Introduction: Systems for Magnetic Resonance Image Guided Radiation Therapy
As in-room image guidance has become the standard of practice in radiation therapy, the soft-tissue contrast of x-ray-based imaging techniques has become limiting. This has motivated several institutions to work on the integration of in-room magnetic resonance imaging (MRI) and external-beam radiotherapy. Such an approach poses many technical challenges, and a range of solutions have been explored, investigated, and reported. To date, we are aware of 5 groups that are pursuing a system integration of in-room MRI into radiotherapy guidance. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: Cynthia Ménard, Uulke van der Heide Source Type: research
Magnetic Resonance Image Guided Brachytherapy
The application of magnetic resonance image (MRI)–guided brachytherapy has demonstrated significant growth during the past 2 decades. Clinical improvements in cervix cancer outcomes have been linked to the application of repeated MRI for identification of residual tumor volumes during radiotherapy. This has changed clinical practice in the direction of individualized dose administration, and resulted in mounting evidence of improved clinical outcome regarding local control, overall survival as well as morbidity. MRI-guided prostate high-dose-rate and low-dose-rate brachytherapies have improved the accuracy of target and ...
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: Kari Tanderup, Akila N. Viswanathan, Christian Kirisits, Steven J. Frank Source Type: research
Counterpoint: Opportunities and Challenges of a Magnetic Resonance Imaging–Only Radiotherapy Work Flow
Magnetic resonance (MR) imaging plays an important role in modern radiotherapy. The benefits of MR as compared with those of computed tomography for the definition of target volumes is evident for many soft tissue tumor types. It has been suggested that for these patient groups, the computed tomography examination is unnecessary as part of the preparation for radiotherapy. Here, we review the rationale for an MR-only radiotherapy work flow, as well as the technical challenges and solutions connected to it. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: Tufve Nyholm, Joakim Jonsson Source Type: research
Point: Principles of Magnetic Resonance Imaging Integration in a Computed Tomography–Based Radiotherapy Workflow
Computed tomography (CT) is the primary imaging modality on which radiation therapy has been based, leading to a CT-based workflow that is well established. CT provides a geometrically accurate patient model on which accurate radiation planning occurs, and it is the basis of the present state-of-the-art image guidance systems, which are well integrated with the treatment unit. Magnetic resonance imaging (MRI) is becoming an increasingly important tool in radiation oncology, as it can provide anatomical and functional information regarding the tumor and normal tissues, which may be complimentary to information from CT alone...
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: Kristy K. Brock, Laura A. Dawson Source Type: research
Magnetic Resonance Imaging Acquisition Techniques for Radiotherapy Planning
Magnetic resonance imaging (MRI) has a number of benefits for the planning of radiotherapy (RT), but its uptake into clinical practice has often been restricted to specialist research sites. There is often a lack of detailed MRI knowledge within the RT community and an apprehension of geometric distortions, both of which prevent its best utilization and merit the introduction of a standardized approach and common guidelines. This review sets out to address some of the issues involved in acquiring MRI scans for RT planning in the context of a number of clinical sites of interest and concludes with recommendations for its be...
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: Gary P. Liney, Marinus A. Moerland Source Type: research
The Value of Magnetic Resonance Imaging for Radiotherapy Planning
The success of highly conformal radiotherapy techniques in the sparing of normal tissues or in dose escalation, or both, relies heavily on excellent imaging. Because of its superior soft tissue contrast, magnetic resonance imaging is increasingly being used in radiotherapy treatment planning. This review discusses the current clinical evidence to support the pivotal role of magnetic resonance imaging in radiation oncology. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: Piet Dirix, Karin Haustermans, Vincent Vandecaveye Source Type: research
Introduction: Magnetic Resonance Imaging Comes of Age in Radiation Oncology
With the invention of spatial encoding of the nuclear magnetic resonance (MR) signal by Lauterbur and Mansfield, MR imaging (MRI) was born. After the first image of in vivo human anatomy in 1977, evolution of the technology accelerated over the ensuing decade, and clinical translation to the field of diagnostic radiology flourished. Because MRI, much like radiation oncology, is at the crossroads between medicine and chemistry, physics, and computer science, groups with strong interdisciplinary relationships and cross-fertilization became scientifically fruitful. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - June 16, 2014 Category: Cancer & Oncology Authors: Cynthia Ménard, Uulke A. van der Heide Source Type: research
Stereotactic Body Radiotherapy in the Treatment of Pancreatic Cancer
Most patients diagnosed with pancreatic cancer are unable to have a curative surgical resection. Chemoradiation is a standard of care treatment for patients with locally advanced unresectable disease, but local failure rates are high with conventionally fractionated radiotherapy. However, stereotactic body radiotherapy (SBRT) or stereotactic ablative radiotherapy offers an alternative type of radiation therapy, which allows for the delivery of high-dose, conformal radiation. The high doses and shorter overall treatment time with SBRT may provide advantages in local control, disease outcomes, quality of life, and cost-effec...
Source: Seminars in Radiation Oncology - March 13, 2014 Category: Cancer & Oncology Authors: Nicholas Trakul, Albert C. Koong, Daniel T. Chang Source Type: research
Utilization of Intensity-Modulated Radiation Therapy and Image-Guided Radiation Therapy in Pancreatic Cancer: Is It Beneficial?
