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Objective Paraneoplastic neurologic syndrome (PNS) is a rare condition indirectly caused by an underlying malignancy. In many cases, the malignancy is occult at the time of the PNS diagnosis, and the optimal diagnostic modality to detect the underlying tumour is unclear. In the present study, we aimed to assess the utility of 18F-fluorodeoxyglucose positron-emission tomography (FDG-PET) or pet integrated with computed tomography (PET/CT) in the investigation of these patients. Methods We retrospectively analyzed data from the PET Access Program (PAP) database in the province of Ontario to identify patients who underwent FDG-PET/CT imaging as part of a workup for PNS. In all patients, prior conventional imaging was negative or indeterminate. To determine the diagnostic accuracy of FDG-PET/CT, data about demographics, presenting symptoms, and biochemical and radiologic workup, including FDG-PET/CT imaging results, were compared with data collected by the Ontario Cancer Registry (OCR). A systematic review of the literature and meta-analysis using our study inclusion criteria were performed for studies of FDG-PET accuracy. Results Of 29 patients identified in the pap database, 9 had FDG-PET/CT results suspicious for malignancy. When correlated with data from the OCR, 5 FDG-PET/CT results were informative, resulting in a detection rate of 17%. Local sensitivity and specificity were 0.83 and 0.83 respectively. Two studies meeting our criteria were identified in the literature. The pooled sensitivity and specificity from the literature and local data were 0.88 and 0.90 respectively. Conclusions When investigating for underlying malignancy in patients with suspected PNS and negative conventional imaging, pet has high sensitivity and specificity. [ABSTRACT FROM AUTHOR]

Rationale and Objectives: Recently, the Response Evaluation Using PSMA PET/CT in Patients with Metastatic Castration-Resistant Prostate Cancer (RECIP 1.0) was proposed to better evaluate treatment response in prostate cancer patients using PET/CT with prostate-specific membrane antigen (PSMA) than more traditional approaches like metabolic PET evaluation response criteria in solid tumor (PERCIST 1.0). This system showed promising results in single-center studies. We aim to evaluate the prognostic performance of RECIP 1.0 in assessing treatment outcomes in metastatic prostate cancer patients with a systematic review and meta-analysis., Materials and Methods: Searches were conducted across PubMed/MEDLINE, EMBASE, and Web of Science databases through March 2024. Only studies involving patients with metastatic prostate cancer who underwent PSMA PET/CT to assess therapeutic response and who were evaluated using the RECIP 1.0 criteria were included. Pooled hazard ratios for mortality and concordance indices (c-index) of RECIP were assessed. A secondary analysis compared RECIP 1.0 to PSMA PET Progression Criteria (PPP) in head-to-head studies., Results: From an initial 553 reports, eight met the eligibility criteria after full-text review (n=516 patients) and six underwent quantitative analysis. RECIP 1.0 significantly differentiated between disease progression and non-progression in terms of mortality risk (HR: 3.48; 95% CI: 2.64-4.59). A sub-analysis of three studies with 174 patients demonstrated a pooled c-index of 0.68 (95% CI: 0.65-0.71). Comparison involving 224 patients from three studies indicated a non-significant trend favoring RECIP 1.0 over PPP., Conclusion: RECIP 1.0 offers robust prognostic value for assessing metastatic prostate cancer treatment outcomes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Rationale and Objectives: To determine the role of dynamic contrast-enhanced (DCE) MRI-radiomics in predicting the International Society of Urological Pathology Grade Group (ISUP-GG) in therapy-naïve prostate cancer (PCa) patients., Materials and Methods: In this ethics review board-approved retrospective study on two prospective clinical trials between 2017 and 2020, 73 men with suspected/confirmed PCa were included. All participants underwent multiparametric MRI. On MRI, dominant lesions (per PI-RADS) were identified. DCE-MRI radiomic features were extracted from the segmented volumes following the image biomarker standardisation initiative (IBSI) guidelines through 14 time points. Histopathology evaluation on the cognitive-fusion targeted biopsies was set as the reference standard. Univariate regression was done to evaluate potential predictors across all calculated features. Random forest imputation was used for multivariate modelling., Results: 73 index lesions were reviewed. Histopathology revealed 28, 16, 13 and 16 lesions with ISUP-GG-Negative/1/2, ISUP-GG-3, ISUP-GG-4 and ISUP-GG-5, respectively. From the extracted features, total lesion enhancement (TLE), minimum enhancement intensity and Grey-Level Run Length Matrix (GLRLM) were the most significantly different parameters among ISUP-GGs (Neg/1/2 vs 3/4 vs 5). 16 features with significant cross-sectional associations with ISUP-GGs entered the multivariate analysis. The final DCE partitioning model used only four features (lesion sphericity, TLE, GLRLM and Grey-Level Zone Length Matrix). For the binarized diagnosis (ISUP-GG≤2 vs ISUP-GG>2), the accuracy reached 81%., Conclusion: DCE-MRI radiomics might be used as a non-invasive tool for aiding pathological grade group prediction in therapy-naïve PCa patients, potentially adding complementary information to PI-RADS for supporting tailored diagnostic pathways and treatment planning., Competing Interests: Declaration of Competing Interest Patrick Veit-Haibach—IIS grants: Bayer Switzerland, Roche Pharmaceuticals, Siemens Healthineers, GE Healthcare, Point Biopharma; Speaker fees and travel support: Siemens Healthineers, GE Healthcare; Speaker fees: Ontario Association of Radiologists; Speaker fees: JCA PET/CT course; Springer Nature: Editor fee; Reviewer compensation: Wellcome Trust; German Cancer Center: Strategic panel advisory compensation and travel support. Alejandro Berlin—Participation on a Data Safety Monitoring Board or Advisory Board from Princess Margaret Cancer Center, University Health Network. Ur Metser—Consulting fees from POINT Biopharm; Chair, Ontario PET Steering Committee and Ontario Health-Cancer Care Ontario; The remaining authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article., (Copyright © 2024 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Rationale and Objectives: To investigate whether [ 18 F]-FDG PET/CT-derived radiomics may correlate with driver gene mutations in non-small cell lung cancer (NSCLC) patients., Materials and Methods: In this IRB-approved retrospective study, 203 patients with surgically treated NSCLC who underwent subsequent genomic analysis of the primary tumour at our institution between December 2004 and January 2014 were identified. Of those, 128 patients (mean age 62.4 ± 10.8 years; range: 35-84) received preoperative [ 18 F]-FDG PET/CT as part of their initial staging and thus were included in the study. PET and CT image segmentation and feature extraction were performed semi-automatically with an open-source software platform (LIFEx, Version 6.30, lifexsoft.org). Molecular profiles using different next-generation sequencing (NGS) panels were collected from a web-based resource (cBioPortal.ca for Cancer genomics). Two statistical models were then built to evaluate the predictive ability of [ 18 F]-FDG PET/CT-derived radiomics features for driver gene mutations in NSCLC., Results: More than half (68/128, 53%) of all tumour samples harboured three or more gene mutations. Overall, 55% of tumour samples demonstrated a mutation in TP53, 26% of samples had alterations in KRAS and 17% in EGFR. Extensive statistical analysis resulted in moderate to good predictive ability. The highest Youden Index for TP53 was achieved using combined PET/CT features (0.70), for KRAS using PET features only (0.57) and for EGFR using CT features only (0.60)., Conclusion: Our study demonstrated a moderate to good correlation between radiomics features and driver gene mutations in NSCLC, indicating increased predictive ability of genomic profiles using combined [ 18 F]-FDG PET/CT-derived radiomics features., Competing Interests: Declaration of Competing Interest Patrick Veit-Haibach: IIS grants: Bayer Switzerland, Roche Pharmaceuticals, Siemens Healthineers, GE Healthcare, Point Biopharma; Speaker fees and travel support: Siemens Healthineers, GE Healthcare; Speaker fees: Ontario Association of Radiologists; Speaker fees: JCA PET/CT course; Springer Nature: Editor fee; Reviewer compensation: Wellcome Trust; German Cancer Center: Strategic panel advisory compensation and travel support; Ur Metser; Consulting fees from POINT Biopharm; Chair, Ontario PET Steering Committee and Ontario Health-Cancer Care Ontario; the other authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article., (Copyright © 2024 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

