Abstract Background In patients with marginal zone lymphoma (MZL), [ 18 F]FDG PET/CT provided inconsistent diagnostic accuracy. C-X-C motif chemokine receptor 4 (CXCR4) is overexpressed in MZL and thus, may emerge as novel theranostic target. We aimed to evaluate the diagnostic performance of CXCR4-targeting [ 68 Ga]Ga-PentixaFor when compared to [ 18 F]FDG PET/CT in MZL. Methods Thirty-two untreated MZL patients (nodal, n = 17; extranodal, n = 13; splenic, n = 2) received [ 68 Ga]Ga-PentixaFor and [ 18 F]FDG PET/CT within median 2 days. We performed a visual and quantitative analysis of the total lymphoma volume by measuring maximum/peak standardized uptake values (SUV max/peak ), and calculating target-to-background ratios (TBR, defined as lesion-based SUV peak divided by SUV mean from blood pool). Visual comparisons for both radiotracers were carried out for all target lesions (TL), and quantitative analysis of concordant TL evident on both scans. Last, MZL subtype analyses were also conducted. Results On a patient-based level, [ 68 Ga]Ga-PentixaFor identified MZL manifestations in 32 (100%) subjects (vs. [ 18 F]FDG, 25/32 [78.1%]). Of the 256 identified TL, 127/256 (49.6%) manifestations were evident only on CXCR4-directed imaging, while only 7/256 (2.7%) were identified on [ 18 F]FDG but missed by [ 68 Ga]Ga-PentixaFor. In the remaining 122/256 (47.7%) concordant TL, [ 68 Ga]Ga-PentixaFor consistently provided increased metrics when compared to [ 18 F]FDG: SUV max , 10.3 (range, 2.53–37.2) vs. 5.72 (2.32–37.0); SUV peak , 6.23 (1.58–25.7) vs. 3.87 (1.54–27.7); P < 0.01, respectively. Concordant TL TBR on [ 68 Ga]Ga-PentixaFor (median, 3.85; range, 1.05–16.0) was also approximately 1.8-fold higher relative to [ 18 F]FDG (median, 2.08; range, 0.81–28.8; P < 0.01). Those findings on image contrast, however, were driven by nodal MZL ( P < 0.01), and just missed significance for extranodal MZL ( P = 0.06). Conclusions In newly diagnosed MZL patients, [ 68 Ga]Ga-PentixaFor identified more sites of disease when compared to [ 18 F]FDG, irrespective of MZL subtype. Quantitative PET parameters including TBR were also higher on [ 68 Ga]Ga-PentixaFor PET/CT, suggesting improved diagnostic read-out using chemokine receptor-targeted imaging.
Abstract Background Fibroblast activation protein inhibitor (FAPI) targeting PET has been introduced as a novel molecular imaging modality for visualizing cancer-associated fibroblasts. There have also been reports suggesting incidental findings of localized accumulation in the shoulder joints. However, further characterization in a larger patient cohort is still lacking. Methods 77 consecutive patients (28 females; mean age, 63.1 ± 11.6) who underwent Ga-68 FAPI-04 PET/CT for diagnosis of solid tumors were included. The incidence and localization of tracer uptake in shoulder joints were investigated and compared with available F-18 FDG scans serving as reference. Results Ga-68 FAPI-04 uptake was evaluated in 77 patients (154 shoulder joints), of whom 54 subjects (108 shoulder joints) also had available F-18 FDG scans for head-to-head comparison. On FAPI-targeted imaging, 67/154 shoulders (43.5%) demonstrated increased radiotracer accumulation in target lesions, which were distributed as follows: acromioclavicular (AC) joints in 25/67 (37.3%), followed by glenohumeral and subacromial (GH + SA) joints in 23/67 (34.3%), or both (AC and GH + SA joints) in the remaining 19/67 (28.4%). Ga-68 FAPI-04 correlated with quantified F-18 FDG uptake (r = 0.69, p < 0.0001). Relative to the latter radiotracer, however, in-vivo FAP expression in the shoulders was significantly increased (Ga-68 FAPI-04, 4.7 ± 3.2 vs F-18 FDG, 3.6 ± 1.3, p < 0.001). Conclusion Our study revealed focal accumulation of Ga-68 FAPI-04 in the shoulders, particularly in the AC joints, with higher uptake compared to the inflammatory-directed PET radiotracer F-18 FDG in oncological studies. As a result, further trials are warranted to investigate the potential of FAPI-directed molecular imaging in identifying chronic remodeling in shoulder joints. This could have implications for initiating anti-FAP targeted photodynamic therapy based on PET signal strength.
Ziel/Aim Unser Ziel war es, den Einfluss der Fibroblasten-Aktivierungsprotein-Inhibitor (FAPI)-gerichteten PET/CT auf das Staging und das therapeutische Management bei Patient:innen mit Tumoren des Verdauungssystems im Vergleich zur leitliniengerechten Bildgebung zu bestimmen.
