Detection Of Recurrent Prostate Cancer Research Articles

Deep learning detection of prostate cancer recurrence with 18F-FACBC (fluciclovine, Axumin®) positron emission tomography.

To evaluate the performance of deep learning (DL) classifiers in discriminating normal and abnormal 18F-FACBC (fluciclovine, Axumin®) PET scans based on the presence of tumor recurrence and/or metastases in patients with prostate cancer (PC) and biochemical recurrence (BCR). A total of 251 consecutive 18F-fluciclovine PET scans were acquired between September 2017 and June 2019 in 233 PC patients with BCR (18 patients had 2 scans). PET images were labeled as normal or abnormal using clinical reports as the ground truth. Convolutional neural network (CNN) models were trained using two different architectures, a 2D-CNN (ResNet-50) using single slices (slice-based approach) and the same 2D-CNN and a 3D-CNN (ResNet-14) using a hundred slices per PET image (case-based approach). Models' performances were evaluated on independent test datasets. For the 2D-CNN slice-based approach, 6800 and 536 slices were used for training and test datasets, respectively. The sensitivity and specificity of this model were 90.7% and 95.1%, and the area under the curve (AUC) of receiver operating characteristic curve was 0.971 (p < 0.001). For the case-based approaches using both 2D-CNN and 3D-CNN architectures, a training dataset of 100 images and a test dataset of 28 images were randomly allocated. The sensitivity, specificity, and AUC to discriminate abnormal images by the 2D-CNN and 3D-CNN case-based approaches were 85.7%, 71.4%, and 0.750 (p = 0.013) and 71.4%, 71.4%, and 0.699 (p = 0.053), respectively. DL accurately classifies abnormal 18F-fluciclovine PET images of the pelvis in patients with BCR of PC. A DL classifier using single slice prediction had superior performance over case-based prediction.

Automated synthesis of 68 Ga/177 Lu-PSMA on the Trasis miniAllinOne.

Prostate-specific membrane antigen (PSMA)-based radioligands for positron emission tomography (PET)/computed tomography (CT) studies represent the gold standard for detection of recurrent prostate cancer (PCa). [68 Ga]PSMA-HBED-CC is a PET radiotracer suitable for detection of PCa, and its clinical use has become widespread over the last few years. In this contribution, we detail our GMP-compliant production of [68 Ga]PSMA-HBED-CC using the Trasis miniAllinOne radiosynthesizer and report synthetic and clinical data for the first 100 productions of 2019. Additionally, we detail our efforts towards a GMP-compliant production of the radiotherapeutic [177 Lu]PSMA-I&T using the same synthesis module. PSMA-based radioligand therapy (RLT) offers a possible future treatment in cases of metastatic castration-resistant PCa, and GMP-compliant routine production methods are therefore called for. This report highlights how PSMA-based agents for theranostic purposes can be conveniently produced at a single radiochemistry Good Manufacturing Practice (GMP) site, thereby facilitating optimized detection and treatment of PCa.

Diagnostic Performance of 68Ga-PSMA-11 Positron-emission-tomography/Computed-tomography in a Large Cohort of Patients with Biochemical Recurrence of Prostate Carcinoma.

