Radiation Medicine Commons^™

Radiopharmaceutical Validation For Clinical Use, Charles A. Kunos, Rodney Howells, Aman Chauhan, Zin W. Myint, Mark E. Bernard, Riham H. El Khouli, Jacek Capala

Internal Medicine Faculty Publications

Radiopharmaceuticals are reemerging as attractive anticancer agents, but there are no universally adopted guidelines or standardized procedures for evaluating agent validity before early-phase trial implementation. To validate a radiopharmaceutical, it is desirous for the radiopharmaceutical to be specific, selective, and deliverable against tumors of a given, molecularly defined cancer for which it is intended to treat. In this article, we discuss four levels of evidence—target antigen immunohistochemistry, in vitro and in vivo preclinical experiments, animal biodistribution and dosimetry studies, and first-in-human microdose biodistribution studies—that might be used to justify oncology therapeutic radiopharmaceuticals in a drug-development sequence involving early-phase trials. We …

Stereotactic Body Radiation Therapy (Sbrt) For Patients With Stage I Non-Small Cell Lung Cancer Is Applicable To More Tumors Than Sublobar Resection, Andrew Song, Nathaniel R. Evans Iii, Scott W. Cowan, Jenny Guo, Tingting Zhan, Bo Lu, Maria Werner-Wasik

Department of Radiation Oncology Faculty Papers

Background: Virtually all patients with medically inoperable stage I non-small cell lung cancer (NSCLC) can receive stereotactic body radiation therapy. However, the percentage of such patients in whom sublobar resection is technically feasible is unknown. This discrepancy can confound clinical trial eligibility and designs comparing stereotactic body radiation therapy vs. sublobar resection.

Methods: A total of 137 patients treated with stereotactic body radiation therapy for lung lesions (3/2013-11/2017) underwent retrospective review. Diagnostic CT chest and PET/CT images, stereotactic body radiation therapy dates, and demographic data were collected on 100 of 137 patients. Two experienced board-certified thoracic surgeons independently reviewed anonymized …

High-Dose-Rate Brachytherapy For The Treatment Of Basal And Squamous Cell Carcinomas On Sensitive Areas Of The Face: A Report Of Clinical Outcomes And Acute And Subacute Toxicities, James M. Taylor, Bahar Dasgeb, Spencer Liem, Ayesha Ali, Amy Harrison, Mitchell Finkelstein, Jisun Cha, Rani Anne, Steven Greenbaum, William Sherwin, Wenyin Shi

Department of Radiation Oncology Faculty Papers

Purpose Basal cell and cutaneous squamous cell carcinoma are common malignancies (keratinocyte carcinomas [KCs]). Surgical resection is the standard of care. Radiation using high-dose rate brachytherapy (HDR-BT) may serve as a superior alternative where surgical scars may be of cosmetic concern or in elderly patients with significant comorbidity. We aim to describe the clinical and cosmetic outcomes as well as posttreatment radiation toxicities associated with HDR-BT in patients who were treated for KCs of the face.

Methods and Materials Patients with KCs treated with HDR-BT from 2015 to 2018 were included in the study. Patient medical records and clinical photos …

Mir-21 Plays A Dual Role In Tumor Formation And Cytotoxic Response In Breast Tumors, Tu Dan, Anuradha A. Shastri, Ajay Palagani, Simone Buraschi, Thomas Neill, Jason E Savage, Aastha Kapoor, Tiziana Deangelis, Sankar Addya, Kevin Camphausen, Renato V. Iozzo, Nicole L Simone

Department of Radiation Oncology Faculty Papers

Breast cancer (BrCa) relies on specific microRNAs to drive disease progression. Oncogenic miR-21 is upregulated in many cancers, including BrCa, and is associated with poor survival and treatment resistance. We sought to determine the role of miR-21 in BrCa tumor initiation, progression and treatment response. In a triple-negative BrCa model, radiation exposure increased miR-21 in both primary tumor and metastases. In vitro, miR-21 knockdown decreased survival in all BrCa subtypes in the presence of radiation. The role of miR-21 in BrCa initiation was evaluated by implanting wild-type miR-21 BrCa cells into genetically engineered mouse models where miR-21 was intact, heterozygous …

