Protons vs Photons for Brain and Skull Base Tumors
The physical characteristics of proton therapy result in steeper dose gradients and superior dose conformality compared to photon therapy. These properties render proton therapy ideal for skull base tumors requiring dose escalation for optimal tumor control, and may also be beneficial for brain tumors as a means of mitigating radiation-related adverse effects. This review summarizes the literature regarding the role of proton therapy compared to photon therapy in the treatment of adult brain and skull base tumors. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - April 1, 2018 Category: Cancer & Oncology Authors: Safia K. Ahmed, Paul D. Brown, Robert L. Foote Source Type: research

Does Proton Therapy Offer Demonstrable Clinical Advantages for Treating Thoracic Tumors?
The finite range of proton beams in tissues offers unique dosimetric advantages that theoretically allow dose to the target to be escalated while minimizing exposure of surrounding tissues and thus minimizing radiation-induced toxicity. This theoretical advantage has led to widespread adoption of proton therapy around the world for a wide variety of tumors at different anatomical sites. Many treatment-planning comparisons have shown that proton therapy has substantial dosimetric advantages over conventional radiotherapy. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - April 1, 2018 Category: Cancer & Oncology Authors: Zhongxing Liao, Saumil J. Gandhi, Steven H. Lin, Jeffrey Bradley Source Type: research

Finding Value for Protons: The Case of Prostate Cancer?
The standard radiotherapy treatment for prostate cancer is intensity-modulated radiotherapy (IMRT). An alternative option is proton beam therapy (PBT). PBT is a safe and effective treatment, but does it add value over IMRT? We explore this controversial question by examining the available dosimetric and clinical evidence. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - April 1, 2018 Category: Cancer & Oncology Authors: Eric Ojerholm, Justin E. Bekelman Source Type: research

Heavy Charged Particles: Does Improved Precision and Higher Biological Effectiveness Translate to Better Outcome in Patients?
Protons are the most common charged particles used in oncology. Acceleration of heavier ions requires larger accelerators and is more expensive, yet heavy nuclei share the same advantageous dose-depth profile characteristics of protons and have potential additional advantages. These advantages are related to the physical characteristics of the beam, owing to reduced lateral scattering and sharper lateral penumbra. In addition, heavy ions produce an increased biological response. In fact, in the target region heavy ions behave as densely ionizing radiation, which produce distinct biological effects compared to sparsely ioni...
Source: Seminars in Radiation Oncology - April 1, 2018 Category: Cancer & Oncology Authors: Marco Durante, J ürgen Debus Source Type: research

Robust Proton Treatment Planning: Physical and Biological Optimization
Accurate prediction of tumor control and toxicities in radiation therapy faces many uncertainties. Besides interpatient variability in the response to radiation, there are also dosimetric uncertainties, that is, differences between the dose displayed in a treatment planning system and the dose actually delivered to the patient. These uncertainties originate from several sources including imperfect knowledge of the patient geometry, approximation in the physics of radiation interaction with tissues, and uncertainties in the biological effectiveness of radiation. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - April 1, 2018 Category: Cancer & Oncology Authors: Jan Unkelbach, Harald Paganetti Source Type: research

Will There Be a Clinically Significant Role for Protons in Patients With Gastrointestinal Malignancies?
Gastrointestinal malignancies inherently arise amidst visceral organs that are very radiation sensitive. While radiation therapy is an integral part of cancer treatment, its use has historically been limited by normal tissue toxicity. Proton therapy is a form of external-beam radiation associated with several dosimetric advantages as compared to photon therapy. Proton radiation may allow for the delivery of tumoricidal doses while minimizing side effects by decreasing the dose to adjacent organs at risk. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - April 1, 2018 Category: Cancer & Oncology Authors: Ann C. Raldow, Theodore S. Hong Source Type: research

Can Technological Improvements Reduce the Cost of Proton Radiation Therapy?
This article presents an overview of on-going technical developments, which have a reduction of the capital investment or operational costs either as a major goal or as a potential outcome. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - April 1, 2018 Category: Cancer & Oncology Authors: Jacobus Maarten Schippers, Anthony Lomax, Adriano Garonna, Katia Parodi Source Type: research

