scholarly journals Diagnostic efficiency of hybrid imaging using PSMA ligands, PET/CT, PET/MRI and MRI in identifying malignant prostate lesions

2021 ◽  
Author(s):  
Sergiu Scobioala ◽  
Christopher Kittel ◽  
Heidi Wolters ◽  
Sebastian Huss ◽  
Khaled Elsayad ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Youden Index ◽  
Dice Similarity Coefficient ◽  
Diagnostic Efficiency ◽  
Prostate Biopsies ◽  
Psma Pet ◽  
Pet Ct ◽  
Focal Treatment ◽  
Significant Difference ◽  
Large Prostate

Abstract Objective The objective of this study was to assess the accuracy of 68Ga-PSMA-11 PET/MRI, 18F-PSMA-1007 PET/CT, 68Ga-PSMA-11 PET/CT, and multiparametric (mp)MRI for the delineating of dominant intraprostatic lesions (IPL). Materials and methods 35 patients with organ-confined prostate cancer who were assigned to definitive radiotherapy (RT) were divided into three groups based on imaging techniques: 68Ga-PSMA-PET/MRI (n = 9), 18F-PSMA-PET/CT (n = 16) and 68Ga-PSMA-PET/CT (n = 10). All patients without PSMA-PET/MRI received an additional mpMRI. PSMA-PET-based automatic isocontours and manual contours of the dominant IPLs were generated for each modality. The biopsy results were then used to validate whether any of the prostate biopsies were positive in the marked lesion using Dice similarity coefficient (DSC), Youden index (YI), sensitivity and specificity. Factors that can predict the accuracy of IPLs contouring were analysed. Results Diagnostic performance was significantly superior both for manual and automatic IPLs contouring using 68Ga-PSMA-PET/MRI (DSC/YI SUV70%—0.62/0.51), 18F-PSMA-PET/CT (DSC/YI SUV70%—0.67/0.53) or 68Ga-PSMA-PET/CT (DSC/YI SUV70%—0.63/0.51) compared to mpMRI (DSC/YI—0.47/0.41; p < 0.001). The accuracy for delineating IPLs was not improved by combination of PET/CT and mpMRI images compared to PET/CT alone. Significantly superior diagnostic accuracy was found for large prostate lesions (at least 15% from the prostate volume) and higher Gleason score (at least 7b) comparing to smaller lesions with lower GS. Conclusion IPL localization was significantly improved when using PSMA-imaging procedures compared to mpMRI. No significant difference for delineating IPLs was found between hybrid method PSMA-PET/MRI and PSMA-PET/CT. PSMA-based imaging technique should be considered for the diagnostics of IPLs and focal treatment modality.

scholarly journals Development of Discordant Hypermetabolic Prostate Cancer Lesions in the Course of [177Lu]PSMA Radioligand Therapy and Their Possible Influence on Patient Outcome

Cancers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 4270
Author(s):  
Philipp E. Hartrampf ◽  
Constantin Lapa ◽  
Sebastian E. Serfling ◽  
Andreas K. Buck ◽  
Anna Katharina Seitz ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Radioligand Therapy ◽  
Psma Pet ◽  
Number Of Patients ◽  
Pet Ct ◽  
Significant Difference ◽  
Tracer Imaging ◽  
Prognostic Implications ◽  
Dual Tracer