Combined High-Dose Lattice Radiation Therapy And Immune Checkpoint Blockade For Advanced Bulky Tumors: The Concept And A Case Report, Liuqing Jiang, Xiaobo Li, Jianping Zhang, Wenyao Li, Fangfen Dong, Cheng Chen, Qingliang Lin, Chonglin Zhang, Fen Zheng, Weisi Yan, Yi Zheng, Xiaodong Wu, Benhua Xu

Department of Radiation Oncology Faculty Papers

Although the combination of immune checkpoint blockades with high dose of radiation has indicated the potential of co-stimulatory effects, consistent clinical outcome has been yet to be demonstrated. Bulky tumors present challenges for radiation treatment to achieve high rate of tumor control due to large tumor sizes and normal tissue toxicities. As an alternative, spatially fractionated radiotherapy (SFRT) technique has been applied, in the forms of GRID or LATTICE radiation therapy (LRT), to safely treat bulky tumors. When used alone in a single or a few fractions, GRID or LRT can be best classified as palliative or tumor de-bulking treatments. …

Safety And Efficacy Of Hypofractionated Stereotactic Radiosurgery For High-Grade Gliomas At First Recurrence: A Single-Center Experience., Yun Guan, Ji Xiong, Mingyuan Pan, Wenyin Shi, Jing Li, Huaguang Zhu, Xiu Gong, Chao Li, Guanghai Mei, Xiaoxia Liu, Li Pan, Jiazhong Dai, Yang Wang, Enmin Wang, Xin Wang

Department of Radiation Oncology Faculty Papers

BACKGROUND: The optimal treatment for recurrent high-grade gliomas (rHGGs) remains uncertain. This study aimed to investigate the efficacy and safety of hypofractionated stereotactic radiosurgery (HSRS) as a first-line salvage treatment for in-field recurrence of high-grade gliomas.

METHODS: Between January 2016 and October 2019, 70 patients with rHGG who underwent HSRS were retrospectively analysed. The primary endpoint was overall survival (OS), and secondary endpoints included both progression-free survival (PFS) and adverse events, which were assessed according to Common Toxicity Criteria Adverse Events (CTCAE) version 5. The prognostic value of key clinical features (age, performance status, planning target volume, dose, use of …

Computer Automation For Physics Chart Check Should Be Adopted In Clinic To Replace Manual Chart Checking For Radiotherapy, Edward L. Clouser, Quan Chen, Yi Rong

Radiation Medicine Faculty Publications

No abstract provided.

An Analytical Expression For R50% Dependent On Ptv Surface Area And Volume: A Cranial Srs Comparison, Dharmin D. Desai, Ellis Lee Johnson, Ivan L. Cordrey

Radiation Medicine Faculty Publications

The intermediate dose spill for a stereotactic radiosurgery (SRS) plan can be quantified with the metric R50%, defined as the 50% isodose cloud volume (V_IDC50%) divided by the volume of the planning target volume (PTV). By coupling sound physical principles with the basic definition of R50%, we derive an analytical expression for R50% for a spherical PTV. Our analytical expression depends on three quantities: the surface area of PTV (SA_PTV), the volume of PTV (V_PTV), and the distance of dose drop-off to 50% (Δr). The value of ∆r was obtained from a simple set …

A Multidisciplinary Approach To Triage Patients With Breast Disease During The Covid-19 Pandemic: Experience From A Tertiary Care Center In The Developing World, Abida K. Sattar, Hania Shahzad, Adnan Abdul Jabbar, Azmina Tajdin Valimohammad, Sadaf Khan, Yasmin Vellani, Romana Idrees, Nasir Ali, Imrana Masroor, Humera Saeed, Gulzar S. Lakhani, Nadia Ayoub, Atif Waqar, Muhammad Zia-Ul Islam, Salman Kirmani, Asad Latif, Ather Enam

Section of General Surgery

Background: The COVID-19 pandemic has created a need to prioritize care because of limitation of resources. Owing to the heterogeneity and high prevalence of breast cancers, the need to prioritize care in this vulnerable population is essential. While various medical societies have published recommendations to manage breast disease during the COVID-19 pandemic, most are focused on the Western world and do not necessarily address the challenges of a resource-limited setting.
Aim: In this article, we describe our institutional approach for prioritizing care for patients presenting with breast disease.
Methods and results: The breast disease management guidelines were developed and approved …

Treatment Of Orbital Lesions Using Cyberknife Stereotactic Radiosurgery, Emily Morahan