In Canada and across the globe, access to PSMA PET/CT is limited and expensive. For patients with biochemical recurrence (BCR) after treatment for prostate cancer, novel strategies are needed to better stratify patients who may or may not benefit from a PSMA PET scan. The role of the free-to-total prostate-specific antigen (PSA) ratio (FPSAR) in posttreatment prostate cancer, specifically in the PSMA PET/CT era, remains unknown. Our aim in this study was to determine the association of FPSAR in patients referred for 18 F-DCFPyL PSMA PET/CT in the BCR setting and assess the correlation between FPSAR and 18 F-DCFPyL PSMA PET/CT positivity (local recurrence or distant metastases). Methods: This prospective study included 137 patients who were referred for 18 F-DCFPyL PSMA PET/CT and had BCR with a total PSA of less than 1 ng/mL after radical prostatectomy (RP) (including adjuvant or salvage radiotherapy). Blood samples were collected on the day of 18 F-DCFPyL PSMA PET/CT. FPSAR was categorized as less than 0.10 or as 0.10 or more. A positive 18 F-DCFPyL PSMA PET/CT scan was defined by a PROMISE classification lesion score of 2 or 3, irrespective of the site of increased tracer uptake (e.g., prostate, pelvic nodes, bone, or viscera). Results: Overall, 137 blood samples of patients with BCR after RP were analyzed to calculate FPSAR. The median age at 18 F-DCFPyL PSMA PET/CT was 68.6 y (interquartile range, 63.0-72.4 y), and the median PSA at 18 F-DCFPyL PSMA PET/CT was 0.3 ng/mL (interquartile range, 0.3-0.6 ng/mL). Eighty-six patients (62.8%) had an FPSAR of less than 0.10, whereas 51 patients (37.2%) had an FPSAR of 0.10 or more. An FPSAR of 0.10 or more was identified as an independent predictor of a positive 18 F-DCFPyL PSMA PET/CT scan, with an odds ratio of 6.99 (95% CI, 2.96-16.51; P < 0.001). Conclusion: An FPSAR of 0.10 or more after RP independently correlated with increased odds of a positive 18 F-DCFPyL PSMA PET/CT scan among BCR post-RP patients. These findings may offer an inexpensive method by which to triage access to 18 F-DCFPyL PSMA PET/CT in jurisdictions where availability is not replete., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

Our purpose was to prospectively assess the distribution of NETPET scores in well-differentiated (WD) grade 2 and 3 gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) and to determine the impact of the NETPET score on clinical management. Methods: This single-arm, institutional ethics review board-approved prospective study included 40 patients with histologically proven WD GEP NETs. 68 Ga-DOTATATE PET and 18 F-FDG PET were performed within 21 d of each other. NETPET scores were evaluated qualitatively by 2 reviewers, with up to 10 marker lesions selected for each patient. The quantitative parameters that were evaluated included marker lesion SUV max for each tracer; 18 F-FDG/ 68 Ga-DOTATATE SUV max ratios; functional tumor volume (FTV) and metabolic tumor volume (MTV) on 68 Ga-DOTATATE and 18 F-FDG PET, respectively; and FTV/MTV ratios. The treatment plan before and after 18 F-FDG PET was recorded. Results: There were 22 men and 18 women (mean age, 60.8 y) with grade 2 ( n = 24) or grade 3 ( n = 16) tumors and a mean Ki-67 index of 16.1%. NETPET scores of P0, P1, P2A, P2B, P3B, P4B, and P5 were documented in 2 (5%), 5 (12.5%), 5 (12.5%) 20 (50%), 2 (5%), 4 (10%), and 2 (5%) patients, respectively. No association was found between the SUV max of target lesions on 68 Ga-DOTATATE and the SUV max of target lesions on 18 F-FDG PET ( P = 0.505). 18 F-FDG/ 68 Ga-DOTATATE SUV max ratios were significantly lower for patients with low (P1-P2) primary NETPET scores than for those with high (P3-P5) primary NETPET scores (mean ± SD, 0.20 ± 0.13 and 1.68 ± 1.44, respectively; P < 0.001). MTV on 18 F-FDG PET was significantly lower for low primary NETPET scores than for high ones (mean ± SD, 464 ± 601 cm 3 and 66 ± 114 cm 3 , respectively; P = 0.005). A change in the type of management was observed in 42.5% of patients after 18 F-FDG PET, with the most common being a change from systemic therapy to peptide receptor radionuclide therapy and from debulking surgery to systemic therapy. Conclusion: There was a heterogeneous distribution of NETPET scores in patients with WD grade 2 and 3 GEP NETs, with more than 1 in 5 patients having a high NETPET score and a frequent change in management after 18 F-FDG PET. Quantitative parameters including 18 F-FDG/ 68 Ga-DOTATATE SUV max ratios in target lesions and FTV/MTV ratios can discriminate between patients with high and low NETPET scores., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

