Dynamic hybrid-phase computed tomography simulation in lung stereotactic body radiotherapy: A feasibility study
To assess the feasibility of dynamic hybrid-phase computed tomography (CTDHP) simulation when patients undergo lung stereotactic body radiation therapy (SBRT). Eighteen non-small-cell lung-cancer patients were immobilised in a stereotactic body frame with abdominal compression. All underwent dynamic hybrid-phase CT scans that were compared with cone-beam CT (CBCT). We also determined the internal target volume (ITV) and evaluated the following four metrics: the “AND” function in the Boolean module of Eclipse, volume overlap (VO), Dice similarity coefficient (DSC), and dose-volume histogram. (Source: Medical Dosimetry)
Source: Medical Dosimetry - January 2, 2022 Category: Radiology Authors: Jing-Min Hwang, Jing-Yin Hung, You-Kang Chang, Shih-Miao Chang, Yu-Nong Wang, Chun-Shu Lin, Chiou-Shiung Chang Tags: Dosimetry Contribution: Source Type: research
Robust optimization used to mitigate setup uncertainties in vulvar patients receiving VMAT
Many radiation planning techniques have been used to increase dose to the vulvar surface when treating patients with vulvar cancer with volumetric modulated arc therapy. Target volumes near the skin surface, such as vulvar tumors, do not meet the International Commission on Radiation Units and Measurements safety guidelines. Without the needed expansions and setup uncertainties, there are concerns that treated dose to the vulvar surface varies from the planned dose. The purpose of this study was to determine if the robust optimization tool used in volumetric modulated arc therapy planning can reproducibly deliver prescript...
Source: Medical Dosimetry - December 31, 2021 Category: Radiology Authors: Robert Inshetski, Nishele Lenards, Ashley Hunzeker Source Type: research
A retrospective study to establish recommendations for plan quality metrics in Lung SBRT
In this study, we retrospectively evaluated plan quality in lung SBRT patients by calculating conformity, homogeneity, and gradient parameters using an in-house script. The goal of this study was to establish achievable, size-dependent recommendations for these plan quality metrics such that they may be used as a guideline in our clinic. (Source: Medical Dosimetry)
Source: Medical Dosimetry - December 29, 2021 Category: Radiology Authors: Fatemeh Akbari, Somayeh Taghizadeh, David Pearson Source Type: research
Intensity Modulated Proton Therapy Better Spares Non-Adjacent Organs and Reduces the Risk of Secondary Malignant Neoplasms in the Treatment of Sinonasal Cancers
This study compare dosimetric parameters and secondary malignancy risk (SMN) using intensity modulated proton therapy (IMPT) and volumetric modulated arc therapy (VMAT) plans for the treatment of sinonasal cancer (SC). After IRB-approval, 10 patients previously treated with IMPT for cancers of the ethmoid, sphenoid, maxillary, or frontal sinuses were identified. Dosimetrists blinded to the IMPT plans generated VMAT plans for comparison. Volume coverage and dose to organs at risk (OAR) were recorded and compared. (Source: Medical Dosimetry)
Source: Medical Dosimetry - December 21, 2021 Category: Radiology Authors: Luke Lewis, Paul Kreinbrink, Max Richardson, Morgan Westerfield, Madeline Doberstein, Yongbin Zhang, Kevin Redmond, Vinita Takiar Source Type: research
The Impact of COVID-19 on Medical Dosimetry Education: Students ’ Perception on the Effectiveness of Program's Immediate Response
In early 2020, many medical dosimetry programs began to offer lectures and clinical rotations remotely in response to COVID-19. Faculty instituted an IRB-approved study to investigate the effectiveness of medical dosimetry educational programs ’ immediate response to COVID-19 and modifications to teaching practices during the pandemic. The Program Response to COVID-19 Effectiveness Questionnaire (PRCEQ) survey was developed to measure students’ perceptions of their learning experience during COVID-19. (Source: Medical Dosimetry)
