| 1. |
- Gålne, Anni, et al.
(författare)
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AI-based quantification of whole-body tumour burden on somatostatin receptor PET/CT
- 2023
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Ingår i: European Journal of Hybrid Imaging. - 2510-3636. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Segmenting the whole-body somatostatin receptor-expressing tumour volume (SRETVwb) on positron emission tomography/computed tomography (PET/CT) images is highly time-consuming but has shown value as an independent prognostic factor for survival. An automatic method to measure SRETVwb could improve disease status assessment and provide a tool for prognostication. This study aimed to develop an artificial intelligence (AI)-based method to detect and quantify SRETVwb and total lesion somatostatin receptor expression (TLSREwb) from [68Ga]Ga-DOTA-TOC/TATE PET/CT images. Methods: A UNet3D convolutional neural network (CNN) was used to train an AI model with [68Ga]Ga-DOTA-TOC/TATE PET/CT images, where all tumours were manually segmented with a semi-automatic method. The training set consisted of 148 patients, of which 108 had PET-positive tumours. The test group consisted of 30 patients, of which 25 had PET-positive tumours. Two physicians segmented tumours in the test group for comparison with the AI model. Results: There were good correlations between the segmented SRETVwb and TLSREwb by the AI model and the physicians, with Spearman rank correlation coefficients of r = 0.78 and r = 0.73, respectively, for SRETVwb and r = 0.83 and r = 0.81, respectively, for TLSREwb. The sensitivity on a lesion detection level was 80% and 79%, and the positive predictive value was 83% and 84% when comparing the AI model with the two physicians. Conclusion: It was possible to develop an AI model to segment SRETVwb and TLSREwb with high performance. A fully automated method makes quantification of tumour burden achievable and has the potential to be more widely used when assessing PET/CT images.
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| 2. |
- Hvittfeldt, Erland, et al.
(författare)
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PET/CT imaging 2 h after injection of [18F]PSMA-1007 can lead to higher staging of prostate cancer than imaging after 1 h
- 2023
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Ingår i: European journal of hybrid imaging. - 2510-3636. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: [18F]PSMA-1007 is a prostate specific membrane antigen (PSMA) ligand for positron emission tomography (PET) imaging of prostate cancer. Current guidelines recommend imaging 90–120 min after injection but strong data about optimal timing is lacking. Our aim was to study whether imaging after 1 h and 2 h leads to a different number of detected lesions, with a specific focus on lesions that might lead to a change in treatment. Methods: 195 patients underwent PET with computed tomography imaging 1 and 2 h after injection of [18F]PSMA-1007. Three readers assessed the status of the prostate or prostate bed and suspected metastases. We analyzed the location and number of found metastases to determine N- and M-stage of patients. We also analyzed standardized uptake values (SUV) in lesions and in normal tissue. Results: Significantly more pelvic lymph nodes and bone metastases were found and higher N- and M-stages were seen after 2 h. In twelve patients (6.1%) two or three readers agreed on a higher N- or M-stage after 2 h. Conversely, in two patients (1.0%), two readers agreed on a higher stage at 1 h. SUVs in suspected malignant lesions and in normal tissues were higher at 2 h, but lower in the blood pool and urinary bladder. Conclusions: Imaging at 2 h after injection of [18F]PSMA-1007 leads to more suspected metastases found than after 1 h, with higher staging in some patients and possible effect on patient treatment.
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| 3. |
- Hyafil, Fabien, et al.
