Bevacizumab and Other Targeted Agents in the Upfront Treatment of Glioblastoma
The standard treatment for glioblastoma, the most common primary malignant brain tumor, has been maximal safe surgical resection followed by the combination of radiation and temozolomide. Bevacizumab has shown promise in the treatment of glioblastoma; it and a number of other new, targeted agents have been tested in combination with radiation and temozolomide. Results of recent studies of such agents are discussed. Although many of these agents show promise, none as yet has established a new standard of care for these difficult-to-treat tumors. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - September 15, 2014 Category: Cancer & Oncology Authors: Jennifer L. Clarke Source Type: research
New Considerations in Radiation Treatment Planning for Brain Tumors: Neural Progenitor Cell–Containing Niches
The purpose of this critical review is to explore the controversy regarding the relationship between radiation dose to the neural progenitor cell (NPC) niches and patient outcomes, in terms of both toxicity and tumor control. NPCs in the subventricular zone (SVZ) and hippocampus are paradoxically associated with long-term neurocognitive sequelae of brain irradiation, as well as resistance to therapy and tumor recurrence. The reconciliation of these somewhat opposing functions is challenging. Current literature suggests that radiation and other treatments against the NPC in the hippocampus and the SVZ may influence patient ...
Source: Seminars in Radiation Oncology - September 15, 2014 Category: Cancer & Oncology Authors: Carmen Kut, Kristin Janson Redmond Source Type: research
Standardization and Quality Assurance of Radiation Therapy Volumes for Adults With High-Grade Gliomas
Abstract: Standard treatment for Glioblastoma Multiforme (GBM) consists of a combination of chemotherapy and radiation therapy followed by adjuvant chemotherapy. While the optimal dose of radiation therapy has been established, significant variability in volume of tissue irradiated exists. In this article we review the current guidelines, patterns of care, patterns of failure, imaging advances and toxicity related to radiation therapy volumes in the treatment of GBM. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - September 15, 2014 Category: Cancer & Oncology Authors: Shannon Fogh, Michael Wahl, Mekhail Anwar, Daphne Haas-Kogan, Jennifer L. Clarke, Penny K. Sneed Source Type: research
Advanced Magnetic Resonance Imaging Methods for Planning and Monitoring Radiation Therapy in Patients With High-Grade Glioma
(Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - September 15, 2014 Category: Cancer & Oncology Source Type: research
The Genetic Signatures of Pediatric High-Grade Glioma: No Longer a One-Act Play
Advances in understanding pediatric high-grade glioma (pHGG) genetics have revealed key differences between pHGG and adult HGG and have uncovered unique molecular drivers among subgroups within pHGG. The 3 core adult HGG pathways, the receptor tyrosine kinase-Ras-phosphatidylinositide 3-kinase, p53, and retinoblastoma networks, are also disrupted in pHGG, but they exhibit a different spectrum of effectors targeted by mutation. There are also similarities and differences in the genomic landscape of diffuse intrinsic pontine glioma (DIPG) and pediatric nonbrainstem (pNBS)-HGG. In 2012, histone H3 mutations were identified in...
Source: Seminars in Radiation Oncology - September 15, 2014 Category: Cancer & Oncology Authors: Alexander K. Diaz, Suzanne J. Baker Source Type: research
Genetic Markers in Adult High-Grade Gliomas
Diffuse gliomas are the most common primary central nervous system malignancy in adults and most are high grade. Although current morphologic classification by the World Health Organization provides considerable information, significant variability continues to exist in each diagnostic category. Recent molecular advances define distinct molecular signatures and elucidate gliomagenesis pathways, leading to alternative methods for subclassification beyond morphology alone. In addition, each newly described molecular aberration represents a potential new biomarker with variable diagnostic, prognostic, and predictive value for...
Source: Seminars in Radiation Oncology - September 15, 2014 Category: Cancer & Oncology Authors: Melike Pekmezci, Arie Perry Source Type: research
Preface
In this issue of Seminars in Radiation Oncology, experts provide comprehensive reviews of and insights into relevant issues in imaging advances, molecular characterization, and clinical approaches to adult and pediatric high-grade gliomas. It is a privilege for me to be able to serve as the Guest Editor for this issue in which the contributors are mentees, mentors, colleagues, and outstanding physician scientists. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - September 15, 2014 Category: Cancer & Oncology Authors: Daphne Haas-Kogan Source Type: research
Magnetic Resonance–Guided Adaptive Radiotherapy: A Solution to the Future
Magnetic resonance imaging–guided adaptive radiotherapy would make available the best in anatomical and functional imaging during the course of radiation therapy. The possible methodology of magnetic resonance imaging–guided adapted radiotherapy and possible clinical applications are discussed. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: Patrick Kupelian, Jan-Jakob Sonke Source Type: research
Clinical Applications for Diffusion Magnetic Resonance Imaging in Radiotherapy
In this article, we review the clinical applications of diffusion magnetic resonance imaging (MRI) in the radiotherapy treatment of several key clinical sites, including those of the central nervous system, the head and neck, the prostate, and the cervix. Diffusion-weighted MRI (DWI) is an imaging technique that is rapidly gaining widespread acceptance owing to its ease and wide availability. DWI measures the mobility of water within tissue at the cellular level without the need of any exogenous contrast agent. For radiotherapy treatment planning, DWI improves upon conventional imaging techniques, by better characterizatio...
