scholarly journals Day-to-day variability of [68Ga]Ga-PSMA-11 accumulation in primary prostate cancer: effects on tracer uptake and visual interpretation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Judith olde Heuvel ◽  
Berlinda J. de Wit-van der Veen ◽  
Maarten L. Donswijk ◽  
Cornelis H. Slump ◽  
Marcel P. M. Stokkel
Keyword(s):  
Prostate Cancer ◽  
Blood Pool ◽  
Prostate Tumor ◽  
Ct Scans ◽  
Response Monitoring ◽  
Clinical Indication ◽  
Repeatability Coefficient ◽  
Normal Tissues ◽  
Psma Pet ◽  
Pet Ct

Abstract Purpose Prostate-specific membrane antigen (PSMA) agents, such as [68Ga]Ga-PSMA-11, have an unprecedented accuracy in staging prostate cancer (PCa) and detecting disease recurrence. PSMA PET/CT may also be used for response monitoring by displaying molecular changes, instead of morphological changes alone. However, there are still limited data available on the variability in biodistribution and intra-prostatic uptake of PSMA targeting radiotracers. Therefore, the aim of this study was to assess the repeatability of [68Ga]Ga-PSMA-11 uptake in primary PCa patients in a 4-week interval. Methods Twenty-four primary PCa patients were prospectively included, who already were scheduled for [68Ga]Ga-PSMA-11 PET/CT scan on clinical indication (≥ cT3, Gleason score ≥ 7 or PSA ≥ 20 ng/mL). These patients received two [68Ga]Ga-PSMA-11 PET/CT scans with a 4-week interval. No treatment was started in between the scans. Semiquantitative measurements (SULmax, SULmean, and SULpeak) were determined in the prostate tumor, normal tissues, and blood pool. The repeatability coefficient of every region was determined. All scans were visually analyzed by two nuclear medicine physicians. Results Within-subject coefficient of variation of [68Ga]Ga-PSMA-11 uptake between the two scans was on average 10% in the prostate tumor, normal tissues (liver, kidney, parotid), and blood pool. The repeatability coefficient of the prostate tumor was 18% for SULpeak and 22% for SULmax. Lesion uptake was visually different in 5 patients, though not clinically relevant. Conclusion Results of test-retest [68Ga]Ga-PSMA-11 PET/CT scans in a 4-week interval show that [68Ga]Ga-PSMA-11 uptake is repeatable, with a clinical irrelevant variation in tumor and physiological distribution. Based on the presented repeatable uptake, [68Ga]Ga-PSMA-11 PET/CT scans can potentially be used for disease surveillance and therapy response monitoring. Changes in uptake larger than the RC are therefore likely to reflect actual biological changes in PSMA expression. Trial registration NL8263 at Trialregister.nl retrospectively registered on 03-01-2020. https://www.trialregister.nl/trial/8263

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

2019 ◽  
Vol 11 ◽  
pp. 175628721881579 ◽  
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.

68Ga-DOTA-Bombesin (68Ga-RM2 or 68Ga-Bombesin) PET versus 68Ga-PSMA PET: A pilot prospective evaluation in patients with biochemical recurrence of prostate cancer.

2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 331-331
Author(s):  
Andrei Iagaru ◽  
Ryogo Minamimoto ◽  
Steven Lee Hancock ◽  
Erik Mittra ◽  
Andreas Loening ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Renal Clearance ◽  
Biochemical Recurrence ◽  
Conventional Imaging ◽  
Normal Tissues ◽  
Psma Pet ◽  
Pet Ct ◽  
Small Cohort ◽  
Bombesin Receptor ◽  
Fdg Pet Ct