(författare)
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EANM procedural guidelines for myocardial perfusion scintigraphy using cardiac-centered gamma cameras
- 2019
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Ingår i: European Journal of Hybrid Imaging. - : Springer Nature. - 2510-3636. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- An increasing number of Nuclear Medicine sites in Europe are using cardiac-centered gamma cameras for myocardial perfusion scintigraphy (MPS). Three cardiac-centered gamma cameras are currently the most frequently used in Europe: the D-SPECT (Spectrum Dynamics), the Alcyone (Discovery NM 530c and Discovery NM/CT 570c; General Electric Medical Systems), and the IQ-SPECT (Siemens Healthcare). The increased myocardial count sensitivity of these three cardiac-centered systems has allowed for a decrease in the activities of radiopharmaceuticals injected to patients for myocardial perfusion imaging and, consequently, radiation exposure of patients. When setting up protocols for MPS, the overall objective should be to maintain high diagnostic accuracy of MPS, while injecting the lowest activities reasonably achievable to reduce the level of radiation exposure of patient and staff. These guidelines aim at providing recommendations for acquisition protocols and image interpretation using cardiac-centered cameras. As each imaging system has specific design and features for image acquisition and analysis, these guidelines have been separated into three sections for each gamma camera system. These recommendations have been written by the members of the Cardiovascular Committee of EANM and were based on their own experience with each of these systems and on the existing literature.
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| 4. |
- Kjölhede, Henrik, 1981, et al.
(författare)
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Pre-treatment 18F-choline PET/CT is prognostic for biochemical recurrence, development of bone metastasis, and cancer specific mortality following radical local therapy of high-risk prostate cancer.
- 2018
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Ingår i: European journal of hybrid imaging. - : Springer Science and Business Media LLC. - 2510-3636. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to determine whether lymph node metastasis on pre-treatment 18F-choline PET/CT is an independent prognostic factor for biochemical recurrence (BCR), skeletal metastasis, and cancer specific mortality (CSM), after radical local treatment (radical prostatectomy and/or radiotherapy) in men with high-risk prostate cancer. Medical records were reviewed for men with newly diagnosed high-risk prostate cancer who had pre-treatment 18F-choline positron emission tomography fused with computed tomography (PET/CT) scan for primary metastasis staging.Of 174 eligible men, 124 met the criteria for inclusion. The PET/CT scan was negative for metastasis in 97 (78%) men, inconclusive in 15 (12%), and positive in 12 (10%). The men with a positive PET/CT scan had significantly shorter time to BCR (p=0.02), time to skeletal metastasis (p=0.002), and time to prostate cancer specific death (p<0.001). On multivariable Cox regression analysis, including also tumour stage, Gleason score, and PSA, a non-negative PET/CT scan was the only significant covariate for time to BCR (HR 2.6, 95% CI 1.3-5.5) and time to skeletal metastasis (HR 2.7, 95% CI 1.3-5.9).In men with a newly diagnosed high-risk prostate cancer and a negative or inconclusive bone scan, 18F-choline uptake on PET/CT suggestive metastasis was associated with recurrence, progression to distant metastasis, and prostate cancer death. This strongly indicates that the choline uptakes represented metastasis and not false positive findings.
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| 5. |
- Kvernby, Sofia, et al.
