Radiation Medicine Commons^™

Feasibility Evaluation Of Tumor Treating Fields For Brainstem Gliomas, Anthony Chen, Ryan Shah, William Shi, Noa Urman, Nadav Shapira, Nicholas Avgeropoulos, Patrick Conlon, Neil Mookerjee, Wenyin Shi

Department of Radiation Oncology Faculty Papers

PURPOSE: Tumor treating fields (TTFields) are FDA-approved for supratentorial glioblastoma, but feasibility in infratentorial tumors remains poorly defined. This simulation study evaluated TTFields dose in brainstem gliomas using patient-specific modeling with scalp-only transducer arrays.

METHODS: MRI and CT imaging from seven patients with brainstem gliomas were used for TTFields planning with MAXPOINT® (Novocure, Switzerland). Clinical target volume (CTV) was defined as enhancing tumor on T1 post-contrast MRI (Gross tumor volume, GTV) plus a 3 mm peritumoral expansion. The platform optimized scalp-only array layouts, and finite element calculations generated maps of local minimum field intensity (LMiFI, V/cm) and local minimum power …

Reirradiation Treatment Effects In The Clinic (Retec) Proposal - Proof Of Concept Based On Spinal Cord Dose Tolerance For Reirradiation With Stereotactic Body Radiotherapy, Jimm Grimm, Anand Mahadevan, Olusola Obayomi-Davies, Scott G. Soltys, Arjun Sahgal, Kristin J. Redmond, Michael T. Milano, Wolfgang A. Tomé, Kenneth Brooks, Scott Dodd, John Austin Vargo, Gopal Subedi, Jinyu Xue, Bisher Ebid, Felix Ehret, Byung-Han Andrew Rhieu, Christoph Fürweger, Rachel Grimm, Alexander Muacevic, Vitali Moiseenko, Shalom Kalnicki, Mark Mclaughlin, Lawrence R. Kleinberg, John R. Adler, Iris C. Gibbs

College of Health Professions Faculty Papers

BACKGROUND: Since the inception of spinal radiosurgery decades ago, the factors influencing spinal cord recovery have remained unclear. Elucidating these factors would aid in reirradiation planning and delivery. We describe modeling reirradiation normal tissue complication probabilities (NTCP) from compiled published data, akin to the collaborative Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) and High Dose per Fraction, Hypofractionated Treatment Effects in the Clinic (HyTEC) projects.

PURPOSE: Simple dose-time recovery factors for the spinal cord serve as a basis to propose the Reirradiation Treatment Effects in the Clinic (ReTEC) project. ReTEC aims to define human organ recovery factors …

Predicting Ventilation From Single Breathing Phase Non-Contrast Ct Using Swin Transformers, Yi-Kuan Liu, Hsu-Ting Kuo, Alaa Melek, Richard Castillo, Yevgeniy Vinogradskiy, Lili Zhao, Girish Nair, Edward Castillo

Department of Radiation Oncology Faculty Papers

BACKGROUND: Pulmonary ventilation imaging enables functional avoidance radiotherapy treatment plans by quantifying regional lung function. However, current clinical standards, such as 99𝑚Tc-based single-photon emission computed tomography (SPECT), rely on radioactive tracers, which can introduce imaging deposition artifacts. CT ventilation imaging (CTVI) methods based on both physical models and deep learning approaches currently require multiple CT images as input, such as the inhale/exhale phases of a 4DCT. While the theoretical foundation of physics-based CTVI is built on multi-phase information, the feasibility of single-phase deep learning CTV models has not been determined.

PURPOSE: While deep learning methods have predicted SPECT ventilation from …

Computed Tomography For Four-Dimensional Dose Calculation: Effect Of Detector Array Length, Inhwan Yeo, Qianyi Xu

Department of Radiation Oncology Faculty Papers

PURPOSE: Four-dimensional computed tomography (4DCT) is susceptible to a geometrical error when respiration changes upon patient shift. 4DCT using 16-cm detector arrays, not needing the shift, has been shown to improve geometrical accuracy, compared with a conventional 4DCT (4-cm array), albeit with some Hounsfield unit discrepancies. The 4DCTs were validated for 4D planning.

