Article

Functional magnetic resonance imaging for defining the biological target volume

Department of Radiology, Innovative Cancer Diagnostics and Therapy, German Cancer Research Center, Heidelberg, Germany.
Cancer Imaging (Impact Factor: 1.29). 02/2006; 6(1):51-5. DOI: 10.1102/1470-7330.2006.0010
Source: PubMed

ABSTRACT Morphology as demonstrated by CT is the basis for radiotherapy planning. Intensity-modulated and adaptive radiotherapy techniques would greatly benefit from additional functional information allowing for definition of the biological target volume. MRI techniques include several which can characterize and quantify different tissue properties and their tumour-related changes. Results of perfusion MRI represent microvascular density and permeability; MR spectroscopy depicts particular metabolites; diffusion weighted imaging shows tissue at risk and tumour cellularity; while dynamic 3D acquisition (4D MRI) shows organ motion and the mobility of tumours within them.

1 Follower
 · 
99 Views
 · 
4 Downloads
  • Source
    • "In vivo measurement of tumor burden, both in cancer research models and in patients, is an important parameter for the accurate assessment of disease progression and the response to therapeutic intervention [1]. Several in vivo imaging modalities have been utilized in the assessment of tumor burden, including functional magnetic resonance imaging, computer tomography and positron emission tomography [2] [3], fluorescence imaging [4] [5], intravital microscopy [6] and bioluminescence imaging [7] [8]. More recently, the detection and quantification of circulating cancer cells has been explored as a method to evaluate tumor burden in the context of assessing disease stage, prognosis as well as monitoring disease progression following therapeutic intervention in cancer patients [9] [10]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We report a new approach for potential monitoring of tumor burden in experimental animals using multichannel in vivo flow cytometry, a novel optical technique that enables the realtime, continuous detection and quantification of fluorescently labeled cells in the circulation without the need for blood extraction. The ability to non-invasively track circulating cells in real time and in their native environment, opens up enormous possibilities for new investigations into the mechanisms that govern the complex trafficking and tissue interactions of these cells in a wide range of clinical and biological fields such as cancer, stem cell biology and immunology. We have developed the in vivo flow cytometer in order to track circulating cancer cells in a mouse model and provide a new, non-invasive method for the monitoring of cancer disease progression as well as the response to therapeutic intervention.
    Bioinformatics & Bioengineering (BIBE), 2012 IEEE 12th International Conference on; 01/2012
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Accurate target definition is considered essential for sophisticated, image-guided radiation therapy; however, relatively little information has been reported that measures our ability to identify the precise shape of targets accurately. We decided to assess the manner in which eight "experts" interpreted the size and shape of tumors based on "real-life" contrast-enhanced computed tomographic (CT) scans. Four neuroradiologists and four radiation oncologists (the authors) with considerable experience and presumed expertise in treating head-and-neck tumors independently contoured, slice-by-slice, his/her interpretation of the precise gross tumor volume (GTV) on each of 20 sets of CT scans taken from 20 patients who previously were enrolled in Radiation Therapy Oncology Group protocol 91-11. The average proportion of overlap (i.e., the degree of agreement) was 0.532 (95% confidence interval 0.457 to 0.606). There was a slight tendency for the proportion of overlap to increase with increasing average GTV. Our work suggests that estimation of tumor shape currently is imprecise, even for experienced physicians. In consequence, there appears to be a practical limit to the current trend of smaller fields and tighter margins.
    International Journal of Radiation OncologyBiologyPhysics 04/2007; 67(4):972-5. DOI:10.1016/j.ijrobp.2006.10.029 · 4.18 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Several methods exist for evaluating tumor oxygenation as hypoxia is an important prognostic factor for cancer patients. They use different measuring principles that highlight various aspects of oxygenation. The results could be empirically correlated, but it has been suspected that there could be discordances in some cases. This study describes an analysis of the relationship between vascular and tissue oxygenations. Theoretical simulation has been employed to characterize tissue oxygenations for a broad range of distributions of intervessel distances and vascular oxygenations. The results were evaluated with respect to the implications for practical measurements of tissue oxygenations. The findings showed that although the tissue oxygenation is deterministically related to vascular oxygenation, the relationship between them is not unequivocal. Variability also exists between the fractions of values below the sensitivity thresholds of various measurement methods which in turn could be reflected in the power of correlations between results from different methods or in the selection of patients for prognostic studies. The study has also identified potential difficulties that may be encountered at the quantitative evaluation of the results from oxygenation measurements. These could improve the understanding of oxygenation measurements and the interpretation of comparisons between results from various measurement methods.
    Medical Physics 03/2008; 35(2):539-545. DOI:10.1118/1.2830382 · 3.01 Impact Factor
Show more

Preview

Download
4 Downloads
Available from