Pictorial essay: normal variants, lesions, and pitfalls in 68Ga-PSMA PET imaging of prostate cancer

2018 ◽  
Vol 6 (3) ◽  
pp. 239-247 ◽  
Author(s):  
Alessandro Lambertini ◽  
Paolo Castellucci ◽  
Andrea Farolfi ◽  
Stefano Fanti
2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Lindsay S. Rowe ◽  
Stephanie Harmon ◽  
Adam Horn ◽  
Uma Shankavaram ◽  
Soumyajit Roy ◽  
...  

Abstract Background Prostate Membrane Specific Antigen (PSMA) positron emission tomography (PET) and multiparametric MRI (mpMRI) have shown high accuracy in identifying recurrent lesions after definitive treatment in prostate cancer (PCa). In this study, we aimed to outline patterns of failure in a group of post-prostatectomy patients who received adjuvant or salvage radiation therapy (PORT) and subsequently experienced biochemical recurrence, using 18F-PSMA PET/CT and mpMRI. Methods PCa patients with biochemical failure post-prostatectomy, and no evident site of recurrence on conventional imaging, were enrolled on two prospective trials of first and second generation 18F-PSMA PET agents (18F-DCFBC and 18F-DCFPyL) in combination with MRI between October 2014 and December 2018. The primary aim of our study is to characterize these lesions with respect to their location relative to previous PORT field and received dose. Results A total of 34 participants underwent 18F-PSMA PET imaging for biochemical recurrence after radical prostatectomy and PORT, with 32/34 found to have 18F-PSMA avid lesions. On 18F-PSMA, 17/32 patients (53.1%) had metastatic disease, 8/32 (25.0%) patients had locoregional recurrences, and 7/32 (21.9%) had local failure in the prostate fossa. On further exploration, we noted 6/7 (86%) of prostate fossa recurrences were in-field and were encompassed by 100% isodose lines, receiving 64.8–72 Gy. One patient had marginal failure encompassed by the 49 Gy isodose. Conclusions 18F-PSMA PET imaging demonstrates promise in identifying occult PCa recurrence after PORT. Although distant recurrence was the predominant pattern of failure, in-field recurrence was noted in approximately 1/5th of patients. This should be considered in tailoring radiotherapy practice after prostatectomy. Trial registrationwww.clinicaltrials.gov, NCT02190279 and NCT03181867. Registered July 12, 2014, https://clinicaltrials.gov/ct2/show/NCT02190279 and June 8 2017, https://clinicaltrials.gov/ct2/show/NCT03181867.


2021 ◽  
Author(s):  
Teli Liu ◽  
Chen Liu ◽  
Zhongyi Zhang ◽  
Ning Zhang ◽  
Xiaoyi Guo ◽  
...  

Abstract PurposeDevelop a 64Cu labeled radiopharmaceutical targeting prostate specific membrane antigen (PSMA) and investigate its application for prostate cancer imaging. Methods64Cu-PSMA-BCH was prepared and investigated for stability, PSMA specificity and micro-PET imaging. With the approval of Ethics Committee of Beijing Cancer Hospital (No. 2017KT97), PET/CT imaging in 4 patients with suspected prostate cancer was performed and the radiation dosimetry was estimated. Then, PSMA PET-ultrasound image-guided biopsies were performed on 3 patients and the fine needle aspirates were further performed for autoradiography and immunohistochemistry analysis. Results64Cu-PSMA-BCH was prepared with high radiochemical yield and stability. In vivo study showed higher uptake in PSMA (+) 22Rv1 cells than PSMA (-) PC-3 cells (5.59±0.36 and 1.97±0.22 IA%/106 cells at 1 h). It accumulated in 22Rv1 tumor with increasing radioactivity uptake and T/N ratios from 1 h to 24 h post-injection. In patients with suspected prostate cancer, SUVmax and T/N ratios increased within 24 h post-injection. Compared with image at 1 h post-injection, more tumor lesions were detected at 4 h and 24 h post-injection. The human organ radiation dosimetry showed gallbladder wall was most critical, liver and kidneys were followed, and the whole-body effective dose was 0.0292 mSv/MBq. Two fine needle aspirates obtained by PET-ultrasound guided targeted biopsy showed high radioactive signal by autoradiography, with 100% PSMA expression in cytoplasm and 30% expression in nucleus. Conclusion64Cu-PSMA-BCH was PSMA specific and showed high stability in vivo with lower uptake in liver than 64Cu-PSMA-617. Biodistribution in mice and PCa patients showed similar profile compared with other PSMA ligands and it was safe with moderate effective dosimetry. The increased tumor uptake and T/N ratios by delayed imaging may facilitate the detection of small lesions and guiding targeted biopsies.


Author(s):  
Katharina Kessel ◽  
Robert Seifert ◽  
Matthias Weckesser ◽  
Martin Boegemann ◽  
Sebastian Huss ◽  
...  

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.


2018 ◽  
Vol 127 ◽  
pp. S433-S434
Author(s):  
K. Schiller ◽  
M. Devecka ◽  
T. Maurer ◽  
M. Eiber ◽  
S.E. Combs ◽  
...  