Introduction: Positron emission tomography/computer tomography (PET/CT) targeting the prostate-specific membrane antigen (PSMA) is crucial for the assessment of adequate PSMA expression in patients with metastatic castration-resistant prostate cancer (mCRPC) prior to PSMA radioligand therapy (PSMA RLT). Moreover, initial dual tracer staging using combined PSMA and [18F]fluorodeoxyglucose (FDG) PET/CT provides relevant information, since discordant FDG-positive but PSMA-negative (FDG+/PSMA−) lesions constitute a negative prognostic marker of overall survival (OS) after PSMA RLT. However, little is known about the prognostic implications of dual tracer imaging for restaging at follow-up. The aim of this analysis was to investigate the prognostic implications of new FDG+/PSMA− lesions during or after PSMA RLT. Methods: This bicentric analysis included 32 patients with mCRPC who underwent both FDG and PSMA PET/CT imaging after two or four cycles of PSMA RLT. Patients with FDG+/PSMA− lesions prior to PSMA RLT were not considered. The presence of FDG+/PSMA− lesions was assessed with follow-up dual tracer imaging of patients after two or four cycles of PSMA RLT. Patients with at least one new FDG+/PSMA− lesion were compared to patients without any FDG+/PSMA− lesions at the respective time points. A log-rank analysis was used to assess the difference in OS between subgroups. Results: After two cycles of PSMA RLT, four of 32 patients (13%) had FDG+/PSMA− metastases. No significant difference in OS was observed (p = 0.807), as compared to patients without FDG+/PSMA− lesions. Follow-up dual tracer imaging after the 4th cycle of PSMA RLT was available in 18 patients. Of these, four patients presented with FDG+/PSMA− findings (n = 2 already after two cycles). After the fourth cycle of PSMA RLT, no significant difference in OS was observed between patients with and without FDG+/PSMA− lesions (p = 0.442). Conclusion: This study shows that FDG+/PSMA− lesions develop in a limited number of patients undergoing PSMA RLT. Further studies are needed to establish the clinical relevance of such lesions.

scholarly journals Comparison of Manual and Semi-Automatic [18F]PSMA-1007 PET Based Contouring Techniques for Intraprostatic Tumor Delineation in Patients With Primary Prostate Cancer and Validation With Histopathology as Standard of Reference

2020 ◽  
Vol 10 ◽  
Author(s):  
Simon K. B. Spohn ◽  
Maria Kramer ◽  
Selina Kiefer ◽  
Peter Bronsert ◽  
August Sigle ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Gross Tumor Volume ◽  
Interobserver Agreement ◽  
Tumor Volume ◽  
High Sensitivity ◽  
Dice Similarity Coefficient ◽  
Primary Prostate Cancer ◽  
Psma Pet ◽  
Significant Difference ◽  
Automatic Contouring

PurposeAccurate contouring of intraprostatic gross tumor volume (GTV) is pivotal for successful delivery of focal therapies and for biopsy guidance in patients with primary prostate cancer (PCa). Contouring of GTVs, using 18-Fluor labeled tracer prostate specific membrane antigen positron emission tomography ([18F]PSMA-1007/PET) has not been examined yet.Patients and MethodsTen Patients with primary PCa who underwent [18F]PSMA-1007 PET followed by radical prostatectomy were prospectively enrolled. Coregistered histopathological gross tumor volume (GTV-Histo) was used as standard of reference. PSMA-PET images were contoured on two ways: (1) manual contouring with PET scaling SUVmin-max: 0–10 was performed by three teams with different levels of experience. Team 1 repeated contouring at a different time point, resulting in n = 4 manual contours. (2) Semi-automatic contouring approaches using SUVmax thresholds of 20–50% were performed. Interobserver agreement was assessed for manual contouring by calculating the Dice Similarity Coefficient (DSC) and for all approaches sensitivity, specificity were calculated by dividing the prostate in each CT slice into four equal quadrants under consideration of histopathology as standard of reference.ResultsManual contouring yielded an excellent interobserver agreement with a median DSC of 0.90 (range 0.87–0.94). Volumes derived from scaling SUVmin-max 0–10 showed no statistically significant difference from GTV-Histo and high sensitivities (median 87%, range 84–90%) and specificities (median 96%, range 96–100%). GTVs using semi-automatic segmentation applying a threshold of 20–40% of SUVmax showed no significant difference in absolute volumes to GTV-Histo, GTV-SUV50% was significantly smaller. Best performing semi-automatic contour (GTV-SUV20%) achieved high sensitivity (median 93%) and specificity (median 96%). There was no statistically significant difference to SUVmin-max 0–10.ConclusionManual contouring with PET scaling SUVmin-max 0–10 and semi-automatic contouring applying a threshold of 20% of SUVmax achieved high sensitivities and very high specificities and are recommended for [18F]PSMA-1007 PET based focal therapy approaches. Providing high specificities, semi-automatic approaches applying thresholds of 30–40% of SUVmax are recommend for biopsy guidance.

