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Role of FDG-PET scans in staging, response assessment, and follow-up care for non-small cell lung cancer.

Cuaron J, Dunphy M, Rimner A - Front Oncol (2013)

Bottom Line: FDG-PET sensitivity is decreased in tumors <1 cm, at least in part due to respiratory motion.False-negative results can occur in areas of low tumor burden, e.g., small lymph nodes or ground-glass opacities. (18)F-FDG-PET-CT nodal staging is more accurate than CT alone, as hilar and mediastinal involvement is often detected first on (18)F-FDG-PET scan when CT criteria for malignant involvement are not met. (18)F-FDG-PET scans have widely replaced bone scintography for assessing distant metastases, except for the brain, which still warrants dedicated brain imaging. (18)F-FDG uptake has also been shown to vary between histologies, with adenocarcinomas generally being less FDG avid than squamous cell carcinomas. (18)F-FDG-PET scans are useful to detect recurrences, but are currently not recommended for routine follow-up.Further work is underway to identify subsets of patients that might benefit individualized management based on FDG-PET.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center New York, NY, USA.

ABSTRACT
The integral role of positron-emission tomography (PET) using the glucose analog tracer fluorine-18 fluorodeoxyglucose (FDG) in the staging of non-small cell lung cancer (NSCLC) is well established. Evidence is emerging for the role of PET in response assessment to neoadjuvant therapy, combined-modality therapy, and early detection of recurrence. Here, we review the current literature on these aspects of PET in the management of NSCLC. FDG-PET, particularly integrated (18)F-FDG-PET/CT, scans have become a standard test in the staging of local tumor extent, mediastinal lymph node involvement, and distant metastatic disease in NSCLC. (18)F-FDG-PET sensitivity is generally superior to computed tomography (CT) scans alone. Local tumor extent and T stage can be more accurately determined with FDG-PET in certain cases, especially in areas of post-obstructive atelectasis or low CT density variation. FDG-PET sensitivity is decreased in tumors <1 cm, at least in part due to respiratory motion. False-negative results can occur in areas of low tumor burden, e.g., small lymph nodes or ground-glass opacities. (18)F-FDG-PET-CT nodal staging is more accurate than CT alone, as hilar and mediastinal involvement is often detected first on (18)F-FDG-PET scan when CT criteria for malignant involvement are not met. (18)F-FDG-PET scans have widely replaced bone scintography for assessing distant metastases, except for the brain, which still warrants dedicated brain imaging. (18)F-FDG uptake has also been shown to vary between histologies, with adenocarcinomas generally being less FDG avid than squamous cell carcinomas. (18)F-FDG-PET scans are useful to detect recurrences, but are currently not recommended for routine follow-up. Typically, patients are followed with chest CT scans every 3-6 months, using (18)F-FDG-PET to evaluate equivocal CT findings. As high (18)F-FDG uptake can occur in infectious, inflammatory, and other non-neoplastic conditions, (18)F-FDG-PET-positive findings require pathological confirmation in most cases. There is increased interest in the prognostic and predictive role of FDG-PET scans. Studies show that absence of metabolic response to neoadjuvant therapy correlates with poor pathologic response, and a favorable (18)F-FDG-PET response appears to be associated with improved survival. Further work is underway to identify subsets of patients that might benefit individualized management based on FDG-PET.

No MeSH data available.


Related in: MedlinePlus

Lung cancer patient with multiple right lung nodules. Shown are corresponding PET (left), CT (right), and fusion (middle) images of a single coronal plane through the right lung. In the upper lobe, where respiratory motion is least, a punctate nodule (white arrowheads) demonstrates intense FDG uptake with a distinctly focal appearance (black arrowhead). In the lower region of the lung, where respiratory motion is greater, the FDG uptake of larger nodules (white arrows) appears relatively less-intense – probably due to “spreading” of the activity over a spatial volume during each breathing cycle, a kind of respiratory artifact. This “spreading” is most visually evident closest to the diaphragm (black arrow).
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Figure 1: Lung cancer patient with multiple right lung nodules. Shown are corresponding PET (left), CT (right), and fusion (middle) images of a single coronal plane through the right lung. In the upper lobe, where respiratory motion is least, a punctate nodule (white arrowheads) demonstrates intense FDG uptake with a distinctly focal appearance (black arrowhead). In the lower region of the lung, where respiratory motion is greater, the FDG uptake of larger nodules (white arrows) appears relatively less-intense – probably due to “spreading” of the activity over a spatial volume during each breathing cycle, a kind of respiratory artifact. This “spreading” is most visually evident closest to the diaphragm (black arrow).

Mentions: Positron-emission tomography has been shown to be less sensitive for the characterization of smaller lung lesions. This may be at least in part due to respiratory motion, which artificially decreases the FDG signal (Figure 1). Motion artifact can cause a significant underestimation of 18F-FDG uptake, which is commonly quantified with a parameter called the maximum standardized uptake value, or SUVmax (Liu et al., 2009).


