Evaluating the plan quality of a general head-and-neck knowledge-based planning model versus separate unilateral/bilateral models
In this study, our aim was to explore whether site-specific KBP models lead to clinically meaningful differences in plan quality for head-and-neck (HN) patients when compared to a general model. (Source: Medical Dosimetry)
Source: Medical Dosimetry - November 16, 2022 Category: Radiology Authors: Kirk Luca, Justin Roper, Jonathan Wolf, Oluwatosin Kayode, Jeffrey Bradley, William A. Stokes, Jiahan Zhang Source Type: research
Dosimetric benefits of 3D-printed modulated electron bolus following lumpectomy and whole-breast radiotherapy for left breast cancer
In this study, we examine the feasibility of using modulated electron bolus (MEB) to improve PTV conformity and reduce the dose to these OARs. Twenty-seven patients with left breast cancer were retrospectively selected in this study. (Source: Medical Dosimetry)
Source: Medical Dosimetry - November 3, 2022 Category: Radiology Authors: Venus W.Y. Lee, Alex C.H. Liu, Ken W. Cheng, Chi-Leung Chiang, Victor Ho-Fun Lee Source Type: research
VMAT partial arc technique decreases dose to organs at risk in whole pelvic radiotherapy for prostate cancer when compared to full arc VMAT and IMRT
Whole pelvic radiotherapy (WPRT) can sterilize microscopic lymph node metastases in treatment of prostate cancer. WPRT, compared to prostate only radiotherapy (PORT), is associated with increased acute gastrointestinal, and hematological toxicities. To further explore minimizing normal tissue toxicities associated with WPRT in definitive IMRT for prostate cancer, this planning study compared dosimetric differences between static 9-field-IMRT, full arc VMAT, and mixed partial-full arc VMAT techniques. (Source: Medical Dosimetry)
Source: Medical Dosimetry - October 29, 2022 Category: Radiology Authors: Gregory K. Bartlett, Christopher F. Njeh, Ke C. Huang, Colleen DesRosiers, Gordon Guo Source Type: research
Evaluation of RayStation's delivered dose and accumulated dose features for spine stereotactic radiotherapy
We investigated delivered dose and dose accumulation features in the dose tracking module of RayStation version 11B before potential integration into the spine stereotactic radiosurgery (SSRS) program at our institution. End-to-end testing with a rigid Rando phantom was performed, and 10 retrospective clinical cases were selected for evaluation. Pre-treatment cone beam CTs (pCBCT) were corrected for Hounsfield unit (HU) integrity (cCBCT) and contours were rigidly copied from the reference plan. We then calculated the delivered dose to the corrected cone beam CT (cCBCT). (Source: Medical Dosimetry)
Source: Medical Dosimetry - October 26, 2022 Category: Radiology Authors: Marissa Joyce Vaccarelli, Shane Paul Krafft, Tina Marie Briere, Stina Svensson, Eun Young Han Tags: Dosimetry Contribution Source Type: research
Dose verification of virtual bolus application for helical tomotherapy
The objective of the study is to verify the dose delivered on helical tomotherapy based on treatment plan with varying virtual bolus (VB) thickness. The target was localized on the ArcCHECK image by 3 mm margin from the phantom surface. The dimension of target, which includes the ArcCHECK's detectors, with the 4.0 cm width and length 12.0 cm along the phantom The 5 treatment plans were generated, 1 plan without VB application (NoVB) and the 4 plans with varying of VB thickness on the phantom surface by 0.5 cm (VB0.5), 1.0 cm (VB1.0), 1.5 cm (VB1.5), and 2.0 cm (VB2.0), in treatment planning but absent during irradiation. (...
