Application of hypoglossal nerve constraint in definitive radiotherapy for nasopharyngeal carcinoma: A dosimetric feasibility study
Purpose: Radiation-induced hypoglossal nerve palsy is an infrequent but debilitating late complication after definitive radiotherapy for head and neck cancers. D1cc (Source: Medical Dosimetry)
Source: Medical Dosimetry - August 3, 2020 Category: Radiology Authors: James C.H. Chow, Jeffrey C.F. Lui, Kwok-Hung Au, Ka-Man Cheung, Roger K.C. Ngan, Alex K.C. Leung, Kenneth W.S. Li, Jeffrey C.H. Chan, Kam-Hung Wong, Francis K.H. Lee Source Type: research
Rationale for Using a C-Arm Fluoroscope to Deliver a Kilovoltage Radiotherapy Treatment to COVID-19 Patients
In 2013, Calabrese et al. described the effectiveness of early 20th century radiotherapy to treat viral and bacterial pneumonia patients, citing a cure rate of ∼80%.1 These were single fraction treatments of 30-100 cGy dose delivered with 100-200 kVp x-rays. These treatments stopped in the 1940s due to the availability of antibiotics and steroids, but in light of the lack of effective treatment options for COVID-19, radiotherapy could offer a viable and immediate option2,3 until a more effective cure becomes available. (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 24, 2020 Category: Radiology Authors: D. Roa, H. Moyses, S. Leon, B. Hamrick, G. Sarria, T. Tajima, A. Necas, C. Guzman, O. Paucar, A. Gonzales, R. Challco, M. Montoya, Z. Arqque, A. Gonzales, J. Hernandez Source Type: research
Evaluation of a new GPU-enabled VMAT multi-criteria optimisation plan generation algorithm
To evaluate the new Varian, graphical processing unit (GPU)-enabled, volumetric-modulated arc therapy (VMAT) multi-criteria optimisation (MCO) tool for both its dosimetric accuracy and calculation time. This is a new capability within V16.0 and greater of the Varian Eclipse treatment planning system that allows VMAT optimisation and dose calculation using the GPU (termed GPU-VMAT). In versions prior to V16.0 VMAT multi-criteria optimisation calculations were only possible using central processing unit (CPU) (termed CPU-VMAT) and Hybrid-VMAT (H-VMAT). (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 11, 2020 Category: Radiology Authors: Myles Spalding, Anthony Walsh, Trent Aland Source Type: research
A quantitative comparative study of medical dosimetry graduates with and without prior radiation therapy certification
All but a small number of formal medical dosimetry programs require radiation therapy certification for admission. The problem is a lingering perception from the radiation oncology community that medical dosimetry students must have a prior radiation therapy certification and/or experience. There is a paucity of evidence in the literature to support the perception that prior radiation therapy certification equates to better job performance as a medical dosimetrist. The purpose of this quantitative comparative study was to investigate outcomes of medical dosimetry graduates with and without prior radiation therapy certifica...
Source: Medical Dosimetry - July 9, 2020 Category: Radiology Authors: Nishele Lenards Source Type: research
Evaluation of replanning in intensity-modulated proton therapy for oropharyngeal cancer: Factors influencing plan robustness
The head and neck (H&N) region is frequently replanned during intensity-modulated proton therapy (IMPT), but replanning disrupts clinical workflow and presents additional burden on patients. The purpose of this study was to establish a standard treatment planning approach to minimize H&N replanning by identifying a correlation between dosimetric variables and replan frequency. In a retrospective study of 27 bilateral oropharyngeal cancer patients treated with IMPT at a single institution, cases were evaluated using Fisher's exact tests and logistic regression for a significant relationship between replan frequency and the ...
Source: Medical Dosimetry - July 9, 2020 Category: Radiology Authors: Noelle Deiter, Felicia Chu, Nishele Lenards, Ashley Hunzeker, Karen Lang, Daniel Mundy Source Type: research
Effects of gas-filled temporary breast tissue expanders on radiation dose from modulated rotational photon beams
This study therefore builds on previous investigations of the dosimetric effects of gas-filled TTEs in static photon and electron beams, by examining the effects of these implants on dose distributions from common modulated rotational treatment techniques; volumetric modulated arc therapy (VMAT) and helical tomotherapy (HT). (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 9, 2020 Category: Radiology Authors: Tanya Kairn, Marika Lathouras, Michelle Grogan, Benjamin Green, Steven R. Sylvander, Scott B. Crowe Source Type: research
A format for dosimetry comparison studies
There is no standardized format for presenting and discussing the results of a radiotherapy dosimetry comparison study. The purpose of this report is to describe a format that we have found useful in evaluating plans in our department and in reviewing studies from other groups. (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 7, 2020 Category: Radiology Authors: Robert J. Amdur, Roi Dagan, Adam Holtzman, Anamaria R. Yeung, Kathryn E. Hitchcock, William M. Mendenhall Source Type: research
Comparison of conventional and advanced radiotherapy techniques for left-sided breast cancer after breast conserving surgery
This study aims to compare seven WBRT techniques including conventional tangential, field-in-field (FIF), hybrid intensity-modulated radiotherapy (IMRT), IMRT, standard volumetric modulated arc therapy (STD-VMAT), noncoplanar VMAT (NC-VMAT), and multiple arc VMAT (MA-VMAT). Fifteen patients who were previously diagnosed with left-sided early stage breast cancer and treated in our clinic were selected for this study. (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 5, 2020 Category: Radiology Authors: Yibo Xie, Daniel Bourgeois, Beibei Guo, Rui Zhang Source Type: research
Optimized stereotactic volumetric modulated arc therapy as an alternative to brachytherapy for vaginal cuff boost. A dosimetric study
