Purpose: To evaluate the accuracy and biological basis for [¹¹C]choline-PET-CT in the nodal staging of high risk localized prostate cancer patients. Experimental Design: Twenty-eight patients underwent dynamic [¹¹C]choline-PET-CT of the pelvis and lower abdomen prior to extended laparoscopic pelvic lymph node dissection (eLPL). The sensitivity and specificity of [¹¹C]choline PET, [¹¹C]choline PET-CT, and MRI for nodal detection were calculated. Average and maximal standardized uptake values (SUV_ave, SUV_max) were compared with choline kinase alpha (CHKα) and Ki67 immunohistochemistry scores. Results: Four hundred and six lymph nodes (LN), in 26 patients, were assessable. Twenty-seven (6.7%) involved pelvic nodes at eLPL were detected in 9 patients. Seventeen of the 27 involved nodes were subcentimeter. The sensitivity and specificity on a per nodal basis were 18.5% and 98.7%, 40.7% and 98.4%, and 51.9% and 98.4% for MRI, [¹¹C]choline PET, and [¹¹C]choline PET-CT, respectively. Sensitivity was higher for [¹¹C]choline PET-CT compared with MRI (P = 0.007). A higher nodal detection rate, including subcentimeter nodes, was seen with [¹¹C]choline PET-CT than MRI. Malignant lesions showed CHKα expression in both cytoplasm and nucleus. SUV_ave and SUV_max strongly correlated with CHKα staining intensity (r = 0.68, P < 0.0001 and r = 0.63, P = 0.0004, respectively). In contrast, Ki67 expression was generally low in all tumors. Conclusion: This study establishes the relationship between [¹¹C]choline PET-CT uptake with choline kinase expression in prostate cancer and allows it to be used as a noninvasive means of staging pelvic LNs, being highly specific and more sensitive than MRI, including the detection of subcentimeter disease. Clin Cancer Res; 17(24); 7673–83. ©2011 AACR.

The purpose of this study was to assess the value of 2-[F]fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography ([F]FDG PET/CT) in the primary staging of high-risk endometrial cancer patients. This retrospective study was conducted on 32 consecutive patients with histological diagnosis of primary high-risk endometrial cancer, who underwent PET/CT with [F]FDG in addition to conventional clinical and instrumental staging procedures. After surgery, [F]FDG PET/CT findings were correlated with pathological findings on a patient-by-patient basis. The diagnostic accuracy of [F]FDG PET/CT for primary cancer detection, lymph nodal involvement and distant metastases was assessed. [F]FDG PET/CT could correctly detect primary tumor in 29 of the 32 high-risk patients, with a sensitivity of 90.6%. The overall [F]FDG PET/CT patient-based sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 57.1, 100.0, 100.0, 86.4, and 88.5%, respectively, for revealing lymph nodal neoplastic involvement, and 100.0, 96.0, 87.5, 100.0, 96.9%, respectively, for detecting distant metastases. In particular, while the suspicion of distant metastases was documented by conventional imaging in only two patients, [F]FDG PET/CT correctly identified metastatic lesions in seven patients (21.9% of cases). The major benefit provided in high-grade tumor patients by the use of [F]FDG PET/CT in the primary staging of endometrial cancer is its ability to accurately detect distant metastases in the abdomen and extra-abdominal regions. [F]FDG PET/CT adds relevant information that may influence patient management.

Positron emission tomography/computed tomography (PET/CT) with 11C-choline is an established diagnostic tool for restaging prostate cancer patients with biochemical failure after primary treatment. In the present case, 11C-choline PET/CT was performed in a prostate cancer patient with skeletal metastases, treated with hormonal therapy. In addition to the detection of pathologic uptake at prostate and vertebra, 11C-choline uptake occurred in the neck. The finding was suggestive for a parathyroid adenoma on subsequent ultrasound, then finally confirmed by parathyroid scintigraphy and histopathological analysis performed after hemithyroidectomy.