2021 ◽  
Vol 11 ◽  
Author(s):  
Marco M. E. Vogel ◽  
Sabrina Dewes ◽  
Eva K. Sage ◽  
Michal Devecka ◽  
Kerstin A. Eitz ◽  
...  

IntroductionProstate-specific membrane antigen-positron emission tomography-(PSMA-PET) imaging facilitates dose-escalated salvage radiotherapy (DE-SRT) with simultaneous-integrated boost (SIB) for PET-positive lesions in patients with prostate cancer (PC). Therefore, we aimed to compare toxicity rates of DE-SRT with SIB to conventional SRT (C-SRT) without SIB and to report outcome.Materials and MethodsWe evaluated 199 patients who were treated with SRT between June 2014 and June 2020. 101 patients received DE-SRT with SIB for PET-positive local recurrence and/or PET-positive lymph nodes. 98 patients were treated with C-SRT to the prostate bed +/− elective pelvic lymphatic pathways without SIB. All patients received PSMA-PET imaging prior to DE-SRT ([68Ga]PSMA-11: 45.5%; [18F]-labeled PSMA: 54.5%). Toxicity rates for early (<6 months) and late (>6 months) gastrointestinal (GI) toxicities rectal bleeding, proctitis, stool incontinence, and genitourinary (GU) toxicities hematuria, cystitis, urine incontinence, urinary obstruction, and erectile dysfunction were assessed. Further, we analyzed the outcome with disease-free survival (DFS) and prostate-specific antigen (PSA) response.ResultsThe overall toxicity rates for early GI (C-SRT: 2.1%, DE-SRT: 1.0%) and late GI (C-SRT: 1.4%, DE-SRT: 5.3%) toxicities ≥ grade 2 were similar. Early GU (C-SRT: 2.1%, DE-SRT: 3.0%) and late GU (C-SRT: 11.0%, DE-SRT: 14.7%) toxicities ≥ grade 2 were comparable, as well. Early and late toxicity rates did not differ significantly between DE-SRT versus C-SRT in all subcategories (p>0.05). PSA response (PSA ≤0.2 ng/ml) in the overall group of patients with DE-SRT was 75.0% and 86.4% at first and last follow-up, respectively.ConclusionDE-SRT showed no significantly increased toxicity rates compared with C-SRT and thus is feasible. The outcome of DE-SRT showed good results. Therefore, DE-SRT with a PSMA-PET-based SIB can be considered for the personalized treatment in patients with recurrent PC.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 5065-5065
Author(s):  
Judith Stangl-Kremser ◽  
Sazan Rasul ◽  
Jeffrey J. Tosoian ◽  
Simpa Salami ◽  
Alexander Zaslavsky ◽  
...  

5065 Background: The recent introduction of Lu-177 PSMA for the treatment of castration-resistant prostate cancer (CRPC) has been met with much excitement. Initial reports of clinical response are promising, despite known inter- and intra-patient molecular heterogeneity. In this study, we examined the utility of PSMA protein expression in metastatic tumor tissues as a predictor of lesion-specific response to Lu-177 PSMA therapy in men with CRPC. Methods: Between 2015-2020, 19 patients with metastases at multiple sites underwent metastatic lesion biopsy, Ga-68 PSMA PET imaging, and subsequent treatment with three cycles of Lu-177 PSMA. A monoclonal anti-PSMA antibody (EPITOMICS (USA), 1:50) was used to semi-quantitatively assess PSMA protein expression in the biopsy specimen. The histoscore (range 0-300) was derived from intensity and extent of the immunohistochemistry staining and was determined by experienced genitourinary pathologists. Imaging evaluation was performed according to the Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST) criteria. We assessed the association of the PSMA protein expression in metastatic tumor tissues and the lesion-specific response to Lu-177 PSMA therapy. Results: In 12 patients with biopsy specimens available for staining, PSMA expression correlated with enhancement (SUVmax) of the biopsy site on Ga-68 PSMA PET imaging (rs = 0.63). Of the nine patients with repeat imaging after Lu-177 PSMA therapy, five (55.6%) had a lesion-specific response at the site of biopsy. PSMA expression on immunohistochemistry was unable to accurately predict lesion-specific response in univariable analysis (p = 0.81, 95% CI 94.6-76.6). Among the five men with a lesion-specific response, three (60%) experienced overall progression based on PERCIST. There was no association between lesion-specific response and overall progression (p = 0.64). Conclusions: In patients with multiple metastases, PSMA protein expression from a single site biopsy was not predictive of site-specific Lu-177 PSMA response based on PERCIST. Additional studies are necessary to further interrogate the clinical consequence of PSMA expression heterogeneity in metastatic sites as well as the mechanisms underpinning resistance to Lu-177 PSMA in patients with CRPC.


Author(s):  
S.Y. Wu ◽  
L. Boreta ◽  
M. Roach ◽  
F.Y. Feng ◽  
A. Wu ◽  
...  

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