Tumor hypoxia is a negative prognostic factor in many tumors and is predictive of metastatic spread and poor responsiveness to both chemotherapy and radiotherapy. Purpose: To assess the feasibility of using 18 F-Fluoroazomycin arabinoside (FAZA) PET/MR to image tumor hypoxia in patients with locally advanced rectal cancer (LARC) prior to and following neoadjuvant chemoradiotherapy (nCRT). The secondary objective was to compare different reference tissues and thresholds for tumor hypoxia quantification. Patients and Methods: Eight patients with histologically proven LARC were included. All patients underwent 18 F-FAZA PET/MR prior to initiation of nCRT, four of whom also had a second scan following completion of nCRT and prior to surgery. Tumors were segmented using T 2 -weighted MR. Each voxel within the segmented tumor was defined as hypoxic or oxic using thresholds derived from various references: ×1.0 or ×1.2 SUVmean of blood pool [BP] or left ventricle [LV] and SUVmean +3SD for gluteus maximus. Correlation coefficient (CoC) between HF and tumor SUVmax/reference SUVmean TRR for the various thresholds was calculated. Hypoxic fraction (HF), defined as the % hypoxic voxels within the tumor volume was calculated for each reference/threshold. Results: For all cases, baseline and follow-up, the CoCs for gluteus maximus and for BP and LV (×1.0) were 0.241, 0.344, and 0.499, respectively, and HFs were (median; range) 16.6% (2.4-33.8), 36.8% (0.3-72.9), and 30.7% (0.8-55.5), respectively. For a threshold of ×1.2, the CoCs for BP and LV as references were 0.611 and 0.838, respectively, and HFs were (median; range) 10.4% (0-47.6), and 4.3% (0-20.1%), respectively. The change in HF following nCRT ranged from (-18.9%) to (+54%). Conclusions: Imaging of hypoxia in LARC with 18 F-FAZA PET/MR is feasible. Blood pool as measured in the LV appears to be the most reliable reference for calculating the HF. There is a wide range of HF and variable change in HF before and after nCRT.

We aimed to determine if clinical parameters and radiomics combined with sarcopenia status derived from baseline 18 F-FDG-PET/CT could predict developing metastatic disease and overall survival (OS) in gastroesophageal cancer (GEC). Patients referred for primary staging who underwent 18 F-FDG-PET/CT from 2008 to 2019 were evaluated retrospectively. Overall, 243 GEC patients (mean age = 64) were enrolled. Clinical, histopathology, and sarcopenia data were obtained, and primary tumor radiomics features were extracted. For classification (early-stage vs. advanced disease), the association of the studied parameters was evaluated. Various clinical and radiomics models were developed and assessed. Accuracy and area under the curve (AUC) were calculated. For OS prediction, univariable and multivariable Cox analyses were performed. The best model included PET/CT radiomics features, clinical data, and sarcopenia score (accuracy = 80%; AUC = 88%). For OS prediction, various clinical, CT, and PET features entered the multivariable analysis. Three clinical factors (advanced disease, age ≥ 70 and ECOG ≥ 2), along with one CT-derived and one PET-derived radiomics feature, retained their significance. Overall, 18 F-FDG PET/CT radiomics seems to have a potential added value in identifying GEC patients with advanced disease and may enhance the performance of baseline clinical parameters. These features may also have a prognostic value for OS, improving the decision-making for GEC patients.

We aimed to investigate whether [ 18 F]F-FDG-PET/CT-derived radiomics can classify histologic subtypes and determine the anatomical origin of various malignancies. In this IRB-approved retrospective study, 391 patients (age = 66.7 ± 11.2) with pulmonary (n = 142), gastroesophageal (n = 128) and head and neck (n = 121) malignancies were included. Image segmentation and feature extraction were performed semi-automatically. Two models (all possible subset regression [APS] and recursive partitioning) were employed to predict histology (squamous cell carcinoma [SCC; n = 219] vs. adenocarcinoma [AC; n = 172]), the anatomical origin, and histology plus anatomical origin. The recursive partitioning algorithm outperformed APS to determine histology (sensitivity 0.90 vs. 0.73; specificity 0.77 vs. 0.65). The recursive partitioning algorithm also revealed good predictive ability regarding anatomical origin. Particularly, pulmonary malignancies were identified with high accuracy (sensitivity 0.93; specificity 0.98). Finally, a model for the synchronous prediction of histology and anatomical disease origin resulted in high accuracy in determining gastroesophageal AC (sensitivity 0.88; specificity 0.92), pulmonary AC (sensitivity 0.89; specificity 0.88) and head and neck SCC (sensitivity 0.91; specificity 0.92). Adding PET-features was associated with marginal incremental value for both the prediction of histology and origin in the APS model. Overall, our study demonstrated a good predictive ability to determine patients' histology and anatomical origin using [ 18 F]F-FDG-PET/CT-derived radiomics features, mainly from CT.

This study aimed to compare the detection of neuroendocrine tumor liver metastases (NLMs) in hepatobiliary-specific contrast-enhanced MRI (pMR) versus 68 Ga-DOTATATE PET/CT (DT-PET). This retrospective study cohort included 30 patients with well-differentiated neuroendocrine tumors who underwent both DT-PET and pMR. Two readers independently assessed NLMs count, SUVmax on DT-PET, and signal characteristics on pMR. A consensus review by two additional readers resolved discrepancies between the modalities. Results showed concordance between DT-PET and pMR NLM count in 14/30 patients (47%). pMR identified more NLMs in 12/30 patients (40%), of which 4 patients showed multiple deposits on pMR but only 0-1 lesions on DT-PET. DT-PET detected more in 4/30 patients (13%). Overall, pMR detected more metastases than DT-PET ( p = 0.01). Excluding the four outliers, there was excellent agreement between the two methods (ICC: 0.945, 95%CI: 0.930, 0.958). Notably, pMR had a higher NLM detection rate than DT-PET, with correlations found between lesion size on pMR and DT-PET detectability, as well as diffusion restriction on pMR and SUVmax on DT-PET. In conclusion, in consecutive patients with well-differentiated NETs, the detection rate of NLM is higher with pMR than with DT-PET. However, when excluding patients whose tumors do not overexpress somatostatin receptors (13% of the cohort), high concordance in the detection of NLM is observed between DT PET and pMR.