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.

scholarly journals Maximum Standardized Uptake Value of 18F-deoxyglucose PET Imaging Increases the Effectiveness of CT Radiomics in Differentiating Benign and Malignant Pulmonary Ground-Glass Nodules

2021 ◽  
Vol 11 ◽  
Author(s):  
Rong Niu ◽  
Jianxiong Gao ◽  
Xiaoliang Shao ◽  
Jianfeng Wang ◽  
Zhenxing Jiang ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Fdg Pet ◽  
Standardized Uptake Value ◽  
Ground Glass ◽  
Semantic Features ◽  
Diagnostic Efficiency ◽  
Maximum Standardized Uptake Value ◽  
Pet Ct ◽  
Significant Difference ◽  
Ground Glass Nodules

To investigate whether the maximum standardized uptake value (SUVmax) of 18F-deoxyglucose (FDG) PET imaging can increase the diagnostic efficiency of CT radiomics-based prediction model in differentiating benign and malignant pulmonary ground-glass nodules (GGNs). We retrospectively collected 190 GGNs from 165 patients who underwent 18F-FDG PET/CT examination from January 2012 to March 2020. Propensity score matching (PSM) was performed to select GGNs with similar baseline characteristics. LIFEx software was used to extract 49 CT radiomic features, and the least absolute shrinkage and selection operator (LASSO) algorithm was used to select parameters and establish the Rad-score. Logistic regression analysis was performed combined with semantic features to construct a CT radiomics model, which was combined with SUVmax to establish the PET + CT radiomics model. Receiver operating characteristic (ROC) was used to compare the diagnostic efficacy of different models. After PSM at 1:4, 190 GGNs were divided into benign group (n = 23) and adenocarcinoma group (n = 92). After texture analysis, the Rad-score with three CT texture features was constructed for each nodule. Compared with the Rad-score and CT radiomics model (AUC: 0.704 (95%CI: 0.562-0.845) and 0.908 (95%CI: 0.842-0.975), respectively), PET + CT radiomics model had the best diagnostic efficiency (AUC: 0.940, 95%CI: 0.889-0.990), and there was significant difference between each two of them (P = 0.001-0.030). SUVmax can effectively improve CT radiomics model performance in the differential diagnosis of benign and malignant GGNs. PET + CT radiomics might become a noninvasive and reliable method for differentiating of GGNs.

scholarly journals Prostate cancer GTV delineation with biparametric MRI and 68Ga-PSMA-PET: comparison of expert contours and semi-automated methods

2021 ◽  
Vol 94 (1119) ◽  
pp. 20201174
Author(s):  
Nathan Hearn ◽  
John Blazak ◽  
Philip Vivian ◽  
Dinesh Vignarajah ◽  
Katelyn Cahill ◽  
...  
Keyword(s):  
Dice Similarity Coefficient ◽  
Optimal Method ◽  
Pet Scanning ◽  
Psma Pet ◽  
Pet Ct ◽  
Apparent Diffusion ◽  
And Performance ◽  
Radiotherapy Dose ◽  
And Diffusion ◽  
Automated Methods

