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Detection of relevant colonic neoplasms with PET/CT: promising accuracy with minimal CT dose and a standardised PET cut-off.

Luboldt W, Volker T, Wiedemann B, Zöphel K, Wehrmann U, Koch A, Toussaint T, Abolmaali N, Middendorp M, Aust D, Kotzerke J, Grünwald F, Vogl TJ, Luboldt HJ - Eur Radiol (2010)

Bottom Line: This cut-off resulted in a better per-segment sensitivity and negative predictive value (NPV) than the average PET/CT reviews (sensitivity: 89% vs. 82%; NPV: 99% vs. 98%).Low dose and lack of iodine contrast in the CT component do not impact the accuracy.The PET cut-off SUV(max) > or = 5 improves the accuracy.

View Article: PubMed Central - PubMed

Affiliation: Multiorgan Screening Foundation, Frankfurt, Germany. luboldt@screening.org

ABSTRACT

Objective: To determine the performance of FDG-PET/CT in the detection of relevant colorectal neoplasms (adenomas > or =10 mm, with high-grade dysplasia, cancer) in relation to CT dose and contrast administration and to find a PET cut-off.

Methods: 84 patients, who underwent PET/CT and colonoscopy (n = 79)/sigmoidoscopy (n = 5) for (79 x 6 + 5 x 2) = 484 colonic segments, were included in a retrospective study. The accuracy of low-dose PET/CT in detecting mass-positive segments was evaluated by ROC analysis by two blinded independent reviewers relative to contrast-enhanced PET/CT. On a per-lesion basis characteristic PET values were tested as cut-offs.

Results: Low-dose PET/CT and contrast-enhanced PET/CT provide similar accuracies (area under the curve for the average ROC ratings 0.925 vs. 0.929, respectively). PET demonstrated all carcinomas (n = 23) and 83% (30/36) of relevant adenomas. In all carcinomas and adenomas with high-grade dysplasia (n = 10) the SUV(max) was > or =5. This cut-off resulted in a better per-segment sensitivity and negative predictive value (NPV) than the average PET/CT reviews (sensitivity: 89% vs. 82%; NPV: 99% vs. 98%). All other tested cut-offs were inferior to the SUV(max).

Conclusion: FDG-PET/CT provides promising accuracy for colorectal mass detection. Low dose and lack of iodine contrast in the CT component do not impact the accuracy. The PET cut-off SUV(max) > or = 5 improves the accuracy.

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Related in: MedlinePlus

Maximum standardised uptake value (SUVmax) in relation to histological examination. The cut-off SUVmax ≥ 5 (red line) includes the detection of all carcinomas and adenomas with high-grade dysplasia, provides higher sensitivity and NPV than the PET and PET/CT reviews (Table 1), and allows for computer-aided detection
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Fig5: Maximum standardised uptake value (SUVmax) in relation to histological examination. The cut-off SUVmax ≥ 5 (red line) includes the detection of all carcinomas and adenomas with high-grade dysplasia, provides higher sensitivity and NPV than the PET and PET/CT reviews (Table 1), and allows for computer-aided detection

Mentions: Incidental focal colorectal FDG uptake in the sigmoid colon (carcinoma (arrow)) in a 57-year-old man on low-dose PET/CT performed for follow-up after resection of a seminoma. A rotating maximal intensity projection (MIP) (a) allows for screening for focal FDG uptakes that are evaluated further on the multiplanar reconstructions (here axial PET (b), axial low-dose CT (c), axial low-dose PET/CT (d). Besides stool, sphincters and inflammation, the urinary tract (here diverticulum of the bladder (arrowhead 1)) and focal colonic collapse (arrowhead 2) constitute the only physiological pitfalls. Any shortcomings, however, can mostly be differentiated from masses based on CT anatomy and the maximum standardised uptake value (SUVmax). The SUVmax of 24.6 for the lesion in the sigmoid colon (arrow) is a trigger for colonoscopy (Fig. 5)


Detection of relevant colonic neoplasms with PET/CT: promising accuracy with minimal CT dose and a standardised PET cut-off.

