Imaging As A Marker Of Biological Activity

Imaging techniques are used to evaluate the biological activity of a drug candidate by performing pre- and posttreatment measurements (and in many instances, performing measurements during treatment). These include:

• Oncology: CT scan or MRI for the measurement of the size of solid tumors

• Neurology: MRI for the measurement of multiple sclerosis lesions and for the evaluation and quantification of brain atrophy in Alzheimer disease (e.g., brain boundary shift integral or ROI-based MRI)

• Musculoskeletal diseases: x-ray and DEXA to evaluate vertebral fractures and BMD in osteoporosis; x-ray and MRI for the evaluation of erosions and joint space in rheumatoid arthritis and psoriatic arthritis; x-ray and MRI for the evaluation of joint space and cartilage volume in osteoar-thritis; and the same techniques to evaluate spinal changes in spondyloarthritis

In addition to the use of imaging to capture anatomical changes, imaging can be used to perform a functional evaluation of a tissue/organ before and after treatment. Classical examples include:

• Oncology: the evaluation of tumor metabolism with fluorodeoxyglucose (FDG)-PET. This may be helpful as an early predictor of a later anatomical response. Indeed, the reduction in tumor size with imatinib was preceded by decreased tumor glucose intake by a median of 7 weeks (Stroobants et al., 2003). Another example is the measurement of tumor blood flow and blood volume with CT: after bevacizumab (VEGF- Ab) treatment a decreased blood flow and volume in colorectal cancer was observed as early as 12 days after initiation of treatment (Miller et al., 2005 ).

• Neurology: FDG-PET was used in Alzheimer disease (AD) to evaluate regional cerebral metabolic rate and SPECT was used to evaluate blood flow in AD.

In multiple sclerosis, PET and SPECT have shown a reduction in cerebral metabolism and blood flow. It should be noted, however, that these approaches have not been tested and qualified to measure the potential effect of a therapeutic intervention (Bakshi et al., 2005).

Project Management Made Easy

Project Management Made Easy

What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.

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