331 Background: Detection of prostate cancer (PC) after biochemical recurrence (BCR) remains a great challenge. RM2 is a synthetic bombesin receptor antagonist, which targets gastrin-releasing peptide receptors (GRPr). PSMA is a membrane antigen expressed on prostate cancer cells. Here we present a comparison of 2 novel PET tracers, 68Ga-RM2 and 68Ga-PSMA, in patients with BCR with prior non-contributory conventional imaging. Methods: Ten men (67-83 year-old; mean ± SD: 74.3 ± 5.9) with BCR PC were imaged with 68Ga-RM2 and 7 of them also had 68Ga-PSMA PET. The SUVmax and SUVmean measurements were recorded in normal tissues and areas of uptake outside the expected physiologic biodistribution. Results: All 7 patients who had both scans had rising PSA (range: 3.5-36.5 ng/mL; mean±SD: 13.5 ± 11.5) and non-contributory conventional imaging (CT, MRI, 18F FDG PET/CT, 18F NaF PET/CT, 99mTc MDP bone scan). 68Ga-PSMA had the highest physiologic uptake in the salivary glands and small bowel, with hepatobiliary and renal clearance noted, while 68Ga-RM2 had the highest physiologic uptake in the pancreas, with renal clearance noted. Uptake values uptake outside the expected physiologic biodistribution were not statistically different between 68Ga-PSMA and 68Ga-RM2. 68Ga-PSMA localized in a lymph node and seminal vesicle in one patient with no abnormal 68Ga-RM2 uptake. In 2 patients abdominal peri-aortic lymph nodes were more easily visualized by 68Ga-RM2 due to lack of interference by radioactivity accumulation in the small intestine. Conclusions: 68Ga-PSMA and 68Ga-RM2 have distinct biodistribution in this small cohort of patients with BCR PC. High uptake in multiple areas outside the expected physiologic biodistribution suggests that both 68Ga-PSMA and 68Ga-RM2 are promising PET radiopharmaceuticals for localization of disease in patients with BCR PC and non-contributory conventional imaging. The differences in target density, biodistribution and clearance pathways may result in the superiority of one of the two tracers in different patients. 68Ga-RM2 shows similar sensitivity to 68Ga-PSMA and has the potential for being FDA-approved in the future. Clinical trial information: NCT02440308.

scholarly journals Metabolic Tumour Volume from PSMA PET/CT Scans of Prostate Cancer Patients during Chemotherapy—Do Different Software Solutions Deliver Comparable Results?

2020 ◽  
Vol 9 (5) ◽  
pp. 1390
Author(s):  
Philipp E. Hartrampf ◽  
Marieke Heinrich ◽  
Anna Katharina Seitz ◽  
Joachim Brumberg ◽  
Ioannis Sokolakis ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Therapy Response ◽  
Tumour Volume ◽  
Ct Scans ◽  
Metabolic Tumour Volume ◽  
Positron Emission ◽  
Psma Pet ◽  
Pet Ct ◽  
Before And After ◽  
Statistical Comparability

(1) Background: Prostate-specific membrane antigen (PSMA)-derived tumour volume (PSMA-TV) and total lesion PSMA (TL-PSMA) from PSMA PET/CT scans are promising biomarkers for assessing treatment response in prostate cancer (PCa). Currently, it is unclear whether different software tools for assessing PSMA-TV and TL-PSMA produce comparable results. (2) Methods: 68Ga-PSMA PET/CT scans from n = 21 patients with castration-resistant PCa (CRPC) receiving chemotherapy were identified from our single-centre database. PSMA-TV and TL-PSMA were calculated with Syngo.via (Siemens) as well as the freely available Beth Israel plugin for FIJI (Fiji Is Just ImageJ) before and after chemotherapy. While statistical comparability was illustrated and quantified via Bland-Altman diagrams, the clinical agreement was estimated by matching PSMA-TV, TL-PSMA and relative changes of both variables during chemotherapy with changes in serum PSA (ΔPSA) and PERCIST (Positron Emission Response Criteria in Solid Tumors). (3) Results: Comparing absolute PSMA-TV and TL-PSMA as well as Bland–Altman plotting revealed a good statistical comparability of both software algorithms. For clinical agreement, classifying therapy response did not differ between PSMA-TV and TL-PSMA for both software solutions and showed highly positive correlations with BR. (4) Conclusions: due to the high levels of statistical and clinical agreement in our CRPC patient cohort undergoing taxane chemotherapy, comparing PSMA-TV and TL-PSMA determined by Syngo.via and FIJI appears feasible.

The effect of androgen deprivation therapy on 68GA-PSMA-tracer uptake in nonmetastatic prostate cancer patients.

2020 ◽  
Vol 38 (6_suppl) ◽  
pp. 22-22
Author(s):  
Onal Cem ◽  
Ozan Cem Guler ◽  
Nese Torun ◽  
Mehmet Reyhan ◽  
Ali Fuat Yapar
Keyword(s):  
Prostate Cancer ◽  
Cancer Patients ◽  
Tracer Uptake ◽  
Androgen Deprivation ◽  
Post Treatment ◽  
Ct Scans ◽  
Baseline Serum ◽  
Psma Pet ◽  
Pet Ct ◽  
Psa Response