Gallium-68 (Ga) prostate-specific-membrane-antigen positron-emission-tomography/computed-tomography is a highly promising method for imaging primary and recurrent prostate cancer. These dual-modality imaging technologies enable whole-body functional and anatomical evaluation in a single session. This study investigated the performance of Ga-prostate-specific-membrane-antigen-11 positron-emission-tomography/computed-tomography for detecting prostate carcinoma in patients with rising prostate-specific-antigen after primary therapy. Six hundred sixty (660) patients with biochemical recurrence referred for positron-emission-tomography/computed-tomography with Ga-prostate-specific-membrane-antigen-11 were evaluated retrospectively. Prostate-specific-antigen-stratified cohorts of pathological scan results were analyzed, and relationships between prostate-specific-antigen kinetics and PSMA-positive tumor lesions were correlated. Gallium-68 prostate-specific-membrane-antigen-11 positron-emission-tomography/computed-tomography showed a pathological prostate-specific-membrane-antigen uptake in 76% (500 of 660 patients). Positive scans were positively associated with prostate-specific-antigen (p<0.001). For patients with prostate-specific-antigen <0.2 ng mL, the PSMA-positive tumor lesions rate was 41%. Patients with prostate-specific-antigen of 0.2-<0.5 ng mL, 0.5-<1.0 ng mL, 1.0-<2.0 ng mL, and 2.0-<5.0 ng mL showed rates of 44.7%, 61.7%, 72.3%, 85.2%, respectively, and for prostate-specific-antigen of ≥5.0 ng mL it increased to 94%. Prostate-specific-antigen velocity was also correlated with PSMA-positive tumor lesions (p<0.001). In contrast, no association was found for prostate-specific-antigen doubling time (p=0.74). PSMA-positive tumor lesions were significantly increased in patients with primary intermediate- (Gleason Score7) and high-risk (Gleason Score>7) vs. low-risk prostate cancer (Gleason Score<7) (p<0.001). Our data confirm the high performance of Ga-prostate-specific-membrane-antigen positron-emission-tomography/computed-tomography for the detection of recurrent prostate cancer. This may alter treatment planning and has been documented in other studies as well.

PSMA-PET and MRI for Detection of Recurrent Prostate Cancer After Radical Treatment

PSMA-PET and MRI for Detection of Recurrent Prostate Cancer After Radical Treatment

Multiphasic 68Ga-PSMA PET/CT in the Detection of Early Recurrence in Prostate Cancer Patients with a PSA Level of Less Than 1 ng/mL: A Prospective Study of 135 Patients.

The main objective of this prospective study was to determine the impact of multiphasic acquisition of 68Ga-PSMA PET/CT in the detection of recurrent prostate cancer in the early stage of biochemical recurrence with a prostate-specific antigen (PSA) level of less than 1 ng/mL. Also, 68Ga-PSMA PET/CT positivity was correlated with clinical parameters for the assessment of predictive markers. Methods: A prospective monocentric study was conducted on 135 prostate cancer patients with biochemical recurrence and a PSA level of less than 1 ng/mL. All patients had undergone initial prostatectomy, with additional radiation therapy in 19.3% of patients and androgen-deprivation therapy in 7.4%. The patients underwent dynamic acquisitions from the prostate bed (1-8 min after injection), standard whole-body acquisitions (60 min after injection), and limited-bed-position delayed acquisitions (120-150 min after injection). The studies were reviewed by 2 board-certified nuclear medicine specialists, independently. A combination of visual and semiquantitative analyses and correlation with morphologic (e.g., MRI) or clinical follow-up findings was used for the final interpretation of lesions as benign or malignant. 68Ga-prostate-specific membrane antigen (PSMA) PET/CT positivity was also correlated with primary clinical findings. Results: Incorporating the information from all phases, we were able to detect 116 lesions in 49.6% of patients (22 local recurrences, 63 lymph nodes, and 31 distant metastases). The detection rates were 31.8%, 44.9%, and 71.4% for PSA < 0.2 ng/mL, 0.2 ≤ PSA < 0.5, and 0.5 ≤ PSA < 1, respectively. Additional dynamic or delayed phases resulted in better determination of equivocal lesions and a higher diagnostic performance in 25.9% of patients. Stand-alone dynamic and delayed images led to better interpretation of equivocal findings in the prostate bed (31.4%) and in other lesions (lymph node or bone) (20%), respectively. Conclusion:68Ga-PSMA PET/CT showed promise for early detection of recurrent disease in patients with a PSA level of 0.5-1.0 ng/mL. However, it showed limited value in patients with a PSA level of less than 0.5 ng/mL. Multiphasic 68Ga-PSMA PET/CT led to a better determination of equivocal findings. Although dynamic images may provide helpful information for assessment of the prostate bed, delayed acquisitions seem to have a greater impact in clarifying equivocal findings.

Localization and restaging of carcinoma prostate by 68Gallium prostate-specific membrane antigen positron emission tomography computed tomography in patients with biochemical recurrence.

