Expanding the Use of Magnetic Resonance in the Assessment of Tumor Response to Therapy: Workshop Report

Abstract

Although dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and magnetic resonance spectroscopy (MRS) have great potential to provide routine assessment of cancer treatment response, their widespread application has been hampered by a lack of standards for use. Thus, the National Cancer Institute convened a workshop to assess developments and applications of these methods, develop standards for methodology, and engage relevant partners (drug and device industries, researchers, clinicians, and government) to encourage sharing of data and methodologies. Consensus recommendations were reached for DCE-MRI methodologies and the focus for initial multicenter trials of MRS. In this meeting report, we outline the presentations, the topics discussed, the ongoing challenges identified, and the recommendations made by workshop participants for the use of DCE-MRI and 1 H MRS in the clinical assessment of antitumor therapies. Workshop GoalsIn the quest to tailor and fine-tune cancer therapies, clinicians may exploit the capacity of magnetic resonance to produce rapid, accurate, in vivo assessment. Two methods in particular, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and magnetic resonance spectroscopy (MRS), have outstanding potential. In recent years, they have been advancing the field of assessment and treatment significantly, despite the fact that issues such as standardization and reliability have limited their broad use.MRI has served in clinical cancer detection, diagnosis, and intervention and has been employed in the development of drug therapies. There is a need to move beyond the many isolated successes of magnetic resonance applications to widespread routine use of these tools to assess response to cancer treatment. This will require overcoming hurdles that are logistic rather than scientific. It will require the establishment of standards of use, leading to comparable data and reliability.On November [22][23] 2004 in Bethesda, Maryland, the National Cancer Institute (NCI) convened a workshop on the use of MRI, MRS, and related technologies. Presentations were combined with strategy sessions that focused on ways to assess developments and applications of MRI and MRS, to develop standards for methods of use, and to engage relevant partners (drug and device industries, researchers, clinicians, and government) to encourage the sharing of data and methodologies. The meeting participants also identified ongoing challenges. The main points of discussion from the meeting are given below. Perspectives from the FieldThe oncologist must choose from an array of new drugs, many of which share targets in cancer treatment. MRI and MRS can help identify drug effects within a tumor, revealing which drugs work best, alone or in combination. To the oncologist, some drug effects may be more important than tumor shrinkage, and magnetic resonance can reveal these effects. MRI and MRS can be important tools in new drug development, especially to show biological activity and evaluate pharmacokin...

Radiation Therapy of Glioblastoma

“…Several recent reviews have provided a thorough description of the methodology and examples patient data [29]. Briefly, DCE imaging takes advantage of the changes in the T1 associated with the passage of gadolinium through the vasculature and leakage into the extracellular space for regions in which the blood-brain barrier has been compromised [38][39][40][41][42]. When applying certain sampling techniques in conjunction with the latest parallel reconstructions strategies, time resolution of 5-10 s can be achieved for threedimensional imaging sequence that covers an axial slab of 6-8 cm, partial brain volume.…”

Metabolic assessment of the action of targeted cancer therapeutics using magnetic resonance spectroscopy

“…Developing quality assurance protocols and standardising data acquisition methodologies are important aspects that will help evaluate and integrate findings from multiple centres, thereby reducing effort and keeping duplication to a minimum (Leach et al, 1994;Evelhoch et al, 2005). Continuing progress in this area signifies that the technology could in the near future be available to assess whether the metabolic signatures detectable in pre-clinical models could eventually be translated into robust imaging biomarkers for clinical use.…”

Imaging Surrogates of Tumor Response to Therapy: Anatomic and Functional Biomarkers

“…Over the past several years, consensus recommendations for design and analysis of clinical trials that incorporate DCE-MRI investigations have been outlined and are being used for developing and validating DCE-MRI as a surrogate imaging biomarker in early clinical trials worldwide (44,45). These recommendations have addressed mainly the following issues: imaging protocol, type of measurement methods, primary and secondary endpoints, trial design, pharmacokinetic models, data analysis, measurement reproducibility, and future developments.…”