Background Prostate-specific membrane antigen (PSMA) PET is useful in the early detection of oligorecurrent prostate cancer (PCa), but whether PSMA PET parameters can be used to identify patients who would benefit from metastasis-directed therapy (MDT) with radiation or surgery remains uncertain. Purpose To assess the association of PSMA PET parameters with outcomes of patients with oligorecurrent PCa after MDT. Materials and Methods In this retrospective analysis of a single-center phase II trial that enrolled patients with biochemical recurrence of PCa after maximal local therapy and with no evidence of disease at conventional imaging, patients underwent PSMA PET (between May 2017 and November 2021), and unveiled recurrences were treated with MDT. Maximum standardized uptake value (SUV max ) and mean standardized uptake value (SUV mean ) and PSMA tumor volume derived using thresholds of 2.5 (SUV mean2.5 ) and 41% (SUV mean41% ), respectively, were recorded for sites of recurrence on PSMA PET scans, and a molecular imaging PSMA score was assigned. These parameters were also corrected for smooth filter and partial volume effects, and the PSMA score was reassigned. Cox proportional hazards models were used to evaluate the relationship between PSMA PET parameters and outcomes. Results A total of 74 men (mean age, 68.3 years ± 6.6 [SD]) with biochemical recurrence of PCa were included. PSMA PET revealed 145 lesions in the entire cohort, of which 125 (86%) were metastatic lymph nodes. Application of the correction factor changed the PSMA score in 88 of 145 lesions (61%). Mean SUV max , SUV mean2.5 , and SUV mean41% were associated with lower risk of biochemical progression (hazard ratio [HR] range, 0.77-0.95; 95% CI: 0.61, 1.00; P = .03 to P = .04). For corrected parameters, mean SUV max , mean SUV mean2.5 , mean SUV mean41% , mean PSMA score, maximum SUV mean2.5 , maximum SUV mean41% , and maximum PSMA score were associated with a lower risk of biochemical progression (HR, 0.61-0.98; 95% CI: 0.39, 1.00; P = .01 to P = .04). Conclusion Measured and corrected PSMA PET parameters were associated with biochemical progression in men with oligorecurrent PCa treated with MDT. Clinical trial registration no. NCT03160794 © RSNA, 2023 See also the editorial by Civelek in this issue.

To assess the impact of the COVID-19 pandemic on the diagnosis, staging and outcome of a selected population throughout the first two years of the pandemic, we evaluated oncology patients undergoing PET/CT at our institution. A retrospective population of lung cancer, melanoma, lymphoma and head and neck cancer patients staged using PET/CT during the first 6 months of the years 2019, 2020 and 2021 were included for analysis. The year in which the PET was performed was our exposure variable, and our two main outcomes were stage at the time of the PET/CT and overall survival (OS). A total of 1572 PET/CTs were performed for staging purposes during the first 6 months of 2019, 2020 and 2021. The median age was 66 (IQR 16), and 915 (58%) were males. The most prevalent staged cancer was lung cancer (643, 41%). The univariate analysis of staging at PET/CT and OS by year of PET/CT were not significantly different. The multivariate Cox regression of non-COVID-19 significantly different variables at univariate analysis and the year of PET/CT determined that lung cancer (HR 1.76 CI95 1.23-2.53, p < 0.05), stage III (HR 3.63 CI95 2.21-5.98, p < 0.05), stage IV (HR 11.06 CI95 7.04-17.36, p < 0.05) and age at diagnosis (HR 1.04 CI95 1.02-1.05, p < 0.05) had increased risks of death. We did not find significantly higher stages or reduced OS when assessing the year PET/CT was performed. Furthermore, OS was not significantly modified by the year patients were staged, even when controlled for non-COVID-19 significant variables (age, type of cancer, stage and gender).

The purpose of this study was to determine the impact of [ 18 F]FDG PET/CT on the initial staging, restaging, clinical management, and outcomes of patients with soft-tissue and bone sarcomas. Methods: This single-arm, prospective multicenter registry enrolled 304 patients with 320 [ 18 F]FDG PET/CT scans (November 2018 to October 2021). Eligibility included the initial staging of a grade 2 or higher or ungradable soft-tissue or bone sarcoma, with negative or equivocal findings for nodal or distant metastases on conventional imaging before curative-intent therapy, or restaging of patients with a history of treated sarcoma with a suspicion or confirmation of local recurrence or limited metastatic disease who were being considered for curative-intent or salvage therapy. The presence of local recurrence or metastases on [ 18 F]FDG PET/CT was recorded. Clinical management after [ 18 F]FDG PET/CT compared with pre-[ 18 F]FDG PET/CT planned management and quantitative metabolic tumor parameters (SUV max , metabolic tumor volume, total lesion glycolysis) were correlated with the outcome data for 171 patients. Results: At the initial staging, [ 18 F]FDG PET/CT detected metastases in 17 of 105 patients (16.2%) with no metastases on conventional work-up and confirmed metastases in 44 of 92 patients (47.8%) with equivocal findings for metastases. At the time of restaging, [ 18 F]FDG PET/CT detected local recurrence in 37 of 123 patients (30.1%) and distant metastases in 71 of 123 patients (57.7%). Overall, the change in treatment intent and treatment type was recorded in 64 of 171 cases (37.4%) and 56 of 171 cases (32.8%), respectively. The presence of metastases on [ 18 F]FDG PET/CT was associated with shorter progression-free survival at the initial staging ( P = 0.04) and shorter overall survival at the time of recurrence ( P = 0.002). All quantitative metabolic tumor parameters correlated with progression-free survival and overall survival. Conclusion: [ 18 F]FDG PET/CT frequently detects additional sites of disease compared with conventional imaging in patients with sarcomas that were being considered for curative-intent or salvage therapy. This increased detection impacts the clinical management in a third of patients referred for initial staging or presumed limited recurrence after primary therapy. The presence of metastases on [ 18 F]FDG PET/CT is associated with poorer outcomes., (© 2023 by the Society of Nuclear Medicine and Molecular Imaging.)

Background: The impact of molecular imaging (MI) on patient management after biochemical recurrence (BCR) following radical prostatectomy has been described in many studies. However, it is not known if MI-induced management changes are appropriate. This study aimed to determine if androgen deprivation therapy (ADT) management plan is improved by MI in patients who are candidates for salvage radiation therapy., Methods: Data were analyzed from the multicenter prospective PROPS trial evaluating PSMA/Choline PET in patients being considered for salvage radiotherapy (sRT) with BCR after prostatectomy. We compared the pre- and post-MI ADT management plans for each patient and cancer outcomes as predicted by the MSKCC nomogram. A higher percentage of predicted BCR associated with ADT treatment intensification after MI was considered as an improvement in a patient's management., Results: Seventy-three patients with a median PSA of 0.38 ng/mL were included. In bivariate analysis, a positive finding on MI (local or metastatic) was associated with decision to use ADT with an odds ratio of 3.67 (95% CI, 1.25 to 10.71; p = 0.02). No factor included in the nomogram was associated with decision to use ADT. Also, MI improved selection of patients to receive ADT based on predicted BCR after sRT : the predicted nomogram 5-year biochemical-free survivals were 52.5% and 43.3%, (mean difference, 9.2%; 95% CI 0.8 to 17.6; p = 0.03) for sRT alone and ADT±sRT subgroups, while there was no statistically significant difference between subgroups before MI., Conclusions: PSMA and/or Choline PET/CT before sRT can potentially improve patient ADT management by directing clinicians towards more appropriate intensification., (© 2023. The Author(s).)