Introduction:Radical prostatectomy (RP) and radical radiotherapy (RT) are well established primary curative options for localized prostate cancer. Despite technical improvements, prostate-specific antigen (PSA)-recurrence after RP and RT is a common clinical scenario. We aimed to assess the role of 68Gallium (68Ga) prostate-specific membrane antigen positron emission tomography computed tomography (PSMA PET/CT) in patients with biochemical recurrence of prostate cancer after RP or RT for the detection and localization recurrent and metastatic disease.Materials and Methods:We ambispectively (70 retrospective and 100 prospective) analyzed the data of men with biochemical recurrence post-RP and post-RT who were evaluated by 68Ga PSMA PET/CT at our institute. We aimed to assess the relationship between serum PSA levels and the probability of having a positive scan in patients with recurrent prostate cancer.Results:The study included 170 men, all had adenocarcinoma of the prostate, 124/170 had previous RP and 46/170 had prior RT. The median serum PSA in the RP group was 1.8 ng/ml and 5.2 ng/ml in the RT group. In the post-RP cohort, the detection rate of 68Ga PSMA PET/CT was 39.3% for PSA 0.2 to <0.5 ng/ml, 47.3% for PSA 0.5 to <1 ng/ml, 68.4% for PSA 1 to <2 ng/ml and 93.1% for PSA ≥2 ng/ml. In the post-RT group, the detection rate was 88.8% for PSA 2 to <4 ng/ml and 100% for PSA ≥4 ng/ml.Conclusions:68Ga PSMA PET/CT provides a novel imaging modality for the detection of prostate cancer recurrence and metastases at low posttreatment PSA levels, which may help in directing appropriate salvage treatments.

Post-treatment prostate MRI.

Accurate early detection of recurrent prostate cancer after surgical or nonsurgical treatment is increasingly relevant in the era of evolving options for salvage therapy. The importance of differentiating between local tumor recurrence, distant metastatic disease, and a combination of both in a patient with biochemical recurrence of prostate cancer is essential for appropriate treatment selection. Magnetic resonance imaging (MRI) is the best test for localization and characterization of locally residual or recurrent prostate cancer. It is essential for the radiologist involved in prostate MRI interpretation to be familiar with key imaging findings and advantages of different sequences to reach a confident diagnosis in the post-treatment setting. In this pictorial review, we present imaging findings of post-treatment prostate MRI including expected post-treatment anatomy and imaging characteristics, and the typical appearances of local tumor recurrence after radical prostatectomy, radiation therapy, and focal therapy for prostate cancer. While a multi-parametric MRI approach remains key just as in the treatment-naïve gland, this review emphasizes the much greater importance of the dynamic contrast-enhanced MRI sequence for evaluation in the post-treatment setting.

A pilot study of prostate-specific membrane antigen (PSMA) dynamics in men undergoing treatment for advanced prostate cancer.

Prostate-specific membrane antigen (PSMA) is a rational target for noninvasive detection of recurrent prostate cancer (PCa) and for therapy of metastatic castration-resistant prostate cancer (mCRPC) with PSMA-targeted agents. Here we conducted serial measurements of PSMA expression on circulating tumor cells (CTCs) to evaluate patterns of longitudinal PSMA dynamics over the course of multiple sequential therapies. A retrospective investigation of men with mCRPC undergoing evaluation at medical oncology clinics at our institution assessed the dynamics of PSMA expression in the context of different systemic treatments administered sequentially. Eligibility included patients who began systemic therapies with androgen receptor (AR)-directed agents or taxane agents for whom peripheral blood samples were tested for CTC mRNA of AR splice variant-7 (AR-V7), prostate-specific antigen (PSA), and PSMA (with >2 CTC + results) in a CLIA-accredited laboratory. From August 2015 to November 2017, we identified 96 eligible men. Fifteen had greater than or equal to 2 sequential therapies and evaluable CTC samples, greater than or equal to 1 expressing PSMA (PSMA+). Among the 15 patients included in this analysis, a total of 54 PSMA status evaluations were performed in the context of 48 therapies during a median follow-up of 18 months. At baseline, PSMA signal was detected ("positive") in 11 of 15 (73.3%) patients, while for 4 of 15 (26.7%) patients PSMA signal was undetectable ("negative"). In all but two patients, the baseline collection corresponded with a change in treatment. On the second assessment, PSMA increases were detected in all 4/4 (100%) PSMA-negative patients and 8 of 11 (72.7%) PSMA-positive patients. PSMA significantly decreased in a patient treated with 177 Lu-PSMA-617. Serum PSA declines were seen in 7 of 8 (88%) of the treatment periods where PSMA decreased. PSMA expression in CTCs is a dynamic marker. PSMA transcript declines appear to be associated with concurrent decreases in serum PSA. Sequential CTC sampling could provide a noninvasive response assessment to systemic treatment for mCRPC.

