Repeatability of [68Ga]DKFZ11-PSMA PET Scans for Detecting Prostate-specific Membrane Antigen-positive Prostate Cancer

213 Background: Metastases-directed therapy by metastasectomy or radiotherapy (RT) might delay disease progression and postpone systemic treatment in patients with oligometastatic prostate cancer. Here, we evaluated retrospectively the efficacy and toxicity of 68Ga prostate-specific membrane antigen (PSMA) PET-CT guided radiotherapy (RT) in the treatment of oligometastatic prostate cancer. Methods: A total of 23 prostate cancer patients with biochemical relapse, of which 13 castration-sensitive and 10 castration-resistant, were treated with intensity-modulated and image-guided RT (IMRT-IGRT) on ≤ 3 metastases detected by 68Ga PSMA PET-CT. Androgen deprivation therapy was continued in castration-resistant patients. Local control (LC), progression-free survival (PFS) and overall survival (OS) were estimated with the Kaplan-Meier method. Results: A total of 38 metastases were treated. Involved sites were pelvic bone (n = 16), pelvic lymph nodes (n = 11), para-aortic lymph nodes (n = 6), ribs (n = 3) and vertebral body (n = 2). The median PSA prior to RT was 1.06 ng/ml (range 0.10 – 29.0 ng/ml). A median dose of 43.5 Gy (range, 30-64 Gy) was delivered by IMRT-IGRT in 12-27 fractions. At a median follow-up of 7 months (range, 2-17 months), 19 patients (83%) are in remission. Four patients (17%) developed distant recurrence. The actuarial 1-year LC, PFS and OS rates were 100%, 51% (95% CI 8-83%) and 100%. Castration-sensitive patients displayed a statistically significantly superior PFS on univariate analysis as compared to castration-resistant patients (1-year PFS 67% vs 0%, p < 0.01). One patient experienced grade 2 acute gastro-intestinal toxicity. No grade 3 or more toxic events were observed. Conclusions: By providing optimal LC, low toxicity and a promising PFS in castration-sensitive patients, the current retrospective study illustrated that 68Ga PSMA PET-CT guided RT may be an attractive treatment option in patients with oligometastatic prostate cancer. Validation by randomized trials is eagerly awaited.

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Prostate-specific membrane antigen and fibroblast activation protein distribution in prostate cancer: preliminary data on immunohistochemistry and PET imaging

Annals of Nuclear Medicine ◽

10.1007/s12149-021-01702-8 ◽

2021 ◽

Author(s):

Katharina Kessel ◽

Robert Seifert ◽

Matthias Weckesser ◽

Martin Boegemann ◽

Sebastian Huss ◽

...

Keyword(s):

Prostate Cancer ◽

Lymph Node ◽

Pet Imaging ◽

Fibroblast Activation Protein ◽

Prostate Specific Membrane Antigen ◽

Psma Pet ◽

Node Metastases ◽

Small Patient ◽

Specific Membrane ◽

Psma Expression

Abstract Introduction Fibroblast activation protein (FAP) has been recently presented as new imaging target for malignant diseases and offers high contrast to surrounding normal tissue. FAP tracer uptake has been reported in various tumor entities. The aim of this study was to compare FAP and Prostate-specific membrane antigen (PSMA) expression in primary prostate cancer employing histological analyses and PET imaging in two small patient collectives. Methods Two independent small patient collectives were included in this study. For cohort A, data of 5 prostate cancer patients and 3 patients with benign prostate hyperplasia were included. Patients with prostate cancer were initially referred for PSMA PET staging. Radical prostatectomy was performed in all patients and prostate specimen of patients and biopsies of healthy controls were available for further evaluation. Histological workup included HE and immunohistochemistry using PSMA Ab, FAP Ab. Cohort B consists of 6 Patients with diagnosed mCRPC and available PSMA as well as FAP PET. Results Patients with proven prostate cancer infiltration exhibited strong positivity for PSMA in both primary tumors and lymph node metastases while stainings for FAP were found positive in some cases, but not all (2/5). Controls with BPH presented moderate PSMA staining and in one case also with a positive FAP staining (1/3). PET imaging with FAP seemed to result in more precise results in case of low PSMA expression than PSMA-PET. Conclusions While PSMA staining intensity is a valid indicator of prostate cancer in both primary tumor and lymph node metastases, the expression of FAP seems to be heterogeneous but not necessarily linked to cancer-associated fibroblasts. It is also present in inflammation-associated myofibroblasts. Therefore, its ultimate role in prostate cancer diagnosis remains a subject of discussion.

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Prostate-specific membrane antigen positron emission tomography compared to multiparametric MRI for prostate cancer diagnosis: a protocol for a systematic review and meta-analysis

BMJ Open ◽

10.1136/bmjopen-2021-052277 ◽

2021 ◽

Vol 11 (12) ◽

pp. e052277

Author(s):

Yi Zhao ◽

Naomi Morka ◽

Benjamin Scott S Simpson ◽

Alex Freeman ◽

Alex Kirkham ◽

...