Clinical Trial Strategies to Compare Protons With Photons
The favorable beam properties of protons can be translated into clinical benefits by target dose escalation to improve local control without enhancing unacceptable radiation toxicity or to spare normal tissues to prevent radiation-induced side effects without jeopardizing local tumor control. For the clinical validation of the added value of protons to improve local control, randomized controlled trials are required. For the clinical validation of the added value of protons to prevent side effects, both model-based validation or randomized controlled trials can be used. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - April 1, 2018 Category: Cancer & Oncology Authors: Johannes A. Langendijk, Liesbeth J. Boersma, Coen R.N. Rasch, Marco van Vulpen, Johannes B. Reitsma, Arjen van der Schaaf, Ewoud Schuit Source Type: research

Potential Morbidity Reduction With Proton Radiation Therapy for Breast Cancer
Proton radiotherapy confers significant dosimetric advantages in the treatment of malignancies that arise adjacent to critical radiosensitive structures. To date, these advantages have been most prominent in the treatment of pediatric and central nervous system malignancies, although emerging data support the use of protons among other anatomical sites in which radiotherapy plays an important role.With advances in the overall treatment paradigm for breast cancer, most patients with localized disease now exhibit long-term disease control and, consequently, may manifest the late toxicities of aggressive treatment. (Source: S...
Source: Seminars in Radiation Oncology - April 1, 2018 Category: Cancer & Oncology Authors: Lior Z. Braunstein, Oren Cahlon Source Type: research

Charged Issues: Particle Radiation Therapy
This issue of Seminars in Radiation Oncology revisits the issue of protons and charged particle radiation, one that was addressed in the April 2013 (volume 23, number 2) issue. We refer the reader to that issue, which included many excellent articles focused on proton and charged particle radiation therapy. Since the time of that publication, the number of charged particle facilities in operation has continued to increase, there has been a significant migration to delivery with scanned beams, and multiple, randomized clinical trials to compare outcomes with protons compared to photons have been activated. (Source: Seminars...
Source: Seminars in Radiation Oncology - April 1, 2018 Category: Cancer & Oncology Authors: Thomas F. DeLaney Source Type: research

Comparing Intensity-Modulated Proton Therapy With Intensity-Modulated Photon Therapy for Oropharyngeal Cancer: The Journey From Clinical Trial Concept to Activation
Intensity-modulated proton therapy minimizes the incidental irradiation of normal tissues in patients with head and neck cancer relative to intensity-modulated photon (x-ray) therapy and has been associated with lesser treatment-related toxicity and improved quality of life. A phase II/III randomized trial sponsored by the US National Cancer Institute is currently underway to compare deintensification treatment strategies with intensity-modulated proton therapy vs intensity-modulated photon (x-ray) therapy for patients with advanced-stage oropharyngeal tumors. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - April 1, 2018 Category: Cancer & Oncology Authors: Steven J. Frank, Pierre Blanchard, J. Jack Lee, Erich M. Sturgis, Merrill S. Kies, Mitchell Machtay, Bhadrasain Vikram, Adam S. Garden, David I. Rosenthal, G. Brandon Gunn, C. David Fuller, Katherine Hutcheson, Stephen Lai, Paul M. Busse, Nancy Y. Lee, Al Source Type: research

Current Status and Future Directions of Treatment Deintensification in Human Papilloma Virus-associated Oropharyngeal Squamous Cell Carcinoma
The prevalence of patients with human papilloma virus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) is rapidly increasing, and it is now well known that these patients have a significantly better prognosis than patients with HPV-negative OPSCC. Though standard treatments result in excellent cancer control, they are also associated with substantial long-term toxicity. There is now great interest in evaluating less intensive (ie, deintensified) treatment regimens to improve the therapeutic ratio (maintain excellent cancer control and decrease toxicity). (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - November 24, 2017 Category: Cancer & Oncology Authors: Bhishamjit S. Chera, Robert J. Amdur Source Type: research