Comparison of PSMA-ligand PET/CT and multiparametric MRI for the detection of recurrent prostate cancer in the pelvis

So far, there have been very few studies which provide a direct comparison between MRI and PSMA-ligand PET/CT for the detection of recurrent prostate cancer (rPC). This present study therefore aims to provide further clinical data in order to resolve this urgent clinical question, and thereby strengthen clinical recommendations. A retrospective analysis was performed for patients who were scanned at our institution with whole-body PSMA-PET/CT (tracer: 68Ga-PSMA-11) between January 2017 and September 2018 in order to detect rPC. Amongst them, 43 underwent an additional pelvic MRI within 2months. Both modalities were compared as follows: a consensus read of the PET data was performed by two nuclear physicians. All lesions were recorded with respect to their type and localization. The same process was conducted by two radiologists for pelvic MRI. Thereafter, both modalities were directly compared for every patient and lesion. Overall, 30/43 patients (69.8%) presented with a pathologic MRI and 38/43 (88.4%) with a pathologic PSMA-PET/CT of the pelvis. MRI detected 53 pelvic rPC lesions (13 of them classified as "uncertain") and PSMA-PET/CT detected 75 pelvic lesions (three classified as "uncertain"). The superiority of PSMA-PET/CT was statistically significant only if uncertain lesions were classified as false-positive. PSMA-PET/CT detected more pelvic lesions characteristic for rPC when compared to MRI. In order to detect rPC, a potential future scenario could be conducting first a PSMA-PET/CT. Combining the advantages of both modalities in hybrid PET/MRI scanners would be an ideal future scenario.

The role of 18F-fluciclovine PET in the management of prostate cancer: a systematic review and meta-analysis

To investigate the diagnostic performance of 18F-fluciclovine positron-emission tomography (PET) or combined PET and computed tomography (PET/CT) for diagnosis of primary cancer, preoperative lymph node (LN) staging, and detection of recurrent disease of prostate cancer (PCa) through a systematic review and meta-analysis. The PubMed and EMBASE databases were searched from the earliest available date of indexing through 31 December 2018, for studies evaluating the diagnostic performance of 18F-fluciclovine PET or PET/CT for the management of PCa patients. The sensitivities, specificities, and positive and negative likelihood ratios (LR+ and LR-) across the studies were calculated and summary receiver operating characteristic curves were constructed. Across 13 studies (563 patients), the pooled sensitivity for 18F-fluciclovine PET or PET/CT for diagnosis of primary PCa was 0.87 (95% confidence interval [CI]: 0.77-0.93) and a pooled specificity of 0.84 (95% CI: 0.68-0.93). For LN staging, the pooled sensitivity was 0.56 (95% CI: 0.37-0.74) and a pooled specificity of 0.98 (95% CI: 0.88-1.00). For detection of recurrent disease, the pooled sensitivity was 0.79 (95% CI: 0.60-0.91) and a pooled specificity of 0.69 (95% CI: 0.59-0.77). In meta-regression analysis, no definite variable was the source of the study heterogeneity. The current meta-analysis showed the moderate sensitivity and specificity of 18F-fluciclovine PET or PET/CT for the diagnosis of primary cancer, preoperative LN staging, and detection of recurrent PCa. Further large multicentre studies will be necessary to substantiate the diagnostic accuracy of 18F-fluciclovine PET/CT for management of PCa patients.

Fluorine-18-Labeled Fluciclovine PET/CT in Clinical Practice: Factors Affecting the Rate of Detection of Recurrent Prostate Cancer.

