Prostate-specific Membrane Antigen PET-CT Research Articles

The added value of 68Ga-PSMA PET/CT in anatomical staging of prostatic carcinoma in correlation with the histopathological zonal staging

BackgroundProstate cancer is well known as the commonest cancer in men and the second leading cause of cancer-related death. CT, MRI and bone scintigraphy are considered the commonly widely used imaging diagnostic tools for detection, staging and follow-up of prostate cancer. Prostate-specific membrane antigen (PSMA) is a membrane glycoprotein, that can be concentrated in prostate cancer cells up to 100 times higher than in normal cells. PSMA-targeted imaging modalities have now proven their efficacy in diagnosis, staging and follow-up of prostate cancer. The use of 68Ga PSMA PET-CT has efficiently improved the detection of loco-regional and metastatic disease. 68Ga PSMA PET-CT also has an effective role in the primary diagnosis, staging, and detecting biochemical recurrence after curative treatment and in metastasis-targeted therapy. This work aims to review the role of 68Ga PSMA PET-CT in anatomical staging of prostate cancer in correlation with histopathological staging.ResultsZonal correlation between 68Ga PSMA findings and biopsy results showed sensitivity ranging between 76.9 and 90.6% and specificity ranging from 85.7 to 100%. There was high significant correlation between the SUVmax uptake and the biopsy results, between the SUVmax uptake and the local staging as well as between the Gleason score and 68Ga PSMA PET/CT findings.Conclusions68Ga PSMA PET/CT is a highly promising imaging modality with an effective role in detection of prostate cancer showing high sensitivity and specificity in prediction of zonal histopathological results and loco-regional Gleason score staging with significant positive correlation between the SUV uptake results, Gleason score and the PSA levels.

The diagnostic value of prostate-specific membrane antigen PET-CT in differentiating medication-related osteonecrosis of the jaw and metastasis to the jawbone.

Medication-related osteonecrosis of the jaw (MRONJ) and jaw metastasis might share similar clinical and radiographic characteristics, with both demonstrating F-18 fluorodeoxyglucose (FDG) uptake on PET-CT. Prostate-specific membrane antigen (PSMA) PET-CT is used to demonstrate prostate cancer dissemination. Unlike FDG PET-CT, PSMA PET-CT is more specific to cancer than to inflammation. Therefore, we hypothesized that it might be a useful tool to differentiate between MRONJ and jaw metastasis. All files of prostate cancer patients diagnosed with MRONJ and with available PSMA PET-CT studies were retrieved. A similar number of solid cancer patients with MRONJ and with available FDG PET-CT studies served as a second study group. All studies were reviewed by 2 blinded co-investigators (L.D. and M.F.). Seventeen patients who underwent PSMA PET-CT (24 studies) and 15 patients who underwent FDG PET-CT (29 studies) met the inclusion criteria. All patients with FDG PET-CT studies showed pathological uptake at the site of MRONJ in at least one of their studies versus only 23.5% of patients in the PSMA PET-CT group (P < .001). FDG PET-CT studies showed pathological uptake in 89.6% of the studies compared with only 20.8% in the PSMA PET-CT group (P < .001). The mean standardized uptake value (SUVmax) and the mean uptake volume in the FDG PET-CT group were significantly higher compared with the PSMA PET-CT group (P < .001 and P < .005, respectively). The interclass correlation coefficient for all parameters was higher than 0.95. PSMA PET-CT is useful to differentiate between MRONJ and jaw metastasis.

From biology to the clinic - exploring liver metastasis in prostate cancer.

Liver metastases from prostate cancer are associated with an aggressive disease course and poor prognosis. Results from autopsy studies indicate a liver metastasis prevalence of up to 25% in patients with advanced prostate cancer. Population data estimate that ~3-10% of patients with metastatic castration-resistant prostate cancer harbour liver metastases at the baseline, rising to 20-30% in post-treatment cohorts, suggesting that selective pressure imposed by novel therapies might promote metastatic spread to the liver. Liver metastases are associated with more aggressive tumour biology than lung metastases. Molecular profiling of liver lesions showed an enrichment of low androgen receptor, neuroendocrine phenotypes and high genomic instability. Despite advancements in molecular imaging modalities such as prostate-specific membrane antigen PET-CT, and liquid biopsy markers such as circulating tumour DNA, early detection of liver metastases from prostate cancer remains challenging, as both approaches are hampered by false positive and false negativeresults, impeding the accurate identification of early liver lesions. Current therapeutic strategies showed limited efficacy in this patient population. Emerging targeted radionuclide therapies, metastasis-directed therapy, and novel systemic agents have shown preliminary activity against liver metastases, but require further validation. Treatment with various novel prostate cancer therapies might lead to an increase in the prevalence of liver metastasis, underscoring the urgent need for coordinated efforts across preclinical and clinical researchers to improve characterization, monitoring, and management of liver metastases from prostate cancer. Elucidating molecular drivers of liver tropism and interactions with the liver microenvironment might ultimately help to identify actionable targets to enhance survival in this high-risk patient group.