Organ-Sparing in Radiotherapy for Head-and-Neck Cancer: Improving Quality of Life
This is an overview of select studies characterizing the effect of radiation on normal tissues in the treatment of head-and-neck cancer. Recommendations for organ-at-risk dose constraints aiming to reduce risks of xerostomia and dysphagia, the factors which have the highest effect on patient quality of life, are discussed, along with their supporting evidence. Recent advances in technology and biology, and their implications for reducing toxicity are explored. Considerations related to organ-sparing in the setting of treatment deintensification for good-prognosis head-and-neck cancer are also discussed. (Source: Seminars i...
Source: Seminars in Radiation Oncology - November 24, 2017 Category: Cancer & Oncology Authors: Peter G. Hawkins, Amrut S. Kadam, William C. Jackson, Avraham Eisbruch Source Type: research

Molecular Imaging-Guided Radiotherapy for the Treatment of Head-and-Neck Squamous Cell Carcinoma: Does it Fulfill the Promises?
With the routine use of intensity modulated radiation therapy for the treatment of head-and-neck squamous cell carcinoma allowing highly conformed dose distribution, there is an increasing need for refining both the selection and the delineation of gross tumor volumes (GTV). In this framework, molecular imaging with positron emission tomography and magnetic resonance imaging offers the opportunity to improve diagnostic accuracy and to integrate tumor biology mainly related to the assessment of tumor cell density, tumor hypoxia, and tumor proliferation into the treatment planning equation. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - November 24, 2017 Category: Cancer & Oncology Authors: Vincent Gr égoire, Daniela Thorwarth, John Aldo Lee Source Type: research

Proton Therapy for Head and Neck Cancers
Because of its sharp lateral penumbra and steep distal fall-off, proton therapy offers dosimetric advantages over photon therapy. In head and neck cancer, proton therapy has been used for decades in the treatment of skull-base tumors. In recent years the use of proton therapy has been extended to numerous other disease sites, including nasopharynx, oropharynx, nasal cavity and paranasal sinuses, periorbital tumors, skin, and salivary gland, or to reirradiation. The aim of this review is to present the physical properties and dosimetric benefit of proton therapy over advanced photon therapy; to summarize the clinical benefi...
Source: Seminars in Radiation Oncology - November 24, 2017 Category: Cancer & Oncology Authors: Pierre Blanchard, Gary Brandon Gunn, Alexander Lin, Robert L. Foote, Nancy Y. Lee, Steven J. Frank Source Type: research

Therapeutic Implications of the Genetic Landscape of Head and Neck Cancer
Large-scale sequencing studies of head and neck squamous cell carcinoma (HNSCC) have elucidated the genetic changes that characterize HNSCC. These findings have supported the development of therapeutic strategies that target key components of aberrant signaling pathways and immune dysregulation. Cumulative evidence suggests that these agents in combination with radiotherapy may have synergistic effects. This review highlights the predictive biomarkers that have been identified from HNSCC genomic studies and implications on the development of molecular-targeting agents that may effectively treat patients with HNSCC, especia...
Source: Seminars in Radiation Oncology - November 24, 2017 Category: Cancer & Oncology Authors: Janice Cho, Daniel E. Johnson, Jennifer R. Grandis Source Type: research

Introduction
Recent advances in the treatment of head and neck cancer (HNC) described in this issue of Seminars include assessments of major recent development in the epidemiology, prognostic factors, and therapy of HNC. The implications of the changes in the biology of oropharyngeal cancers, better understanding of the genomic landscapes and their utilization in targeted therapy, the role of immunotherapy in conjuction with radiotherapy, technological advances and their effect on tumor control, toxicities and quality of life, are the subject of the articles in this issue. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - November 24, 2017 Category: Cancer & Oncology Authors: Avraham Eisbruch Source Type: research

The Current State of Biological and Clinical Implications of Human Papillomavirus-Related Oropharyngeal Cancer
In the effort to control human papillomavirus-related oropharyngeal cancer, the head and neck oncology community has devoted much effort to understanding its disease biology and clinical behavior, and refining strategies to address early diagnosis and optimal management for the affected population. This review identifies articles published up to March 2017 on tumor biology and clinical implications of human papillomavirus-related oropharyngeal cancer, and summarizes the findings in some key areas. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - November 24, 2017 Category: Cancer & Oncology Authors: Shao Hui Huang, Brian O'Sullivan, John Waldron Source Type: research

