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 ◽  
...  

(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.

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Lei Peng ◽  
Jinze Li ◽  
Chunyang Meng ◽  
Jinming Li ◽  
Chengyu You ◽  
...  

Abstract Objective This article aims to evaluate the diagnostic value of 68Gallium-PSMA positron emission tomography/computerized tomography (68Ga-PSMA PET/CT) for lymph node (LN) staging in patients with prostate cancer (PCa) by a meta-analysis of diagnostic tests. Methods We systematically retrieved articles from Web of Science, EMBASE, Cochrane Database, PubMed. The time limit is from the creation of the database until June 2019, and Stata 15 was used for calculation and statistical analyses. Results Sensitivity, specificity, positive and negative likelihood ratio (PLR, NLR), diagnostic odds ratio (DOR) and 95% confidence intervals (CI) be used to evaluate the diagnostic value. A total of 10 studies were included in our meta-analysis, which included 701 individuals. The results of each consolidated summary are as follows: sensitivity of 0.84 (95% CI 0.55–0.95), specificity of 0.95 (95% CI 0.87–0.98), PLR and NLR was 17.19 (95% CI 6.27, 47.17) and 0.17 (95% CI 0.05–0.56), respectively. DOR of 100 (95% CI 18–545), AUC of 0.97 (95% CI 0.95–0.98). Conclusion Our study demonstrates that 68Ga-PSMA PET/CT has a high overall diagnostic value for LN staging in patients with moderate and high-risk PCa. But our conclusions still require a larger sample size, multi-center prospective randomized controlled trial to verify.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Naresh Regula ◽  
Vasileios Kostaras ◽  
Silvia Johansson ◽  
Carlos Trampal ◽  
Elin Lindström ◽  
...  

AbstractPositron emission tomography (PET) imaging is used to localize recurrent disease in prostate cancer (PCa). The tracer 68Ga-PSMA-11 visualizes lesions overexpressing prostate-specific membrane antigen (PSMA), while 11C-acetate visualizes lesions with increased anabolic metabolism. The aim of this study was to compare the performance of PSMA-PET and acetate-PET in re-staging patients with biochemical relapse. Thirty PCa patients with prostate-specific antigen (PSA) relapse after primary curative therapy were prospectively evaluated. PET/CT examinations using 11C-acetate and 68Ga-PSMA-11 were performed. Identified lesions were categorized according to anatomical location and PET measurements were correlated with PSA at time of scan. Tumour lesions showed higher semi-quantitative uptake values on PSMA-PET than acetate-PET. PSMA-PET identified more lesions in 11 patients, fewer lesions in eight patients, and identical number of lesions in 11 patients. This study indicates better diagnostic performance of PSMA-PET, particularly in detecting lymph node (81% vs 60%, p = 0.02) and bone metastasis (95% vs 61%, p = 0.0001) compared to acetate-PET. However, 38% of PSMA-expressing metastases appear to be metabolically inactive and 15% of metabolically active metastases lack PSMA expression. Addition of PET with a metabolic tracer, such as 11C-acetate, might be beneficial before making treatment decisions.


2019 ◽  
Vol 11 ◽  
pp. 175628721881579 ◽  
Author(s):  
Masood Moghul ◽  
Bhaskar Somani ◽  
Tim Lane ◽  
Nikhil Vasdev ◽  
Brian Chaplin ◽  
...  

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.


2021 ◽  
Author(s):  
Jinling Song ◽  
Maomao Wei ◽  
Xuejuan Wang

Abstract Purpose: Identification of microsatellite instability high (MSI-H) colorectal cancer (CRC) is crucial for screening patients most likely to benefit from immunotherapy. We aim to investigate whether the metabolic characteristics is related to MSI status and can be used to predict the MSI-H CRC. Methods: A retrospective analysis was conducted on 420 CRC patients who were identified via [18F]fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography(CT) prior to therapy. Maximum standardised uptake (SUVmax), mean standardised uptake (SUVmean), metabolic tumour volume (MTV) and total lesion glycolysis (TLG) of the primary tumour were calculated and compared between MSI-H and microsatellite stability (MSS). Predictive factors of MSI status were selected from metabolic parameters and clinicopathological profiles via a multivariate analysis.Results: Of 420 colorectal cancers, 44 exhibited a high incidence of MSI. Both MTV and TLG were significantly higher in MSI-H group compared with the MSS group (P=0.004 and P=0.010, respectively). Logistic regression analysis indicated that CRC with MSI-H were related to younger age (P=0.013), primary lesion located at right hemi-colon (P<0.001) and larger MTV on PET/CT imaging (P=0.019). MTV more than 32.19 cm3 of colorectal cancer was linked to the presence of MSI (P=0.019). Conclusion: Tumor metabolic burden were higher in MSI-H CRC which may be useful for predicting the MSI status of CRC patient and thus aid in determination of immunotherapy for patients with CRC.


Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 847
Author(s):  
Sjoerd Rijnsdorp ◽  
Mark J. Roef ◽  
Albert J. Arends

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.


2021 ◽  
Author(s):  
Elisa Perry ◽  
Arpit Talwar ◽  
Sanjana Sharma ◽  
Daisy O'Connor ◽  
Lih-Ming Wong ◽  
...  

Abstract PurposeProstate cancer (PCa) imaging has been revolutionized by Positron emission tomography (PET) tracers targeted to prostate specific membrane antigen (PSMA). Identification and characterization of non-PCa tumors has become an increasing clinical dilemma with growing use. The primary aim of this retrospective multicenter analysis was to determine atypical PSMA expression in PCa and expression in non-PCa tumors to aid providing clinically relevant reports and guiding multidisciplinary discussion.MethodsRetrospective multicenter study examining 1445 consecutive 18F-DCFPyL PSMA PET/CT between 2016-2020. Referrals were from public and private, secondary and tertiary referral centres serving New Zealand and Melbourne. Repeat studies were excluded. Lesions atypical for PCa were categorized into four groups: 1. Atypical PCa metastases 2. Non-PCa tumors 3. Benign and 4. Indeterminate.Results67 patients had lesions atypical for PCa metastases; 11.9% atypical prostate cancer metastases, 25.4% non-PCa tumors, 40.3% indeterminate, 10.4% benign. With the exception of Renal Cell Carcinoma (RCC), the non-PCa tumors, indeterminate and benign lesions demonstrated low PSMA expression. Most atypical PCa metastases demonstrated significant expression. Limitations included retrospective design and lack of histopathological correlation/follow up in some.Conclusions: Non-PCa tumor detection is low. Lesions demonstrating significant PSMA expression were almost exclusively PCa metastases. Differentiation of atypical PCa metastases from second primary malignancies is vital to avoid unnecessary investigation, delayed therapy and additional costs.


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