MATERIALS AND METHODS: A lung-mimicking phantom containing a spherical target with ten respiratory traces and three tumor-shaped targets with their traces was respectively imaged when, to each of the ten-positions/phases, the lung was moved (1) step-wisely by helical scan at each movement (ground truth; 4DCT_GT), …

Evaluation Of The Intempo Path Set For Cyberknife Prostate And Lung Sbrt: A Single-Institution Experience, Yingcui Jia, Lei Fu, Shari Rudoler, Eric Gressen, Yevgeniy Vinogradskiy, Qianyi Xu

Department of Radiation Oncology Faculty Papers

PURPOSE: The InTempo adaptive imaging system is an important component of the Accuray CyberKnife System, designed to enhance the system's ability to track and correct tumor motion during treatment. However, a limitation of this feature is the reduction of available nodes for treatment planning. The impact of a reduced number of nodes on the quality of InTempo-based treatment plans has not previously been evaluated. This retrospective study aims to compare the dosimetry of CyberKnife plans with and without The InTempo path set for both prostate and lung stereotactic body radiotherapy (SBRT).

METHODS: This study included twelve consecutive prostate SBRT patients …

Clinical Test Cases For Commissioning, Qa, And Benchmarking Of Model-Based Dose Calculation Algorithms In 1⁹2ir Hdr Gynecologic Tandem And Ring Brachytherapy, Vasiliki Peppa, Maude Robitaille, Fatemeh Akbari, Shirin Enger, Rowan Thomson, Firas Mourtada, Gabriel Fonseca

Department of Radiation Oncology Faculty Papers

PURPOSE: To develop clinically relevant test cases for commissioning Model-Based Dose Calculation Algorithms (MBDCAs) for ¹⁹²Ir High Dose Rate (HDR) gynecologic brachytherapy following the workflow proposed by the TG-186 report and the WGDCAB report 372.

ACQUISITION AND VALIDATION METHODS: Two cervical cancer intracavitary HDR brachytherapy models were developed based on a real patient, using either uniformly structured regions or realistic segmentation. The patient's computed tomography (CT) images were processed, converted to a series of digital imaging and communications in medicine (DICOM) CT images, and imported into two treatment planning systems (TPSs), the Oncentra Brachy and BrachyVision. The original segmentation …

Detection Of Phase-Binning And Interpolation Artifacts In 4-Dimensional Computed Tomography Imaging Using Deep Learning And Rule-Based Approaches, Jorge Cisneros, Nathan H. Feldt, Yevgeniy Vinogradskiy, Richard Castillo, Edward Castillo

Department of Radiation Oncology Faculty Papers

BACKGROUND: Four-dimensional computed tomography (4DCT) imaging is a crucial component to lung cancer radiotherapy planning and enables CT-ventilation-based functional avoidance planning to mitigate radiation toxicity. However, 4DCT scans are frequently impaired by acquisition artifacts that corrupt downstream analyses that depend on lung segmentation and deformable image registration, such as CT-ventilation and dose accumulation.

PURPOSE: This study develops 3D deep learning models to identify phase-binning artifacts at the voxel level and a heuristic, rule-based method to identify interpolation slices within 4DCT images.

METHODS: We introduce a generator that systematically inserts synthetic phase-binning and interpolation artifacts into any artifact-free breathing phase obtained …

A Feasibility Study Of Sexual Organ-Dose Sparing Volumetric Modulated Arc Therapy In Female Low Rectal Cancer Patients Treated With Three-Dimensional Conformal Radiation Therapy, Margaret Downes, Victoria Olsen, Andre Williams, Rendi Sheu, Maria Thor, Lucy Greenwald, Vishruta Dumane, Kristin Hsieh, Ayesha Ali, Orly Morgan, Michael Buckstein, Deborah Marshall

Department of Radiation Oncology Faculty Papers

BACKGROUND: Sexual dysfunction is a significant toxicity of pelvic radiation therapy (RT) for female rectal cancer patients and may be more common with intensity-modulated techniques compared to three-dimensional conformal radiation therapy (3D-CRT). However, limited research has evaluated dose sparing of female sexual organs at risk (OARs), particularly erectile tissues that are critical for sexual function.

PURPOSE: This feasibility study aimed to demonstrate the practicality of contouring and sparing female sexual OARs in rectal cancer RT by generating sexual organ-sparing volumetric modulated arc therapy (SO-VMAT) plans from a small 3D-CRT cohort and comparing dose distributions to guide future planning.

