TY - JOUR
T1 - The Role of Functional Imaging in the Diagnosis and Management of Late Normal Tissue Injury
AU - Evans, Elizabeth S.
AU - Hahn, Carol A.
AU - Kocak, Zafer
AU - Zhou, Su Min
AU - Marks, Lawrence B.
N1 - Funding Information:
Supported in part by grants 17-98-1-8071 and BC010663 from the Department of Defense and NIH RO1 Grant CA69579.
PY - 2007/4
Y1 - 2007/4
N2 - Normal tissue injury after radiation therapy (RT) can be defined based on either clinical symptoms or laboratory/radiologic tests. In the research setting, functional imaging (eg, single-photon emission computed tomography [SPECT], positron-emission tomography [PET], and magnetic resonance imaging [MRI]) is useful because it provides objective quantitative data such as metabolic activity, perfusion, and soft-tissue contrast within tissues and organs. For RT-induced lung, heart, and parotid gland injury, pre- and post-RT SPECT images can be compared with the dose- and volume-dependent nature of regional injury. In the brain, SPECT can detect changes in perfusion and blood flow post-RT, and PET can detect metabolic changes, particularly to regions of the brain that have received doses above 40 to 50 Gy. On MRI, changes in contrast-enhanced images, T1 and T2 relaxation times, and pulmonary vascular resistance at different intervals pre- and post-RT show its ability to detect and distinguish different phases of radiation pneumonitis. Similarly, conventional and diffusion-weighted MRI can be used to differentiate between normal tissue edema, necrosis, and tumor in the irradiated brain, and magnetic resonance spectroscopy can measure changes in compounds, indicative of membrane and neuron disruption. The use of functional imaging is a powerful tool for early detection of RT-induced normal tissue injury, which may be related to long-term clinically significant injury.
AB - Normal tissue injury after radiation therapy (RT) can be defined based on either clinical symptoms or laboratory/radiologic tests. In the research setting, functional imaging (eg, single-photon emission computed tomography [SPECT], positron-emission tomography [PET], and magnetic resonance imaging [MRI]) is useful because it provides objective quantitative data such as metabolic activity, perfusion, and soft-tissue contrast within tissues and organs. For RT-induced lung, heart, and parotid gland injury, pre- and post-RT SPECT images can be compared with the dose- and volume-dependent nature of regional injury. In the brain, SPECT can detect changes in perfusion and blood flow post-RT, and PET can detect metabolic changes, particularly to regions of the brain that have received doses above 40 to 50 Gy. On MRI, changes in contrast-enhanced images, T1 and T2 relaxation times, and pulmonary vascular resistance at different intervals pre- and post-RT show its ability to detect and distinguish different phases of radiation pneumonitis. Similarly, conventional and diffusion-weighted MRI can be used to differentiate between normal tissue edema, necrosis, and tumor in the irradiated brain, and magnetic resonance spectroscopy can measure changes in compounds, indicative of membrane and neuron disruption. The use of functional imaging is a powerful tool for early detection of RT-induced normal tissue injury, which may be related to long-term clinically significant injury.
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U2 - 10.1016/j.semradonc.2006.11.003
DO - 10.1016/j.semradonc.2006.11.003
M3 - Article
C2 - 17395037
AN - SCOPUS:33947505362
SN - 1053-4296
VL - 17
SP - 72
EP - 80
JO - Seminars in Radiation Oncology
JF - Seminars in Radiation Oncology
IS - 2
ER -