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Accuracy of FDG-PET/CT for Detection of Incidental Pre- Malignant and Malignant Colonic Lesions - Correlation with Colonoscopic and Histopathologic Findings |
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| รหัสดีโอไอ | |
| Creator | 1. Anchisa Kunawudhi 2. Alexandra K Wong; Tarik K Alkasab; Umar Mahmood |
| Title | Accuracy of FDG-PET/CT for Detection of Incidental Pre- Malignant and Malignant Colonic Lesions - Correlation with Colonoscopic and Histopathologic Findings |
| Publisher | APJCP |
| Publication Year | 2559 |
| Journal Title | Asian Pacific Journal of Cancer Prevention |
| Journal Vol. | 17 |
| Journal No. | 8 |
| Page no. | 4143-4147 |
| Keyword | PET/CT ; screening ; colon cancer ; pre-malignant ; incidental ndings |
| Abstract | Purpose: We evaluated all PET/CTs acquired for patients without a primary diagnosis of colorectal cancer, and compared results for those who had subsequent colonoscopy within 6 months, to assess the accuracy of FDG PET/CT for detection of incidental pre-malignant polyps and malignant colon cancers. Materials and Methods: Medical records of 9,545 patients who underwent F-18 FDG PET/CT studies over 3.5 years were retrospectively reviewed. Due to pre-existing diagnosis of colorectal cancer, 818 patients were excluded. Of the remainder, 157 patients had colonoscopy within 6 months (79 males- mean age 61). We divided the colon into 4 regions and compared PET/CT results for each region with colonoscopy and histopathologic ndings. True positive lesions included colorectal cancer, villous adenoma, tubulovillous adenoma, tubular adenoma and serrated hyperplastic polyp/hyperplastic polyposis. Results: Of 157 patients, 44 had incidental colonic uptake on PET/CT (28%). Of those, 25 had true positive (TP) uptake, yielding a 48% positive predictive value (PPV)- 9% (4/44) were adenocarcinoma. There were 23 false positive (FP) lesions of which 4 were hyperplastic polyp, one was juvenile polyp and 7 were explained by diverticulitis. Fifty eight patients had false negative PET scans but colonoscopy revealed true pre-malignant and malignant pathology, yielding 23% sensitivity. The speci city, negiative predictive value (NPV) and accuracy were 96%, 90% and 87%, respectively. The average SUVmax values of TP, FP and FN lesions were 7.25, 6.11 and 2.76, respectively. There were no signi cant difference between SUVmax of TP lesions and FP lesions (p>0.95) but signi cantly higher than in FN lesions (p<0.001). The average size (by histopathology and colonoscopy) of TP lesions was 18.1 mm, statistically different from that of FN lesions which was 5.9 mm (p<0.001). Fifty-one percent of FN lesions were smaller than 5 mm (29/57) and 88% smaller than 10 mm (50/57). Conclusions: The high positive predictive value of incidental focal colonic FDG uptake of 48% for colonic neoplasia suggests that colonoscopy follow-up is warranted with this nding. We observed a low sensitivity of standardly acquired FDG-PET/CT for detecting small polyps, especially those less than 5 mm. Clinician and radiologists should be aware of the high PPV of focal colonic uptake re ecting pre-malignant and malignant lesions, and the need for appropriate follow up. |