Source: Medical Dosimetry - November 26, 2021 Category: Radiology Authors: Mahsa Dehghanpour, Jamie Baker Source Type: research
Application of an automated dose accumulation workflow in high-risk prostate cancer - validation and dose-volume analysis between planned and delivered dose
This study compared planned (DP) vs accumulated doses (DA) obtained from daily cone-beam computed tomography (CBCT) scans in high-risk- prostate cancer with pelvic lymph nodes irradiation. An intensity-based deformable image registration algorithm used to estimate contours for DA was validated using geometrical agreement between radiation oncologist's and deformable image registration algorithm propagated contours. (Source: Medical Dosimetry)
Source: Medical Dosimetry - November 2, 2021 Category: Radiology Authors: Ashley Ong, Kellie Knight, Vanessa Panettieri, Mathew Dimmock, Jeffrey Kit Loong Tuan, Hong Qi Tan, Zubin Master, Caroline Wright Source Type: research
Analysis of R50% location dependence on LINAC-based VMAT cranial stereotactic treatments
Stereotactic radiosurgery (SRS) and stereotactic radiation therapy (SRT) techniques are used to deliver high doses per fraction to various types of intra-cranial targets. LINAC-based solutions are growing in prevalence due to recent advances in technologies such as high-definition multi-leaf collimators and volumetric arc therapy radiation delivery. A wide variety of clinical pathologies including intracranial metastases, meningioma, glioblastoma, arteriovenous malformation, acoustic neuroma, and trigeminal neuralgia have been successfully treated using SRS/SRT techniques. (Source: Medical Dosimetry)
Source: Medical Dosimetry - November 2, 2021 Category: Radiology Authors: Ivan L. Cordrey, Dharmin D. Desai, E. Lee Johnson Tags: Medical Physics Contribution Source Type: research
Dosimetric comparison and validation of Eclipse Anisotropic Analytical Algorithm (AAA) and AcurosXB (AXB) algorithms in RapidArc-based radiosurgery plans of patients with solitary brain metastasis
This study aims to compare and validate Anisotropic Analytical Algorithm (AAA) and AcurosXB (AXB) algorithms of Eclipse Treatment Planning System (TPS) in RapidArc-based SRS plans of patients with solitary brain metastasis. Twenty patients with solitary brain metastasis who have been already treated with RapidArc SRS plans calculated using AAA plans were selected for this study. These plans were recalculated using AXB algorithm keeping the same arc orientations, multi-leaf collimator apertures, and monitor units. (Source: Medical Dosimetry)
Source: Medical Dosimetry - November 2, 2021 Category: Radiology Authors: Sharika Venugopal Menon, Raghukumar P, Saju Bhasi, Zhenia Gopalakrishnan, Sarin B, Shilpa K, Raghuram K Nair Tags: Medical Physics Contribution Source Type: research
Dose accumulation of daily adaptive plans to decide optimal plan adaptation strategy for head-and-neck patients treated with MR-Linac
Advances in magnetic resonance linear accelerators (MR-Linacs) allow for superior visualization of soft tissue to guide online adaptive replanning for precise radiotherapy delivery. Elekta Unity MR-Linacs (Elekta AB, Stockholm, Sweden) provides 2 plan adaptation approaches, adapt-to-position (ATP), plan reoptimization based on the reference CT with the iso-shift measured from daily MR scans, and adapt-to-shape (ATS), full plan reoptimization based on the re-contoured daily MR scans. Our study aims to close the gap in knowledge regarding the use of the ATP technique in the treatment of head and neck (HN) cancers through the...
