluwa O. Esho, Christine V. Chung, Juanita U. Thompson, Mahsa Dehghanpour, Jordan R. Sutton, Simona F. Shaitelman, Kelly K. Kisling, Laurence E. Court Tags: 2019 Student Writing Competition —1st Place Source Type: research
MR-Linac Collimator Size Limitation and Impact on the Treatment of GYN Patients
(Source: Medical Dosimetry)
Source: Medical Dosimetry - January 12, 2020 Category: Radiology Source Type: research
Controlling heterogeneity within the lymphatic target volume for dose painted treatment of prostate cancer
We describe the creation of a control structure that can be incorporated into the optimization objective function. (Source: Medical Dosimetry)
Source: Medical Dosimetry - January 1, 2020 Category: Radiology Authors: Andrew M. McDonald, Robert S. Kirkland, Jared A. Mass, Allison P. Dalton Source Type: research
A sliding-window approach for improved VMAT dose calculation accuracy
The continuous delivery of volumetric modulated arc therapy (VMAT) plans is usually approximated by discrete apertures at evenly-spaced gantry angles for dose calculation purposes. This approximation can potentially lead to large dose calculation errors if the gantry angle spacings are large and/or there are large changes in the MLC apertures from one control point (CP) to the next. In this work, we developed a sliding-window (SW) method to improve VMAT dose calculation accuracy. For any 2 adjacent VMAT CPs ni and ni + 1, the dose distribution was approximated by a 2-CP SW IMRT beam with the starting MLC positions at ...
Source: Medical Dosimetry - December 30, 2019 Category: Radiology Authors: Haitham N Alahmad, Ji-Yeon Park, Nicholas J Potter, Bo Lu, Guanghua Yan, Chihray Liu, Jonathan G Li Source Type: research
Proton pencil beam scanning treatment with feedback based voluntary moderate breath hold
Introduction The aim of this article is to introduce a novel protocol for proton pencil beam scanning treatment with moderate deep inspiration breath hold (mDIBH) and report on our clinical implementation results. Methods Three computed tomography (CT) scannings to build the patient's anatomy model were performed during the patient's voluntary mDIBH. All 3 CT scans were used in the optimization during the treatment planning process. Both orthogonal kV imaging and cone-beam computed tomography (CBCT) were implemented for patient alignment with BH prior to the treatment. (Source: Medical Dosimetry)
Source: Medical Dosimetry - December 19, 2019 Category: Radiology Authors: Peng Wang, Shikui Tang, Karla Leach, Victor Mangona, Charles B. Simone, Katja Langen, Chang Chang Source Type: research
Small bowel dose in subserosal tandem insertion during cervical cancer brachytherapy
In this study, we aimed to quantify and further predict individual SB dose increase and to increase focus on the SB in subserosal tandem insertions. Images and dosimetry data of cervical cancer brachytherapy with subserosal insertion (SI) were reviewed. The percentage increases in the SB dose compared with intracavitary insertion (II) at 8 points of D(x)cc with 10 cc intervals were assessed. (Source: Medical Dosimetry)
Source: Medical Dosimetry - December 17, 2019 Category: Radiology Authors: Yu-Lun Tsai, Pei-Chieh Yu, Louis Tak Lui, Suzun Shaw, Ching-Jung Wu Source Type: research
Functional cranio-spinal irradiation: A hippocampal and hypothalamic-pituitary axis sparing radiation technique using two IMRT modalities
In this study, we compared the efficacy of Volumetric Modulated Arc Therapy (VMAT) and Helical Tomotherapy (HT) in delivering this n ovel CSI technique. (Source: Medical Dosimetry)
Source: Medical Dosimetry - December 12, 2019 Category: Radiology Authors: Jack Zheng, Saif Aljabab, Patricia Lacasse, Jamie Bahm, Katie Lekx-Toniolo, Laval Grimard Source Type: research
Optimization of the accelerated partial breast brachytherapy fractionation considering radiation effect on planning target and organs at risk
The same fractionation scheme of accelerated partial breast irradiation (APBI) with brachytherapy is usually applied to APBI patients without considering the radiaton effect on the planning target and organs at risk (OARs) for an individual patient. The purpose of this study is to report the results of optimization of the fractionation scheme by evaluating the radiation effect on target and OARs with a modified linear-quadratic model, universal survival curve (USC), based on dose-volume histograms (DVHs). (Source: Medical Dosimetry)
Source: Medical Dosimetry - December 6, 2019 Category: Radiology Authors: Weihua Fu, Mohammed Saiful Huq Source Type: research
The mean absolute dose deviation –A common metric for the evaluation of dose-volume histograms in radiation therapy
Radiation therapy needs to balance between delivering a high dose to targets and the lowest possible dose to the organs at risk. Dose-volume histograms (DVHs) summarize the distribution of radiation doses in the irradiated structures. The interpretation can however be a challenge when the number of structures is high. We propose the use of a simple summary metric. We define the mean absolute dose deviation (MADD) as the average of absolute differences between a DVH and a reference dose. The properties are evaluated through numerical analysis. (Source: Medical Dosimetry)
Source: Medical Dosimetry - November 18, 2019 Category: Radiology Authors: Vincent Vinh-Hung, Nicolas Leduc, Dirk Verellen, Claire Verschraegen, Giovanna Dipasquale, Nam P. Nguyen Source Type: research