Student Research Poster Presentations 2021

The purpose of the research done was to evaluate the use of CyberKnife Stereotactic Radiosurgery (SRS) for treating orbital lesions. Efficacy and tolerability of such treatment was analyzed with data drawn from multiple sources, regarding dose and fractionation, quality of life following treatment(s) and prognosis. CyberKnife SRS is the newest, most advanced model of radiation delivery systems, featuring a robotic arm capable of manipulating the linear accelerator into thousands of unique angles. The addition of new angles allows for a more precise concentration of radiation delivered to the lesions. In the case of optic lesions, it is crucial to minimize …

Targeting Accuracy Considerations For Simultaneous Tumor Treating Fields Antimitotic Therapy During Robotic Hypofractionated Radiation Therapy., Sharmi Biswas, Irina Kapitanova, Sabrina Divekar, Jimm Grimm, Ian J Butterwick, Daniel Garren, Lawrence R Kleinberg, Kristin J Redmond, Michel Lacroix, Anand Mahadevan, Kenneth M Forster

College of Health Professions Faculty Papers

Purpose: Tumor treating fields (TTFields) is a novel antimitotic treatment that was first proven effective for glioblastoma multiforme, now with trials for several extracranial indications underway. Several studies focused on concurrent TTFields therapy with radiation in the same time period, but were not given simultaneously. This study evaluates the targeting accuracy of simultaneous radiation therapy while TTFields arrays are in place and powered on, ensuring that radiation does not interfere with TTFields and TTFields does not interfere with radiation. This is one of several options to enable TTFields to begin several weeks sooner, and opens potential for synergistic effects of …

Development And Clinical Validation Of Knowledge-Based Planning Models For Stereotactic Body Radiotherapy Of Early-Stage Non-Small-Cell Lung Cancer Patients, Justin David Visak

Theses and Dissertations--Radiation Medicine

Lung stereotactic body radiotherapy (SBRT) is a viable alternative to surgical intervention for the treatment of early-stage non-small-cell lung cancer (NSCLC) patients. This therapy achieves strong local control rates by delivering ultra-high, conformal radioablative doses in typically one to five fractions. Historically, lung SBRT plans are manually generated using 3D conformal radiation therapy, dynamic conformal arcs (DCA), intensity-modulated radiation therapy, and more recently via volumetric modulated arc therapy (VMAT) on a C-arm linear accelerator (linac). Manually planned VMAT is an advanced technique to deliver high-quality lung SBRT due to its dosimetric capabilities and utilization of flattening-filter free beams to improve …

Development Of A Robust Linac-Based Radiosurgery Program For Multiple Brain Metastases & Estimation The Radiobiological Response Of Indirect Cell Kill, Allison Palmiero

Theses and Dissertations--Radiation Medicine

Accurate and precise delivery of Stereotactic Radiosurgery (SRS) using Gamma Knife (GK) unit by Leksell is a gold standard for multiple intracranial lesions. SRS provides less brain toxicity compared to whole brain radiotherapy techniques historically used. However, these treatments are limited in availability and are accompanied by long treatment times with painful, intolerable headframe fixation. With advancements in linear accelerator (Linac) based SRS, multiple brain lesions can be treated separately with individual isocenters or, more recently, altogether with a single isocenter multi-target (SIMT) volumetric modulated arc therapy (VMAT) technique. SIMT methods reduce the challenges of treating patients with GK by …

Dosimetric Comparison Of Rapidplan And Manually Optimized Plans For Hippocampus Avoidance Whole Brain Radiation Therapy, Laksamon Phimolasawakun

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, whole-brain radiation therapy (WBRT) is a good method to cure brain metastases. However, it has been noted that whole-brain radiation therapy could be a cause to neurological toxicity which could damage the hippocampus that is an important part of forming long-term memories. The HA-WBRT is a complicated plan depending on planner skills, the researcher would like to simplify this problem using knowledge-based planning called RapidPlan. The objective of this study was to compare the dosimetric difference of RapidPlan and manually optimized plans for the treatment of HA-WBRT. The RapidPlan model was created for HA-WBRT. The PTV and OARs constraints …

Hepatic Lesion Detectability On Dual Energy Computed Tomography Imaging : Phantom Study, Hataipat Jantawong