We conducted and previously published a phase 2 trial of metastasis-directed therapy (MDT) in men with recurrence of prostate cancer at a low prostate-specific antigen level following radical prostatectomy and postoperative radiotherapy. All patients had negative conventional imaging and underwent prostate-specific membrane antigen (PSMA) positron emission tomography (PET). Patients without visible disease ( n  = 16) or with metastatic disease not amenable to MDT ( n  = 19) were excluded from the interventional study. The remaining patients with disease visible on PSMA-PET received MDT ( n  = 37). We analyzed all three groups to identify distinct phenotypes in the era of molecular imaging-based characterization of recurrent disease. Median follow up was 37 mo (interquartile range 27.5-43.0). There was no significant difference in time to the development of metastasis on conventional imaging among the groups; however, castrate-resistant prostate cancer-free survival was significantly shorter for patients with PSMA-avid disease not amenable to MDT ( p  = 0.047). Our findings suggest that PSMA-PET findings can help in discriminating diverging clinical phenotypes among men with disease recurrence and negative conventional imaging after local therapies with curative intent. There is a pressing need for better characterization of this rapidly growing population of patients with recurrent disease defined by PSMA-PET to derive robust selection criteria and outcome definitions for ongoing and future studies., Patient Summary: In men with prostate cancer with rising PSA levels following surgery and radiation, a newer type of scan called PSMA-PET (prostate-specific membrane antigen positron emission tomography) can be used to characterize and differentiate the patterns of recurrence, and inform future cancer outcomes., (© 2023 The Author(s).)

Background: Cardiac and respiratory motions in clinical positron emission tomography (PET) are a major contributor to inaccurate PET quantification and lesion characterisation. In this study, an elastic motion-correction (eMOCO) technique based on mass preservation optical flow is adapted and investigated for positron emission tomography-magnetic resonance imaging (PET-MRI) applications., Methods: The eMOCO technique was investigated in a motion management QA phantom and in twenty-four patients who underwent PET-MRI for dedicated liver imaging and nine patients for cardiac PET-MRI evaluation. Acquired data were reconstructed with eMOCO and gated motion correction techniques at cardiac, respiratory and dual gating modes, and compared to static images. Standardized uptake value (SUV), signal-to-noise ratio (SNR) of lesion activities from each gating mode and correction technique were measured and their means/standard deviation (SD) were compared using 2-ways ANOVA analysis and post-hoc Tukey's test., Results: Lesions' SNR are highly recovered from phantom and patient studies. The SD of the SUV resulted from the eMOCO technique was statistically significantly less (P<0.01) than the SD resulted from conventional gated and static SUVs at the liver, lung and heart., Conclusions: The eMOCO technique was successfully implemented in PET-MRI in a clinical setting and produced the lowest SD compared to gated and static images, and hence provided the least noisy PET images. Therefore, the eMOCO technique can potentially be used on PET-MRI for improved respiratory and cardiac motion correction., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-22-1017/coif). JS, IH and JJ are full-time employees of Siemens Healthcare. UM reports that he received consulting fee from POINT Biopharma Inc. (2020–2022). KH reports that he received honoraria from Sanofi-genzyme. PVH reports that he received grants, support for attending meetings and WIP software from Siemens Healthineers; and he also received speaker fees from Spring Nature, JCA Seminars, and Ontario association of radiologists. The other authors have no conflicts of interest to declare., (2023 Quantitative Imaging in Medicine and Surgery. All rights reserved.)

Background There have been conflicting results regarding fluorine 18-labeled fluorodeoxyglucose ( 18 F-FDG) PET/MRI diagnostic performance in lung malignant neoplasms. Purpose To evaluate the diagnostic performance of 18 F-FDG PET/MRI for the detection of pulmonary malignant neoplasms. Materials and Methods A systematic search was conducted within the Scopus, Web of Science, and PubMed databases until December 31, 2021. Published original articles that met the following criteria were considered eligible for meta-analysis: (a) detecting malignant lesions in the lung, (b) comparing 18 F-FDG PET/MRI with a valid reference standard, and (c) providing data for the meta-analytic calculations. A hierarchical method was used to pool the performances. The bivariate model was used to find the summary points and 95% CIs. The hierarchical summary receiver operating characteristic model was used to draw the summary receiver operating characteristic curve and calculate the area under the curve. The Higgins I 2 statistic and Cochran Q test were used for heterogeneity assessment. Results A total of 43 studies involving 1278 patients met the inclusion criteria and were included in the meta-analysis. 18 F-FDG PET/MRI had a pooled sensitivity and specificity of 96% (95% CI: 84, 99) and 100% (95% CI: 98, 100), respectively. 18 F-FDG PET/CT had a pooled sensitivity and specificity of 99% (95% CI: 61, 100) and 99% (95% CI: 94, 100), respectively, which were comparable with those of 18 F-FDG PET/MRI. At meta-regression, studies in which contrast media ( P = .03) and diffusion-weighted imaging ( P = .04) were used as a part of a pulmonary 18 F-FDG PET/MRI protocol showed significantly higher sensitivities. Conclusion Fluorine 18-labeled fluorodeoxyglucose ( 18 F-FDG) PET/MRI was found to be accurate and comparable with 18 F-FDG PET/CT in the detection of malignant pulmonary lesions, with significantly improved sensitivity when advanced acquisition protocols were used. © RSNA, 2023 Supplemental material is available for this article.

Lung cancer remains the leading cancer-related death across North America. Imaging is fundamental. Recently, healthcare disparities came into research focus. Our aim was to explore disparity from an imaging, genetic, and outcome perspective. We utilized the AACR Project GENIE Biopharma Consortium (BPC) dataset v 1.1 to build a collated NSCLC dataset. Descriptive and analytical statistics were applied according to data characteristics. From 1849 patients, mean age was 64.4 y (±10.5), 58% ( n = 1065) were female, 23% ( n = 419) never smoked, 84% ( n = 1545) were of white race, and 57% ( n = 1052) were < stage III. No difference ( p > 0.05) was found for baseline imaging by race. White race showed higher 3-month surveillance imaging ( p = 0.048) and a baseline stage < IV (OR 0.61). KRAS (33.3 vs. 17.9%), STK11 (14.8 vs. 7.3%), and KEAP1 (13.3 vs. 5.3%) mutations were predominant among white patients while EGFR mutation (19.2 vs. 44.1%) was less predominant. Mutations in TP53 or KEAP1 had worse PFS and OS. The latter was also reduced in STK11, KRAS + STK11, and KRAS + KEAP1 mutations. Meanwhile, EGFR mutation had increased OS. Multivariate analysis showed that progression on imaging at 3 or 6 months (HR 1.69 and 1.43, respectively), TP53 (HR 1.37) and KRAS (HR 1.26) had lower OS while EGFR and LRP1B (HR 0.69 and 0.39, respectively) had higher OS. No racial disparity at baseline imaging was observed. Higher initial stages among non-white patients might reflect inequalities in accessing healthcare. However, race wasn't associated to OS. Finally, progression in imaging at 3 or 6 months showed the higher hazard ratios for death.

