TY - JOUR
T1 - Dynamics of metabolic changes in intracranial metastases and distant normal-appearing brain tissue after stereotactic radiosurgery
T2 - A serial proton magnetic resonance spectroscopy study
AU - Chernov, Mikhail F.
AU - Hayashi, M.
AU - Izawa, M.
AU - Nakaya, K.
AU - Tamura, N.
AU - Ono, Y.
AU - Abe, K.
AU - Usukura, M.
AU - Yoshida, S.
AU - Nakamura, R.
AU - Suzuki, T.
AU - Muragaki, Y.
AU - Iseki, H.
AU - Kubo, O.
AU - Hori, T.
AU - Takakura, K.
PY - 2009/2
Y1 - 2009/2
N2 - The present study evaluated the dynamics of metabolic changes in intracranial metastases and distant normal-appearing brain after stereotactic radiosurgery (SRS). Forty neoplasms were evaluated with single-voxel proton magnetic resonance spectroscopy (1H-MRS) both before and after treatment. From one to six examinations (median, 3) were done in each individual case during follow-up. At the time of each investigation additional 1H-MRS was obtained from the normal-appearing brain distant from the radiosurgical target. Investigated metabolites included N-acetylaspartate (NAA), choline-containing compounds (Cho), creatine (Cr), and mobile lipids (Lip). Within the first month after SRS responded tumors showed a statistically significant increase in NAA/Cho ratio, and decrease of Cho content and Lip-to-normal brain Cr (nCr) ratio. By contrast, statistically significant metabolic alterations were not detected in stabilized tumors. Statistically significant volumetric and metabolic changes were not marked between three and 12 months after treatment in non-progressing lesions. Alternatively, decrease of NAA/Cho ratio, NAA content and Cr content, and increase in Lip/nCr ratio and Cho content were evident in progressive neoplasms, and subtle metabolic alterations could be revealed even before the increase in the lesion volume. Metabolic characteristics of normal-appearing brain distant from the radiosurgical target did not show statistically significant changes within the first year after treatment. In conclusion, additional use of serial 1H-MRS during follow-up after SRS for intracranial metastases permits detailed evaluation of the metabolic tumor response and may be potentially helpful for early prediction of recurrence.
AB - The present study evaluated the dynamics of metabolic changes in intracranial metastases and distant normal-appearing brain after stereotactic radiosurgery (SRS). Forty neoplasms were evaluated with single-voxel proton magnetic resonance spectroscopy (1H-MRS) both before and after treatment. From one to six examinations (median, 3) were done in each individual case during follow-up. At the time of each investigation additional 1H-MRS was obtained from the normal-appearing brain distant from the radiosurgical target. Investigated metabolites included N-acetylaspartate (NAA), choline-containing compounds (Cho), creatine (Cr), and mobile lipids (Lip). Within the first month after SRS responded tumors showed a statistically significant increase in NAA/Cho ratio, and decrease of Cho content and Lip-to-normal brain Cr (nCr) ratio. By contrast, statistically significant metabolic alterations were not detected in stabilized tumors. Statistically significant volumetric and metabolic changes were not marked between three and 12 months after treatment in non-progressing lesions. Alternatively, decrease of NAA/Cho ratio, NAA content and Cr content, and increase in Lip/nCr ratio and Cho content were evident in progressive neoplasms, and subtle metabolic alterations could be revealed even before the increase in the lesion volume. Metabolic characteristics of normal-appearing brain distant from the radiosurgical target did not show statistically significant changes within the first year after treatment. In conclusion, additional use of serial 1H-MRS during follow-up after SRS for intracranial metastases permits detailed evaluation of the metabolic tumor response and may be potentially helpful for early prediction of recurrence.
KW - Metabolic effects
KW - Metastatic brain tumor
KW - Proton magnetic resonance spectroscopy
KW - Stereotactic radiosurgery
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U2 - 10.1177/197140090902200109
DO - 10.1177/197140090902200109
M3 - Article
AN - SCOPUS:64149089557
SN - 1971-4009
VL - 22
SP - 58
EP - 71
JO - Neuroradiology Journal
JF - Neuroradiology Journal
IS - 1
ER -