Head and Neck Cancer Survivorship: Learning the Needs, Meeting the Needs
Cancers of the head and neck and the treatments required to control them frequently result in serious and persistent impairments that can affect participation and quality of life. Increased recognition of the needs of cancer survivors and their caregivers has prompted research focused on the unique concerns of this complex group. Unmet needs have been identified among 60 –70% of patients and a similar proportion of their partners; impacts can include profound social effects, isolation, and psychiatric conditions. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - November 24, 2017 Category: Cancer & Oncology Authors: Jolie Ringash, Lori J. Bernstein, Gerald Devins, Colleen Dunphy, Meredith Giuliani, Rosemary Martino, Sara McEwen Source Type: research

Role of Immunotherapy in Head and Neck Cancer
Immune system dysfunction plays a role in both the development and progression of head and neck squamous cell carcinoma (HNSCC), highlighting the potential role for immunotherapy to improve outcomes in this disease. The application of anti-PD-1 therapies for recurrent or metastatic HNSCC has found promising results. This has led to interest in combining immunotherapy with radiation therapy (RT) for the primary treatment of locally advanced HNSCC. RT with concurrent cetuximab is an option for patients who are medically unfit to receive cisplatin, and ongoing trials seek to determine to role of cetuximab-RT in treatment de-i...
Source: Seminars in Radiation Oncology - November 24, 2017 Category: Cancer & Oncology Authors: Diane C. Ling, Chris J. Bakkenist, Robert L. Ferris, David A. Clump Source Type: research

Mechanisms of Normal Tissue Injury From Irradiation
Normal tissue injury from irradiation is an unfortunate consequence of radiotherapy. Technologic improvements have reduced the risk of normal tissue injury; however, toxicity causing treatment breaks or long-term side effects continues to occur in a subset of patients. The molecular events that lead to normal tissue injury are complex and span a variety of biologic processes, including oxidative stress, inflammation, depletion of injured cells, senescence, and elaboration of proinflammatory and profibrogenic cytokines. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - September 1, 2017 Category: Cancer & Oncology Authors: Deborah E. Citrin, James B. Mitchell Source Type: research

Radiation-Induced Liver Toxicity
The advent of highly conformal radiation therapy (RT) has defined a new role for RT in the treatment of both primary and metastatic liver cancer. Despite major advances in how RT is delivered, radiation-induced liver disease (RILD) remains a concern. Classic RILD, characterized by anicteric ascites and hepatomegaly, is unlikely to occur if treating to doses of ≤30Gy in 2Gy per fraction in patients with baseline Child-Pugh A liver function. On the other hand, nonclassic RILD is a spectrum of liver toxicity, including a general decline in liver function and elevation of liver enzymes. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - September 1, 2017 Category: Cancer & Oncology Authors: Pablo Munoz-Schuffenegger, Sylvia Ng, Laura A. Dawson Source Type: research

Functional Assays for Individual Radiosensitivity: A Critical Review
This article is a critical review devoted to the major functional assays to predict radiosensitivity and their strengths and weaknesses, notably those based on the quantification of clonogenic cell survival, micronuclei, p21 expression, apoptosis, chromosome and DNA repair, and signaling. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - September 1, 2017 Category: Cancer & Oncology Authors: M élanie L. Ferlazzo, Michel Bourguignon, Nicolas Foray Source Type: research

Imaging Radiation-Induced Normal Tissue Injury to Quantify Regional Dose Response
Noninvasive imaging has and will continue to play a pivotal role in the assessment of radiation-induced normal tissue toxicity. In this review, we will examine key literature regarding the use of anatomic and physiological imaging in relation to radiation-induced normal tissue toxicity. Additionally, this review contains a novel methodology for potentially incorporating dose-response data into treatment planning and normal tissue toxicity modeling. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - September 1, 2017 Category: Cancer & Oncology Authors: David V. Fried, Shiva K. Das, Lawrence B. Marks Source Type: research

Radiogenomics: Identification of Genomic Predictors for Radiation Toxicity
The overall goal of radiogenomics is the identification of genomic markers that are predictive for the development of adverse effects resulting from cancer treatment with radiation. The principal rationale for a focus on toxicity in radiogenomics is that for many patients treated with radiation, especially individuals diagnosed with early-stage cancers, the survival rates are high, and therefore a substantial number of people will live for a significant period of time beyond treatment. However, many of these patients could suffer from debilitating complications resulting from radiotherapy. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - September 1, 2017 Category: Cancer & Oncology Authors: Barry S. Rosenstein Tags: Articles Source Type: research