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purpose of this study is to determine the hepatic lesion detectability in abdomen from various phantom sizes by dual-energy computed tomography (DECT) imaging and to investigate the factors affecting the detectability of hepatic lesion in abdomen by dual-energy CT in phantom study. The anthropomorphic liver with nodule inserted phantom with extension rings simulating the small, medium, and large patients were scanned under DECT acquisitions by varying three kVp combinations (80/-,90/-, and 100/Sn150-kVp). The series of 40-,50-,60-, and 70-keV VMI were generated from DECT data set. All images were used to assess the task-based image quality; task transfer function (TTF), …

Determination Of Field Output Correction Factors In Elongated Small Field Photon Beams, Mananchaya Vimolnoch

Chulalongkorn University Theses and Dissertations (Chula ETD)

IAEA along with AAPM have published a code of practice TRS 483 for small field dosimetry. The field correction output factors of various detectors were introduced to correct detector response changes in relative dosimetry. However, the publication of TRS 483 has focused on symmetry field sizes, the correction factors for elongated small fields are not included in the protocol. The overall objective of this work is to determine the field output correction factor in elongated small field. The correction factors of IBA CC01, Sun nuclear EDGE, and Exradin W2 PSD for 6 MV photon beam were determined using Monte Carlo …

Evaluation Of Integral Depth-Dose Curves In Proton Pencil Beam Scanning Using Plane-Parallel Ionization Chambers, Phatthraporn Thasasi

Chulalongkorn University Theses and Dissertations (Chula ETD)

Proton therapy is an advanced form of radiation therapy treatment that can potentially decrease side effects and increase tumor control probability. The integral depth-dose curve is an essential parameter that has to be determined and introduced into the proton treatment planning system for the dose calculation. Besides the halo, the integral depth-dose curve measurements should be performed with a large-diameter plane-parallel ionization chamber. The purpose of this research is to determine the integral depth-dose curves and assess the geometrical collection efficiency at intermediate depths of different detector diameters in proton pencil beam scanning. The integral depth-dose curves with a proton …

Baselines Of Daily Quality Assurance For Proton Pencil Beam Scanning Using The Sphinx Compact, Tanapat Tiajaroen

Chulalongkorn University Theses and Dissertations (Chula ETD)

Quality assurance (QA) is a systematic process used to determine whether the product meets specified requirements. The American Association of Physicists in Medicine (AAPM) published a comprehensive proton therapy machine QA in TG-224 to provide confidence in use. King Chulalongkorn Memorial Hospital (KCMH) recently operated the first proton therapy center in Thailand, and the data of daily QA are not available or established. This study aims to apply the control chart for establishing the baselines of daily QA for the proton pencil beam scanning system using the Sphinx Compact detector. The Sphinx Compact was used to perform the proton daily …

Moderated Neutron Detector For Accumulated Ambient Dose Equivalent In Proton Therapy, Tanawat Tawonwong

Chulalongkorn University Theses and Dissertations (Chula ETD)

The Varian ProBeam compact was installed at Her Royal Highness Princess Maha Chakri Sirindhorn Proton Center. Since 2017, the project has started at the King Chulalongkorn Memorial Hospital and after 4 years, during Covid19 pandemic, the 1st patient treatment received proton therapy on August, 2021. The radiation safety of the center was accomplished through firstly, the shielding calculation and secondary, the radiation survey at the milestone points such as cyclotron installation and 1st Beam ON at the treatment room. The only one WENDI-II dosimeter was used in radiation survey. The main purpose of this study is to validate the in-house …

Dosimetric Impact Of Interplay Effects Instereotactic Body Radiation Therapy (Sbrt) Lung Cancer, Vanida Poolnapol

Chulalongkorn University Theses and Dissertations (Chula ETD)

Lung cancer patient breathing induced interplay effects in the volumetric modulated arc therapy (VMAT) together with stereotactic body radiation therapy (SBRT), which lead to non-uniform doses within the target volume and unwanted dose to the surrounding tissues. The purpose of this study was to investigate the dosimetric impact of interplay effects in 6 MV FFF of photon beams for lung cancer and to calculate the novel interplay effects factor (IEF) for VMAT-SBRT lung cancer. This study performed the static and dynamic measurements using two dimensions (2D) robotic platform and diode array for 3D-conformal radiation therapy (3D-CRT) plans, while using three …