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4D PET/CT as a Strategy to Reduce Respiratory Motion Artifacts in FDG-PET/CT.

Chi A, Nguyen NP - Front Oncol (2014)

Bottom Line: The improved accuracy in tumor identification with FDG-PET has led to its increased utilization in target volume delineation for radiotherapy treatment planning in the treatment of lung cancer.However, PET/CT has constantly been influenced by respiratory motion-related image degradation, which is especially prominent for small lung tumors in the peri-diaphragmatic regions of the thorax.Furthermore, we describe the evidence suggesting 4D PET/CT to be one strategy to minimize the impact of respiratory motion-related image degradation on tumor target delineation for thoracic IGRT.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, Mary Babb Randolph Cancer Center, West Virginia University , Morgantown, WV , USA.

ABSTRACT
The improved accuracy in tumor identification with FDG-PET has led to its increased utilization in target volume delineation for radiotherapy treatment planning in the treatment of lung cancer. However, PET/CT has constantly been influenced by respiratory motion-related image degradation, which is especially prominent for small lung tumors in the peri-diaphragmatic regions of the thorax. Here, we describe the current findings on respiratory motion-related image degradation in PET/CT, which may bring uncertainties to target volume delineation for image guided radiotherapy (IGRT) for lung cancer. Furthermore, we describe the evidence suggesting 4D PET/CT to be one strategy to minimize the impact of respiratory motion-related image degradation on tumor target delineation for thoracic IGRT. This, in our opinion, warrants further investigation in future IGRT-based lung cancer trials.

No MeSH data available.


Related in: MedlinePlus

Misalignment of a recurrent squamous cell carcinoma between free-breathing PET and CT is demonstrated. The superior portion of the PET avid tumor does not correspond to any anatomically visible tumor on CT.
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Figure 1: Misalignment of a recurrent squamous cell carcinoma between free-breathing PET and CT is demonstrated. The superior portion of the PET avid tumor does not correspond to any anatomically visible tumor on CT.

Mentions: Computed tomography and positron emission tomography imaging are done at different speeds. While a CT scan can be completed in seconds, the PET is usually done through a sequence of fields of view (FOV) in a matter of several minutes per FOV. As a result, the CT image may capture the lung tumor in a segment of the respiratory cycle only, while the PET image tends to represent an average of the tumor position over several respiratory cycles. This often leads to blurring and/or misrepresentation of the extent of the gross tumor in the registered PET/CT images of the thorax (Figure 1). At the same time, the pattern of FDG uptake intensity within the gross tumor can be changed by respiration, leading to a decrease in the max SUV of the tumor.


4D PET/CT as a Strategy to Reduce Respiratory Motion Artifacts in FDG-PET/CT.

Chi A, Nguyen NP - Front Oncol (2014)

Misalignment of a recurrent squamous cell carcinoma between free-breathing PET and CT is demonstrated. The superior portion of the PET avid tumor does not correspond to any anatomically visible tumor on CT.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4120690&req=5

Figure 1: Misalignment of a recurrent squamous cell carcinoma between free-breathing PET and CT is demonstrated. The superior portion of the PET avid tumor does not correspond to any anatomically visible tumor on CT.
Mentions: Computed tomography and positron emission tomography imaging are done at different speeds. While a CT scan can be completed in seconds, the PET is usually done through a sequence of fields of view (FOV) in a matter of several minutes per FOV. As a result, the CT image may capture the lung tumor in a segment of the respiratory cycle only, while the PET image tends to represent an average of the tumor position over several respiratory cycles. This often leads to blurring and/or misrepresentation of the extent of the gross tumor in the registered PET/CT images of the thorax (Figure 1). At the same time, the pattern of FDG uptake intensity within the gross tumor can be changed by respiration, leading to a decrease in the max SUV of the tumor.

Bottom Line: The improved accuracy in tumor identification with FDG-PET has led to its increased utilization in target volume delineation for radiotherapy treatment planning in the treatment of lung cancer.However, PET/CT has constantly been influenced by respiratory motion-related image degradation, which is especially prominent for small lung tumors in the peri-diaphragmatic regions of the thorax.Furthermore, we describe the evidence suggesting 4D PET/CT to be one strategy to minimize the impact of respiratory motion-related image degradation on tumor target delineation for thoracic IGRT.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, Mary Babb Randolph Cancer Center, West Virginia University , Morgantown, WV , USA.

ABSTRACT
The improved accuracy in tumor identification with FDG-PET has led to its increased utilization in target volume delineation for radiotherapy treatment planning in the treatment of lung cancer. However, PET/CT has constantly been influenced by respiratory motion-related image degradation, which is especially prominent for small lung tumors in the peri-diaphragmatic regions of the thorax. Here, we describe the current findings on respiratory motion-related image degradation in PET/CT, which may bring uncertainties to target volume delineation for image guided radiotherapy (IGRT) for lung cancer. Furthermore, we describe the evidence suggesting 4D PET/CT to be one strategy to minimize the impact of respiratory motion-related image degradation on tumor target delineation for thoracic IGRT. This, in our opinion, warrants further investigation in future IGRT-based lung cancer trials.

No MeSH data available.


Related in: MedlinePlus