A comparison study of 68gallium-prostate-specific membrane antigen positron emission tomography-computed tomography and multiparametric magnetic resonance imaging for locoregional staging of prostate cancer.

Prostate cancer (PCa) is the most common malignancy in men aged 50 years and older and the second cause of cancer death among men. Accurate staging of PCa preoperatively is of high importance for treatment decisions and patient management. Conventional imaging modalities (ultrasound, computed tomography [CT], and magnetic resonance imaging) are inaccurate for the staging of PCa. Newer modality multiparametric magnetic resonance imaging (mpMRI) and prostate-specific membrane antigen (PSMA) positron emission tomography (PET) scan show promising results for the staging of PCa. Only fewer studies are available for comparison of these modalities with histopathology as reference. The objective of our study is to evaluate the diagnostic accuracy of independent 68gallium PSMA (68Ga-PSMA) PET-CT compared with mpMRI for preoperative staging of PCa, using histopathology as the reference standard. From August 2021 to December 2022, 30 patients of biopsy-proven PCa were prospectively enrolled as per eligibility criteria. Preoperatively, 68Ga-PSMA PET scan and mpMRI were done in all the patients. Extracapsular extension (ECE), seminal vesicle invasion (SVI), and lymph node metastasis (LNM) were investigated separately. Subsequently, the patients underwent robotic-assisted radical prostatectomy with bilateral pelvic lymph node dissection. mpMRI prostate was more sensitive (66.66%) but less specific than PSMA PET-CT (55.55%) for ECE. mpMRI and PSMA PET-CT both had similar sensitivity (83.3%) and specificity (87.5%) for SVI. PSMA PET-CT was more sensitive (85.71%) and specific (95.6%) than mpMRI prostate (62.5% and 91.30%, respectively) for LNM. PSMA PET-CT is more specific for the detection of ECE and more sensitive and specific for the detection of LNM than mpMRI, and similar for the detection of SVI. mpMRI provides only local staging, while PSMA PET-CT provides information about local, regional, and distal staging. Overall, PSMA PET-CT is superior to mpMRI for locoregional staging of PCa.

Location of Local Recurrences Post-Prostatectomy Detected by 18F-DCPFyL and Implications for Salvage Radiotherapy Target Volumes.

The use of prostate-specific membrane antigen (PSMA) PET scans have improved detection of recurrent prostate cancer for biochemical failure post-prostatectomy. The primary aim of this study is to assess the location of local recurrences for PSMA PET positive disease post-prostatectomy relative to anatomical landmarks and to inform salvage radiotherapy contouring guidelines. This is a retrospective study of patients who underwent a staging PSMA PET-CT scan with 18F-DCFPyL tracer. Eligible patients included men with biochemical recurrence (PSA >0.2ng/mL) post-prostatectomy for prostate adenocarcinoma. PSMA positive local disease (GTV) was marked on the CT scan of the PSMA PET/CT, using the PSMA PET scan fused as the secondary dataset. Reference structures were contoured to compare the positional relationship to the GTV local recurrence. Centroids of each GTV position were measured to the closest border of the reference structures and distance measured. Forty-five patients had a local recurrence on PSMA PET, 28/45 with prostate bed recurrence and 17/45 with seminal vesicle bed recurrence. The median age was 72.7 years, median pre-treatment PSA 0.515 ng/ml (0.2-11.1), pT2 in 37.8% and pT3 in 62.2, ISUP G2-3 was 66.7%, ISUP 4-5 29.6%, 67% ECE, 15.4% SV involvement and 40% positive margin. For prostate bed recurrences, 93.6% of GTVs were within 15mm from the inferior border of pubic symphysis (median 3.3mm [-9.8-15.4]), 83.9% within 10mm from the VUA (median 3.3mm [-17.4-15.9]), and 80.6% were greater than 10mm from the most superior slice of the penile bulb (median 16.4mm [1-29.5]). Laterally, 83.9% of recurrences were within 10mm of midline and 41.9% within 5mm (median 3.3mm [-13.56-11.59]) and all were contained within levator, 35.5% within 5mm (median 7.7 [1-22.6]) of the medial muscle border. 29.0% were within 5mm from the anterior edge of the rectal wall (median -7mm [-32.3-0.5]). Seminal vesicle bed recurrences were within 17.5mm of upper border of pubic symphysis for 88.9% of patients (median -4.69mm[-30.8to18.2]), 100% were more than 7.5mm inferiorly from the vas deferens (median-22.1mm[-32.7to-7.7]). Laterally, 100% recurrences were more than 7.5mm medial from obturator internus (median 5.37mm [-23.1to37.8]), and 88.9% were more than 10mm from midline (median 23.1mm [2.0-36.6]). The 18F-DCFPyL PSMA PET local recurrences can provide detailed localization of prostate bed and seminal vesicle recurrences. Our data can inform contouring guidelines for salvage radiotherapy to the prostate bed, particularly when using anatomical landmarks to define cranio-caudal extent of target volumes. For target volume laterally, the medial wall of levator ani would encompass all prostate bed recurrences, and no seminal vesicles recurrences were seen at the medial border of the obturator internus muscle.