OBJECTIVE. The purpose of this study is to show the performance and evaluate the factors influencing the positivity rate (PR) of commercially produced 18F-fluciclovine PET/CT in the detection of recurrent prostate cancer in clinical practice. MATERIALS AND METHODS. We performed a retrospective cohort study of 152 men who had suspected biochemical recurrence of prostate cancer after receiving initial treatment and underwent fluciclovine PET/CT. PRs were calculated for whole-body, prostate and prostate bed, and extraprostatic locations. The influence of different factors, such as the absolute prostate-specific antigen (PSA) level, PSA kinetics, the Gleason score, and Gleason grade groups, on the PR was evaluated. RESULTS. The overall PR was 81% (123/152) for the whole body, 61% (92/152) for the prostate and prostate bed, and 55% (83/152) for extraprostatic locations. There was a linear increase in the PR with an increasing PSA level (p < 0.001). For the whole body, the PR for PSA levels of less than 1 ng/mL, 1 to less than 2 ng/mL, 2 to less than 5 ng/mL, and 5 or more ng/mL were 58% (32/55), 87% (13/15), 100% (39/39), and 92% (35/38), respectively. No statistically significant linear trend was found between the PR and the PSA level doubling time (p > 0.05). In addition, no statistically significant linear trend was found between the PR and increasing Gleason grade group. However, for every 1-unit increase in a patient's Gleason score, the odds of a positive finding in the extraprostatic location increased by 49% (p < 0.05). CONCLUSION. Commercially produced fluciclovine PET/CT has a high PR for detection of prostate cancer recurrence and is positively correlated with increasing PSA levels. For extraprostatic disease, the PR increases with higher Gleason scores.

MP13-01 PET/CT WITH 18 F-FLUCICLOVINE TO PREDICT RECURRENCE IN POST-TREATMENT PROSTATE CANCER AND ITS ROLE IN ALTERING TREATMENT PLANS

INTRODUCTION AND OBJECTIVES:Positron emission tomography/computed tomography (PET/CT) with 18F-fluciclovine can improve the detection of recurrent prostate cancer (PCa). We assessed for factors whi...

PD17-07 DETECTION RATE OF 68GA-PSMA-11 PET/MRI IN PATIENTS WITH RECURRENT PROSTATE CANCER FOLLOWING RADICAL PROSTATECTOMY AND LOW PSA VALUES ≤ 0.5 NG/ML

INTRODUCTION AND OBJECTIVES:Simultaneous 68Ga-PSMA-11 PET/MRI showed some improvement in the detection of recurrent prostate cancer at low serum prostate specific antigen (PSA) levels between 0.2 -...

18F-Fluciclovine PET/CT Detection of Recurrent Prostate Carcinoma in Patients With Serum PSA ≤ 1 ng/mL After Definitive Primary Treatment.

The aims of this study were to report on our initial experience using F-fluciclovine PET/CT to detect recurrent prostate carcinoma in patients with low serum prostate-specific antigen (PSA) after definitive treatment of primary disease and to conduct a preliminary investigation for factors associated with positive scan findings. In this retrospective study, F-fluciclovine PET/CT scans from 28 men with suspected recurrence of prostate carcinoma and PSA values of 1 ng/mL or less were examined to identify the site(s) of disease recurrence. Differences in detection rate for Gleason scores of 7 and greater than 7, T2 and T3 disease, negative and positive surgical margins, and negative and positive seminal vesicle invasion were compared using the Fisher exact test. Mean PSA and mean PSA doubling time of patients with positive scans and negative scans were compared using the independent 2-group t test. At least one site of disease recurrence was identified in 13 (46.4%) of 28 patients. Disease detection rate was significantly higher in patients with history of Gleason score greater than 7 (Fisher exact test, P = 0.004). Mean PSA and PSA doubling time were not significantly different between patients with positive and negative F-fluciclovine PET/CT scans (P = 0.29 and 0.70, respectively). Detection of recurrent prostate cancer using F-fluciclovine PET/CT is possible in patients with low but rising PSA levels of 1 ng/mL or less. In such patients, local and nodal recurrences are more common than distant metastasis, and Gleason score greater than 7 is associated with positive scan results.

