Comparison of [18F]PSMA-1007 with [68Ga]Ga-PSMA-11 PET/CT in Restaging of Prostate Cancer Patients with PSA Relapse

Abstract

This study aimed to compare the diagnostic performance of [18F]PSMA-1007 positron emission tomography/computed tomography (PET/CT) (18F-PSMA) and [68Ga]Ga-PSMA-11 PET/CT (68Ga-PSMA) by identifying prostate-specific antigen (PSA) threshold levels for optimal detecting recurrent prostate cancer (PC) and to compare both methods. Retrospectively, the study included 264 patients. The performances of 18F-PSMA and 68Ga-PSMA in relation to the pre-scan PSA were assessed by receiver operating characteristic (ROC) curve. 18F-PSMA showed PC-lesions in 87.5% (112/128 patients), while 68Ga-PSMA identified them in 88.9% (121/136). For 18F-PSMA biochemical recurrent (BCR) patients treated with radical prostatectomy (78/128, patient group: F-RP), a PSA of 1.08 ng/mL was found to be the optimal cut-off level for predicting positive and negative scans (AUC = 0.821; 95%, CI: 0.710–0.932), while for prostatectomized 68Ga-PSMA BCR-patients (89/136, patient group: Ga-RP), the cut-off was 1.84 ng/mL (AUC = 0.588; 95%, CI: 0.410–0.766). In patients with PSA < 1.08 ng/mL (F-RP) 76.3% and <1.84 ng/mL (Ga-RP) 78.6% scans were positive, whereas patients with PSA ≥ 1.08 ng/mL (F-RP) or 1.84 ng/mL (Ga-RP) had positive scan results in 100% and 91.5% (p < 0.001/p = 0.085). The identified PSA thresholds for PSMA-mappable PC lesions in BCR-patients (RP) showed a better separation for 18F-PSMA with regard to the distinguishing of positive and negative PC-lesions compared to 68Ga-PSMA. However, the two PSMA PET/CT tracers gave similar overall findings.

Primary Staging of Prostate Cancer Patients with [18F]PSMA-1007 PET/CT Compared with [68Ga]Ga-PSMA-11 PET/CT

“…A prospective intraindividual comparative study on 18 F-PSMA and 68 Ga-PSMA for PC staging, evaluation at biochemical recurrence and assessment of metastatic disease, by Pattison et al demonstrated a high concordance of 92% for TNM stage [ 10 ]. Further studies confirmed similar findings in PSMA PET/CT imaging with the two radiopharmaceuticals in the setting of restaging PC patients, too [ 11 , 12 ]. Rauscher et al showed similar detection rates in patients with biochemical recurrence after radical prostatectomy.…”

Analysis of Pros and Cons in Using [68Ga]Ga-PSMA-11 and [18F]PSMA-1007: Production, Costs, and PET/CT Applications in Patients with Prostate Cancer

“…Furthermore, the positron yield of [ 68 Ga]Gallium is lower than that of [ 18 F]Fluoride (89.14% vs. 96.86%), increasing image noise by possible prompt gamma contamination in PET data and negatively impacting the detection sensitivity [14]. The anatomical sites of "normal" uptake are the same for both diagnostic PSMA ligands, and the different contrast on PET/CT images is due to the density of   generated by the decay, which is major for [ 18 F]Fluoride [14,18].…”

“…According to our experience with more than 2000 patients using either 68 Ga-labeled or 18 F-labeled PSMA, we have tried to summarize the advantages and the limitations of the two PET radioligands and their application in the clinical routine at our site.…”

“…The anatomical sites of "normal" uptake are the same for both diagnostic PSMA ligands, and the different contrast on PET/CT images is due to the density of β + generated by the decay, which is major for [ 18 F]Fluoride [14,18].…”

The Value of Multimodality PET/CT Imaging in Detecting Prostate Cancer Biochemical Recurrence

“…The study by Hoffmann et al. compared the detection rates of 18 F-PSMA and 68 Ga-PSMA PET, and the results showed that the detection rates of the two tracers were similar, 87.5% (112/128) and 88.9% (121/136), respectively ( 46 ). A recent study showed, 68 Ga-P16-093, a small molecule PSMA ligand, detected 71% of lesions in BCR patients ( 47 ) ( Table 3 )…”