Radiation Toxicity in the Central Nervous System: Mechanisms and Strategies for Injury Reduction
The potential for radiation-induced toxicities in the brain produces significant anxiety, both among patients receiving radiation therapy and those radiation oncologists providing treatment. These concerns often play a significant role in the medical decision-making process for most patients with diseases in which radiotherapy may be a treatment consideration. Although the precise mechanisms of neurotoxicity and neurodegeneration after ionizing radiation exposure continue to be poorly understood from a biological perspective, there is an increasing body of scientific and clinical literature that is producing a better under...
Source: Seminars in Radiation Oncology - September 1, 2017 Category: Cancer & Oncology Authors: DeeDee Smart Source Type: research

Emphasis on Repair, Not Just Avoidance of Injury, Facilitates Prudent Stereotactic Ablative Radiotherapy
Stereotactic ablative radiotherapy (SAbR) is a potent, hypofractionated treatment against cancer which puts adjacent normal tissue in potential peril. Accurate delineation of normal tissue injury risks from SAbR has been challenging, and lack of clear understanding of SAbR tolerance continues to limit its potential. In this review, we contend that SAbR effects on normal tissue could be akin to a surgical “wound,” and that adequate wound repair of organs at risk is an essential component of effective SAbR therapy. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - September 1, 2017 Category: Cancer & Oncology Authors: D.W. Nathan Kim, Paul M. Medin, Robert D. Timmerman Source Type: research

Management of Radiation Toxicity in Head and Neck Cancers
Head and neck cancers account for approximately 3% of all cancers in the United States with 62,000 new cases diagnosed annually. The global incidence is approximately 700,000 new cases a year. There has also been a recent increase in human papilloma virus –related oropharyngeal cancers. External beam radiation therapy (RT) is commonly used as an effective therapy for head and neck (H&N) cancers. This is used as a definitive treatment (alone or in combination with chemotherapy) or as an adjuvant treatment after surgical resection of the tumors. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - September 1, 2017 Category: Cancer & Oncology Authors: Farzan Siddiqui, Benjamin Movsas Tags: Articles Source Type: research

Thoracic Radiation Normal Tissue Injury
Thoracic malignancies are often a difficult group of tumors to treat definitively as the radiation doses needed to achieve a high probability for tumor control are often associated with high rates of radiation-induced toxicities. The lungs are particularly radiosensitive and are susceptible to radiation pneumonitis in the acute and subacute settings and pulmonary fibrosis in the late setting. Acute esophagitis is common and affects patient quality of life. Beyond acute pericarditis, late cardiac toxicities are increasingly being recognized as clinically relevant when delivering thoracic radiotherapy and can affect overall ...
Source: Seminars in Radiation Oncology - September 1, 2017 Category: Cancer & Oncology Authors: Charles B. Simone Source Type: research

Pelvic Radiation and Normal Tissue Toxicity
Radiation is a component of treatment for many pelvic malignancies, most often originating in the gynecologic, gastrointestinal, and genitourinary systems. Therefore, the management of acute and long-term side effects is an important part of practice as a radiation oncologist, and limiting morbidity is a primary goal. Toxicities vary and are dependent on treatment techniques. Advances in radiation delivery, imaging, and knowledge of underlying biologic determinants of radiation-induced normal tissue toxicity can guide treatment of acute and long-term side effects from pelvic radiation. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - September 1, 2017 Category: Cancer & Oncology Authors: Sarah Nicholas, Linda Chen, Amanda Choflet, Amanda Fader, Zachary Guss, Sarah Hazell, Daniel Y. Song, Phuoc T. Tran, Akila N. Viswanathan Source Type: research

Introduction
Technological advancements in Radiation Oncology have occurred at an impressive pace over the past few decades, fundamentally altering the practice of radiotherapy. The development of modern imaging modalities has enhanced our certainty of tumor location and extent. Simultaneously, radiation treatment delivery has undergone a revolution of conformality spurred by techniques such as intensity-modulated radiation therapy, image-guided radiation therapy, and proton therapy. The proliferation of these techniques into clinical practice has not only led to enhanced certainty of the accuracy of daily tumor targeting, but has also...
Source: Seminars in Radiation Oncology - September 1, 2017 Category: Cancer & Oncology Authors: Deborah E. Citrin Source Type: research

