To prospectively determine the accuracy of combination positron emission tomography-computed tomography (PET/CT) in lymph node staging in patients with early-stage cervical cancer, with histopathologic results as the reference standard. The study was institutional review board approved, and all patients gave informed consent. Forty-seven consecutive women aged 29-71 years with clinical stage IA or IB cervical carcinoma were included in the study. All 47 patients were scheduled for radical hysterectomy with pelvic lymph node dissection. Before surgery, all patients underwent fluorine 18 fluorodeoxyglucose (FDG) PET/CT. PET/CT findings were interpreted by two readers in consensus and then compared with histopathologic results. At histopathologic examination, the dissected lymph nodes were classified as nonmetastatic or metastatic. Fifteen (32%) patients had metastatic lymph nodes at histopathologic examination, and 32 (68%) had no histopathologically confirmed nodal metastasis. Of the total 1081 lymph nodes histopathologically sampled, 18 were found to be positive for malignant cells. The overall node-based sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT were 72% (13 of 18), 99.7% (1060 of 1063), 81% (13 of 16), 99.5% (1060 of 1065), and 99.3% (1073 of 1081), respectively. Corresponding values for PET/CT-based diagnosis of lymph nodes larger than 0.5 cm in diameter were 100% (13 of 13), 99.6% (675 of 678), 81% (13 of 16), 100% (675 of 675), and 99.6% (688 of 691), respectively. The overall patient-based sensitivity, specificity, PPV, NPV, and accuracy of PET/CT were 73% (11 of 15), 97% (31 of 32), 92% (11 of 12), 89% (31 of 35), and 89% (42 of 47), respectively. PET/CT proved to be valuable for lymph node staging in patients with early-stage cervical cancer, with short-axis diameter greater than 0.5 cm being the size threshold for accurate depiction of metastatic nodes.

We compared [11C]choline-positron emission tomography (PET) with [18F]fluorodeoxyglucose-PET for re-staging prostate cancer in a group of 100 patients. A total of 100 consecutive patients referred for whole body [18F]fluorodeoxyglucose-PET for clinical prostate re-staging after radical treatment for prostate cancer were retrospectively included in the study. Mean prostate specific antigen (PSA) was 6.57 ng./ml. In all cases [11C]choline-PET was also performed. PET studies were done with a multiring device 5 minutes after intravenous injection of approximately 370 MBq. [11C]choline and 60 minutes after injection of approximately 370 MBq. [18F]fluorodeoxyglucose. PET findings were compared with those obtained with different conventional imaging and with PSA assessed at the time of PET and 1 year later. Areas of abnormal focal increases were noted in 47% of patients on [11C]choline-PET and in 27% on [18F]fluorodeoxyglucose-PET. Of the 100 patients 49 had positive conventional imaging findings. All except 14 [11C]choline-PET findings were concordant with conventional imaging, including 6 negative and 8 positive conventional imaging results. All except 1 [11C]choline-PET negative cases also had negative conventional imaging after 1 year. PSA at 1 year remained stable or decreased in 80% and 62% of [11C]choline-PET negative and positive cases, respectively. [11C]choline-PET seems to be useful for re-staging prostatectomy cases with increasing serum PSA levels. It is superior to [18F]fluorodeoxyglucose-PET and complementary to conventional imaging but with the advantage of staging disease at a single step.

68Gallium prostate-specific membrane antigen (PSMA) ligand 68Ga-HBED-CC-PSMA (68Ga-PSMA) is a promising radiotracer for positron emission tomography (PET)/computed tomography (CT) of prostate cancer. To conduct a meta-analysis to evaluate detection rate, diagnostic test accuracy, and adverse effects of 68Ga-PSMA PET/CT or PET/magnetic resonance imaging (MRI) for staging of prostate cancer and for restaging of rising prostate-specific antigen (PSA) after initial treatment. Following the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines, our systematic review searched for articles in PubMed and EMBASE databases from 2012 to July 2016. The reference standard was pathology after biopsy or surgery. The analyses used a random effect model and a hierarchical summary receiver operating characteristic model. Fifteen 68Ga-PSMA PET/CT studies with 1256 patients met the inclusion criteria. Seven studies of staging PET/CT or PET/MRI detected a regional site of cancer for 203 of 273 patients (74%). Nine studies of restaging PET/CT detected sites of recurrence in 799 of 983 patients (81%) with a 50% detection rate (74 of 147 patients) for restaging PSA of 0.2-0.49 ng/ml and a 53% detection rate (56 of 195 patients) for restaging PSA of 0.50-0.99 ng/ml. Staging 68Ga-PSMA PET/CT in the studies had higher detection rates of sites in the prostate bed than restaging 68Ga-PSMA PET/CT (mean 57% vs 14%, p=0.031, t test). Both staging and restaging 68Ga-PSMA PET/CT found that a subgroup of the patients had metastatic sites in pelvic lymph nodes or distant organs. Eight studies of staging PET/CT undertook histologic correlations. We performed prostate-segment-based analysis specifically regarding the primary cancer lesion for four of these studies, and patient-based analysis specifically regarding pelvic lymph node metastases for four other studies. The pooled sensitivities for staging in the two groups of studies were 70% and 61%, and the pooled specificities were 84% and 97%. None of the studies reported complications from the PET/CT imaging. 68Ga-PSMA PET/CT has clinical relevance to detect sites of recurrence for patients with PSA recurrence after radical prostatectomy (RP) with PSA levels less than 1.0 ng/ml. Choline positron emission tomography (PET)/computed tomography (CT) can detect sites of recurrent prostate cancer in an earlier phase of prostate-specific antigen (PSA) recurrence than bone scans and CT scans, but choline PET/CT is rarely positive for patients with restaging PSA levels under 1 ng/ml. A new radiotracer called 68Ga-PSMA for PET/CT was able to detect sites of recurring cancer in up to 50% of patients who had an early rise in PSA exceeding 0.5 ng/ml after initial radical prostatectomy. The published studies did not report adverse effects of 68Ga-PSMA PET/CT imaging.