22 Background: To evaluate the effect of neoadjuvant androgen deprivation treatment (ADT) on prostate specific membrane antigen (PSMA) tracer uptake demonstrated in 68Ga-PSMA-positron emission tomography (PET/CT) in non-metastatic hormone-naïve prostate cancer patients. Methods: The clinical data of 108 prostate cancer patients who received neoadjuvant ADT were retrospectively analyzed. All patients had a baseline 68Ga-PSMA-PET/CT scan and a second scan was delivered median of 2.9 months after initiation of ADT. Patients with clinical and radiological evidence of distant metastasis were excluded from the study. The maximum standardized uptake value (SUVmax) of primary tumor (SUVp) and metastatic lymph nodes (SUVln) as well as PSA response were assessed between pre- and post-ADT 68Ga-PSMA-PET/CT scans. Results: The median SUVp and SUVln were 14.0 (range, 4.9 – 78.4) and 13.2 (range, 3.6 – 64.5), respectively. There was a significant moderate correlation between baseline serum PSA and SUVp (Spearman = 0.513, p<0.001). There were significant decreases in post-treatment serum PSA, SUVp, and SUVp. A decrease in SUVp was seen in 91 patients (84%) with a median value of 66% (range, 5% – 100%), while 17 patients (16%) had no change in or an increase in PSMA tracer uptake with a median value of 24% (range, 0% – 198%). Patients with Gleason score (GS) of 7 had significantly higher metabolic response rates compared to other patients. The disease progression was significantly higher only in patients with GS > 7 disease compared to GS 7 disease. The PSA response to ADT was lowest in patients with ISUP high-grade tumors. A total of 16 patients (15%) had progressive disease, and in 9 patients (8%), radiotherapy decisions were modified according to post-treatment 68Ga-PSMA-PET/CT scans. Conclusions: The current study includes the largest number of patients analyzed to date and demonstrates that ADT causes a significant decrease in serum PSA values and SUVp and SUVln. The authors demonstrate that 68Ga-PSMA-PET/CT may be used as a quantitative imaging modality after neoadjuvant ADT in hormone-naïve non-metastatic PC patients.

scholarly journals Analytical performance of aPROMISE: automated anatomic contextualization, detection, and quantification of [18F]DCFPyL (PSMA) imaging for standardized reporting

2021 ◽  
Author(s):  
Kerstin Johnsson ◽  
Johan Brynolfsson ◽  
Hannicka Sahlstedt ◽  
Nicholas G. Nickols ◽  
Matthew Rettig ◽  
...  
Keyword(s):  
Deep Learning ◽  
Lymph Nodes ◽  
Low Dose ◽  
Learning Algorithm ◽  
Blood Pool ◽  
Ct Scans ◽  
Deep Learning Algorithm ◽  
Psma Pet ◽  
Pet Ct ◽  
Standardized Reporting

Abstract Purpose The application of automated image analyses could improve and facilitate standardization and consistency of quantification in [18F]DCFPyL (PSMA) PET/CT scans. In the current study, we analytically validated aPROMISE, a software as a medical device that segments organs in low-dose CT images with deep learning, and subsequently detects and quantifies potential pathological lesions in PSMA PET/CT. Methods To evaluate the deep learning algorithm, the automated segmentations of the low-dose CT component of PSMA PET/CT scans from 20 patients were compared to manual segmentations. Dice scores were used to quantify the similarities between the automated and manual segmentations. Next, the automated quantification of tracer uptake in the reference organs and detection and pre-segmentation of potential lesions were evaluated in 339 patients with prostate cancer, who were all enrolled in the phase II/III OSPREY study. Three nuclear medicine physicians performed the retrospective independent reads of OSPREY images with aPROMISE. Quantitative consistency was assessed by the pairwise Pearson correlations and standard deviation between the readers and aPROMISE. The sensitivity of detection and pre-segmentation of potential lesions was evaluated by determining the percent of manually selected abnormal lesions that were automatically detected by aPROMISE. Results The Dice scores for bone segmentations ranged from 0.88 to 0.95. The Dice scores of the PSMA PET/CT reference organs, thoracic aorta and liver, were 0.89 and 0.97, respectively. Dice scores of other visceral organs, including prostate, were observed to be above 0.79. The Pearson correlation for blood pool reference was higher between any manual reader and aPROMISE, than between any pair of manual readers. The standard deviations of reference organ uptake across all patients as determined by aPROMISE (SD = 0.21 blood pool and SD = 1.16 liver) were lower compared to those of the manual readers. Finally, the sensitivity of aPROMISE detection and pre-segmentation was 91.5% for regional lymph nodes, 90.6% for all lymph nodes, and 86.7% for bone in metastatic patients. Conclusion In this analytical study, we demonstrated the segmentation accuracy of the deep learning algorithm, the consistency in quantitative assessment across multiple readers, and the high sensitivity in detecting potential lesions. The study provides a foundational framework for clinical evaluation of aPROMISE in standardized reporting of PSMA PET/CT.