(författare)
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Quantitative comparison of data-driven gating and external hardware gating for 18F-FDG PET-MRI in patients with esophageal tumors
- 2021
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Ingår i: European Journal of Hybrid Imaging. - : Springer Nature. - 2510-3636. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundRespiratory motion during PET imaging reduces image quality. Data-driven gating (DDG) based on principal component analysis (PCA) can be used to identify respiratory signals. The use of DDG, without need for external devices, would greatly increase the feasibility of using respiratory gating in a routine clinical setting. The objective of this study was to evaluate data-driven gating in relation to external hardware gating and regular static image acquisition on PET-MRI data with respect to SUVmax and lesion volumes.MethodsSixteen patients with esophageal or gastroesophageal cancer (Siewert I and II) underwent a 6-min PET scan on a Signa PET-MRI system (GE Healthcare) 1.5-2 h after injection of 4 MBq/kg F-18-FDG. External hardware gating was done using a respiratory bellow device, and DDG was performed using MotionFree (GE Healthcare). The DDG raw data files and the external hardware-gating raw files were created on a Matlab-based toolbox from the whole 6-min scan LIST-file. For comparison, two 3-min static raw files were created for each patient. Images were reconstructed using TF-OSEM with resolution recovery with 2 iterations, 28 subsets, and 3-mm post filter. SUVmax and lesion volume were measured in all visible lesions, and noise level was measured in the liver. Paired t-test, linear regression, Pearson correlation, and Bland-Altman analysis were used to investigate difference, correlation, and agreement between the methods.ResultsA total number of 30 lesions were included in the study. No significant differences between DDG and external hardware-gating SUVmax or lesion volumes were found, but the noise level was significantly reduced in the DDG images. Both DDG and external hardware gating demonstrated significantly higher SUVmax (9.4% for DDG, 10.3% for external hardware gating) and smaller lesion volume (- 5.4% for DDG, - 6.6% for external gating) in comparison with non-gated static images.ConclusionsData-driven gating with MotionFree for PET-MRI performed similar to external device gating for esophageal lesions with respect to SUVmax and lesion volume. Both gating methods significantly increased the SUVmax and reduced the lesion volume in comparison with non-gated static acquisition. DDG resulted in reduced image noise compared to external device gating and static images.
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| 6. |
- Pihl, Vilhelm, et al.
(författare)
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FDG-PET/CT for lymph node staging prior to radical cystectomy
- 2023
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Ingår i: European Journal of Hybrid Imaging. - 2510-3636. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: 18F-Fluorodeoxyglucose positron emission combined with computed tomography (FDG-PET/CT) has been proposed to improve preoperative staging in patients with bladder cancer subjected to radical cystectomy (RC).Objective: Our aim was to assess the accuracy of FDG-PET/CT for lymph node staging ascertained at the multidisciplinary tumour board compared to lymph node status in the surgical lymphadenectomy specimen obtained at RC, and to explore potential factors associated with false-positive FDG-PET/CT results.Design, setting and participants: Consecutive patients with bladder cancer undergoing RC with extended lymph node dissection between 2011 and 2019 without preoperative chemotherapy in a tertial referral cystectomy unit were included in the study.Outcome measurements and statistical analyses: Sensitivity, specificity, positive and negative predictive values and likelihood ratios were calculated. Potential factors investigated for association with false-positive FDG-PET/CT were; bacteriuria within four weeks prior to FDG-PET/CT, Bacillus Calmette–Guerin (BCG) treatment within 12 months prior to FDG-PET/CT and transurethral resection of bladder tumour (TURB) within four weeks prior to FDG-PET/CT.Results: Among 157 patients included for analysis, 44 (28%) were clinically node positive according to FDG-PET/CT. The sensitivity and specificity for detection of lymph node metastasis were 50% and 84%, respectively, and the corresponding positive predictive and negative predictive values were 61% and 76%. Positive and negative likelihood ratios were 3.0 and 0.6, respectively. No association was found between bacteriuria, previous BCG treatment or TURB within 28 days and false-positive FDG-PET/CT results.Conclusions: Preoperative FDG-PET/CT prior to RC had a clinically meaningful high specificity (84%) but lower sensitivity (50%) for detection of lymph node metastases compared to lymph node status in an extended pelvic lymphadenectomy template. We could not identify any factors associated with false-positive FDG-PET/CT outcomes.
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| 7. |
- Regula, Naresh Kumar, et al.