Keyword(s):

Prostate Cancer ◽

Systematic Review ◽

Positron Emission Tomography ◽

Meta Analysis ◽

Multiparametric Mri ◽

Emission Tomography ◽

Prostate Specific Membrane Antigen ◽

Positron Emission ◽

Psma Pet ◽

Specific Membrane

IntroductionThe introduction of multiparametric MRI (mpMRI) has improved almost every aspect of the prostate cancer diagnostic pathway. However, the novel imaging technique, prostate-specific membrane antigen positron emission tomography (PSMA PET) may have demonstrable accuracy in detecting and staging prostate cancer. Here, we describe a protocol for a systematic review and meta-analysis comparing mpMRI to PSMA PET for the diagnosis of suspected prostate cancer.Methods and analysisA systematic search of MEDLINE, EMBASE, PubMed and Cochrane databases will be conducted. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines will be followed for screening, data extraction, statistical analysis and reporting. Included papers will be full-text articles providing original data, written in English articles and comparing the use of PSMA PET with mpMRI in the diagnosis of prostate cancer. All studies published between July 1977 and March 2021 will be eligible for inclusion. Study bias and quality will be assessed using Quadas-2 score. To ensure the quality of the reporting of studies, this protocol is written following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols 2015 checklist.Ethics and disseminationEthical approval will not be required for this systematic review. Findings will be disseminated through peer-reviewed publications and presentations at both national and international conferences.PROSPERO registration numberCRD42021239296.

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Detection rates of recurrent prostate cancer: 68Gallium (Ga)-labelled prostate-specific membrane antigen versus choline PET/CT scans. A systematic review

Therapeutic Advances in Urology ◽

10.1177/1756287218815793 ◽

2019 ◽

Vol 11 ◽

pp. 175628721881579 ◽

Cited By ~ 6

Author(s):

Masood Moghul ◽

Bhaskar Somani ◽

Tim Lane ◽

Nikhil Vasdev ◽

Brian Chaplin ◽

...

Keyword(s):

Prostate Cancer ◽

Systematic Review ◽

Ct Scans ◽

Prostate Specific Membrane Antigen ◽

Recurrent Prostate Cancer ◽

Detection Rates ◽

Psma Pet ◽

Pet Ct ◽

Significant Difference ◽

Specific Membrane

Background: The aim of this work was to assess the use of prostate-specific membrane antigen (PSMA)-labelled radiotracers in detecting the recurrence of prostate cancer. PSMA is thought to have higher detection rates when utilized in positron emission tomography (PET)/computed tomography (CT) scans, particularly at lower prostate-specific antigen (PSA) levels, compared with choline-based scans. Methods: A systematic review was conducted comparing choline and PSMA PET/CT scans in patients with recurrent prostate cancer following an initial curative attempt. The primary outcomes were overall detection rates, detection rates at low PSA thresholds, difference in detection rates and exclusive detection rates on a per-person analysis. Secondary outcome measures were total number of lesions, exclusive detection by each scan on a per-lesion basis and adverse side effects. Results: Overall detection rates were 79.8% for PSMA and 66.7% for choline. There was a statistically significant difference in detection rates favouring PSMA [OR (M–H, random, 95% confidence interval (CI)) 2.27 (1.06, 4.85), p = 0.04]. Direct comparison was limited to PSA < 2 ng/ml in two studies, with no statistically significant difference in detection rates between the scans [OR (M–H, random, 95% CI) 2.37 (0.61, 9.17) p = 0.21]. The difference in detection on the per-patient analysis was significantly higher in the PSMA scans ( p < 0.00001). All three studies reported higher lymph node, bone metastasis and locoregional recurrence rates in PSMA. Conclusions: PSMA PET/CT has a better performance compared with choline PET/CT in detecting recurrent disease both on per-patient and per-lesion analysis and should be the imaging modality of choice while deciding on salvage and nonsystematic metastasis-directed therapy strategies.

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Prostate-specific membrane antigen (PSMA) PET-CT imaging in the investigation and management of biochemical recurrence in prostate cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2018.36.6_suppl.208 ◽

2018 ◽

Vol 36 (6_suppl) ◽

pp. 208-208 ◽

Cited By ~ 1

Author(s):

Fergus Keane ◽

Yasser Ged ◽

Megan Greally ◽

Michael A. Maher ◽

Kieran O'Malley ◽

...

Keyword(s):

Prostate Cancer ◽

Metastatic Disease ◽

Biochemical Recurrence ◽

Systemic Disease ◽

Ct Imaging ◽

Prostate Specific Membrane Antigen ◽

Psma Pet ◽

Pet Ct ◽

Specific Membrane

208 Background: It is estimated that within ten years of primary treatment for prostate cancer up to 40% of patients post radical prostatectomy, and up to 50% of patients post radiotherapy will develop disease recurrence. While monitoring of PSA levels is informative of biochemical recurrence, it may precede radiologically detectable recurrence by months to years, and cannot differentiate local/regional recurrence from systemic disease. This represents a management dilemma for treating physicians. The incorporation of PET probes targeting prostate-specific membrane antigen (PSMA) for prostate cancer shows promise for improving the management of patients with prostate cancer, when used alongside existing imaging techniques, like CT, MRI and bone scans. Methods: Retrospective review of all patients referred from our institution for PSMA imaging was carried out. Baseline clinical features were determined and we analyzed impact of PSMA imaging on management outcomes and survival data. Results: 33 patients referred for 68Ga-PSMA-PET imaging were identified. Median age at diagnosis was 65 years (51 -75). The indication for referral in all patients was biochemical recurrence in the absence of radiological evidence of disease by CT imaging and bone scan. Median PSA at time of referral for PSMA scan was 7.3ug/L (1.4ug/L to 87.7ug/L). 100% of patients (n = 33) were upstaged following PSMA imaging, and 30% (n = 10) had more than one site of metastatic disease identified. Most common sites of metastasis were lymph node and bone. Median number of sites of metastatic disease identified by PSMA imaging was one. These results led to a change in management for 96% patients (n = 32). All patients at the time of this review are alive with a median follow up of 13 months, and median progression-free survival of 11 months. Conclusions: PSMA PET-CT directly led to an alteration in the treatment of the majority of patients in this study. This real world data reflects the growing role of PSMA imaging in influencing clinical decisions for prostate cancer patients with biochemical recurrence. Prospective data from randomized studies are awaited to further validate the role of PSMA PET-CT in this patient cohort.

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