Evaluation of (pre-)malignant colonic abnormalities: endoscopic validation of FDG-PET findings
ABSTRACT The diagnostic accuracy of 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) for the detection of (pre-)malignant lesions of the colon was compared with that of endoscopy. We selected a cohort of 39 patients [13 females and 26 males; mean age 62.3 years standard deviation (SD) 9.6 years] who underwent both FDG-PET and endoscopy (total of 44 procedures) in a 2-year period with a maximum interval between the examinations of 3 months (mean 30 days, SD 28 days). The underlying pathology was colorectal malignancies (24 patients), other malignancies (nine patients) and other disorders (six patients). Follow-up of resected colorectal cancer was the most common reason for the performance of endoscopy. In 19 patients FDG bowel uptake was interpreted as non-physiological, and in 18 patients abnormal findings (adenomatous polyps >3 mm or carcinoma) were detected by endoscopy. Compared with colonoscopy, FDG-PET had a sensitivity of 74% and specificity of 84%. The positive predictive value of FDG-PET was 78%. FDG-PET failed to detect small (diameter 3-10 mm) polyps in four patients. In nine cases abnormal FDG accumulation on PET imaging was the sole reason for performance of an endoscopic procedure. In these cases, endoscopy detected large adenomatous polyps in four patients and carcinomas in two patients, but no abnormalities were detected on endoscopy in the other three patients. There was a good correlation between the location of FDG uptake and endoscopy-positive lesions. FDG-PET is able to detect clinically relevant lesions of the colon. Our study suggests that it can be regarded as a useful adjunct in the non-invasive follow-up of patients with colorectal carcinomas.
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ABSTRACT: Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is used in the imaging workup of various malignancies. Incidental gastrointestinal observations on FDG PET/CT may be of clinical significance. The aim of the present study was to evaluate endoscopic and histopathological observations in patients referred for colonoscopy due to incidental FDG colonic uptake on a PET/CT study. Fifty-six patients with incidental colonic findings on FDG PET/CT underwent colonoscopy. Normal colonoscopies were observed in 63% of the patients. In 37% of the colonoscopies, we identified an endoscopic observation, including 67% with benign adenomatous polyps, 3% with hyperplastic polyps, 20% with advanced histological lesions and 10% with a malignancy.Oncology letters 02/2014; 7(2):479-482. · 0.24 Impact Factor
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ABSTRACT: To determine the accuracy of 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET) in the detection of advanced colorectal adenomas. In this retrospective study, patient consent was waived by the institutional review board. Combined FDG whole-body PET and computed tomography (CT) images (2000-2009) were re-read and compared with reports of complete colonoscopy performed up to 1 year after the PET examination. One or more areas of focal colonic uptake greater than the background indicated a positive PET result, irrespective of standardized uptake value (SUV). Lesion and patient-level measures of PET accuracy with their 95% confidence intervals (CI) were calculated. One hundred and eighty patients undergoing colonoscopy with or without biopsy underwent PET within 1 year prior to colonoscopy. There were 92 women and 88 men (mean age 63.3 years). Indications for PET were extent of disease and treatment response in all cases. Patients had non-colorectal cancer (n = 160) or colon cancer (n = 20). One hundred and fourteen FDG-avid lesions were present. In 33, there was no colonoscopic correlate. Two hundred and fifty-eight biopsies revealed tubular adenomas (n = 91, one with intra-mucosal cancer), tubulovillous adenomas (n = 28), adenocarcinoma (n = 37), inflammation (n = 22), hyperplastic polyps (n = 54), serrated adenoma (n = 5), metastatic disease (n = 5), normal/benign mucosa or submucosal benign tumors (n = 13) or miscellaneous (n = 3). Per-lesion performance of PET showed a sensitivity of 38% (95% CI: 31-46; 64/167) for all adenomas and carcinomas and 58% (95% CI: 49-67; 57/98) for lesions ≥10 mm. At the patient level, for all adenomas and carcinomas the sensitivity was 54% (95% CI: 44-63; 61/113), specificity 100% (pre-defined), positive predictive value (PPV) 100% (pre-defined), and negative predictive value (NPV) 56% (95% CI: 47-65; 67/119). For patients with advanced adenoma, PET sensitivity was 49% (95% CI: 35-63; 26/53) specificity, 100%, PPV 100% and NPV 82% (95% CI: 76-88; 127/154). Five of 37 adenocarcinomas were not detected, one of which was mucinous at histology. FDG PET detected most cancers, but only identified one-half of patients harbouring advanced adenomas. Based on the data, PET cannot be relied upon to accurately identify patients with advanced adenoma.Clinical radiology 02/2014; · 1.65 Impact Factor
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ABSTRACT: The aim of this study was to analyze the detection rate for CRC and adenomas for asymptomatic subjects in Japan by FDG-PET cancer screening program carried out between 2006 and 2009. The "FDG-PET cancer screening program" included both PET and positron emission tomography with computed tomography (PET/CT) with or without other screening tests. A total of 154,783 asymptomatic subjects underwent FDG-PET cancer screening program; we analyzed the 1,808 cases with findings from any detection method that indicated suspected CRC. Among the 1,808 cases, the number of cases verified as CRC and adenoma was 394 and 679, respectively. The sensitivity and positive predictive value (PPV) of FDG-PET were 86.0 and 31.7 % for CRC, and 63.6 and 63.8 % for CRC and adenoma. The sensitivity and PPV of fecal occult blood test (FOBT) for CRC were lower than those of FDG-PET, but higher for adenoma. Therefore, FDG-PET and FOBT were complementary for screening for CRC, and CRC and adenoma. The majority of CRC detected by the FDG-PET imaging was UICC stage 0 or I, however, detection of smaller or less invasive cancer was limited. The FDG-PET screening program in Japan has detected CRC at an early stage and adenomas as premalignant lesions. A combination of FDG-PET and FOBT yields the best results if the intent is to detect either CRC or adenoma. However, it is absolutely clear that an FDG-PET cancer screening program cannot detect all colon lesions.Annals of Nuclear Medicine 12/2013; · 1.41 Impact Factor