Prognostic Value of End-of-Treatment PSMA PET/CT in Patients Treated with 177Lu-PSMA Radioligand Therapy: A Retrospective, Single-Center Analysis.

Our objective was to evaluate the prognostic value of end-of-treatment prostate-specific membrane antigen (PSMA) PET/CT (PSMA-PET) in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with 177Lu-PSMA radioligand therapy (PSMA-RLT). Methods: This was a single-center retrospective study. mCRPC patients who underwent PSMA-RLT with available baseline PSMA-PET (bPET) and end-of-treatment PSMA-PET (ePET) within 6 mo of the last PSMA-RLT cycle were eligible. Overall survival (OS) and prostate-specific antigen (PSA) progression status at the time of ePET (by Prostate Cancer Clinical Trials Working Group 3 criteria) were collected. PSMA-PET tumor segmentation was performed to obtain whole-body PSMA tumor volume (PSMA-VOL) and define progressive (≥20% increase) versus nonprogressive disease. Pairs of bPET and ePET were interpreted for appearance of new lesions. Response Evaluation Criteria in PSMA-PET/CT (RECIP) 1.0 were also applied to define progressive versus nonprogressive disease. The associations between changes in PSMA-VOL, new lesions, RECIP 1.0, and PSA progression status at the time of ePET with OS were evaluated by Kaplan-Meier analysis. Results: Twenty mCRPC patients were included. The median number of treatment cycles was 3.5 (interquartile range [IQR], 2-4). The median time between bPET and cycle 1 of PSMA-RLT was 1.0 mo (IQR, 0.7-1.8 mo). The median time between the last cycle of PSMA-RLT and ePET was 1.9 mo (IQR, 1.2-3.5 mo). Twelve of 20 patients (60%) had died at the last follow-up. The median follow-up time from ePET for survivors was 31.2 mo (IQR, 6.8-40.7 mo). The median OS from ePET was 11.4 mo (IQR, 6.8-30.7 mo). Patients with new lesions on ePET had shorter OS than those without new lesions (median OS, 10.7 mo [95% CI, 9.2-12.2] vs. not reached; P = 0.002). Patients with progressive PSMA-VOL had shorter OS than those with nonprogressive PSMA-VOL (median OS, 10.7 mo [95% CI: 9.7-11.7 mo] vs. not reached; P = 0.007). Patients with progressive RECIP had shorter OS than those with nonprogressive RECIP (median OS, 10.7 mo [95% CI, 9.7-11.7 mo] vs. not reached; P = 0.007). PSA progression at the time of ePET was associated with shorter OS (median, 10.9 mo [95% CI, 9.4-12.4 mo] vs. not reached; P = 0.028). Conclusion: In this retrospective study of 20 mCRPC patients treated with PSMA-RLT, progression on ePET by the appearance of new lesions, changes in PSMA-VOL, and RECIP 1.0 was prognostic for OS. Validation in larger, prospective multicentric clinical trials is warranted.

PD22-05 IS PRE OPERATIVE PSMA (PROSTATE SPECIFIC MEMBRANE ANTIGEN) PET/CT A RELIABLE PREDICTOR OF PELVIC LYMPH NODE METASTASIS IN INTERMEDIATE AND HIGH RISK LOCALISED PROSTATE CANCER:A MULTI CENTRE RETROSPECTIVE ANALYSIS