METHODS: Nine …

Enhancing Cyberattack Resiliency Through The Radiotherapy Backup And Recovery Dashboard Tool, Justin Pijanowski, Eric Nguyen, Yasin Abdulkadir, Justin Hink, Yevgeniy Vinogradskiy, James Lamb

Department of Radiation Oncology Faculty Papers

PURPOSE: Radiation Oncology departments impacted by recent cyberattacks were unable to access data backups or their Record and Verify (R&V) system and therefore faced challenges to resume patient treatments in a timely manner. We present a novel software tool that backs-up critical radiotherapy treatment information and displays essential information for on-treatment patients in an intuitive and accessible dashboard allowing clinics to continue radiotherapy treatments. The purpose of this report is to describe implementation details, challenges, and share open-source code to facilitate radiation oncology clinics' efforts to develop tools to improve cyberattack resiliency.

METHODS: The Radiotherapy Backup and Recovery Dashboard Tool …

Evaluation Of Image Quality In Mobile Cone-Beam Ct With Dose Modulation Using Automatic Exposure Control: A Phantom Study, Keita Okazaki, Wenchao Cao, Reza Taleei, Firas Mourtada, Jun Li, Karen Mooney, Pramila Rani Anne, Yingxuan Chen

Department of Radiation Oncology Faculty Papers

BACKGROUND: The integration of mobile cone-beam computed tomography (CBCT) into brachytherapy workflows offers clinical advantages such as immediate verification of applicator placement and adaptive treatment planning. These benefits require sufficient image quality to delineate applicators, target volumes, and organs at risk. A systematic evaluation of automatic exposure control (AEC) settings, radiation dose, and image quality is essential to ensure clinically acceptable imaging while minimizing patient exposure.

PURPOSE: This study evaluates the characteristics of AEC and its impact on image quality and radiation dose in a mobile CBCT system used for brachytherapy.

METHODS: The Elekta ImagingRing CBCT system was used to …

Investigating The Necessity Of Adaptive Radiotherapy In Tomotherapy Of Head And Neck Cancer Patients, Ali Chaparian, Mahsa Kianinia, Mahnaz Roayaei, Nadia Najafizade, Abolfazl Kanani, Leili Mahani, Hamidreza Nourzadeh

Department of Radiation Oncology Faculty Papers

BACKGROUND: Anatomical variations that occur during radiation therapy in head and neck cancer (HNC) patients can lead to significant dosimetric changes. The purpose of this study is to evaluate dosimetric and volume changes in key anatomical structures for different treatment sites in HNC patients, and to determine the percentage of patients who need adaptive radiotherapy (ART) per treatment site.

METHODS: A total of 1,740 megavoltage computed tomography (MVCT) images from 58 HNC patients treated with helical tomotherapy (HT) were exported to the PreciseART™ (Accuray) software. Volume changes in the planning target volume (PTV) and the organs at risk (OARs) in …

Cone Beam Ct Dose Optimisation: A Review And Expert Consensus By The 2022 Estro Physics Workshop Igrt Working Group, Lydia J. Wilson, Andria Hadjipanteli, Daniella E. Østergaard, Evelien Bogaert, Kirstie F. Brown, Rianne Dejong, James Earley, Magali Edouard, Marina Khan, Josh Lindsay, Jessica Van Der Himst, George X. Ding, Tim Wood, Marianne C. Aznar, Nuria Jornet, Georgios Ntentas

Department of Radiation Oncology Faculty Papers

Image guided radiotherapy (IGRT) using kilovoltage cone-beam CT (CBCT) has become an indispensable tool to ensure the geometric accuracy of radiotherapy treatment delivery. Although significant technical advances have been made in reducing imaging dose, the repeated imaging procedures can still accumulate significant dose to healthy tissues. Despite the widespread use, we still lack clear guidance for optimisation and widely accepted frameworks for evaluating the quality and suitability of CBCT imaging protocols. To address this gap, the 2022 European Society for Radiotherapy and Oncology (ESTRO) Physics Workshop focused on image-quality and imaging-dose optimisation for IGRT using CBCT. This publication represents a …

Evaluating Artifact-Free Four-Dimensional Computer Tomography With 16 Cm Detector Array, Inhwan Yeo, Wei Nie, Jiajin Fan, Mindy Joo, Michael Correa, Qianyi Xu

Department of Radiation Oncology Faculty Papers

PURPOSE: To evaluate a 16 cm-array axial four-dimensional computer tomography (4DCT) in comparison with a 4 cm-array 4DCT in the presence of respiration irregularity.