Prospective head-to-head comparative phase 3 study between 18F-fluciclovine and 68Ga-PSMA-11 PET/CT in patients with early biochemical recurrence of prostate cancer.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 5014-5014
Author(s):  
Jeremie Calais ◽  
Francesco Ceci ◽  
Matthias Eiber ◽  
Tore Bach-Gansmo ◽  
Cristina Nanni ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Biochemical Recurrence ◽  
Ct Scans ◽  
Study Endpoint ◽  
Primary Study ◽  
Time Interval ◽  
Phase 3 ◽  
Detection Rates ◽  
Psma Pet ◽  
Pet Ct

5014 Background: This is a prospective single-center, single-arm, head-to-head phase 3 study of paired 18F-fluciclovine (FACBC) and 68Ga-PSMA-11 (PSMA) PET/CT scans for localizing early biochemical recurrence (BCR) of prostate cancer (PCa) after radical prostatectomy (RP) (NCT02940262). Methods: Fifty consecutive patients with BCR and prostate specific antigen (PSA) levels ranging from ≥0.2 to ≤2.0 ng/mL without any prior salvage therapy were included. All patients underwent FACBC and PSMA PET/CT scans within ≤15 days. PET/CT scans were each interpreted by 3 independent blinded expert readers not involved in study design and data acquisition. Region consensus interpretation (T,N,M1a,M1b,M1c) was generated based on majority rule in cases of reader disagreement (2 vs 1). PET/CT scans were considered as positive if any region was rated as positive. Detection rates per-patient and per-region served as primary study endpoint. Results: Median time interval between the 2 scans was 6 days (range 1-15). Median PSA level at the time of imaging was 0.50 ng/ml (mean 0.63; range 0.2-2.0 ng/ml). The detection rates were significantly lower with FACBC than with PSMA PET/CT per-patient (26% vs 56%; p = 0.003) and per-region for pelvic nodes (N) (8% vs 30%; p = 0.003) or any extra-pelvic lesions (M) (0% vs 16%; p = 0.008). Reader agreement for PSMA PET/CT image interpretations was significantly higher than for FACBC PET/CT (0.67 vs 0.20; p = 0.015). Conclusions: In patients with BCR and low serum PSA levels after RP, PSMA PET/CT demonstrates higher detection rates and superior reader agreement when compared with FACBC PET/CT. Therefore, PSMA PET/CT should be the imaging modality of choice in patients with early BCR. Clinical trial information: NCT03515577.

scholarly journals One-year experience with 68Ga-PSMA PET/CT: applications and results in biochemical recurrence of prostate cancer

2018 ◽  
Vol 51 (3) ◽  
pp. 151-155 ◽  
Author(s):  
Luciano Monteiro Prado Júnior ◽  
Fiorella Menegatti Marino ◽  
Renato Barra ◽  
Leonardo Fonseca Monteiro do Prado ◽  
Alaor Barra Sobrinho
Keyword(s):  
Prostate Cancer ◽  
Cancer Patients ◽  
Kidney Cancer ◽  
Specific Antigen ◽  
First Year Experience ◽  
Clinical Indication ◽  
Great Promise ◽  
Psma Pet ◽  
Pet Ct ◽  
One Year

Abstract Objective: To show the initial (first-year) experience with 68Ga-PSMA PET/CT at a clinic in Brazil. Materials and Methods: Over a one-year period, 96 examinations with 68Ga-PSMA PET/CT (85 related to prostate cancer and 11 related to kidney cancer) were performed in 90 patients. Results: In the prostate and kidney cancer patients alike, the main clinical indication for 68Ga-PSMA PET/CT was suspicion of recurrence during follow-up (in 65.8% and 63.0% of the cases, respectively). Among the prostate cancer patients, 38.5% of those with a prostate specific antigen (PSA) < 0.5 ng/mL tested positive for recurrence on 68Ga-PSMA PET/CT, compared with 71.0% of those with a PSA of 0.5-0.99, 85.7% of those with a PSA of 1.0-1.99, and 92.6% of those with a PSA > 1.99. Conclusion: Although 68Ga-PSMA PET/CT is a technique that has only recently been applied in clinical settings, despite its high cost, 68Ga-PSMA PET/CT shows great promise as a tool in the clinical management of patients with kidney and prostate cancer, especially in those with prostate cancer whose PSA levels are elevated even after treatment.

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