You have accessJournal of UrologyCME1 Apr 2023PD22-05 IS PRE OPERATIVE PSMA (PROSTATE SPECIFIC MEMBRANE ANTIGEN) PET/CT A RELIABLE PREDICTOR OF PELVIC LYMPH NODE METASTASIS IN INTERMEDIATE AND HIGH RISK LOCALISED PROSTATE CANCER:A MULTI CENTRE RETROSPECTIVE ANALYSIS Kishore Ta, Dinesh Cherian, Deepak Kaddu, Bikramjit Sodhi, Ravi Chandran, and Ginil Kumar Pooleri Kishore TaKishore Ta More articles by this author , Dinesh CherianDinesh Cherian More articles by this author , Deepak KadduDeepak Kaddu More articles by this author , Bikramjit SodhiBikramjit Sodhi More articles by this author , Ravi ChandranRavi Chandran More articles by this author , and Ginil Kumar PooleriGinil Kumar Pooleri More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003295.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Functional imaging techniques have been incorporated into conventional anatomical imaging to help improve identification of metastasis in normal sized nodes The primary objective of this study was to retrospectively analyse the percentage of patients “negative for metastasis” on 68Ga PSMA PETCT that translated to absent pelvic node metastasis on histopathology (Negative predictive value-NPV). The secondary objective was to analyse if pathological T stage and biopsy ISUP grades influenced the NPV of the PSMA PET CT. METHODS: A total of 217 biopsy-proven, treatment-naive, intermediate and high-risk (D’Amico classification) localised prostate cancer patients from two institutions were included in the study. All the patients had undergone a pre operative PSMA PET/ CT assessment of their pelvic lymph nodes and the patients “negative for metastasis” underwent Robotic assisted radical prostatectomy with extended pelvic lymph node dissection-ePLND. RESULTS: 49/217 patients had positive nodes despite PSMA PET/CT showing no evidence of lymph node metastasis,of which 27(55.10%) of them were obese. Thus the negative predictive value(NPV) was 77.42%. The NPV of PSMA PET CT in patients with intermediate risk prostate cancer was 86.9% compared to 71.43% in patients with high risk prostate cancer. As the ISUP biopsy grade increased the NPV decreased from 94.12% in ISUP 1 to 44.83%(p<0.0001) in ISUP 5.On retrospective analysis, all intermediate risk patients with a <pT3 stage had a 100% NPV on the PSMA PET/CT while high risk patients with a <pT3 had a NPV of 91.6%.The secondary objective was to analyse if T stage influenced the NPV .In comparison to organ confined disease(pT2) the NPV of those with disease extending beyond the prostate(pT3) was significantly lower, (80.36% vs100%) in intermediate risk and (66.97% vs 91.6%)in high risk patients. CONCLUSIONS: PSMA PET CT cannot replace e PLND with respect to accurate preoperative lymph nodal staging in intermediate and high risk prostate cancer since the NPV is below 95% (86.9%,71.43% respectively. PSMA PET CT is also not accurate with the T staging because pre operative T2 was upstaged to pT3 in 66.6 % of intermediate risk and 81.9% of high risk patients.Thus preoperative PSMA PET CT is not reliable for accurate T and N staging and e PLND should be the standard of care for precise staging in intermediate and high risk localized prostate cancer. Source of Funding: Self funded study © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e666 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kishore Ta More articles by this author Dinesh Cherian More articles by this author Deepak Kaddu More articles by this author Bikramjit Sodhi More articles by this author Ravi Chandran More articles by this author Ginil Kumar Pooleri More articles by this author Expand All Advertisement PDF downloadLoading ...

Irreversible electroporation for prostate cancer using PSMA PET-CT.

To demonstrate the clinical usefulness of prostate-specific membrane antigen (PSMA) positron emission tomography (PET) computerized tomography (CT) for irreversible electroporation (IRE) in prostate cancer patients. From January to May 2021, 17 men were diagnosed with localized prostate cancer through preoperative mpMRI and [18F] florastamin PSMA PET-CT imaging, followed by transperineal MRI-ultrasound fusion-guided biopsy. The patients underwent IRE focal therapy at the target lesions under general anesthesia. To evaluate the treatment outcome, serum prostate-specific antigen (PSA) levels were followed up in the 1st, 3rd, 6th, 9th, 12th months, and mpMRI was taken in the 1st and 12th months, followed by MR fusion biopsy in the 12th month post-IRE. The mean age of the patients was 66.1±9.3 with a median PSA of 7.5ng/ml. After the treatment, PSA nadir was 4.06±3.4, and 11 (64.7%) achieved decline of PSA more than 50% from the baseline. Rate of negative biopsy for prostate cancer is 88% (15/17) at 12monthsMR fusion biopsy after the IRE treatment. Among the relapsed cases, 1 (6.9%) patient recurred at margin of treated area, and 1 (6.9%) patient was from outfield recurrence. When excluding initial four patients, none of the patients had cancer recur. When treating with IRE focal therapy, PSMA-PET CT is a potentially valuable diagnostic approach for localizing prostate cancer; it supports the detection of lesions with conventional mpMRI, enabling to perform the procedure more completely.

PSMA Receptor-Based PET-CT: The Basics and Current Status in Clinical and Research Applications

Prostate-specific membrane antigen (PSMA) is a 100 kD, 750 amino acid (AA) long type II transmembrane glycoprotein that has a short N-terminal intracellular domain with 19 AA, 24 AA transmembrane proteins and a large C-terminal extracellular domain with 707 AA. PSMA has been mapped to chromosome 11p 11-12 in the region of the folate hydrolase gene (FOLH1) and has no known natural ligand. The protein possesses enzymatic activity-glutamate carboxypeptidase II (GCP-II)-and is thought to have role in folate uptake (FOLH1 gene). 'PSMA' expression, although significantly up-regulated in prostate carcinoma (more in high-risk and aggressive variants), is not exclusive for it and is noted in various other benign and malignant conditions, especially in the neovasculature. Currently, PSMA PET-CT is approved for high-risk and biochemically recurrent prostate carcinoma (PCa), and in patient selection for PSMA based theranostics. This review aims to highlight the clinical evolution of the PSMA molecule and PSMA PET-CT as a diagnostic modality, various indications of PSMA PET-CT, the appropriateness criteria for its use, pitfalls and artefacts, and other uses of PSMA PET apart from prostate carcinoma.