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: Christina Tsien, Yue Cao, Thomas Chenevert Source Type: research
Magnetic Resonance Imaging of the Tumor Microenvironment in Radiotherapy: Perfusion, Hypoxia, and Metabolism
The tumor microenvironment is characterized by hypoxia, low pH, and high interstitial fluid pressure. Hypoxic regions in tumors with low partial pressure of oxygen (pO2) levels can result in resistance to radiotherapy, thus causing local failure. Therefore, it would be desirable to noninvasively measure pO2 levels in the tumor before, during, and after treatment to better customize therapy and follow treatment response. Several techniques used in preclinical and clinical studies to obtain the pO2 status of tissue, such as dynamic contrast-enhanced magnetic resonance imaging, blood oxygen level–dependent imaging, and elec...
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: Masayuki Matsuo, Shingo Matsumoto, James B. Mitchell, Murali C. Krishna, Kevin Camphausen Source Type: research
The Magnetic Resonance Imaging–Linac System
The current image-guided radiotherapy systems are suboptimal in the esophagus, pancreas, kidney, rectum, lymph node, etc. These locations in the body are not easily accessible for fiducials and cannot be visualized sufficiently on cone-beam computed tomographies, making daily patient set-up prone to geometrical uncertainties and hinder dose optimization. Additional interfraction and intrafraction uncertainties for those locations arise from motion with breathing and organ filling. To allow real-time imaging of all patient tumor locations at the actual treatment position a fully integrated 1.5-T, diagnostic quality, magneti...
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: Jan J.W. Lagendijk, Bas W. Raaymakers, Marco van Vulpen Source Type: research
The Australian Magnetic Resonance Imaging–Linac Program
The Australian magnetic resonance imaging (MRI)–Linac program is a $16-million government-funded project to advance the science and clinical practice of exquisite real-time anatomical and physiological adaptive cancer therapy. The centerpiece of the program is a specifically designed 1-T open-bore MRI/6-MV linac system that is planned for delivery and completion of installation in 2014. Current scientific endeavors include engineering discovery in MRI component design, quantifying MRI and linac interactions, and developing image guidance and adaptation strategies. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: Paul J. Keall, Michael Barton, Stuart Crozier, On behalf of the Australian MRI-Linac Program, including contributors from the Ingham Institute, Illawarra Cancer Care Centre, Liverpool Hospital, Stanford University, Universities of Newcastle, Queensland, S Source Type: research
The Rotating Biplanar Linac–Magnetic Resonance Imaging System
We have successfully built linac–magnetic resonance imaging (MR) systems based on a linac waveguide placed between open MR planes (perpendicular) or through the central opening of one of the planes (parallel) to improve dosimetric properties. It rotates on a gantry to irradiate at any angle. Irradiation during MR imaging and automatic 2-dimensional MR image–based target tracking and automatic beam steering to the moving target have been demonstrated with our systems. The functioning whole-body system (0.6-T MR and 6-MV linac) has been installed in an existing clinical vault without removing the walls or the ceiling and...
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: Biagio Gino Fallone Source Type: research
The ViewRay System: Magnetic Resonance–Guided and Controlled Radiotherapy
A description of the first commercially available magnetic resonance imaging (MRI)–guided radiation therapy (RT) system is provided. The system consists of a split 0.35-T MR scanner straddling 3 60Co heads mounted on a ring gantry, each head equipped with independent doubly focused multileaf collimators. The MR and RT systems share a common isocenter, enabling simultaneous and continuous MRI during RT delivery. An on-couch adaptive RT treatment-planning system and integrated MRI-guided RT control system allow for rapid adaptive planning and beam delivery control based on the visualization of soft tissues. Treatment of pa...
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: Sasa Mutic, James F. Dempsey Source Type: research
A Facility for Magnetic Resonance–Guided Radiation Therapy
Magnetic resonance (MR) imaging is routinely employed in the design of radiotherapy (RT) treatment plans for many disease sites. It is evident that tighter integration of MR imaging into the RT process would increase confidence in dose placement and facilitate the integration of new MR imaging information (including anatomical and functional imaging) into the therapy process. To this end, a dedicated MR-guided RT (MRgRT) facility has been created that integrates a state-of-the-art linear accelerator delivery system, high-dose rate brachytherapy afterloader, and superconducting MR scanner to allow MR-based online treatment ...
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: David A. Jaffray, Marco C. Carlone, Michael F. Milosevic, Stephen L. Breen, Teodor Stanescu, Alexandra Rink, Hamideh Alasti, Anna Simeonov, Michael C. Sweitzer, Jeffrey D. Winter Source Type: research
