68Ga-PSMA 11 ligand PET imaging in patients with biochemical recurrence after radical prostatectomy – diagnostic performance and impact on therapeutic decision-making

Abstract

ObjectiveTo evaluate the diagnostic performance of [68Ga]Ga-PSMAHBED-CC conjugate 11 positron emission tomography (PSMA-PET) in the early detection of metastases in patients with biochemical recurrence (BCR) after radical prostatectomy (RP) for clinically non-metastatic prostate cancer, to compare it to CT/MRI alone and to assess its impact on further therapeutic decisions.Material and methodsWe retrospectively assessed 117 consecutive hormone-naïve BCR patients who had 68Ga-PSMA 11 PET/CT (n = 46) or PET/MRI (n = 71) between May 2014 and January 2017. BCR was defined as two PSA rises above 0.2 ng/ml. Two dedicated uro-oncological imaging experts (radiology/nuclear medicine) reviewed separately all images. All results were presented in a blinded sequential fashion to a multidisciplinary tumorboard in order to assess the influence of PSMA-PET imaging on decision-making.ResultsThe median time from RP to BCR was 36 months (IQR 16–72). Overall, 69 (59%) patients received postoperative radiotherapy. Median PSA level at the time of imaging was 1.04 ng/ml (IQR 0.58–1.87). PSMA-positive lesions were detected in 100 (85.5%) patients. Detection rates were 65% for a PSA value of 0.2 to <0.5 ng/ml, 85.7% for 0.5 to <1, 85.7% for 1 to <2 and 100% for ≥2. PSMA-positive lesions could be confirmed by either histology (16%), PSA decrease in metastasis-directed radiotherapy (45%) or additional information in diffusion-weighted imaging when PET/MRI was performed (18%) in 79% of patients. PSMA-PET detected lesions in 67 patients (57.3%) who had no suspicious correlates according to the RECIST 1.1 criteria on MRI or CT. PSMA-PET changed therapeutic decisions in 74.6% of these 67 patients (p < 0.001), with 86% of them being considered for metastases-directed therapies.ConclusionsWe confirm the high performance of PSMA-PET imaging for the detection of disease recurrence sites in patients with BCR after RP, even at relatively low PSA levels. Moreover, it adds significant information to standard CT/MRI, changing treatment strategies in a significant number of patients.

Preliminary results of a 68Ga‐PSMA PET/CT prospective study in prostate cancer patients with occult recurrence: Diagnostic performance and impact on therapeutic decision‐making

“…Henkenberens et al also reported a significant decrease in PSA serum levels in 29 patients followed up for a similar period, and also treated according to an oligometastatic concept. Grubmüller et al observed a progressive PSA level decrease at 3 and 6 months, however, all study patients were not treated using the same treatment modality. These highly fragmented data on the therapeutic response obtained after treatment based on PSMA PET‐CT results needs to be prospectively explored more broadly.…”

“…To our knowledge, this is the first study to prospectively explore the impact on PSA levels in patients scanned using 68 Ga-PSMA PET-CT for recurrent PCa ( 14,16 The other studies described a therapeutic impact of 68 Ga-PSMA PET-CT between 28.6% and 61% [9][10][11][12]17,18 Interestingly, Calais et al 18 however, all study patients were not treated using the same treatment modality. These highly fragmented data on the therapeutic response obtained after treatment based on PSMA PET-CT results needs to be prospectively explored more broadly.…”

Response assessment using [68Ga]Ga‐PSMA ligand PET in patients undergoing systemic therapy for metastatic castration‐resistant prostate cancer

“…Nowadays, [ 68 Ga]Ga‐prostate specific membrane antigen (PSMA)‐11 ([ 68 Ga]Ga‐PSMA‐HBED‐CC; PSMA 11)‐PET has emerged as a promising molecular imaging tool and is used more and more for the staging of PC. It has shown superior performance compared to standard imaging for primary staging and in patients with biochemical recurrence after local therapy with curative intent . Concerning response to therapy in mCRPC patients, to date, two studies have been published.…”

“…It has shown superior performance compared to standard imaging for primary staging 9,10 and in patients with biochemical recurrence after local therapy with curative intent. 11 Concerning response to therapy in mCRPC patients, to date, two studies have been published. A study by Seitz et al, 12 showed that the PSMA 11-PET mean standardized uptake value (SUVmean) is accurate for response assessment in mPC patients undergoing systemic therapy with docetaxel.…”

The Effect of Including Bone in Dixon-Based Attenuation Correction for 18F-Fluciclovine PET/MRI of Prostate Cancer

“…(4,18,22,23), and detection of disease recurrence after initial treatment with curative intent, e.g. (24)(25)(26)(27). However, in current clinical practice, the high linear attenuation coefficients of the bones in the pelvis and lower abdomen are assumed to be equal to those of soft tissue, which is incorrect.…”