Luboldt W, Volker T, Wiedemann B, Zöphel K, Wehrmann U, Koch A, Toussaint T, Abolmaali N, Middendorp M, Aust D, Kotzerke J, Grünwald F, Vogl TJ, Luboldt HJ - Eur Radiol (2010)

Maximum standardised uptake value (SUVmax) in relation to histological examination. The cut-off SUVmax ≥ 5 (red line) includes the detection of all carcinomas and adenomas with high-grade dysplasia, provides higher sensitivity and NPV than the PET and PET/CT reviews (Table 1), and allows for computer-aided detection
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2914265&req=5

Fig5: Maximum standardised uptake value (SUVmax) in relation to histological examination. The cut-off SUVmax ≥ 5 (red line) includes the detection of all carcinomas and adenomas with high-grade dysplasia, provides higher sensitivity and NPV than the PET and PET/CT reviews (Table 1), and allows for computer-aided detection
Mentions: Incidental focal colorectal FDG uptake in the sigmoid colon (carcinoma (arrow)) in a 57-year-old man on low-dose PET/CT performed for follow-up after resection of a seminoma. A rotating maximal intensity projection (MIP) (a) allows for screening for focal FDG uptakes that are evaluated further on the multiplanar reconstructions (here axial PET (b), axial low-dose CT (c), axial low-dose PET/CT (d). Besides stool, sphincters and inflammation, the urinary tract (here diverticulum of the bladder (arrowhead 1)) and focal colonic collapse (arrowhead 2) constitute the only physiological pitfalls. Any shortcomings, however, can mostly be differentiated from masses based on CT anatomy and the maximum standardised uptake value (SUVmax). The SUVmax of 24.6 for the lesion in the sigmoid colon (arrow) is a trigger for colonoscopy (Fig. 5)

Bottom Line: This cut-off resulted in a better per-segment sensitivity and negative predictive value (NPV) than the average PET/CT reviews (sensitivity: 89% vs. 82%; NPV: 99% vs. 98%).Low dose and lack of iodine contrast in the CT component do not impact the accuracy.The PET cut-off SUV(max) > or = 5 improves the accuracy.

View Article: PubMed Central - PubMed

Affiliation: Multiorgan Screening Foundation, Frankfurt, Germany. luboldt@screening.org

ABSTRACT

Objective: To determine the performance of FDG-PET/CT in the detection of relevant colorectal neoplasms (adenomas > or =10 mm, with high-grade dysplasia, cancer) in relation to CT dose and contrast administration and to find a PET cut-off.

Methods: 84 patients, who underwent PET/CT and colonoscopy (n = 79)/sigmoidoscopy (n = 5) for (79 x 6 + 5 x 2) = 484 colonic segments, were included in a retrospective study. The accuracy of low-dose PET/CT in detecting mass-positive segments was evaluated by ROC analysis by two blinded independent reviewers relative to contrast-enhanced PET/CT. On a per-lesion basis characteristic PET values were tested as cut-offs.

Results: Low-dose PET/CT and contrast-enhanced PET/CT provide similar accuracies (area under the curve for the average ROC ratings 0.925 vs. 0.929, respectively). PET demonstrated all carcinomas (n = 23) and 83% (30/36) of relevant adenomas. In all carcinomas and adenomas with high-grade dysplasia (n = 10) the SUV(max) was > or =5. This cut-off resulted in a better per-segment sensitivity and negative predictive value (NPV) than the average PET/CT reviews (sensitivity: 89% vs. 82%; NPV: 99% vs. 98%). All other tested cut-offs were inferior to the SUV(max).

Conclusion: FDG-PET/CT provides promising accuracy for colorectal mass detection. Low dose and lack of iodine contrast in the CT component do not impact the accuracy. The PET cut-off SUV(max) > or = 5 improves the accuracy.

Show MeSH
Related in: MedlinePlus