The recent development of intensity-modulated radiation therapy (IMRT) and improvements in image-guided radiotherapy (IGRT) have provided considerable advances in the utilization of radiation therapy (RT) for the management of pancreatic cancer. IGRT allows for the reduction of treatment volumes, potentially less chance of a marginal miss, and quality assurance of gastrointestinal filling, while IMRT has been shown to reduce both sudden and late side effects compared with 3-dimensional conformal RT. Here, we review published data and provide essential recommendations on the utilization of IMRT and IGRT for the management o...
Source: Seminars in Radiation Oncology - March 13, 2014 Category: Cancer & Oncology Authors: Adam S. Reese, Wei Lu, William F. Regine Source Type: research
The Role of Intraoperative Radiation Therapy in Patients With Pancreatic Cancer
Intraoperative radiation therapy (IORT) techniques allow for the delivery of high doses of radiation therapy while excluding part or all of the nearby dose-limiting sensitive structures. Therefore, the effective radiation dose is increased and local tumor control potentially improved. This is pertinent in the case of pancreatic cancer because local failure rates are as high as 50%-80% in patients with resected and locally advanced disease. Available data in patients receiving IORT after pancreaticoduodenectomy reveal an improvement in local control, though overall survival benefit is unclear. Series of patients with locall...
Source: Seminars in Radiation Oncology - March 13, 2014 Category: Cancer & Oncology Authors: Manisha Palta, Christopher Willett, Brian Czito Source Type: research
Neoadjuvant vs Adjuvant Therapy for Resectable Pancreatic Cancer: The Evolving Role of Radiation
A major challenge with pancreatic cancer management is in the discrimination of clearly resectable tumors from those that would likely be accompanied by a positive resection margin if upfront surgery was attempted. The standard of care for clearly resectable pancreatic cancer remains surgery followed by adjuvant therapy, but there is considerable controversy over whether such therapeutic adjuvant strategies should include radiotherapy. Furthermore, in a malignancy with such high rates of distant metastasis, investigators are now exploring the feasibility and outcomes of delivering therapy in the neoadjuvant setting, both f...
Source: Seminars in Radiation Oncology - March 13, 2014 Category: Cancer & Oncology Authors: Sarah Hoffe, Nikhil Rao, Ravi Shridhar Source Type: research
Management of Borderline Resectable Pancreatic Cancer
Borderline resectable pancreatic cancers are those that, although technically resectable, are at high risk for margin-positive resection following surgery de novo. Generally, such cancers are characterized by localized primary tumors that involve the mesenteric vasculature to a limited degree and that may require venous or hepatic arterial resection at pancreatectomy. In this article, we review diagnosis and staging algorithms, pretreatment strategies, and multidisciplinary treatment protocols for patients with this stage of disease. The rationale for and results following treatment with neoadjuvant chemotherapy and chemor...
Source: Seminars in Radiation Oncology - March 13, 2014 Category: Cancer & Oncology Authors: Matthew H.G. Katz, Christopher H. Crane, Gauri Varadhachary Source Type: research
Defining the Role of Adjuvant Therapy: Cholangiocarcinoma and Gall Bladder Cancer
Biliary tract cancers are a rare subgroup of malignancies that include gall bladder carcinoma and cholangiocarcinoma. They generally carry a poor prognosis based on the advanced nature of disease at presentation and overall treatment refractoriness. Surgical resection remains the optimal treatment for long-term survival, with consideration of neoadjuvant or adjuvant therapies. In this review, we summarize the role of adjuvant treatments including radiation therapy, chemotherapy, and concurrent chemoradiation with the existing clinical evidence for each treatment decision. Given the rarity of these tumors, the evidence prov...
Source: Seminars in Radiation Oncology - March 13, 2014 Category: Cancer & Oncology Authors: Terence M. Williams, Lonika Majithia, Samuel J. Wang, Charles R. Thomas Source Type: research
Defining the Role of Adjuvant Therapy: Ampullary and Duodenal Adenocarcinoma
Adenocarcinomas of the ampulla of Vater and duodenum are more rare than pancreatic cancer and have a better prognosis. However, studies conducted on the management of these cancers, such as adjuvant chemotherapy and radiation therapy, are limited by small sample sizes and series that are retrospective. This review evaluates ampullary and duodenal adenocarcinomas with regard to incidence, anatomy, prognostic features, patterns of failure, and the available literature studying adjuvant therapy. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - March 13, 2014 Category: Cancer & Oncology Authors: Salma K. Jabbour, David Mulvihill Source Type: research
Intraductal Papillary Mucinous Neoplasm: Clinical Surveillance and Management Decisions
Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a relatively rare cystic neoplasm. Although most IPMNs appear to be benign and may be managed by surveillance, all IPMNs are considered premalignant lesions with malignant potential. As such, current efforts are focused on identifying those neoplasms that are at high risk for malignancy to optimize treatment strategy and outcome. IPMNs with invasive carcinoma have clinical outcomes that approach those of conventional pancreatic ductal adenocarcinoma. Management guidelines recommend surgical resection for IPMNs with high-risk imaging or cytologic features. Th...
Source: Seminars in Radiation Oncology - March 13, 2014 Category: Cancer & Oncology Authors: Joanna Y. Chin, Martha B. Pitman, Theodore S. Hong Source Type: research