Purpose: The aim of the study is to evaluate the prognostic value of a joint evaluation of PET and CT radiomics combined with standard clinical parameters in patients with HL., Methods: Overall, 88 patients (42 female and 46 male) with a median age of 43.3 (range 21-85 years) were included. Textural analysis of the PET/CT images was performed using freely available software (LIFE X). 65 radiomic features (RF) were evaluated. Univariate and multivariate models were used to determine the value of clinical characteristics and FDG PET/CT radiomics in outcome prediction. In addition, a binary logistic regression model was used to determine potential predictors for radiotherapy treatment and odds ratios (OR), with 95% confidence intervals (CI) reported. Features relevant to survival outcomes were assessed using Cox proportional hazards to calculate hazard ratios with 95% CI., Results: albumin ( p = 0.034) + ALP ( p = 0.028) + CT radiomic feature GLRLM GLNU mean ( p = 0.012) (Area under the curve (AUC): 95% CI (86.9; 100.0)-Brier score: 3.9, 95% CI (0.1; 7.8) remained significant independent predictors for PFS outcome. PET-SHAPE Sphericity ( p = 0.033); CT grey-level zone length matrix with high gray-level zone emphasis (GLZLM SZHGE mean ( p = 0.028)); PARAMS XSpatial Resampling ( p = 0.0091) as well as hemoglobin results ( p = 0.016) remained as independent factors in the final model for a binary outcome as predictors of the need for radiotherapy (AUC = 0.79)., Conclusion: We evaluated the value of baseline clinical parameters as well as combined PET and CT radiomics in HL patients for survival and the prediction of the need for radiotherapy treatment. We found that different combinations of all three factors/features were independently predictive of the here evaluated endpoints.

We investigated the prognostic value of sarcopenia measurements and metabolic parameters of primary tumors derived from 18 F-FDG-PET/CT among patients with primary, metastatic esophageal and gastroesophageal cancer. A total of 128 patients (26 females; 102 males; mean age 63.5 ± 11.7 years; age range: 29-91 years) with advanced metastatic gastroesophageal cancer who underwent 18 F-FDG-PET/CT as part of their initial staging between November 2008 and December 2019 were included. Mean and maximum standardized uptake value (SUV) and SUV normalized by lean body mass (SUL) were measured. Skeletal muscle index (SMI) was measured at the level of L3 on the CT component of the 18 F-FDG-PET/CT. Sarcopenia was defined as SMI < 34.4 cm 2 /m 2 in women and <45.4 cm 2 /m 2 in men. A total of 60/128 patients (47%) had sarcopenia on baseline 18 F-FDG-PET/CT. Mean SMI in patients with sarcopenia was 29.7 cm 2 /m 2 in females and 37.5 cm 2 /m 2 in males. In a univariable analysis, ECOG (<0.001), bone metastases ( p = 0.028), SMI ( p = 0.0075) and dichotomized sarcopenia score ( p = 0.033) were significant prognostic factors for overall survival (OS) and progression-free survival (PFS). Age was a poor prognostic factor for OS ( p = 0.017). Standard metabolic parameters were not statistically significant in the univariable analysis and thus were not evaluated further. In a multivariable analysis, ECOG ( p < 0.001) and bone metastases ( p = 0.019) remained significant poor prognostic factors for OS and PFS. The final model demonstrated improved OS and PFS prognostication when combining clinical parameters with imaging-derived sarcopenia measurements but not metabolic tumor parameters. In summary, the combination of clinical parameters and sarcopenia status, but not standard metabolic values from 18 F-FDG-PET/CT, may improve survival prognostication in patients with advanced, metastatic gastroesophageal cancer.

The imaging report is essential for the communication between physicians in patient care. The information it contains must be clear, concise with evidence-based conclusions and sufficient to support clinical decision-making. In recent years, several classification schemes and/or reporting guidelines for PET have been introduced. In this manuscript, we will review the classifications most frequently used in oncology for interpreting and reporting 18 F-FDG PET imaging in lymphoma, multiple myeloma, melanoma and head and neck cancers, PSMA-ligand PET imaging for prostate cancer, and 68 Ga-DOTA-peptide PET in neuroendocrine tumors (NET)., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Murad, Kulanthaivelu, Ortega, Veit-Haibach and Metser.)

We investigate whether computed tomography (CT) derived radiomics may correlate with driver gene mutations in patients with pancreatic ductal adenocarcinoma (PDAC). In this retrospective study, 47 patients (mean age 64 ± 11 years; range: 42-86 years) with PDAC, who were treated surgically and who underwent preoperative CT imaging at our institution were included in the study. Image segmentation and feature extraction was performed semi-automatically with a commonly used open-source software platform. Genomic data from whole genome sequencing (WGS) were collected from our institution's web-based resource. Two statistical models were then built, in order to evaluate the predictive ability of CT-derived radiomics feature for driver gene mutations in PDAC. 30/47 of all tumor samples harbored 2 or more gene mutations. Overall, 81% of tumor samples demonstrated mutations in KRAS, 68% of samples had alterations in TP53, 26% in SMAD4 and 19% in CDKN2A. Extended statistical analysis revealed acceptable predictive ability for KRAS and TP53 (Youden Index 0.56 and 0.67, respectively) and mild to acceptable predictive signal for SMAD4 and CDKN2A (Youden Index 0.5, respectively). Our study establishes acceptable correlation of radiomics features and driver gene mutations in PDAC, indicating an acceptable prognostication of genomic profiles using CT-derived radiomics. A larger and more homogenous cohort may further enhance the predictive ability.

Purpose: Tumor hypoxia is associated with poor response to radiation (RT). We previously discovered a novel mechanism of metformin: enhancing tumor RT response by decreasing tumor hypoxia. We hypothesized that metformin would decrease tumor hypoxia and improve cervical cancer response to RT., Patients and Methods: A window-of-opportunity, phase II randomized trial was performed in stage IB-IVA cervical cancer. Patients underwent screening positron emission tomography (PET) imaging with hypoxia tracer fluoroazomycin arabinoside (FAZA). Only patients with FAZA uptake (hypoxic tumor) were included and randomized 2:1 to receive metformin in combination with chemoRT or chemoRT alone. A second FAZA-PET/CT scan was performed after 1 week of metformin or no intervention (control). The primary endpoint was a change in fractional hypoxic volume (FHV) between FAZA-PET scans, compared using the Wilcoxon signed-rank test. The study was closed early due to FAZA availability and the COVID-19 pandemic., Results: Of the 20 consented patients, 6 were excluded due to no FAZA uptake and 1 withdrew. FHV of 10 patients in the metformin arm decreased by an average of 10.2% (44.4%-34.2%) ± SD 16.9% after 1 week of metformin, compared with an average increase of 4.7% (29.1%-33.8%) ± 11.5% for the 3 controls (P = 0.027). Those with FHV reduction after metformin had significantly lower MATE2 expression. With a median follow-up of 2.8 years, the 2-year disease-free survival was 67% for the metformin arm versus 33% for controls (P = 0.09)., Conclusions: Metformin decreased cervical tumor hypoxia in this trial that selected for patients with hypoxic tumor. See related commentary by Lyng et al., p. 5233., (©2022 American Association for Cancer Research.)