Prostate-Specific Membrane Antigen PET-CT Imaging for the Staging of Prostate Cancer in Canada

&#x0D; Health Canada approved the first prostate-specific membrane antigen (PSMA)-PET radiopharmaceutical in October 2022 for the staging of PSMA-positive lesions in those with prostate cancer. Health Canada also approved a lutetium-177 PSMA-617 therapy for patients with advanced PSMA-positive metastatic castration-resistant prostate cancer in September 2022, a therapy for which patient eligibility is identified with a gallium-68 PSMA-PET exam.&#x0D; With 57 PET-CT units in 9 provinces, access to PET-CT may be limited by the health care system’s capacity to conduct these exams due to wait lists, competing clinical priorities, and staff shortages.&#x0D; It is anticipated that the public funding of PSMA-PET across Canada will increase existing demand for PET-CT by a minimum of 23%.&#x0D; The provision of PSMA-PET would occur within the context of managing competing new demands for this service that could double existing exam volume.&#x0D; Sufficient staffing is needed to ensure sustainable operation and development of PET-CT services, supported by investment in the workforce through education and training opportunities.&#x0D; There is potential to increase the hours of operation of PET-CT units in many facilities, with consideration to the many dependencies, including staffing and the fact that the operating times of PET-CT units are closely tied to the operating times of the cyclotrons that supply the radiopharmaceuticals used in PET-CT exams.&#x0D; The upfront capital and ongoing operational costs of PET-CT, radiopharmaceutical products, and equipment may act as barriers to the further adoption of this technology.&#x0D; A combination of both generator-produced and cyclotron-produced PSMA-PET radiopharmaceuticals will likely be needed to meet the geography of Canadian jurisdictions and to secure a reliable and resilient supply chain.&#x0D;

EP019 - Importance of magnetic resonance imaging and prostate-specific membrane antigen PET-CT in patients treated with salvage radical prostatectomy for radiorecurrent prostate cancer

EP019 - Importance of magnetic resonance imaging and prostate-specific membrane antigen PET-CT in patients treated with salvage radical prostatectomy for radiorecurrent prostate cancer

Cancers and Benign Processes on 68Ga PSMA PET-CT Imaging Other than Prostate Cancer

Background Imaging plays an important role in the evaluation of prostate cancer patients. In recent years, much attention has been focused on gallium 68 prostate-specific membrane antigen positron emission tomography-computed tomography ( 68 Ga PSMA PET-CT) in prostate cancer patients and has been widely used for staging, restaging, and therapy response for these patients. The aim of this study was to report 68 Ga PSMA PET-CT in other cancers and benign processes incidentally detected on 68 Ga PSMA PET-CT in patients with prostate cancer. Materials and Methods A total of 600 68 Ga PSMA PET-CT scans were performed for initial staging, restaging, detection of suspected recurrence, and therapy response in prostate cancer patients between December 2018 and June 2020. A total of 38 patients with histopathologically proven prostate cancer were included in the current study with other malignancies and benign processes. Mainly histopathology in most of cases and clinical and radiological follow-up in few cases after PET/CT scanning served as the standard of reference. Results A total of 38 patients (age range: 52–85 years; mean age: 68.6) with prostate cancer final histopathology results were included in the study. A total of 51 lesion sites were evaluated in 38 patients. Forty-one lesion regions of these 51 regions were based on histopathological diagnosis, whereas 10 of them were based on clinical follow-up and conventional radiological follow-up as differential criteria. Thirty of 51 lesion regions were evaluated as malignant and 21 were benign lesions. The most common 68 Ga PSMA ligand avid malignancy was lung adenocarcinoma (6/38). Conclusions Prostate-specific membrane antigen (PSMA) is a cell surface glycoprotein and mainly expressed in prostate epithelium. 68 Ga PSMA PET-CT imaging is very sensitive and specific imaging modality in prostate cancer patients. However, other malignancies and some benign processes may also have 68 Ga PSMA ligand avidity and some prostate cancer metastases may imitate other malignancies.

Prostate Cancer Imaging: What We Already Know and What Is on the Horizon.

Prostate Cancer Imaging: What We Already Know and What Is on the Horizon.

Elective nodal radiotherapy in prostate cancer.

In patients with prostate cancer who have a high risk of pelvic nodal disease, the use of elective whole pelvis radiotherapy is still controversial. Two large, randomised, controlled trials (RTOG 9413 and GETUG-01) did not show a benefit of elective whole pelvis radiotherapy over prostate-only radiotherapy. In 2020, the POP-RT trial established the role of elective whole pelvis radiotherapy in patients who have more than a 35% risk of lymph node invasion (known as the Roach formula). POP-RT stressed the importance of patient selection. In patients with cN1 (clinically node positive) disease or pN1 (pathologically node positive) disease, the addition of whole pelvis radiotherapy to androgen deprivation therapy significantly improved survival compared with androgen deprivation therapy alone, as shown in large, retrospective studies. This patient population might increase in the future because use of the more sensitive prostate-specific membrane antigen PET-CT will become the standard staging procedure. Additionally, the SPORTT trial suggested a benefit of whole pelvis radiotherapy in biochemical recurrence-free survival in the salvage setting. A correct definition of the upper field border, which should include the bifurcation of the abdominal aorta, is key in the use of pelvic radiotherapy. As a result of using modern radiotherapy technology, severe late urinary and intestinal toxic effects are rare and do not seem to increase compared with prostate-only radiotherapy.