Normal Tissue Constraints for Abdominal and Thoracic Stereotactic Body Radiotherapy
This article reviews the modern toxicity literature and provides updated clinically practical and useful recommendations of SBRT dose constraints for extracranial sites. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 1, 2017 Category: Cancer & Oncology Authors: Erqi L. Pollom, Alexander L. Chin, Maximilian Diehn, Billy W. Loo, Daniel T. Chang Source Type: research

Advances in Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma
Stereotactic Body Radiation Therapy (SBRT) is an emerging effective treatment for hepatocellular carcinoma (HCC) associated with acceptable rates of toxicity in appropriately selected patients. Despite often being reserved for patients unsuitable for other local treatments, prospective and retrospective studies have demonstrated excellent long-term control. SBRT may be used as a stand-alone treatment, or as an adjunct to other HCC therapies. Based on available data, SBRT appears to complement existing local liver therapies. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 1, 2017 Category: Cancer & Oncology Authors: Louise J. Murray, Laura A. Dawson Source Type: research

Safety Considerations in Stereotactic Body Radiation Therapy
Although many error pathways are common to both stereotactic body radiation therapy (SBRT) and conventional radiation therapy, SBRT presents a special set of challenges including short treatment courses and high-doses, an enhanced reliance on imaging, technical challenges associated with commissioning, special resource requirements for staff and training, and workflow differences. Emerging data also suggest that errors occur at a higher rate in SBRT treatments. Furthermore, when errors do occur they often have a greater effect on SBRT treatments. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 1, 2017 Category: Cancer & Oncology Authors: Eric Ford, Sonja Dieterich Source Type: research

Stereotactic Body Radiotherapy for Liver Metastases
This article summarizes the latest advancements in the use of stereotactic body radiotherapy to treat liver metastases. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 1, 2017 Category: Cancer & Oncology Authors: Karyn A. Goodman, Brian D. Kavanagh Source Type: research

Integration of Stereotactic Body Radiation Therapy into the Multidisciplinary Management of Pancreatic Cancer
Although most patients with pancreatic cancer die of metastatic disease, an autopsy study showed that up to one-third of patients die of predominantly local disease. This patient population stands to benefit the most from radiation, surgery, or both. Unfortunately, however, single-agent chemotherapy has had minimal benefit in pancreatic cancer, and most patients progress distantly before receiving radiation therapy (RT). With the addition of multiagent chemotherapy, patients are living longer, and RT has emerged as an important modality in preventing local progression. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 1, 2017 Category: Cancer & Oncology Authors: Lauren M. Rosati, Rachit Kumar, Joseph M. Herman Source Type: research

Stereotactic Body Radiotherapy for Low- and Intermediate-Risk Prostate Cancer
With over a decade ׳s worth of clinical experience to guide stereotactic body radiotherapy (SBRT) for the treatment of clinically localized prostate cancer (PCa), sufficient data exist for robust conclusions to be made regarding its efficacy and the toxicities associated with this treatment. We briefly review the fun damental radiobiological basis of SBRT for PCa and provide a comprehensive synthesis of the medical literature to date, focusing on clinical outcomes and toxicities. When possible, we draw comparisons to comparable data for conventionally fractionated radiotherapy. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 1, 2017 Category: Cancer & Oncology Authors: Amar U. Kishan, Christopher R. King Source Type: research

New Techniques for Irradiating Early Stage Breast Cancer: Stereotactic Partial Breast Irradiation
Several improvements in breast cancer radiation delivery have been realized using new techniques over the past several decades. As an example, for early stage disease, there has been active investigation of partial breast irradiation (PBI) vs whole breast irradiation. Although still investigational, PBI reduces the treatment volumes, doses to organs at risk, and may improve cosmesis. Over the past 2 decades PBI has been delivered via interstitial brachytherapy, intracavitary brachytherapy, intraoperative radiation therapy, or 3-dimensional external beam radiation therapy. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 1, 2017 Category: Cancer & Oncology Authors: Asal Rahimi, Robert Timmerman Source Type: research

