Diagnostic value of SUVmax/ADCmin obtained by 11C-choline PET/MR in patients with prostate cancer

Abstract

Objective To evaluate the value of SUVmax/ADCmin obtained by 11C-choline PET/MR imaging in the differential diagnosis of benign and malignant prostate disease. Methods Suspicious prostate cancer patients who underwent PET/MR before transperineal prostate biopsy in People's Liberation Army General Hospital from April 2014 to January 2015 were observed. Prostate gland was divided into five districts. A ROI with the diameter of 1 cm was drawn at the highest radioactivity concentration and/or lowest ADC signal area in each district, and SUVmax, ADCmin and SUVmax/ADCmin were then calculated. Taking the pathological results as the gold standard, malignant and benign prostate disease districts were separated. Pearson correlation analysis and two-sample t test were used for statistical analysis. Results Biopsy pathology showed 9 cases were malignant (25 prostate cancer districts, and 20 benign prostate disease districts), and 6 cases were benign (30 benign prostate disease districts). The SUVmax had a negative correlation with ADCmin (r=-0.521, P<0.05). The SUVmax/ADCmin of benign and malignant districts was significantly different(5.67±3.03 and 13.76±7.13; t=6.9, P<0.01). The ROC AUC for ADCmin, SUVmax and SUVmax/ADCmin were 0.880, 0.809 and 0.898. Using SUVmax/ADCmin of 7.78 as a cutoff, the sensitivity, specificity and accuracy of 11C-choline PET/MR imaging for differentiating the benign and malignant prostate lesions were 84.0%(21/25), 86.0%(43/50) and 85.3%(64/75), respectively. Conclusions Simultaneous 11C-choline PET/MR could be used for detecting prostate cancer. SUVmax/ADCmin may serve as an effective diagnostic indicator for differentiating benign and malignant prostate lesions. Key words: Prostatic neoplasms; Tomography, emission-computed; Magnetic resonance imaging; Choline; Carbon radioisotopes