The Impact of 18F-DCFPyL PET-CT Imaging on Initial Staging, Radiation, and Systemic Therapy Treatment Recommendations for Veterans With Aggressive Prostate Cancer

PurposeOur purpose was to study the effect of 2-(3-{1-carboxy-5-[(6-[18F]fluoro-pyridine-3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid (18F-DCFPyL) positron emission tomography (PET)-computed tomography (CT) on staging/treatment recommendations of previously untreated prostate cancer. We report here results of a prospective single center single arm imaging trial within Veterans Affairs (Greater Los Angeles): the frequency of patients upstaged to M1 disease (primary endpoint) and the frequency of patients with change in treatment recommendations (secondary endpoint). This is the first report of prostate-specific membrane antigen PET-CT exclusive to U.S. veterans. Methods and MaterialsVeterans with Gleason ≥4 + 3, clinical stage ≥T2c, or prostate-specific antigen >10 ng/mL were eligible. Patients underwent conventional imaging (99mTc-methyl diphosphonate bone scan or 18F-NaF PET-CT; and pelvic CT or pelvic magnetic resonance imaging) in addition to 18F-DCFPyL PET-CT. The effect of 18F-DCFPyL PET-CT on treatment change was determined by applying prespecified treatment recommendations based on National Comprehensive Cancer Network guidelines and modern clinical practice. ResultsOne hundred patients underwent 18F-DCFPyL PET-CT. Nineteen out of 84 (23%) patients initially thought to be nonmetastatic were upstaged to M1; 8/16 (50%) patients initially thought to have M1 disease were downstaged to M0. In total, 39/100 (39%) had a change in prespecified treatment recommendations, including change of radiation therapy volume/dose in 39/100 (39%) and starting abiraterone in 22/100 (22%). ConclusionsIncorporation of 18F-DCFPyL PET-CT into the initial conventional imaging workup for prostate cancer can substantially affect staging/treatment recommendations.

Comparing the Diagnostic Performance of Multiparametric Prostate MRI Versus 68Ga-PSMA PET-CT in the Evaluation Lymph Node Involvement and Extraprostatic Extension

Our research aims to compare the efficacy of PET and MRI for lymph node metastasis and extraprostatic extension in cases with newly diagnosed prostate cancer undergoing radical prostatectomy with extended pelvic lymph node dissection. Thirty-nine cases who underwent radical prostatectomy with pelvic lymph node dissection between June 2015 and January 2020 were included in the study. Patients with gallium (ga-68 Prostate-specific membrane antigen (PSMA) PET) PSMA PET-CT and multiparametric (mp) prostate MRI performed according to PIRADS v2 criteria in our clinic were included. The extraprostatic extension was observed in 16 cases. The sensitivity of MR in detecting extracapsular invasion was calculated as 56.2%, specificity 82.6%, positive predictive value (PPV) 69.2%, negative predictive value (NPV) 73.0%. The sensitivity of PET was 62.5%, specificity 60.8%, PPV 52.6%, NPV 70%. Eleven lymph node metastases were observed in nine cases. The sensitivity, specificity, PPV and NPV of metastatic lymph node detection were; 36.3%, 99.6%, 57.1%, 99.0% for MRI and; 18.1%, 99.4%, 33.3%, 98.8% for PET CT, respectively. Mp prostate MRI showed low sensitivity and high specificity compared to PSMA PET CT in extracapsular invasion evaluation. The sensitivity of both modalities in the detection of metastatic lymph nodes was low.

Peritumoral/vascular expression of PSMA as a diagnostic marker in hepatic lesions

BackgroundThe differential diagnosis between primary cholangiocarcinoma and metastatic pancreatobiliary adenocarcinoma is histologically challenging due to lack of distinct morphological features and reliable molecular markers. Prostate-specific membrane antigen (PSMA) is expressed in prostate epithelium and upregulated on the surface of prostatic adenocarcinoma cells. Studies have shown PSMA enzymatic activity is involved in malignancy-driven neoangiogenesis in the endothelium of tumor-associated neovasculature in breast, lung, thyroid, hepatocellular carcinoma (HCC) and urothelial cancer. Recently, PSMA-targeted imaging technology (PSMA PET-CT) detected the presence of PSMA in primary cholangiocarcinoma. However histological correlation with PSMA expression other mass lesions in the liver has not yet been studied.Methods72 cases of liver mass resection were collected at a tertiary hospital from 2011 to 2019. Immunohistochemical stains for PSMA and CD34 were performed. The expression of PSMA in tumor cells and associated neovascular endothelium were analyzed separately and the locations of vascular structures were confirmed by CD34 expression.ResultsAmong 72 cases, 28 cases (22/72, 38.9%) showed PSMA peritumoral/vascular expression only, 3 cases (3/72, 4.2%) showed tumor cell expression only, and 2 cases (2/72, 2.8%) showed both tumor cell and peritumoral/vascular expression. The remainder (39/72, 54.2%) showed no expression. Particularly, most of primary cholangiocarcinoma showed PSMA vascular expression (13/15, 86.7%), while none of the 18 cases of metastatic pancreatobiliary adenocarcinoma were positive for PSMA (0/18, 0%) (p < 0.01). Outside of pancreatobiliary adenocarcinoma, none of the metastatic tumors, including colon and lung cancers, expressed PSMA. In 8 cases of metastatic prostate carcinoma, 3 showed PSMA expressions in tumor cells only (3/8, 37.5%) and 2 expressed PMSA in both tumor cells and neovasculature (2/8, 25.0%). Out of 22 HCC cases, 15 (15/22, 68.2%) were positive for PSMA in tumor vasculature. None of the 5 hepatic adenoma expressed PSMA (0/5, 0%).ConclusionSignificantly enhanced tumor-associated neovascular PSMA expression was identified in primary cholangiocarcinoma, compared to metastatic pancreatobiliary adenocarcinoma. Our findings potentially provide a sensitive marker in differential diagnosis between otherwise morphologically indistinguishable cases.