Stereotactic Ablative Radiotherapy for Early-Stage Lung Cancer
The rising incidence of early-stage lung cancer, particularly in medically inoperable patients, is anticipated because of the implementation of early detection strategies and population aging in the United States and worldwide. This mandates the development of noninvasive curative treatment approaches for this disease. Stereotactic ablative radiotherapy (SABR) has recently emerged as a standard of care for early-stage lung cancer in medically inoperable patients who cannot safely tolerate surgical lobectomy, the established standard for operable patients. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 1, 2017 Category: Cancer & Oncology Authors: Jennifer L. Shah, Billy W. Loo Source Type: research

Radiation and Immune Checkpoint Blockade: From Bench to Clinic
Immune escape of malignant cells is an important hallmark of cancer, necessary for tumor formation and progression. Accordingly, in recent years, therapies that enhance the immune system have had remarkable success in treating a myriad of malignancies. Particularly successful has been immune checkpoint blockade (ICB), which is a therapy that targets T-cell inhibitory receptors, or immune checkpoints. Despite these encouraging clinical results, most patients do not respond to such agents. Therefore, determining methods to better target and enhance the therapeutic efficacy of ICB is of paramount importance. (Source: Seminars...
Source: Seminars in Radiation Oncology - June 1, 2017 Category: Cancer & Oncology Authors: Jacob E. Shabason, Andy J. Minn Source Type: research

Stereotactic Ablative Body Radiotherapy for Lung Metastases: Where is the Evidence and What are We Doing With It?
This review provides an overview of the use of stereotactic ablative body radiotherapy (SABR) for pulmonary metastases. The local control rates after SABR are generally>90%. Whether this also translates into a significant improvement in overall survival is the subject of ongoing studies. New exciting opportunities including the integration of SABR with targeted and immune therapies as well as some competing treatment strategies are discussed. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 1, 2017 Category: Cancer & Oncology Authors: Shankar Siva, Ben J. Slotman Source Type: research

Stereotactic Body Radiotherapy in the Treatment of Spinal Metastases
Patients with metastatic disease including polymetastatic, oligometastatic, and oligorecurrent spinal lesions have extended life expectancy secondary to improvements in systemic agents, and thus require durable local control of spine metastases. Stereotactic body radiotherapy (SBRT), which uses highly conformal treatment planning techniques coupled with image-guided technology, has enabled the safe delivery of tumor-ablative doses of radiotherapy. The NOMS decision framework has been developed as a tool to aid in the determination of the optimal treatment of spinal metastases, incorporating radiosurgery, separation surgery...
Source: Seminars in Radiation Oncology - June 1, 2017 Category: Cancer & Oncology Authors: Evangelia Katsoulakis, Kiran Kumar, Ilya Laufer, Yoshiya Yamada Source Type: research

Introduction
Stereotactic body radiotherapy (SBRT), also referred to as stereotactic ablative radiotherapy (SABR), is increasingly been used by radiation oncologists to treat a variety of tumors including most commonly those located in the lung, spine, liver, and pancreas. The principles of SBRT or SABR, including the use of hypofractionation and high-dose per fraction to achieve sharp dose gradients, can result in greater tumor control and better integration with other cancer therapies. However, this technology must be applied judiciously as the risk of harming patients is also increased. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 1, 2017 Category: Cancer & Oncology Authors: Albert C. Koong, Joel E. Tepper Source Type: research

Improving Quality and Access to Radiation Therapy —An IAEA Perspective
The International Atomic Energy Agency (IAEA) has been involved in radiation therapy since soon after its creation in 1957. In response to the demands of Member States, the IAEA ׳s activities relating to radiation therapy have focused on supporting low- and middle-income countries to set up radiation therapy facilities, expand the scope of treatments, or gradually transition to new technologies. In addition, the IAEA has been very active in providing internationally harmon ized guidelines on clinical, dosimetry, medical physics, and safety aspects of radiation therapy. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - March 18, 2017 Category: Cancer & Oncology Authors: May Abdel-Wahab, Eduardo Zubizarreta, Alfredo Polo, Ahmed Meghzifene Source Type: research