METHOD: Ten traces of lung tumor motion from CyberKnife treatments were imported to move the lung cylinder, containing a spherical target, of a phantom. Images were acquired for the lung that moved to each of the 10-positions/phases (1) step-wisely by nominal helical scan at each movement (ground truth), (2) continuously by 4D scan with the 16 cm array, and (3) the same with the 4 cm array, involving table shift. Irregularities, consisting of baseline shift and/or …

Deep Learning-Based Auto-Segmentation For Liver Yttrium-90 Selective Internal Radiation Therapy, Jun Li, Wookjin Choi, Rani Anne

Department of Radiation Oncology Faculty Papers

The aim was to evaluate a deep learning-based auto-segmentation method for liver delineation in Y-90 selective internal radiation therapy (SIRT). A deep learning (DL)-based liver segmentation model using the U-Net3D architecture was built. Auto-segmentation of the liver was tested in CT images of SIRT patients. DL auto-segmented liver contours were evaluated against physician manually-delineated contours. Dice similarity coefficient (DSC) and mean distance to agreement (MDA) were calculated. The DL-model-generated contours were compared with the contours generated using an Atlas-based method. Ratio of volume (RV, the ratio of DL-model auto-segmented liver volume to manually-delineated liver volume), and ratio of activity (RA, …

Conference Report: Review Of Clinical Implementation Of Advanced Quantitative Imaging Techniques For Personalized Radiotherapy, Yevgeniy Vinogradskiy, Houda Bahig, Nicholas Bucknell, Jeffrey Buchsbaum, Hui-Kuo George Shu

Department of Radiation Oncology Faculty Papers

The topic of quantitative imaging in radiation therapy was presented as a "Masterclass" at the 2023 annual meeting of the American Society of Radiation Oncology (ASTRO). Dual-energy computed tomography (CT) and single-positron computed tomography were reviewed in detail as the first portion of the meeting session, with data showing utility in many aspects of radiation oncology including treatment planning and dose response. Positron emission tomography/CT scans evaluating the functional volume of lung tissue so as to provide optimal avoidance of healthy lungs were presented second. Advanced brain imaging was then discussed in the context of different forms of magnetic resonance …

Ai-Assisted Segmentation Tool For Brain Tumor Mr Image Analysis, Myungeun Lee, Jong Hyo Kim, Wookjin Choi, Ki Hong Lee

Department of Radiation Oncology Faculty Papers

TumorPrism3D software was developed to segment brain tumors with a straightforward and user-friendly graphical interface applied to two- and three-dimensional brain magnetic resonance (MR) images. The MR images of 185 patients (103 males, 82 females) with glioblastoma multiforme were downloaded from The Cancer Imaging Archive (TCIA) to test the tumor segmentation performance of this software. Regions of interest (ROIs) corresponding to contrast-enhancing lesions, necrotic portions, and non-enhancing T2 high signal intensity components were segmented for each tumor. TumorPrism3D demonstrated high accuracy in segmenting all three tumor components in cases of glioblastoma multiforme. They achieved a better Dice similarity coefficient (DSC) …

Real World Clinical Experience Using Daily Intelligence-Assisted Online Adaptive Radiotherapy For Head And Neck Cancer, Philip Blumenfeld, Eduard Arbit, Robert Den, Ayman Salhab, Tal Falick Michaeli, Marc Wygoda, Yair Hillman, Raphael Pfeffer, Marcel Fang, Yael Misrati, Noam Weizman, Jon Feldman, Aron Popovtzer

Department of Radiation Oncology Faculty Papers

Background

Adaptive radiation therapy (ART) offers a dynamic approach to address structural and spatial changes that occur during radiotherapy (RT) for locally advanced head and neck cancers. The integration of daily ART with Cone-Beam CT (CBCT) imaging presents a solution to enhance the therapeutic ratio by addressing inter-fractional changes.

Methods

We evaluated the initial clinical experience of daily ART for patients with head and neck cancer using an online adaptive platform with intelligence-assisted workflows on daily CBCT. Treatment included auto-contour and structure deformation of Organs at Risk (OARs) and target structures, with adjustments by the treating physician. Two plans were …