Source: Medical Dosimetry - October 25, 2022 Category: Radiology Authors: Saw Yu Nwe, Imjai Chitapanarux, Wannapha Nobnop Source Type: research
Clinical target volume segmentation based on gross tumor volume using deep learning for head and neck cancer treatment
Accurate clinical target volume (CTV) delineation is important for head and neck intensity-modulated radiation therapy. However, delineation is time-consuming and susceptible to interobserver variability (IOV). Based on a manual contouring process commonly used in clinical practice, we developed a deep learning (DL)-based method to delineate a low-risk CTV with computed tomography (CT) and gross tumor volume (GTV) input and compared it with a CT-only input. A total of 310 patients with oropharynx cancer were randomly divided into the training set (250) and test set (60). (Source: Medical Dosimetry)
Source: Medical Dosimetry - October 21, 2022 Category: Radiology Authors: Sayaka Kihara, Yuhei Koike, Hideki Takegawa, Yusuke Anetai, Satoaki Nakamura, Noboru Tanigawa, Masahiko Koizumi Source Type: research
A measurement validation of improved plan deliverability with monitor unit objective tool for spine stereotactic ablative radiotherapy
Spine stereotactic body radiation therapy (SBRT) uses high dose per fraction for palliative pain control. The treatment plans are often heavily modulated due to close proximity to spinal cord and this can lead to poor plan quality which are susceptible to dose delivery discrepancy. Therefore, we aim to assess the effectiveness of the monitor unit (MU) objective tool in Eclipse treatment planning systems in modulating the plan complexity to improve the plan quality in spine SBRT.Seven retrospective spine SBRT plans are re-optimized using the MU objective tool in Eclipse TPS v13.6 and were compared with the original plans. (...
Source: Medical Dosimetry - October 21, 2022 Category: Radiology Authors: Junhao Phua, Glen Yong Jie Mok, Khong Wei Ang, James Cheow Lei Lee, Sung Yong Park, Hong Qi Tan Source Type: research
Dosimetric comparison of robotic- and LINAC-based treatment of spine stereotactic body radiotherapy
To determine which treatment technique and modality would offer better dosimetric results and be preferable for spinal stereotactic body therapy (SBRT) depending on the three different regions of the vertebrae. Linear accelerator (LINAC)- and CyberKnife (CK)-based treatment techniques were compared in terms of their dosimetric quality, treatment efficiency, and delivery accuracy. Thirty previously treated patients were included in this study. Intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) techniques were used for LINAC-based treatment, whereas CK-based treatment plans were generated for...
Source: Medical Dosimetry - September 27, 2022 Category: Radiology Authors: Hilal Acar, Omer Yazici, Dilek Unal Source Type: research
Assessment of semi-automated stereotactic treatment planning for online adaptive radiotherapy in ethos
The Ethos treatment planning system allows for the rapid generation of online adaptive treatment plans while the patient is on the treatment couch. One promising application of online adaptive radiotherapy is its use in stereotactic radiotherapy. The purpose of this study was to ensure the Ethos treatment planning system (TPS) can produce clinically acceptable stereotactic plans, that are non-inferior to those from the Eclipse TPS. (Source: Medical Dosimetry)
Source: Medical Dosimetry - September 18, 2022 Category: Radiology Authors: Mikel Byrne, Ben Archibald-Heeren, Yunfei Hu, Peter Greer, Suhuai Luo, Trent Aland Source Type: research
A Dosimetric evaluation of a high dose rate cobalt-60 brachytherapy source using shielded, single and multi-channel cylinder applicators for gynecological cancers
This study utilizes a pelvis phantom with three different volumes of bladder and rectum to perform dose measurement around the cylindrical applicators. (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 27, 2022 Category: Radiology Authors: M. Abtahi, Afsaneh Maddah Safaei, Peyman Sheikhzade, S. Gholami Source Type: research
Based on 0.35 T magnetic resonance-guided radiotherapy, what are the nonisotropic PTV margins required for conventional prostate radiotherapy?