Objective: The optimal method for delineation of dominant intraprostatic lesions (DIL) for targeted radiotherapy dose escalation is unclear. This study evaluated interobserver and intermodality variability of delineations on biparametric MRI (bpMRI), consisting of T2 weighted (T2W) and diffusion-weighted (DWI) sequences, and 68Ga-PSMA-PET/CT; and compared manually delineated GTV contours with semi-automated segmentations based on quantitative thresholding of intraprostatic apparent diffusion coefficient (ADC) and standardised uptake values (SUV). Methods: 16 patients who had bpMRI and PSMA-PET scanning performed prior to any treatment were eligible for inclusion. Four observers (two radiation oncologists, two radiologists) manually delineated the DIL on: (1) bpMRI (GTVMRI), (2) PSMA-PET (GTVPSMA) and (3) co-registered bpMRI/PSMA-PET (GTVFused) in separate sittings. Interobserver, intermodality and semi-automated comparisons were evaluated against consensus Simultaneous Truth and Performance Level Estimation (STAPLE) volumes, created from the relevant manual delineations of all observers with equal weighting. Comparisons included the Dice Similarity Coefficient (DSC), mean distance to agreement (MDA) and other metrics. Results: Interobserver agreement was significantly higher (p < 0.05) for GTVPSMA (DSC: 0.822, MDA: 1.12 mm) and GTVFused (DSC: 0.787, MDA: 1.34 mm) than for GTVMRI (DSC: 0.705, MDA 2.44 mm). Intermodality agreement between GTVMRI and GTVPSMA was low (DSC: 0.440, MDA: 4.64 mm). Agreement between semi-automated volumes and consensus GTV was low for MRI (DSC: 0.370, MDA: 8.16 mm) and significantly higher for PSMA-PET (0.571, MDA: 4.45 mm, p < 0.05). Conclusion: 68Ga-PSMA-PET appears to improve interobserver consistency of DIL localisation vs bpMRI and may be more viable for simple quantitative delineation approaches; however, more sophisticated approaches to semi-automatic delineation factoring for patient- and disease-related heterogeneity are likely required. Advances in knowledge: This is the first study to evaluate the interobserver variability of prostate GTV delineations with co-registered bpMRI and 68Ga-PSMA-PET.

scholarly journals Identify glioma recurrence and treatment effects with triple-tracer PET/CT

2021 ◽  
Author(s):  
Cong Li ◽  
Chang Yi ◽  
Yingshen Chen ◽  
Shaoyan Xi ◽  
Chengcheng Guo ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Treatment Effects ◽  
Normal Brain ◽  
Diagnostic Efficiency ◽  
Characteristic Analysis ◽  
Standardized Uptake Values ◽  
Glioma Recurrence ◽  
Pet Ct ◽  
Significant Difference ◽  
G Ratio

Abstract Purpose: Differential diagnosis of tumour recurrence (TuR) from treatment effects (TrE), mostly induced by radiotherapy and chemotherapy, is still difficult by using conventional computed tomography (CT) or magnetic resonance (MR) imaging. We have investigated the diagnostic performance of PET/CT with 3 tracers, 13N-NH3, 18F-FDOPA, and 18F-FDG, to identify TuR and TrE in glioma patients following treatment. Methods: Forty-three patients with MR-suspected recurrent glioma were included. The maximum and mean standardized uptake values (SUVmax and SUVmean) of the lesion and the lesion-to-normal grey-matter cortex uptake (L/G) ratio were obtained from each tracer PET/CT. TuR or TrE was determined by histopathology or clinical MR follow-up for at least 6 months. Results: In this cohort, 34 patients were confirmed to have TuR, and 9 patients met the diagnostic standard of TrE. The SUVmax and SUVmean of 13N-NH3 and 18F-FDOPA PET/CT at TuR lesions were significantly higher compared with normal brain tissue (13N-NH3 0.696±0.558, 0.625±0.507 vs 0.486±0.413; 18F-FDOPA 0.455±0.518, 0.415±0.477 vs 0.194±0.203; both P<0.01), but there was no significant difference in 18F-FDG (6.918±3.190, 6.016±2.807 vs 6.356±3.104, P=0.290 and 0.493). L/G ratios of 13N-NH3 and 18F-FDOPA were significantly higher in TuR than in TrE group (13N-NH3, 1.573±0.099 vs 1.025±0.128, P=0.008; 18F-FDOPA, 2.729±0.131 vs 1.514±0.141, P<0.001). The sensitivity, specificity and AUC (area under the curve) by ROC (receiver operating characteristic) analysis were 57.7%, 100% and 0.803, for 13N-NH3; 84.6%, 100% and 0.938, for 18F-FDOPA; and 80.8%, 100%, and 0.952, for the combination, respectively.Conclusion: Our results suggest that although multiple tracer PET/CT may improve differential diagnosis efficacy, for glioma TuR from TrE, 18F-FDOPA PET-CT is the most reliable. The combination of 18F-FDOPA and 13N-NH3 does not increase the diagnostic efficiency, while 18F-FDG is not worthy for differential diagnosis of glioma TuR and TrE.