774 - 68Ga-PSMA-11 PET/MRI for the detection of recurrent prostate cancer following radical prostatectomy at low PSA values ≤ 0.5 ng/ml

774 - 68Ga-PSMA-11 PET/MRI for the detection of recurrent prostate cancer following radical prostatectomy at low PSA values ≤ 0.5 ng/ml

Uptake in non-affected bone tissue does not differ between [18F]-DCFPyL and [68Ga]-HBED-CC PSMA PET/CT.

Introduction[68Ga]PSMA-HBED-CC and [18F]DCFPyL show a high potential for the detection of recurrent prostate cancer. While 18F-based tracers have several advantages in availability and image resolution, their sensitivity in the skeleton might be impaired by released [18F]fluoride due to its high bone affinity. In turn, chemically unbound trivalent 68Ga might also accumulate in osseous tissue, in cases of occupied binding sites of plasma proteins and thereby influence bone signal.MethodsA comparison of average bone SUV was performed in 17 bone-negative and 4 bone-positive patients. All patients underwent PET/CT 125 minutes after application of [18F]DCFPyL and 73 minutes after application of [68Ga]PSMA-HBED-CC at another date.ResultsNative SUVs in unaffected bone tissue and SUVs relative to liver uptake were lower in [18F]DCFPyL (0.49) than in [68Ga]PSMA-HBED-CC scans (0.52). SUVs relative to gluteal muscles did not differ between the two tracers. Average lesional SUVs did not differ between tracers.ConclusionNo difference of average bone signal intensity was observed for [18F]DCFPyL-PET/CT in comparison to [68Ga]PSMA-HBED-CC scans indicating that diagnostic assessment of the skeleton is not affected by non-specific accumulation of free [18F]fluoride or 68Ga.

68Ga-labelled PSMA ligand HBED-CC PET/CT imaging in patients with recurrent prostate cancer

68Ga-PSMA Positron Emission Tomography/Computerized Tomography (PET/CT) has shown promising results for the detection of recurrent prostate cancer (RPCa). However, the diagnostic value of this method is yet to be validated. The aim of this study was to determine the influence of clinical and biochemical variables on the detection rate of 68Ga-PSMA PET/CT in patients with RPCa. This is a prospective study of 121 patients who underwent 68Ga-PSMA-PET/CT and conventional imaging (CI) for RPCa. Detection rates were analyzed and correlated with various clinical and biochemical variables such as Gleason score GS), androgen deprivation therapy (ADT), trigger PSA (tPSA), PSA doubling-time (PSAdt) and PSA velocity (PSAv). 68Ga-PSMA-PET/CT showed at least one focus of pathological 68Ga-PSMA uptake in 92/121 (76%) of patients. Nodal metastases (in 47% of patients) were the most common site of recurrent disease followed by bones (36%) and prostate (32%). Out of 121 patients, 57 (47%) had only positive findings on PSMA scan verified by biopsy or follow-up. The majority of these lesion were located in the lymph nodes (31/57, 54,5%), which were below the detection limit of CT. Univariate analysis showed higher detection rate of PET/CT with increasing tPSA, PSAv and short PSAdt. Best cutoff for tPSA, PSAv and PSAdt was 0.5ng/ml, 2.25ng/ml/year and 8.65months, respectively. The detection rate of PSMA-PET/CT was higher in patients with high grade tumors (GS > 7, 23.7% vs 76.3%) and in patients who were on ADT during of PSMA scan (76.3% vs 96%). In multiple logistic regression analysis, PSAdt and concurrent ADT were identified as predictors of positive 68Ga-PSMA-PET/CT. 68Ga-PSMA-PET/CT is useful for re-staging patients with RPCa and has improved performance compared with CI for disease detection. Detection rates are improved in patients on ADT and with short PSAdt.

Comparison of 11C-choline Positron Emission Tomography/Computed Tomography (PET/CT) and Conventional Imaging for Detection of Recurrent Prostate Cancer.