High Accuracy of PSMA PET in Initial Staging of High-Risk Prostate Cancer.

HomeRadiology: Imaging CancerVol. 2, No. 4 PreviousNext Research HighlightsFree AccessHigh Accuracy of PSMA PET in Initial Staging of High-Risk Prostate CancerJoseph Waller, Robert Flavell, Courtney Lawhn HeathJoseph Waller, Robert Flavell, Courtney Lawhn HeathJoseph WallerRobert FlavellCourtney Lawhn HeathPublished Online:Jul 31 2020https://doi.org/10.1148/rycan.2020204025MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In Take-Away Points■ Major Focus: This prospective randomized study aimed to compare the diagnostic utility of conventional imaging for initial staging of high-risk prostate cancer (CT and bone scintigraphy) with gallium 68 (68Ga) prostate-specific membrane antigen (PSMA)-11 PET/CT.■ Key Result: Compared to conventional imaging, 68Ga-PSMA-11 PET/CT resulted in fewer equivocal imaging findings, less radiation exposure (8.4 mSv vs 19.2 mSv), and greater sensitivity (85% vs 38%) and specificity (98% vs 91%).■ Impact: The results of prospective randomized studies, such as ProPSMA, may lead to the incorporation of PSMA PET into standard clinical management guidelines for the initial staging of prostate cancer due to its superior diagnostic accuracy over conventional imaging.Prostate-specific membrane antigen (PSMA)–targeted PET is being increasingly used for localizing high-risk prostate cancer. Extensive evidence of its diagnostic use has led to the incorporation of PSMA PET into management guidelines for biochemically recurrent prostate cancer, but until recently there was insufficient evidence to effect a change in guidelines in other settings such as initial staging. The proPSMA study is a randomized controlled trial comparing the accuracy and diagnostic utility of conventional imaging (namely, CT and bone scintigraphy) with that of gallium 68 (68Ga)-PSMA-11 PET/CT for the initial staging of prostate cancer. The patient cohort included 300 men (mean age, 69.0 years) with histopathologically confirmed prostate cancer who were under consideration for prostatectomy or radiotherapy. Each patient was randomized to initially undergo either conventional imaging (control group) or PSMA PET/CT within 21 days of randomization. Then, all men who did not have greater than three unequivocal distant metastases underwent second-line crossover imaging 6 months later.PSMA PET/CT had an accuracy (calculated as the mean of the sensitivity and specificity) of 92% compared to 65% for conventional imaging. This 27% difference reflects the finding that, compared to conventional imaging, PSMA PET/CT had both a higher sensitivity (85% vs 38%) and specificity (98% vs 91%) for metastases than conventional imaging. Additionally, results demonstrated that PSMA PET/CT resulted in fewer equivocal imaging findings than conventional imaging for metastatic disease and pelvic nodes. PSMA PET/CT also resulted in less radiation exposure than conventional imaging (a mean of 8.4 mSv vs 19.2 mSv). Neither PSMA PET/CT nor conventional imaging was associated with any adverse events. Finally, patients who underwent first-line PSMA PET/CT imaging also resulted in a higher percentage of high-effect or medium-effect management changes (28%) compared to conventional imaging (15%). High-effect changes were defined as changes in management intent (eg, curative to palliative), while medium-effect changes were changes in modality delivery.Together, these results demonstrate that PSMA PET/CT has superior diagnostic accuracy for prostate cancer compared to conventional imaging. As a whole, the findings of this study demonstrate that PSMA PET/CT is a viable replacement for conventional imaging for prostate cancer and suggest that PSMA PET has value for incorporation into standard clinical management guidelines for the initial staging of prostate cancer.Highlighted ArticleHofman MS, Lawrentschuk N, Francis RJ, et al. Prostate-specific membrane antigen PET-CT in patients with high-risk prostate cancer before curative-intent surgery or radiotherapy (proPSMA): a prospective, randomised, multicentre study. Lancet 2020;395(10231):1208–1216. doi: https://doi.org/10.1016/S0140-6736(20)30314-7Highlighted ArticleHofman MS, Lawrentschuk N, Francis RJ, et al. Prostate-specific membrane antigen PET-CT in patients with high-risk prostate cancer before curative-intent surgery or radiotherapy (proPSMA): a prospective, randomised, multicentre study. Lancet 2020;395(10231):1208–1216. doi: https://doi.org/10.1016/S0140-6736(20)30314-7 Crossref, Medline, Google ScholarArticle HistoryPublished online: July 31 2020 FiguresReferencesRelatedDetailsRecommended Articles Impact of 18F-DCFPyL PET on Staging and Treatment of Unfavorable Intermediate or High-Risk Prostate CancerRadiology2022Volume: 304Issue: 3pp. 600-608Clinical PET Imaging in Prostate CancerRadioGraphics2017Volume: 37Issue: 5pp. 1512-1536Prostate-specific Membrane Antigen PET in Prostate CancerRadiology2021Volume: 299Issue: 2pp. 248-260PSMA-targeted Radiotracers versus 18F Fluciclovine for the Detection of Prostate Cancer Biochemical Recurrence after Definitive Therapy: A Systematic Review and Meta-AnalysisRadiology2020Volume: 296Issue: 1pp. 44-55Gallium 68 PSMA-11 PET/MR Imaging in Patients with Intermediate- or High-Risk Prostate CancerRadiology2018Volume: 288Issue: 2pp. 495-505See More RSNA Education Exhibits 68Ga PSMA PET/CT and PET/MR for Prostate Cancer Metastasis: Beyond Lymphatic and Bone DisseminationDigital Posters2018PSMA PET Imaging for Detection and Primary Staging of Prostate Cancer: Incremental Value Over Conventional Imaging Work-UpDigital Posters2019The Whole is Greater Than the Sum of Its Parts:Â WB-MRI in Metastatic Prostate CancerDigital Posters2018 RSNA Case Collection Locally advanced, metastatic prostate adenocarcinomaRSNA Case Collection2020Parasagittal meningiomaRSNA Case Collection2022Bisphosphonate Induced Mandibular OsteonecrosisRSNA Case Collection2020 Vol. 2, No. 4 Metrics Altmetric Score PDF download