(författare)
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Comparison of Ga-68-PSMA PET/CT with fluoride PET/CT for detection of bone metastatic disease in prostate cancer
- 2022
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Ingår i: European Journal of Hybrid Imaging. - : Springer Nature. - 2510-3636. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- Background F-18-NaF positron emission tomography/computed tomography (fluoride PET/CT) is considered the most sensitive technique to detect bone metastasis in prostate cancer (PCa). Ga-68-PSMA-11 (PSMA) PET/CT is increasingly used for staging of PCa. This study primarily aimed to compare the diagnostic performance of fluoride PET/CT and gallium-based PSMA PET/CT in identifying bone metastasis followed by a comparison of PSMA PET/CT with contrast-enhanced CT (CE-CT) in identifying soft tissue lesions as a secondary objective. Methods Twenty-eight PCa patients with high suspicion of disseminated disease following curative treatment were prospectively evaluated. PET/CT examinations using fluoride and PSMA were performed. All suspicious bone lesions were counted, and the tracer uptake was measured as standardized uptake values (SUV) for both tracers. In patients with multiple findings, ten bone lesions with highest SUVmax were selected from which identical lesions from both scans were considered for direct comparison of SUVmax. Soft tissue findings of local and lymph node lesions from CE-CT were compared with PSMA PET/CT. Results Both scans were negative for bone lesions in 7 patients (25%). Of 699 lesions consistent with skeletal metastasis in 21 patients on fluoride PET/CT, PSMA PET/CT identified 579 lesions (83%). In 69 identical bone lesions fluoride PET/CT showed significantly higher uptake (mean SUVmax: 73.1 +/- 36.8) compared to PSMA PET/CT (34.5 +/- 31.4; p < 0.001). Compared to CE-CT, PSMA PET/CT showed better diagnostic performance in locating local (96% vs 61%, p = 0.004) and lymph node (94% vs 46%, p < 0.001) metastasis. Conclusion In this prospective comparative study, PSMA PET/CT detected the majority of bone lesions that were positive on fluoride PET/CT. Further, this study indicates better diagnostic performance of PSMA PET/CT to locate soft tissue lesions compared to CE-CT.
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| 8. |
- Valind, Kristian, et al.
(författare)
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[18F]PSMA-1007 PET is comparable to [99mTc]Tc-DMSA SPECT for renal cortical imaging.
- 2023
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Ingår i: European journal of hybrid imaging. - 2510-3636. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Scintigraphy using technetium-99m labelled dimercaptosuccinic acid ([99mTc]Tc-DMSA), taken up in the proximal tubules, is the standard in functional imaging of the renal cortex. Recent guidelines recommend performing [99mTc]Tc-DMSA scintigraphy with single photon emission computed tomography (SPECT). Prostate-specific membrane antigen (PSMA) targeted positron emission tomography (PET) is used for staging and localization of recurrence in prostate cancer. A high renal uptake is often seen on PSMA PET, concordant with known PSMA expression in proximal tubules. This suggests PSMA PET could be used analogous to [99mTc]Tc-DMSA scintigraphy for renal cortical imaging. [18F]PSMA-1007 is a promising radiopharmaceutical for this purpose due to low urinary clearance. In this study, we aimed to compare [18F]PSMA-1007 PET to [99mTc]Tc-DMSA SPECT regarding split renal uptake and presence of renal uptake defects, in patients with prostate cancer. Three readers interpreted PET and SPECT images regarding presence of renal uptake defects, with each kidney split into cranial, mid and caudal segments. Kidneys were segmented in PET and SPECT images, and left renal uptake as a percentage of total renal uptake was measured. RESULTS: Twenty patients with prostate cancer were included. 2 participants had single kidneys; thus 38 kidneys were evaluated. A total of 29 defects were found on both [99mTc]Tc-DMSA SPECT and [18F]PSMA-1007 PET. Cohen's kappa for concordance regarding presence of any defect was 0.76 on a per-segment basis and 0.67 on a per-kidney basis. Spearman's r for left renal uptake percentage between [99mTc]Tc-DMSA SPECT and [18F]PSMA-1007 PET was 0.95. CONCLUSIONS: [18F]PSMA-1007 PET is comparable to [99mTc]Tc-DMSA SPECT for detection of uptake defects in this setting. Measurements of split renal function made using [18F]PSMA-1007 PET are valid and strongly correlated to measurements made with [99mTc]Tc-DMSA SPECT.
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