The clinical value and pitfalls of ¹⁸F-fluoroethylcholine PET/CT imaging in the diagnosis of prostate cancer

Objective: To evaluate the clinical value of ¹⁸F-fluoroethylcholine (FECH) PET/CT imaging in the diagnosis of prostate cancer and to investigate its physiological or non-cancerous uptake. Methods: The subjects consisted of 30 patients (age ranged from 56 to 83 years, mean age 61 years) with pathologically confirmed prostate cancer, in whom ¹⁸F-FECH and ¹⁸F-FDG PET/CT scans were undertaken from October 2009 to December 2011. The sensitivity and accuracy of the two tracers in detecting prostate cancer were compared.SUV_max was obtained for quantitative analysis. χ² test and t test were used for statistic analysis. Results: Of the 30 patients, 41 lesions presented high uptake in prostate region. The sensitivity and accuracy for diagnosing prostate cancer with ¹⁸F-FECH PET/CT were 87.9% (29/33) and 82.9%(34/41), respectively, while the sensitivity and accuracy with ¹⁸F-FDG PET/CT were 36.4% (12/33) and 36.6% (15/41), respectively. There were significant differences in sensitivity and accuracy between the two methods (χ²=8.1 and 11.1, both P<0.05). Physiological uptake appeared in the liver, pancreas, spleen, salivary gland, and also, owing to renal excretion,in the urinary tract. The SUV_max in liver and pancreas were 10.1 ± 1.6 and 6.1 ± 1.1, respectively. The SUV_max was 6.0 ± 2.2 in prostate cancer, while it was 2.6 ± 1.3 in benign lesions (t=2.9, P<0.05). Other abnormalities that were not related to prostate cancer were detected in 10 patients. Of these 10 patients, there were 6 with inflammation, 1 with lymphoma, 1 with tuberculosis, 1 with lung cancer and 1 with germinoma in pineal body. Conclusions: ¹⁸F-FECH PET/CT is promising for diagnosis of prostate cancer.Understanding the biodistribution and pitfalls of ¹⁸F-FECH is very important for image interpretation. (authors)