Limits...
The potential role of magnetic resonance spectroscopy in image-guided radiotherapy.

Nguyen ML, Willows B, Khan R, Chi A, Kim L, Nour SG, Sroka T, Kerr C, Godinez J, Mills M, Karlsson U, Altdorfer G, Nguyen NP, Jendrasiak G, International Geriatric Radiotherapy Gro - Front Oncol (2014)

Bottom Line: Magnetic resonance spectroscopy (MRS) is a non-invasive technique to detect metabolites within the normal and tumoral tissues.Preliminary studies suggest that the integration of MRS into radiotherapy planning for these tumors is feasible and safe.Image-guided radiotherapy (IGRT) by virtue of daily tumor imaging and steep dose gradient may allow for tumor dose escalation with the simultaneous integrated boost technique (SIB) and potentially decrease the complications rates in patients with GBM and prostate cancers.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Stanford University , Palo Alto, CA , USA.

ABSTRACT
Magnetic resonance spectroscopy (MRS) is a non-invasive technique to detect metabolites within the normal and tumoral tissues. The ability of MRS to diagnose areas of high metabolic activity linked to tumor cell proliferation is particularly useful for radiotherapy treatment planning because of better gross tumor volume (GTV) delineation. The GTV may be targeted with higher radiation dose, potentially improving local control without excessive irradiation to the normal adjacent tissues. Prostate cancer and glioblastoma multiforme (GBM) are two tumor models that are associated with a heterogeneous tumor distribution. Preliminary studies suggest that the integration of MRS into radiotherapy planning for these tumors is feasible and safe. Image-guided radiotherapy (IGRT) by virtue of daily tumor imaging and steep dose gradient may allow for tumor dose escalation with the simultaneous integrated boost technique (SIB) and potentially decrease the complications rates in patients with GBM and prostate cancers.

No MeSH data available.


Related in: MedlinePlus

This patient with a glioblastoma multiforme shows the voxel over the area of interest in the tumor over the sagittal T1 (A) and axial FLAIR (B) image. Magnetic resonance spectroscopy (C) shows an elevated choline peak (single arrow) and decreased creatine (double arrow) and N-acetyl aspartate (NAA) peaks (triple arrow), which is the typical pattern for tumor (Images courtesy of Dr. Ashok Srinivasan, University of Michigan).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4017160&req=5

Figure 1: This patient with a glioblastoma multiforme shows the voxel over the area of interest in the tumor over the sagittal T1 (A) and axial FLAIR (B) image. Magnetic resonance spectroscopy (C) shows an elevated choline peak (single arrow) and decreased creatine (double arrow) and N-acetyl aspartate (NAA) peaks (triple arrow), which is the typical pattern for tumor (Images courtesy of Dr. Ashok Srinivasan, University of Michigan).

Mentions: Magnetic resonance spectroscopy (MRS) is based on nuclear magnetic resonance technique to investigate the metabolism of chemicals in the body. Different chemicals containing the same nucleus exhibit characteristic chemical shifts in resonance frequency, allowing the chemical form of the element to be identified. Since the most abundant atom in the body is hydrogen (H), 1H MRS estimates the concentration of different metabolites within normal tissues of the body, which are displayed as a spectrum of resonances (peaks) along the x-axis as parts per million (ppm) and the amplitude of resonances is measured on the y-axis using an arbitrary scale. Depending on the clinical question, many major metabolites can be measured with MRS. In the brain, N-acetyl aspartate (NAA) is a marker for neuronal and axonal integrity. A decrease in NAA level is usually associated with neuronal loss or damage. Choline (Cho) represents the constituents of cell membrane. Increased Cho is associated with increased concentration of cells and or/cell membrane synthesis such as cancer. Creatinine (Cr) is a marker for cell energy metabolism. Decreased in Cr is associated with tissue death or necrosis. Lactate is a marker for anaerobic glycolysis. Increased lactate is associated with hypoxemia and tumors because of their anaerobic metabolism. Increased lipids concentration is observed in necrotic areas of the tumor. In gliomas, NAA is reduced because of neurons destruction by the tumor and Cho is increased because of tumor cell proliferation. Thus, abnormal Cho/NAA ratio is observed in areas of tumor infiltration such as the area of vasogenic edema around the gross tumor. Figure 1 illustrates the potential of MRS to outline the gross tumor volume (GTV) in a patient with glioblastoma multiforme (GBM).


