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.

The significance of FNAC in diagnosing differentiated thyroid cancer and the discrepancy between theory and practice - a multi-centre study.

INTRODUCTION: After non-invasive diagnostic modalities high risk thyroid nodules are investigated with fine needle aspiration cytology in order to find the right surgical strategy for suspected malignancies. Despite the clear recommendation by the European and the American associations (ETA, ATA) its clinical value is doubted and its importance in clinical practice not fully clarified. METHODS: A multicentric study of 119 patients with differentiated thyroid cancer operated on in 24 surgical departments was conducted. The aim was not only to evaluate the use of FNAC as a diagnostic tool, but also to investigate its diagnostic validity and compare it with that of other, non-invasive diagnostic methods. RESULTS: FNAC was used only in 25 % of malignant thyroid nodules. In these patients sensitivity of FNAC was 60 %. In 40 % with preoperative FNAC, the result had an impact on the surgical approach. 17 % underwent surgery only because of the FNAC result, and 23 % underwent a planned surgical resection with total thyroidectomy and lymphadenectomy on account of the FNAC result. In comparison to non-invasive diagnostics (ultrasonography in conjunction with scintigraphy with Na99mTcO4) FNAC reached the same sensitivity. DISCUSSION: The results of our study reveal a limited application of preoperative FNAC in diagnosing thyroid nodules as well as a limited conclusiveness in our study population if not performed according to standards. In order to increase the benefits of this diagnostic modality, it seems to be important to perform FNAC according to the guidelines and in a standardized manner. FNAC should always be conducted in combination with ultrasonography. An experienced cytopathologist should be consulted and the Bethesda classification system should be established.

PSA and PSA Kinetics Thresholds for the Presence of 68Ga-PSMA-11 PET/CT-Detectable Lesions in Patients With Biochemical Recurrent Prostate Cancer.

68Ga-PSMA-11 positron-emission tomography/computed tomography (PET/CT) is commonly used for restaging recurrent prostate cancer (PC) in European clinical practice. The goal of this study is to determine the optimum time for performing these PET/CT scans in a large cohort of patients by identifying the prostate-specific-antigen (PSA) and PSA kinetics thresholds for detecting and localizing recurrent PC. This retrospective analysis includes 581 patients with biochemical recurrence (BC) by definition. The performance of 68Ga-PSMA-11 PET/CT in relation to the PSA value at the scan time as well as PSA kinetics was assessed by the receiver-operating-characteristic-curve (ROC) generated by plotting sensitivity versus 1-specificity. Malignant prostatic lesions were identified in 77%. For patients that were treated with radical prostatectomy (RP) a PSA value of 1.24 ng/mL was found to be the optimal cutoff level for predicting positive and negative scans, while for patients previously treated with radiotherapy (RT) it was 5.75 ng/mL. In RP-patients with PSA value <1.24 ng/mL, 52% scans were positive, whereas patients with PSA ≥1.24 ng/mL had positive scan results in 87%. RT-patients with PSA <5.75 ng/mL had positive scans in 86% and and for those with PSA ≥5.75 ng/mL 94% had positive scans. This study identifies the PSA and PSA kinetics threshold levels for the presence of 68Ga-PSMA-11 PET/CT-detectable PC-lesions in BC patients.

The positivity rate of 68Gallium-PSMA-11 ligand PET/CT depends on the serum PSA-value in patients with biochemical recurrence of prostate cancer.

Background: The aim of the present study is to analyze the efficacy of 68Gallium (Ga)-PSMA-11 PET/CT for detecting and localizing recurrent prostate carcinoma (PC) in patients with different prostate-specific antigen (PSA), PSA velocity (PSAvel) and doubling time (PSAdt). Results: The PR of 68Ga-PSMA-11 PET/CT showed a positive relationship with PSA levels. Even at restaging PSA-values (PSAV) of lower than 0.2 ng/ml, PR was 41%. For PSAV of 0.2-<0.5 ng/ml the PR was 45%, 62% for PSAV of 0.5-<1.0 and 72% for PSAV of 1.0-<2.0 ng/ml. The PR increased to 85% for PSAV of 2.0-<5.0 and reached 94% at PSAV of ≥5.0 ng/ml. At PSA of <1 ng/ml/y the PR of PSAvel was 50% and increased to 98% at PSA >5 ng/ml/y. No significant association was found for PSAdt. Methods: PET/CT scans of 660 patients with biochemical recurrence (BCR) after primary therapy of PC were included in the analysis. We correlated serum PSA levels, measured at the time of imaging with PSMA PET/CT-positivity rates (PR) as well as PSAvel (in 225 patients) and PSAdt (660 patients). Additionally we compared the incidence of localized disease to metastases as related to these PSA-biomarkers. Conclusion: We have shown, in a large cohort of patients, that 68Ga-PSMA-11 PET/CT is a sensitive tool for restaging PC and has a high detection efficacy, even in patients with very low PSA levels (<0.2 ng/ml). Thus 68Ga-PSMA-11 PET/CT both identify and localize recurrent disease with implications for a more direct treatment approach (localized vs. systemic therapy).