We investigated, whether 18[18F]-FDG PET/CT-derived radiomics combined with sarcopenia measurements improves survival prognostication among patients with advanced, metastatic gastroesophageal cancer. In our study, 128 consecutive patients with advanced, metastatic esophageal and gastroesophageal cancer (n = 128; 26 females; 102 males; mean age 63.5 ± 11.7 years; age range: 29−91 years) undergoing 18[18F]-FDG PET/CT for staging between November 2008 and December 2019 were included. Segmentation of the primary tumor and radiomics analysis derived from PET and CT images was performed semi-automatically with a commonly used open-source software platform (LIFEX, Version 6.30, lifexsoft.org). Patients’ nutritional status was determined by measuring the skeletal muscle index (SMI) at the level of L3 on the CT component. Univariable and multivariable analyses were performed to establish a survival prediction model including radiomics, clinical data, and SMI score. Univariable Cox proportional hazards model revealed ECOG (<0.001) and bone metastasis (p = 0.028) to be significant clinical parameters for overall survival (OS) and progression free survival (PFS). Age (p = 0.017) was an additional prognostic factor for OS. Multivariable analysis showed improved prognostication for overall and progression free survival when adding sarcopenic status, PET and CT radiomics to the model with clinical parameters only. PET and CT radiomics derived from hybrid 18[18F]-FDG PET/CT combined with sarcopenia measurements and clinical parameters may improve survival prediction among patients with advanced, metastatic gastroesophageal cancer.

Purpose: Radiomics is an emerging imaging assessment technique that has shown promise in predicting survival among nasopharyngeal carcinoma (NPC) patients. Studies so far have focused on PET or MR-based radiomics independently. The aim of our study was to evaluate the prognostic value of clinical and radiomic parameters derived from both PET/CT and MR., Methods: Retrospective evaluation of 124 NPC patients with PET/CT and radiotherapy planning MR (RP-MR). Primary tumors were segmented using dedicated software (LIFEx version 6.1) from PET, CT, contrast-enhanced T1-weighted (T1-w), and T2-weighted (T2-w) MR sequences with 376 radiomic features extracted. Summary statistics describe patient, disease, and treatment characteristics. The Kaplan-Meier (KM) method estimates overall survival (OS) and progression-free survival (PFS). Clinical factors selected based on univariable analysis and the multivariable Cox model were subsequently constructed with radiomic features added., Results: The final models comparing clinical, clinical + RP-MR, clinical + PET/CT and clinical + RP-MR + PET/CT for OS and PFS demonstrated that combined radiomic signatures were significantly associated with improved survival prognostication (AUC 0.62 vs 0.81 vs 0.75 vs 0.86 at 21 months for PFS and 0.56 vs 0.85 vs 0.79 vs 0.96 at 24 months for OS). Clinical + RP-MR features initially outperform clinical + PET/CT for both OS and PFS (<18 months), and later in the clinical course for PFS (>42 months)., Conclusion: Our study demonstrated that PET/CT-based radiomic features may improve survival prognostication among NPC patients when combined with baseline clinical and MR-based radiomic features., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Kulanthaivelu, Kohan, Hinzpeter, Liu, Hope, Huang, Waldron, O’Sullivan, Ortega, Metser and Veit-Haibach.)

Objectives: Glutamate carboxypeptidase-II (GCP-II), a zinc metalloenzyme that resides in cell membrane, has been reported as overexpressed in the neovasculature of ovarian cancers. The study objective was to determine whether GCP-II targeted imaging with 18 F-DCFPyL PET/CT can detect disease sites in women with advanced high-grade serous ovarian cancer (HGSOC)., Materials and Methods: Twenty treatment-naïve women with advanced HGSOC were recruited (median age 60 years). Prior to commencing therapy (primary cytoreductive surgery [n=9] or neoadjuvant chemotherapy [n=11]), subjects underwent routine staging with contrast-enhanced abdominopelvic CT (=CT), followed by 18 F-DCFPyL PET/CT (=PET). CT and PET were reported independently using a standardized reporting template assessing 25 sites. The performance of PET was compared to CT in all subjects and to surgery and surgical histopathology in 9 patients who underwent primary cytoreductive surgery., Results: Of the 25 sites assessed in 20 patients, CT detected disease in 292/500 (58.4%) locations and PET detected disease in 171/500 (34.2%). Compared to CT the sensitivity (95% CI) of PET to detect disease in the upper abdomen, the gastrointestinal tract or the peritoneum was 0.29 (0.20,0.40), 0.21 (0.11,0.33) and 0.74 (0.64,0.82), respectively. In the surgical cohort, 220 sites in 9 patients were evaluated. The sensitivity and specificity of CT and PET were 0.85 versus 0.54 (p<0.001) and 0.73 versus 0.93 (p<0.001), respectively., Conclusion: Although 18 F-DCFPyL has higher specificity than CT in detecting advanced HGSOC tumor sites, it detects less disease sites than CT, especially in the upper abdomen and along the gastrointestinal tract, likely limiting its clinical utility., Clinical Trial Registration: ClinicalTrials.gov, NCT03811899., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Metser, Kulanthaivelu, Chawla, Johnson, Avery, Hussey, Veit-Haibach, Bernardini and Hogen.)

Background/rationale: PET/CT plays a crucial role in esophageal (EC) and gastroesophageal junction cancer (GEJ) diagnosis and management. Despite endorsement in clinical guidelines, variation in acceptance of PET/CT exists. The aim of this study was to assess the early use of PET/CT among EC and GEJ patients in a regionalized setting and identify factors contributing to disparity in access., Materials and Methods: Retrospective cohort study of adults with EC or GEJ between 2012 and 2014 from the Population Registry of Esophageal and Stomach Tumours of Ontario and Ontario Health (Cancer Care Ontario). Receipt of PET/CT and relevant demographics were collected, and statistical analysis performed. Continuous data were analysed with t-tests and Wilcoxon rank sum test. Categorical data were analysed with chi-square test. Kaplan-Meier methods were used to estimate median survival., Results: Fifty-five percent of patients diagnosed with EC or GEJ between 2012 and 2014 received PET/CT (1321/2390). Eighty-four percent of patients underwent surgical resection (729/870), and 80% receiving radical treatment (496/622) underwent PET/CT. The use of PET/CT increased from 2012 to 2014. Male patients received more PET/CT than females (85% vs.78% p  < 0.001).Median survival for the overall cohort was 11.1 months, 17.2 vs. 5.2 months among those who did and did not receive PET/CT and 35 vs. 27 months among the surgical cohort ( p  = 0.16)., Conclusions: We found that PET/CT use increased from 2012 to 2014 and that the majority of EC/GEJ patients being considered for curative therapy received PET/CT. There were also gender disparities identified. PET/CT appears to confer a potential survival benefit in our study, although our assessment is limited. Our findings may serve as learned lessons for other new imaging modalities, new indications for PET/CT or even for the introduction of new radiopharmaceuticals for PET/CT., Competing Interests: PV-H received (in the last 5 years) IIS grants from: Roche Pharmaceuticals, Siemens Healthineers and Speaker fees and travel support from Siemens Healthineers (all outside of this work). UM – POINT Biopharm Inc (consultant; unrelated to this work). The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2022 Gupta, Kulanthaivelu, Metser, Ortega, Darling, Coburn and Veit-Haibach.)

