scholarly journals Correction: Rijnsdorp et al. Impact of the Noise Penalty Factor on Quantification in Bayesian Penalized Likelihood (Q.Clear) Reconstructions of 68Ga-PSMA PET/CT Scans. Diagnostics 2021, 11, 847

Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1371
Author(s):  
Sjoerd Rijnsdorp ◽  
Mark J. Roef ◽  
Albert J. Arends
Keyword(s):  
Penalized Likelihood ◽  
Ct Scans ◽  
Penalty Factor ◽  
Psma Pet ◽  
Pet Ct

In the original article [...]

scholarly journals Impact of the Noise Penalty Factor on Quantification in Bayesian Penalized Likelihood (Q.Clear) Reconstructions of 68Ga-PSMA PET/CT Scans

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 847
Author(s):  
Sjoerd Rijnsdorp ◽  
Mark J. Roef ◽  
Albert J. Arends
Keyword(s):  
Penalized Likelihood ◽  
Ct Scans ◽  
Ct Scanner ◽  
Scan Time ◽  
Standardized Uptake Values ◽  
Positron Emission ◽  
Penalty Factor ◽  
Psma Pet ◽  
Pet Ct ◽  
Voxel Grid

Functional imaging with 68Ga prostate-specific membrane antigen (PSMA) and positron emission tomography (PET) can fulfill an important role in treatment selection and adjustment in prostate cancer. This article focusses on quantitative assessment of 68Ga-PSMA-PET. The effect of various parameters on standardized uptake values (SUVs) is explored, and an optimal Bayesian penalized likelihood (BPL) reconstruction is suggested. PET acquisitions of two phantoms consisting of a background compartment and spheres with diameter 4 mm to 37 mm, both filled with solutions of 68Ga in water, were performed with a GE Discovery 710 PET/CT scanner. Recovery coefficients (RCs) in multiple reconstructions with varying noise penalty factors and acquisition times were determined and analyzed. Apparent recovery coefficients of spheres with a diameter smaller than 17 mm were significantly lower than those of spheres with a diameter of 17 mm and bigger (p < 0.001) for a tumor-to-background (T/B) ratio of 10:1 and a scan time of 10 min per bed position. With a T/B ratio of 10:1, the four largest spheres exhibit significantly higher RCs than those with a T/B ratio of 20:1 (p < 0.0001). For spheres with a diameter of 8 mm and less, alignment with the voxel grid potentially affects the RC. Evaluation of PET/CT scans using (semi-)quantitative measures such as SUVs should be performed with great caution, as SUVs are influenced by scanning and reconstruction parameters. Based on the evaluation of multiple reconstructions with different β of phantom scans, an intermediate β (600) is suggested as the optimal value for the reconstruction of clinical 68Ga-PSMA PET/CT scans, considering that both detectability and reproducibility are relevant.

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.

Evaluating a machine learning based tool for the detection of pathological hotspots in whole-body PSMA-PET-CT scans

2020 ◽  
Author(s):  
A Erle ◽  
S Moazemi ◽  
M Essler ◽  
T Schultz ◽  
RA Bundschuh
Keyword(s):  
Machine Learning ◽  
Whole Body ◽  
Ct Scans ◽  
Psma Pet ◽  
Pet Ct

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.

scholarly journals 68Ga-PSMA PET/CT for Patients with PSA Relapse after Radical Prostatectomy or External Beam Radiotherapy

Diagnostics ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 622
Author(s):  
Finn Edler von Eyben ◽  
Cigdem Soydal ◽  
Rie von Eyben
Keyword(s):  
Cox Regression ◽  
External Beam Radiotherapy ◽  
Ct Scans ◽  
External Beam ◽  
Regression Analyses ◽  
Psa Relapse ◽  
Psma Pet ◽  
Pet Ct ◽  
Positive Site ◽  
Pet Ct Scan

The study aimed to summarize clinical characteristics associated with Gallium-68-prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (68Ga-PSMA PET/CT) scans as patients were restaged for prostate-specific antigen (PSA) relapse after radical prostatectomy (RP) or external beam radiotherapy (EBRT). Our analyses included multiple cox regression analyses. The study evaluated 95 patients with rising values of PSAs after RP and after EBRT. Sixty 63% of patients had a positive 68Ga-PSMA PET/CT scan. Twelve patients (13%) had a positive site in the prostate bed, 29 patients (30%) had a positive site in the regional lymph nodes, and 19 (20%) had positive sites in distant organs. After four years follow-up, 21 patients (22%) died. Using multiple Cox regression analyses, the number of positive sites on the 68Ga-PSMA PET/CT scan significantly predicted overall survival (OS) (p = 0.0001), whereas risk score and regional locations of the positive sites were not significant in the multiple Cox regression analyses. Our study indicates that the specific findings of 68Ga-PSMA PET/CT scans are important because detailed findings of the scans predict the outcome after salvage treatment of patients with PSA relapse examined with 68Ga-PSMA PET/CT scans.

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

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.

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