The potential role of magnetic resonance spectroscopy in image-guided radiotherapy.

Nguyen ML, Willows B, Khan R, Chi A, Kim L, Nour SG, Sroka T, Kerr C, Godinez J, Mills M, Karlsson U, Altdorfer G, Nguyen NP, Jendrasiak G, International Geriatric Radiotherapy Gro - Front Oncol (2014)

This patient with a glioblastoma multiforme shows the voxel over the area of interest in the tumor over the sagittal T1 (A) and axial FLAIR (B) image. Magnetic resonance spectroscopy (C) shows an elevated choline peak (single arrow) and decreased creatine (double arrow) and N-acetyl aspartate (NAA) peaks (triple arrow), which is the typical pattern for tumor (Images courtesy of Dr. Ashok Srinivasan, University of Michigan).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4017160&req=5

Figure 1: This patient with a glioblastoma multiforme shows the voxel over the area of interest in the tumor over the sagittal T1 (A) and axial FLAIR (B) image. Magnetic resonance spectroscopy (C) shows an elevated choline peak (single arrow) and decreased creatine (double arrow) and N-acetyl aspartate (NAA) peaks (triple arrow), which is the typical pattern for tumor (Images courtesy of Dr. Ashok Srinivasan, University of Michigan).
Mentions: Magnetic resonance spectroscopy (MRS) is based on nuclear magnetic resonance technique to investigate the metabolism of chemicals in the body. Different chemicals containing the same nucleus exhibit characteristic chemical shifts in resonance frequency, allowing the chemical form of the element to be identified. Since the most abundant atom in the body is hydrogen (H), 1H MRS estimates the concentration of different metabolites within normal tissues of the body, which are displayed as a spectrum of resonances (peaks) along the x-axis as parts per million (ppm) and the amplitude of resonances is measured on the y-axis using an arbitrary scale. Depending on the clinical question, many major metabolites can be measured with MRS. In the brain, N-acetyl aspartate (NAA) is a marker for neuronal and axonal integrity. A decrease in NAA level is usually associated with neuronal loss or damage. Choline (Cho) represents the constituents of cell membrane. Increased Cho is associated with increased concentration of cells and or/cell membrane synthesis such as cancer. Creatinine (Cr) is a marker for cell energy metabolism. Decreased in Cr is associated with tissue death or necrosis. Lactate is a marker for anaerobic glycolysis. Increased lactate is associated with hypoxemia and tumors because of their anaerobic metabolism. Increased lipids concentration is observed in necrotic areas of the tumor. In gliomas, NAA is reduced because of neurons destruction by the tumor and Cho is increased because of tumor cell proliferation. Thus, abnormal Cho/NAA ratio is observed in areas of tumor infiltration such as the area of vasogenic edema around the gross tumor. Figure 1 illustrates the potential of MRS to outline the gross tumor volume (GTV) in a patient with glioblastoma multiforme (GBM).

Bottom Line: Magnetic resonance spectroscopy (MRS) is a non-invasive technique to detect metabolites within the normal and tumoral tissues.Preliminary studies suggest that the integration of MRS into radiotherapy planning for these tumors is feasible and safe.Image-guided radiotherapy (IGRT) by virtue of daily tumor imaging and steep dose gradient may allow for tumor dose escalation with the simultaneous integrated boost technique (SIB) and potentially decrease the complications rates in patients with GBM and prostate cancers.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Stanford University , Palo Alto, CA , USA.

ABSTRACT
Magnetic resonance spectroscopy (MRS) is a non-invasive technique to detect metabolites within the normal and tumoral tissues. The ability of MRS to diagnose areas of high metabolic activity linked to tumor cell proliferation is particularly useful for radiotherapy treatment planning because of better gross tumor volume (GTV) delineation. The GTV may be targeted with higher radiation dose, potentially improving local control without excessive irradiation to the normal adjacent tissues. Prostate cancer and glioblastoma multiforme (GBM) are two tumor models that are associated with a heterogeneous tumor distribution. Preliminary studies suggest that the integration of MRS into radiotherapy planning for these tumors is feasible and safe. Image-guided radiotherapy (IGRT) by virtue of daily tumor imaging and steep dose gradient may allow for tumor dose escalation with the simultaneous integrated boost technique (SIB) and potentially decrease the complications rates in patients with GBM and prostate cancers.

No MeSH data available.


Related in: MedlinePlus