Bridging Innovation and Outreach to Overcome Global Gaps in Radiation Oncology Through Information and Communication Tools, Trainee Advancement, Engaging Industry, Attention to Ethical Challenges, and Political Advocacy
This report highlights 4 information and communication technology tools in action today: (1) the NCCN Framework for Resource Stratification of NCCN guidelines, (2) ASTRO e-Contouring, (3) i.treatsafely.org, and (4) ChartRounds.com. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - March 18, 2017 Category: Cancer & Oncology Authors: Luqman Dad, Trevor J. Royce, Zachary Morris, Meena Moran, Todd Pawlicki, Deepak Khuntia, Patricia Hardenbergh, Bernard Cummings, Nina Mayr, Kenneth Hu Source Type: research

Global Health in Radiation Oncology: The Emergence of a New Career Pathway
The massive global shortfall in radiotherapy equipment and human resources in developing countries is an enormous challenge for international efforts in cancer control. This lack of access to treatment has been long-standing, but there is now a growing consensus about the urgent need to prioritize solutions to this problem and that a global strategy is required for them to be successful. An essential element of making radiotherapy universally accessible is a coordinated approach to clinical training and practice. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - March 18, 2017 Category: Cancer & Oncology Authors: Danielle Rodin, Mei Ling Yap, Surbhi Grover, John M. Longo, Onyinye Balogun, Sandra Turner, Jesper G. Eriksen, C. Norman Coleman, Meredith Giuliani Source Type: research

Radiation Oncology Quality and Safety Considerations in Low-Resource Settings: A Medical Physics Perspective
The past few years have seen a significant growth of interest in the global radiation therapy (RT) crisis. Various organizations have quantified the need and are providing aid in support of addressing the shortfalls existing in many low-to-middle income countries. With the tremendous demand for new facilities, equipment, and personnel, it is very important to recognize the quality and safety challenges and to address them directly. An examination of publications on quality and safety in RT indicates a consistency in a number of the recommendations; however, these authoritative reports were generally based on input from hig...
Source: Seminars in Radiation Oncology - March 18, 2017 Category: Cancer & Oncology Authors: Jacob Van Dyk, Ahmed Meghzifene Source Type: research

The Unique Issues With Brachytherapy in Low- and Middle-Income Countries
This article examines the role and delivery of brachytherapy in gynecological cancer treatment; brachytherapy capacity in LMICs, including infrastructure, equipment, and human resources considerations; commissioning, training, and clinical implementation of brachytherapy in LMICs; other challenges, and strategies for improvement in brachytherapy delivery in LMICs, including innovation and current and upcoming international initiatives. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - March 18, 2017 Category: Cancer & Oncology Authors: Surbhi Grover, John Longo, John Einck, Priya Puri, Derek Brown, Junzo Chino, Umesh Mahantshetty, Catheryn Yashar, Beth Erickson Source Type: research

Cancer Care Access and Outcomes for American Indian Populations in the United States: Challenges and Models for Progress
Low socioeconomic and health care access realities of being American Indian/Alaskan Native (AI/AN) in the United States combined with decades of data documenting poor cancer outcomes for this population provide a population nested within the United States that is analogous to the cancer care landscape of low- and middle-income countries internationally. We reviewed the medical literature with respect to cancer prevention, access to cancer treatment, and access to effective supportive and palliative care for AI/AN populations in the United States. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - March 18, 2017 Category: Cancer & Oncology Authors: B. Ashleigh Guadagnolo, Daniel G. Petereit, C. Norman Coleman Source Type: research

Radiation Oncology in India: Challenges and Opportunities
Rising cancer incidence and mortality in India emphasize the need to address the increasing burden of this disease and the stark inequities in access to radiotherapy and other essential medical treatments. State-of-the-art technology is available within the private sector and a few hospitals in the public sector, but 75% of patients in the public sector in India do not have access to timely radiotherapy. This inequity in access to radiotherapy in the public sector is amplified in rural areas, where most of India ׳s population lives. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - March 18, 2017 Category: Cancer & Oncology Authors: Surbhi Grover, Shivakumar Gudi, Ajeet Kumar Gandhi, Priya M. Puri, Adam C. Olson, Danielle Rodin, Onyi Balogun, Preet K. Dhillon, Daya Nand Sharma, Goura Kishor Rath, Shyam Kishore Shrivastava, Akila N. Viswanathan, Umesh Mahantshetty Source Type: research