The role of PSMA PET/CT imaging in the diagnosis, staging and restaging of prostate cancer

2021 ◽  
Author(s):  
Dominic Bagguley ◽  
Sean Ong ◽  
James P Buteau ◽  
Sam Koschel ◽  
Nattakorn Dhiantravan ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Imaging Technique ◽  
Imaging Techniques ◽  
Multiparametric Mri ◽  
Prostate Specific Membrane Antigen ◽  
Recurrent Prostate Cancer ◽  
Psma Pet ◽  
Pet Ct ◽  
Specific Membrane

Prostate-specific membrane antigen (PSMA) PET/CT is a novel imaging technique for the detection and staging of either primary or recurrent prostate cancer. Early studies demonstrated its improved sensitivity and specificity over and in combination with other currently employed imaging techniques, such as multiparametric MRI, bone scan, PET and CT. However, the lack of strength and confidence in these studies has meant incorporation of PSMA PET/CT into clinical guidelines and practice has been limited to date. In response, a number of high-quality prospective studies have recently emerged and reflect exciting results seen in preceding publications. Here we recount some of the key earlier publications, report results from the latest studies and look to the future discussing some of the eagerly awaited ongoing clinical trials.

scholarly journals Identify glioma recurrence and treatment effects with triple-tracer PET/CT

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Cong Li ◽  
Chang Yi ◽  
Yingshen Chen ◽  
Shaoyan Xi ◽  
Chengcheng Guo ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Treatment Effects ◽  
Normal Brain ◽  
Diagnostic Efficiency ◽  
Characteristic Analysis ◽  
Standardized Uptake Values ◽  
Glioma Recurrence ◽  
Pet Ct ◽  
Significant Difference ◽  
G Ratio

Abstract Background Differential diagnosis of tumour recurrence (TuR) from treatment effects (TrE), mostly induced by radiotherapy and chemotherapy, is still difficult by using conventional computed tomography (CT) or magnetic resonance (MR) imaging. We have investigated the diagnostic performance of PET/CT with 3 tracers, 13N-NH3, 18F-FDOPA, and 18F-FDG, to identify TuR and TrE in glioma patients following treatment. Methods Forty-three patients with MR-suspected recurrent glioma were included. The maximum and mean standardized uptake values (SUVmax and SUVmean) of the lesion and the lesion-to-normal grey-matter cortex uptake (L/G) ratio were obtained from each tracer PET/CT. TuR or TrE was determined by histopathology or clinical MR follow-up for at least 6 months. Results In this cohort, 34 patients were confirmed to have TuR, and 9 patients met the diagnostic standard of TrE. The SUVmax and SUVmean of 13N-NH3 and 18F-FDOPA PET/CT at TuR lesions were significantly higher compared with normal brain tissue (13N-NH3 0.696 ± 0.558, 0.625 ± 0.507 vs 0.486 ± 0.413; 18F-FDOPA 0.455 ± 0.518, 0.415 ± 0.477 vs 0.194 ± 0.203; both P < 0.01), but there was no significant difference in 18F-FDG (6.918 ± 3.190, 6.016 ± 2.807 vs 6.356 ± 3.104, P = 0.290 and 0.493). L/G ratios of 13N-NH3 and 18F-FDOPA were significantly higher in TuR than in TrE group (13N-NH3, 1.573 ± 0.099 vs 1.025 ± 0.128, P = 0.008; 18F-FDOPA, 2.729 ± 0.131 vs 1.514 ± 0.141, P < 0.001). The sensitivity, specificity and AUC (area under the curve) by ROC (receiver operating characteristic) analysis were 57.7%, 100% and 0.803, for 13N-NH3; 84.6%, 100% and 0.938, for 18F-FDOPA; and 80.8%, 100%, and 0.952, for the combination, respectively. Conclusion Our results suggest that although multiple tracer PET/CT may improve differential diagnosis efficacy, for glioma TuR from TrE, 18F-FDOPA PET-CT is the most reliable. The combination of 18F-FDOPA and 13N-NH3 does not increase the diagnostic efficiency, while 18F-FDG is not worthy for differential diagnosis of glioma TuR and TrE.

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