Detecting Metastatic Prostate Cancer with Prostate-Specific Membrane Antigen PET-CT

The limitations in sensitivity and specificity of conventional imaging using computed tomography (CT) and bone scans in staging patients with locally

Prostate-specific membrane antigen PET-CT in patients with high-risk prostate cancer before curative-intent surgery or radiotherapy (proPSMA): a prospective, randomised, multicentre study

Conventional imaging using CT and bone scan has insufficient sensitivity when staging men with high-risk localised prostate cancer. We aimed to investigate whether novel imaging using prostate-specific membrane antigen (PSMA) PET-CT might improve accuracy and affect management. In this multicentre, two-arm, randomised study, we recruited men with biopsy-proven prostate cancer and high-risk features at ten hospitals in Australia. Patients were randomly assigned to conventional imaging with CT and bone scanning or gallium-68 PSMA-11 PET-CT. First-line imaging was done within 21 days following randomisation. Patients crossed over unless three or more distant metastases were identified. The primary outcome was accuracy of first-line imaging for identifying either pelvic nodal or distant-metastatic disease defined by the receiver-operating curve using a predefined reference-standard including histopathology, imaging, and biochemistry at 6-month follow-up. This trial is registered with the Australian New Zealand Clinical Trials Registry, ANZCTR12617000005358. From March 22, 2017 to Nov 02, 2018, 339 men were assessed for eligibility and 302 men were randomly assigned. 152 (50%) men were randomly assigned to conventional imaging and 150 (50%) to PSMA PET-CT. Of 295 (98%) men with follow-up, 87 (30%) had pelvic nodal or distant metastatic disease. PSMA PET-CT had a 27% (95% CI 23-31) greater accuracy than that of conventional imaging (92% [88-95] vs 65% [60-69]; p<0·0001). We found a lower sensitivity (38% [24-52] vs 85% [74-96]) and specificity (91% [85-97] vs 98% [95-100]) for conventional imaging compared with PSMA PET-CT. Subgroup analyses also showed the superiority of PSMA PET-CT (area under the curve of the receiver operating characteristic curve 91% vs 59% [32% absolute difference; 28-35] for patients with pelvic nodal metastases, and 95% vs 74% [22% absolute difference; 18-26] for patients with distant metastases). First-line conventional imaging conferred management change less frequently (23 [15%] men [10-22] vs 41 [28%] men [21-36]; p=0·008) and had more equivocal findings (23% [17-31] vs 7% [4-13]) than PSMA PET-CT did. Radiation exposure was 10·9 mSv (95% CI 9·8-12·0) higher for conventional imaging than for PSMA PET-CT (19·2 mSv vs 8·4 mSv; p<0·001). We found high reporter agreement for PSMA PET-CT (κ=0·87 for nodal and κ=0·88 for distant metastases). In patients who underwent second-line image, management change occurred in seven (5%) of 136 patients following conventional imaging, and in 39 (27%) of 146 following PSMA PET-CT. PSMA PET-CT is a suitable replacement for conventional imaging, providing superior accuracy, to the combined findings of CT and bone scanning. Movember and Prostate Cancer Foundation of Australia. VIDEO ABSTRACT.