Source: Medical Dosimetry - October 27, 2021 Category: Radiology Authors: Shin Yun Lim, Alan Tran, Anh Ngoc Kieu Tran, Angela Sobremonte, Clifton D. Fuller, Lori Simmons, Jinzhong Yang Tags: 2021 Student Writing Competition - 1st Place Source Type: research
Difference in VMAT dose distribution for prostate cancer with/without rectal gas removal and/or adaptive replanning
We investigated differences in the volumetric-modulated arc therapy (VMAT) dose distribution in prostate cancer patients treated by rectal gas removal and/or adaptive replanning. Cone-beam computed tomography (CBCT) scans were performed daily for 22 treatments in eight prostate cancer patients with excessive rectal gas, and the CBCT images were analyzed. Rectal gas removal was performed, and irradiation was delivered after prostate matching. We compared dose-volume histograms for the daily CBCT images before and after rectal gas removal. (Source: Medical Dosimetry)
Source: Medical Dosimetry - October 24, 2021 Category: Radiology Authors: Yutaro Wada, Hajime Monzen, Masakazu Otsuka, Hiroshi Doi, Kiyoshi Nakamatsu, Yasumasa Nishimura Source Type: research
Interfraction dose deviation and catheter position in cervical interstitial and intracavitary image guided HDR brachytherapy
Interstitial and intracavitary gynecological HDR brachytherapy involve precise, localized delivery to targets with high dose gradients, sparing adjacent organs at risk (OAR). Due to the proximity of the rectum, bowel and bladder to the target, deviations in the applicator or catheter with respect to patient anatomy can significantly increase dose to OAR. The magnitude and direction of applicator and catheter migration at each fraction was assessed for template interstitial and tandem and ring (T&R) cohorts. (Source: Medical Dosimetry)
Source: Medical Dosimetry - October 23, 2021 Category: Radiology Authors: Yiwen Xu, Thomas Harris, Desmond O'Farrell, Robert Cormack, Larissa Lee, Martin King, Ivan Buzurovic Tags: Medical physics contribution Source Type: research
Systematic evaluation and plan quality assessment of the Leksell ® gamma knife® lightning dose optimizer
To compare stereotactic radiosurgery (SRS) plan quality metrics of manual forward planning (MFP) and Elekta Fast Inverse Planning ™ (FIP)-based inversely optimized plans for patients treated with Gamma Knife®. Clinically treated, MFP SRS plans for 100 consecutive patients (115 lesions; 67 metastatic and 48 benign) were replanned with the FIP dose optimizer based on a convex linear programming formulation. Comparative plans were generated to match or exceed the following metrics in order of importance: Target Coverage (TC), Paddick Conformity Index (PCI), beam-on time (BOT), and Gradient Index (GI). (Source: Medical Dosimetry)
Source: Medical Dosimetry - October 22, 2021 Category: Radiology Authors: D Jay Wieczorek, Rupesh Kotecha, Matthew D. Hall, Martin C. Tom, Stephen Davis, Manmeet S. Ahluwalia, Michael W. McDermott, Minesh P. Mehta, Alonso N. Gutierrez, Ranjini Tolakanahalli Source Type: research
Automatic one-click planning for hippocampal-avoidance whole-brain irradiation in RayStation
This study aimed to verify the accuracy of auto-contouring and auto-dose optimization for hippocampal-avoidance whole-brain radiation therapy (HA-WBRT). Head computed tomography (CT) images of 15 patients were selected. The regions of interest, containing the brain, hippocampus, eyes, and lacrimal glands, were contoured manually and automatically on CT images. They were compared and evaluated for concordance rates using the Simpson coefficient. To verify the performance of dose optimization, auto-dose planning was compared with manual planning for 15 cases. (Source: Medical Dosimetry)
Source: Medical Dosimetry - October 19, 2021 Category: Radiology Authors: Hiroaki Okada, Makoto Ito, Yoshitaka Minami, Kazuhiko Nakamura, Ayumi Asai, Sou Adachi, Arisa Takeuchi, Yukihiko Oshima, Kojiro Suzuki Tags: Clinical radiation oncology contribution Source Type: research
A Comparison of Robustness of Volumetric Modulated Arc Therapy and Dynamic Conformal Arc Therapy for Lung Stereotactic Body Radiation Therapy
(Source: Medical Dosimetry)
Source: Medical Dosimetry - October 6, 2021 Category: Radiology Source Type: research
Dosimetric benefits of dynamic conformal arc therapy-combined with active breath-hold in lung stereotactic body radiotherapy
To test the hypothesis that dynamic conformal arc therapy (DCAT) in Monaco, compared with volumetric modulated arc therapy (VMAT), maintains plan quality with higher delivery efficiency for lung stereotactic body radiotherapy (SBRT) and to investigate dosimetric benefits of DCAT with active breath-hold (DCAT+ABH), compared with free-breathing (DCAT+FB) for varying tumor sizes and motions. Fifty DCAT plans were used for lung SBRT. Randomly selected 17 DCAT plans were evaluated with respect to the retrospectively generated volumetric modulated arc therapy (VMAT) plans. (Source: Medical Dosimetry)
Source: Medical Dosimetry - September 25, 2021 Category: Radiology Authors: Soyoung Lee, Danny Lee, Vivek Verma, Danielle Waters, Seungjong Oh, Athanasios Colonias, Rodney Wegner, Daniel Pavord, Bryan Coopey, Russell Fuhrer, Jason W. Sohn Source Type: research