We evaluate the role of stereotactic body radiotherapy using volumetric modulated arc therapy (VMAT) technique as an alternative to high-dose rate brachytherapy (HDR-BT) in the treatment of vaginal cuff in postoperative endometrial cancer. CT scans of 8 patients were used in this study. The clinical target volume (CTV) was defined as the 0.5 cm tissue around the applicator (then subtracting the applicator). Total dose was 30Gy delivered in 5 fractions. In HDR-BT, dose was prescribed at a distance of 0.5 cm from the surface applicator. (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 18, 2020 Category: Radiology Authors: Savino Cilla, Gabriella Macchia, Giancarlo Mattiucci, Anna Ianiro, Carmela Romano, Milly Buwenge, Luigi Azario, Vincenzo Valentini, Francesco Deodato, Alessio G. Morganti Source Type: research
Flattening filter free beam energy selection and its impact in multitarget intracranial stereotactic radiosurgery treatments
This study aims to present a systematic dosimetric comparison of plan quality between 10 FFF vs 6 FFF beams in intracranial stereotactic radiosurgery (SRS) treatments using volumetric modulated arc therapy (VMAT). The dosimetric evaluation is based on radiation therapy oncology group (RTOG) dose conformity (CIRTOG) and gradient (GIRTOG) indices, and irradiated normal brain tissue volume. (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 13, 2020 Category: Radiology Authors: Samir Laoui, Dante E. Roa, Jeffrey Kuo, Maxim Baldytchev, Jonathan Gonzales, Salam Dietrich, Nilam Ramsinghani, Parima Daroui, Hanako Farol Source Type: research
Evaluation of beam-on time and number of breath-holds using a flattening-filter-free beam with the deep inspiration breath-hold method in left-sided breast cancer
We performed a dosimetric study to evaluate the benefits of using a flattening-filter-free (FFF) beam with the deep inspiration breath-hold (DIBH) method for left-breast cancer. We used data from 30 previous patients with treatment plans that included DIBH for left-breast cancer with a flattened beam. FFF beam plans were calculated from previous treatment plan images and compared to the original plans in terms of monitor units (MU), number of segments, beam-on time, and breath-holds. Beam-on time was calculated by adding the traveling time of 1.5 second between segments to the time calculated from the MU and dose rate. (So...
Source: Medical Dosimetry - June 12, 2020 Category: Radiology Authors: Toru Takakura, Satoshi Koubuchi, Aiki Uehara, Ayano Tashima, Tomoyo Hirose, Hiroto Kimura, Seiji Tachiiri, Masahiko Koizumi Source Type: research
Dosimetric and planning efficiency comparison for lung SBRT: CyberKnife vs VMAT vs knowledge-based VMAT
This is the first study that compared treatment plan quality and planning efficiency for lung stereotactic body radiation therapy (SBRT) using CyberKnife (CK) Multiplan vs Varian Eclipse treatment planning systems, including volumetric modulated arc therapy (VMAT) and knowledge-based VMAT (KBP-VMAT). Thirteen lung SBRT patients treated with 50 to 55 Gy in 3 or 5 fractions were retrospectively included in this study. CK plans created with Multiplan V. 4.6.1 using 2 fixed circular cones were previously approved used for treatment. (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 9, 2020 Category: Radiology Authors: Suhong Yu, Huijun Xu, Asa Sinclair, Xin Zhang, Ulrich Langner, Kimberley Mak Source Type: research
Dosimetric comparison of inverse and forward planning for Gamma Knife stereotactic radiosurgery of brain metastases
The Leksell GammaPlan (LGP) with an inverse planning (IP) tool has been upgraded to version 11.1 since its launch in 2010. We evaluated its IP planning performance by re-planning 16 targets that had been planned using forward planning (FP). The FP and IP plans were compared. A planning guideline for IP process was developed aiming for an unbiased comparison. Sixteen brain metastases (BMs) without nearby critical structures were included in the study (size> 1 cm for all targets). All prior FP were re-planned in the LGP using IP and maintaining the same beam-on time and coverage. (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 6, 2020 Category: Radiology Authors: Qianyi Xu, Dershan Luo, David Mulvihill, Warren Goldman, Alan Turtz, Gregory J. Kubicek Source Type: research
Dosimetric effects of dose calculation grid size on the epidural space dose
Introduction: The epidural disease progression is the most common pattern of failure after spine stereotactic body radiotherapy. The aim of this study was to clarify the effect of the dose calculation grid size (CGS) during volumetric modulated arc therapy planning on the dose to the epidural space target. Materials and Methods: In the planning, the volume obtained by subtracting the planning organ at risk volume (PRV) of the spinal cord and/or cauda equina from the planning target volume (PTV) was defined as the PTVeval. (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 6, 2020 Category: Radiology Authors: Hidetoshi Shimizu, Koji Sasaki, Hiroshi Tanaka, Takahiro Aoyama, Hiroyuki Tachibana, Yutaro Koide, Tohru Iwata, Tomoki Kitagawa, Takeshi Kodaira Tags: Research Article Source Type: research
A retrospective evaluation of mixed energy volumetric modulated arc therapy for anal cancers with lymph node involvement
Applying dual, or mixed photon energies during radiation therapy is a common practice in 3-dimensional conformal radiation therapy (3D-CRT). Mixed photon energies are used to provide uniform dose coverage to a planning target volume (PTV) that ranges in depth from the skin surface. Though the application of mixed photon energies in 3D-CRT was once the convention for treating anal cancers with lymph node involvement (AC-LNI), the advantages offered by volumetric modulated arc therapy (VMAT) prove to be the optimal form of therapy for AC-LNI. (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 6, 2020 Category: Radiology Authors: Mikayla Eskens, Helen Nguyen, William Deere, Nishele Lenards, Ashley Hunzeker, Matt Tobler Source Type: research