Role of FDG-PET scans in staging, response assessment, and follow-up care for non-small cell lung cancer.

Cuaron J, Dunphy M, Rimner A - Front Oncol (2013)

Lung cancer patient with multiple right lung nodules. Shown are corresponding PET (left), CT (right), and fusion (middle) images of a single coronal plane through the right lung. In the upper lobe, where respiratory motion is least, a punctate nodule (white arrowheads) demonstrates intense FDG uptake with a distinctly focal appearance (black arrowhead). In the lower region of the lung, where respiratory motion is greater, the FDG uptake of larger nodules (white arrows) appears relatively less-intense – probably due to “spreading” of the activity over a spatial volume during each breathing cycle, a kind of respiratory artifact. This “spreading” is most visually evident closest to the diaphragm (black arrow).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3539654&req=5

Figure 1: Lung cancer patient with multiple right lung nodules. Shown are corresponding PET (left), CT (right), and fusion (middle) images of a single coronal plane through the right lung. In the upper lobe, where respiratory motion is least, a punctate nodule (white arrowheads) demonstrates intense FDG uptake with a distinctly focal appearance (black arrowhead). In the lower region of the lung, where respiratory motion is greater, the FDG uptake of larger nodules (white arrows) appears relatively less-intense – probably due to “spreading” of the activity over a spatial volume during each breathing cycle, a kind of respiratory artifact. This “spreading” is most visually evident closest to the diaphragm (black arrow).
Mentions: Positron-emission tomography has been shown to be less sensitive for the characterization of smaller lung lesions. This may be at least in part due to respiratory motion, which artificially decreases the FDG signal (Figure 1). Motion artifact can cause a significant underestimation of 18F-FDG uptake, which is commonly quantified with a parameter called the maximum standardized uptake value, or SUVmax (Liu et al., 2009).

Bottom Line: FDG-PET sensitivity is decreased in tumors <1 cm, at least in part due to respiratory motion.False-negative results can occur in areas of low tumor burden, e.g., small lymph nodes or ground-glass opacities. (18)F-FDG-PET-CT nodal staging is more accurate than CT alone, as hilar and mediastinal involvement is often detected first on (18)F-FDG-PET scan when CT criteria for malignant involvement are not met. (18)F-FDG-PET scans have widely replaced bone scintography for assessing distant metastases, except for the brain, which still warrants dedicated brain imaging. (18)F-FDG uptake has also been shown to vary between histologies, with adenocarcinomas generally being less FDG avid than squamous cell carcinomas. (18)F-FDG-PET scans are useful to detect recurrences, but are currently not recommended for routine follow-up.Further work is underway to identify subsets of patients that might benefit individualized management based on FDG-PET.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center New York, NY, USA.

ABSTRACT
The integral role of positron-emission tomography (PET) using the glucose analog tracer fluorine-18 fluorodeoxyglucose (FDG) in the staging of non-small cell lung cancer (NSCLC) is well established. Evidence is emerging for the role of PET in response assessment to neoadjuvant therapy, combined-modality therapy, and early detection of recurrence. Here, we review the current literature on these aspects of PET in the management of NSCLC. FDG-PET, particularly integrated (18)F-FDG-PET/CT, scans have become a standard test in the staging of local tumor extent, mediastinal lymph node involvement, and distant metastatic disease in NSCLC. (18)F-FDG-PET sensitivity is generally superior to computed tomography (CT) scans alone. Local tumor extent and T stage can be more accurately determined with FDG-PET in certain cases, especially in areas of post-obstructive atelectasis or low CT density variation. FDG-PET sensitivity is decreased in tumors <1 cm, at least in part due to respiratory motion. False-negative results can occur in areas of low tumor burden, e.g., small lymph nodes or ground-glass opacities. (18)F-FDG-PET-CT nodal staging is more accurate than CT alone, as hilar and mediastinal involvement is often detected first on (18)F-FDG-PET scan when CT criteria for malignant involvement are not met. (18)F-FDG-PET scans have widely replaced bone scintography for assessing distant metastases, except for the brain, which still warrants dedicated brain imaging. (18)F-FDG uptake has also been shown to vary between histologies, with adenocarcinomas generally being less FDG avid than squamous cell carcinomas. (18)F-FDG-PET scans are useful to detect recurrences, but are currently not recommended for routine follow-up. Typically, patients are followed with chest CT scans every 3-6 months, using (18)F-FDG-PET to evaluate equivocal CT findings. As high (18)F-FDG uptake can occur in infectious, inflammatory, and other non-neoplastic conditions, (18)F-FDG-PET-positive findings require pathological confirmation in most cases. There is increased interest in the prognostic and predictive role of FDG-PET scans. Studies show that absence of metabolic response to neoadjuvant therapy correlates with poor pathologic response, and a favorable (18)F-FDG-PET response appears to be associated with improved survival. Further work is underway to identify subsets of patients that might benefit individualized management based on FDG-PET.

No MeSH data available.


Related in: MedlinePlus