Background Data regarding 2-(3-{1-carboxy-5-[(6-[ 18 F]fluoro-pyridine 3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid ( 18 F-DCFPyL) PET in primary staging of prostate cancer (PCa) are limited. Purpose To compare the performance of 18 F-DCFPyL PET/CT or PET/MRI (PET) with bone scan and CT with or without multiparametric MRI (hereafter, referred to as conventional imaging) in the initial staging of men with unfavorable intermediate or high-risk PCa and to assess treatment change after PET. Materials and Methods This prospective study evaluated men with biopsy-proven, untreated, unfavorable intermediate or high-risk PCa with 0 to four metastases or equivocal for extensive metastases (more than four) who underwent PET between May 2018 and December 2020. The diagnostic performance of PET in detecting pelvic nodal and distant metastases was compared with conventional imaging alone. Metastatic sites at conventional imaging and PET were compared with a composite reference standard including histopathologic analysis, correlative imaging, and/or clinical and biochemical follow-up. The intended treatment before PET was compared with the treatment plan established after performing PET. Detection rate, sensitivity, and specificity of conventional imaging and PET were compared by using McNemar exact test on paired proportions. Results The study consisted of 108 men (median age, 66 years; IQR, 61-73 years) with no metastases ( n = 84), with oligometastases (four or fewer metastases; 22 men), or with equivocal findings for extensive metastases ( n = 2). Detection rates at PET and conventional imaging for nodal metastases were 34% (37 of 108) and 11% (12 of 108) ( P < .001), respectively, and those for distant metastases were 22% (24 of 108) and 10% (11 of 108) ( P = .02), respectively. PET altered stage in 43 of 108 (40%) and treatment in 24 of 108 (22%) men. The most frequent treatment change was from systemic to local-regional therapy in 10 of 108 (9%) and from local-regional to systemic therapy in nine of 108 (8%) men. Equivocal findings were encountered less frequently with PET (one of 108; 1%) than with conventional imaging (29 of 108; 27%). Conclusion Initial staging with 2-(3-{1-carboxy-5-[(6-[ 18 F]fluoro-pyridine 3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid ( 18 F-DCFPyL) PET after conventional imaging (bone scan and CT with or without multiparametric MRI) helped to detect more nodal and distant metastases than conventional imaging alone and changed treatment in 22% of men. Clinical trial registration no. NCT03535831, NCT03718260 © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Jadvar in this issue.

Background There is limited consensus regarding the relative diagnostic performance of cardiac MRI and fluorodeoxyglucose (FDG) PET for cardiac sarcoidosis. Purpose To perform a systematic review and meta-analysis to compare the diagnostic accuracy of cardiac MRI and FDG PET for cardiac sarcoidosis. Materials and Methods Medline, Ovid Epub, Cochrane Central Register of Controlled Trials, Embase, Emcare, and Scopus were searched from inception until January 2022. Inclusion criteria included studies that evaluated the diagnostic accuracy of cardiac MRI or FDG PET for cardiac sarcoidosis in adults. Data were independently extracted by two investigators. Summary accuracy metrics were obtained by using bivariate random-effects meta-analysis. Meta-regression was used to assess the effect of different covariates. Risk of bias was assessed using the Quality Assessment Tool for Diagnostic Accuracy Studies-2 tool. The study protocol was registered a priori in the International Prospective Register of Systematic Reviews (Prospero protocol CRD42021214776). Results Thirty-three studies were included (1997 patients, 687 with cardiac sarcoidosis); 17 studies evaluated cardiac MRI (1031 patients) and 26 evaluated FDG PET (1363 patients). Six studies directly compared cardiac MRI and PET in the same patients (303 patients). Cardiac MRI had higher sensitivity than FDG PET (95% vs 84%; P = .002), with no difference in specificity (85% vs 82%; P = .85). In a sensitivity analysis restricted to studies with direct comparison, point estimates were similar to those from the overall analysis: cardiac MRI and FDG PET had sensitivities of 92% and 81% and specificities of 72% and 82%, respectively. Covariate analysis demonstrated that sensitivity for FDG PET was highest with quantitative versus qualitative evaluation (93% vs 76%; P = .01), whereas sensitivity for MRI was highest with inclusion of T2 imaging (99% vs 88%; P = .001). Thirty studies were at risk of bias. Conclusion Cardiac MRI had higher sensitivity than fluorodeoxyglucose PET for diagnosis of cardiac sarcoidosis but similar specificity. Limitations, including risk of bias and few studies with direct comparison, necessitate additional study. © RSNA, 2022 Online supplemental material is available for this article.

Purpose: We aim determine the value of PET and CT radiomic parameters on survival with serial follow-up PET/CT in patients with nasopharyngeal carcinoma (NPC) for which curative intent therapy is undertaken., Methods: Patients with NPC and available pre-treatment as well as follow up PET/CT were included from 2005 to 2006 and were followed to 2021. Baseline demographic, radiological and outcome data were collected. Univariable Cox proportional hazard models were used to evaluate features from baseline and follow-up time points, and landmark analyses were performed for each time point., Results: Sixty patients were enrolled, and two-hundred and seventy-eight (278) PET/CT were at baseline and during follow-up. Thirty-eight percent (38%) were female, and sixty-two patients were male. All patients underwent curative radiation or chemoradiation therapy. The median follow-up was 11.72 years (1.26-14.86). Five-year and ten-year overall survivals (OSs) were 80.0% and 66.2%, and progression-free survival (PFS) was 90.0% and 74.4%. Time-dependent modelling suggested that, among others, PET gray-level zone length matrix (GLZLM) gray-level non-uniformity (GLNU) (HR 2.74 95% CI 1.06, 7.05) was significantly associated with OS. Landmark analyses suggested that CT parameters were most predictive at 15 month, whereas PET parameters were most predictive at time points 3, 6, 9 and 15 month., Conclusions: This study with long-term follow up data on NPC suggests that mainly PET-derived radiomic features are predictive for OS but not PFS in a time-dependent evaluation. Furthermore, CT radiomic measures may predict OS and PFS best at initial and long-term follow-up time points and PET measures may be more predictive in the interval. These modalities are commonly used in NPC surveillance, and prospective validation should be considered.