We aimed to compare 11C-choline positron emission tomography/computed tomography (PET/CT) with conventional imaging, including pelvic magnetic resonance imaging (MRI), contrast-enhanced chest, abdomen, and pelvic computed tomography (CT), and bone scintigraphy, for prostate cancer restaging. Thirty patients (median prostate-specific antigen [PSA: 11.8 ng/mL]) with suspected recurrent prostate cancer following definitive treatment underwent 11C-choline PET/CT and conventional imaging, including pelvic MRI, contrast-enhanced chest, abdomen, and pelvic CT, and bone scintigraphy. The results were compared with regard to patient- and lesion-based diagnostic performance for local recurrence, and for lymph node and bony metastases using receiver operating characteristic (ROC) analysis and McNemar’s test. Documented local recurrence and node and bony metastases were present in 11 (36.7%), 10 (33.3%), and 17 (56.7%) cases, respectively, of the enrolled patients. Patient-based sensitivity / specificity / accuracy / area under the ROC curve for 11C-choline-PET/CT for diagnosing local recurrence were 90.9% / 94.7% / 93.3% / 0.975 and for conventional imaging were 90.9% / 100% / 96.7% / 1.0. Those who underwent 11C-choline-PET/CT for node metastasis were 90.0% / 95.0% / 93.3% / 0.925 and for conventional imaging were 70.0% / 95.0% / 86.7% / 0.905. Those who underwent 11C-choline-PET/CT for bone metastasis were 94.1% / 92.3% / 93.3% / 0.991 and who underwent conventional imaging were 94.1% / 84.6% / 90.0% / 0.982. No significant differences were observed among them. The lesion-based detection rate of 11C-choline PET/CT for local recurrences and node and bone metastases as compared to conventional imaging was 92.9% (13/14) vs. 92.9% (13/14); 87.1% (27/31) vs. 54.8% (17/31); and 96.9% (219/226) vs. 90.3% (204/226) respectively, with significant differences noted for detection of node and bone lesions (p=0.0044 and p=0.00030, respectively). 11C-choline-PET/CT is more accurate in the detection of recurrent prostate cancer nodes and bony metastatic lesions compared to conventional imaging and has the advantage of restaging the disease in a single step.

68Ga-Labeled PSMA Uptake in Nonprostatic Malignancies

PET/CT with Ga-labeled prostate-specific membrane antigen (PSMA) is increasingly recognized as the best imaging modality for disease staging and detection of recurrent prostate cancer. Despite its name, PSMA expression has been reported in a number of nonprostatic benign and malignant pathologies. Apparently, angioneogenesis is the mechanism attributed to increased Ga-PSMA uptake at these sites. Here we illustrate the utility of Ga-PSMA in 5 nonprostatic malignancies that could open up new possibilities for diagnostics and theranostic concepts with PSMA labeled radioligands in nonprostate tumor entities.

68Ga-PSMA PET/CT in Patients with Rising Prostatic-Specific Antigen After Definitive Treatment of Prostate Cancer: Detection Efficacy and Diagnostic accuracy

68Ga-prostate-specific membrane antigen-11 (68Ga-PSMA-11) is a recently developed positron emission tomography (PET) tracer that can detect prostate cancer (PC) relapses and metastases with high contrast resolution. The aim of this study was to assess the detection efficacy and diagnostic accuracy of 68Ga-PSMA PET/CT image in patients with rising prostatic-specific antigen (PSA) after treatment of PC. The present prospective study included 188 patients who exhibited rising of PSA level on a routine follow-up examination after definitive treatment of PC. All patients underwent a 68Ga-PSMA PET/CT examination. For each patient, we determined the disease stage, the Gleason score, and the maximum standardized uptake value of the local recurrence and extraprostatic metastases. The detection efficacy and diagnostic accuracy of 68Ga-PSMA PET/CT were established by histopathology and clinical and imaging follow-up as the reference standards. 68Ga-PSMA PET/CT detected tumour relapse in 165 patients (35 patients had local recurrence, 106 patients had extraprostatic metastases, and 24 patients had combined lesions). The sensitivity, specificity, and accuracy values of 68Ga-PSMA PET/CT examination in the detection of PC recurrence were 98.8%, 100%, and 98.8%, respectively. 68Ga-PSMA PET/CT revealed an overall detection rate of 87.8% (165/188) in patients with rising PSA (median of 2.2 ng/mL, and range of 0.01-70 ng/mL). 68Ga-PSMA PET/CT is a valuable tool for the detection of PC local recurrence or extraprostatic metastases following rising PSA levels after primary definitive therapy and should be incorporated during routine work-up.