This study aims to calculate planning target volume (PTV) margins for the prostate and seminal vesicles (SVs) from the use of magnetic resonance-guided radiation therapy (MRgRT). And whether nonisotropic PTV margins are beneficial for these structures. Organ motion is linked to the displacement of the prostate and SVs. From the use of MRgRT, the nearby organs at risk (OAR) can be visualized both inter- and intrafraction. This study looked to determine if there is a correlation between interfractional OAR changes and displacements to the prostate and SVs. (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 27, 2022 Category: Radiology Authors: Joseph Drabble, Prantik Das, Ben George, Philip Camilleri, Alex Morris Source Type: research
Statistical analysis of correlation of gamma passing results for two quality assurance phantoms used for patient-specific quality assurance in volumetric modulated arc radiotherapy
Patient-specific quality assurance (QA) data must be migrated from outdated QA systems to new ones to produce objective results that can be understood by oncologists. We aimed to evaluate a method for obtaining a high correlation of dose distributions according to various gamma passing rates among two types of 2D detectors for the migration of patient-specific QA data of volumetric modulated arc therapy (VMAT). The patient-specific QA of 20 patients undergoing VMAT was measured in two different modes: standard single measurement (SM) mode and multiple merged measurements (MM) techniques using ArcCHECK (AC) and OCTAVIUS (OT...
Source: Medical Dosimetry - July 15, 2022 Category: Radiology Authors: Yuki Kunii, Yoshinori Tanabe, Akira Nakamoto, Kunio Nishioka Source Type: research
A survey of medical dosimetrists ’ perceptions of efficiency and consistency of auto-contouring software
Although auto-contouring methods were created to reduce the workload for the radiation oncology team, concern lies in whether auto-contouring can improve efficiency regarding generated contours of a treatment plan. Researchers have measured differences between auto-contouring algorithms and manual contour methods specific to the contouring of organs at risk (OAR). The problem lies in the paucity of literature specific to perceptions of auto-contouring and the impact on workflow efficiency. The purpose of this study was to measure medical dosimetrists ’ perceptions of how auto-contouring software impacts the treatment pla...
Source: Medical Dosimetry - July 13, 2022 Category: Radiology Authors: Amber Coffey, Jose Moreno, Nishele Lenards, Ashley Hunzeker, Matt Tobler Source Type: research
Comparison of setup errors of immobilization devices for thoracic radiotherapy
This study was performed to compare setup errors of TAFIDs and ICTIDs. Forty-four patients with lung cancer were retrospectively reviewed; 22 patients were immobilized with a TAFID and 22 with an ICTID. In total, 343 cone-beam computed tomography images of these patients were collected for radiotherapy setup. The 3-dimensional setup errors and the displacement of the acromioclavicular joint against the supraclavicular region were calculated. (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 13, 2022 Category: Radiology Authors: Bao Wan, Bin Liang, Fukui Huan, Fengyu Lu, Wenbo Zhang, Yu Zhao, Tianhang Hong, Boyu Yang, Tantan Li, DongFu Chen, Qinfu Feng, Zefeng Xiao, Jima Lv, Nan Bi, Zongmei Zhou, Xin Feng, Wenyang Liu Tags: Research Article Source Type: research
Feasibility Study of Stereotactic Radiosurgery Treatment of Glomus Jugulare Tumors via HyperArc VMAT
This study aims to report on the clinical validation and feasibility of utilizing a novel fully automated treatment planning and delivery system, HyperArc VMAT stereotactic radiosurgery (SRS) for glomus jugulare tumors (GJT). Independent dose verification of the HyperArc module via the MD Anderson's SRS head phantom irradiation and credentialing results showed compliance with the SRS treatment requirements per IROC MD Anderson's standard. Following the Alliance clinical trial, AAPM, RTOG protocols, and QUENTAC requirements, utilizing selected three-partial arc geometry of HyperArc module on TrueBeam Linac with 6MV-FFF beam...
Source: Medical Dosimetry - June 15, 2022 Category: Radiology Authors: Damodar Pokhrel, Richard Mallory, Matthew Bush, William St. Clair, Mark E. Bernard Tags: Medical Physics Contribution Source Type: research