Background Recommended by current guidelines, prostate-specific membrane antigen (PSMA)–directed PET/CT is increasingly used in men with prostate cancer (PC). We aimed to provide concordance rates using the PSMA reporting and data system (RADS) for scan interpretation and also determine whether such agreement rates are affected by available patient characteristics at time of scan. Patients and Methods Sixty men with PC, who all underwent 68 Ga-PSMA-11 PET/CT, were included. Three independent, experienced readers indicated general scan parameters (including overall scan result, organ or lymph node [LN] involvement, and appropriateness of radioligand therapy). Applying PSMA-RADS 1.0, observers also had to conduct RADS scoring on a target lesion (TL) and overall scan level. During the first read, observers were masked to all relevant clinical information, whereas on a second read, relevant patient characteristics were displayed, thereby allowing for determination of impact of available clinical information for scan interpretation. We used intraclass correlation coefficients (ICCs; with 95% confidence intervals [CIs]), which were then rated according to Cicchetti (0.4–0.59 fair, 0.6–0.74 good, and 0.75–1 excellent agreement). Results For general parameters, agreement rates were excellent, including an overall scan result (ICC, 0.85; 95% CI, 0.76–0.90), LN metastases (ICC, 0.89; 95% CI, 0.83–0.93), organ involvement (ICC, 0.82; 95% CI, 0.72–0.89), and indication for radioligand therapy (ICC, 0.94; 95% CI, 0.90–0.96). Overall RADS scoring was also excellent with an ICC of 0.91 (95% CI, 0.96–09.4). On a TL-based level, 251 different lesions were selected by the 3 observers (with 73 chosen by all 3 readers). RADS-based concordance rates were fair to excellent: all lesions, ICC of 0.78 (95% CI, 0.67–0.85); LN, ICC of 0.81 (95% CI, 0.63–0.92); skeleton, ICC of 0.55 (95% CI, 0–0.84); and prostate, ICC of 0.48 (95% CI, 0.17–0.78). When performing a second read displaying patient’s characteristics, there were only minor modifications to the previously applied RADS scoring on a TL-based level (overall, n = 8): each reader 1 and 2 in 3/60 (5%) instances, and reader 3 in 2/60 (3.3%) instances. The main reason for recategorization (mainly upstaging) was provided information on PSA levels (4/8, 50%). Conclusions Applying PSMA-RADS, concordance rates were fair to excellent, whereas relevant modifications were rarely observed after providing clinical data. As such, even in the absence of patient information, standardized frameworks still provide guidance for reading PSMA PETs. Those findings may have implications for a high throughput in a busy PET practice, where patient details cannot always be retrieved at time of scan interpretation or in the context of clinical trials or central reviews in which readers may be blinded to clinical data.
We aimed to determine the impact of fibroblast activation protein inhibitor (FAPI)-directed molecular imaging on staging and therapeutic management in patients affected with digestive system tumors when compared with guideline-compatible imaging (GCI).Thirty-two patients with tumors of the digestive system were included: colon adenocarcinoma, 2/32 (6.3%); hepatocellular carcinoma (HCC), 6/32 (18.8%); pancreatic duct adenocarcinoma (PDAC), 6/32 (18.8%), and gastroenteropancreatic neuroendocrine neoplasms, 18/32 (56.3%). All patients underwent GCI and 68 Ga-FAPI-04 PET/CT within median 4 days. Staging outcomes and subsequent treatment decisions were compared between GCI and 68 Ga-FAPI-04 PET/CT.Compared with GCI, 68 Ga-FAPI-04 PET/CT led to staging changes in 15/32 patients (46.9%). Among those, downstaging was recorded in 3/15 cases (20.0%) and upstaging in the remaining 12/15 patients (HCC, 4/12 [33.3%]; PDAC, 4/12 [33.3%]; neuroendocrine neoplasms, 3/12 [25%]; colon adenocarcinoma, 1/12 [8.3%]). Therapeutic management was impacted in 8/32 patients (25.0%), including 4 instances of major and 4 instances of minor therapeutic changes. The highest proportion of treatment modifications was observed in patients diagnosed with PDAC and HCC in 6/8 (75%).In patients affected with digestive system tumors, 68 Ga-FAPI-04 PET/CT resulted in staging changes in more than 46% and therapeutic modifications in 25% of the cases, in particular in patients with HCC and PDAC. In clinical routine, such findings may favor a more widespread adoption of FAP-directed imaging in those tumor types.We aimed to determine the impact of fibroblast activation protein inhibitor (FAPI)–directed molecular imaging on staging and therapeutic management in patients affected with digestive system tumors when compared with guideline-compatible imaging (GCI).Thirty-two patients with tumors of the digestive system were included: colon adenocarcinoma, 2/32 (6.3%); hepatocellular carcinoma (HCC), 6/32 (18.8%); pancreatic duct adenocarcinoma (PDAC), 6/32 (18.8%), and gastroenteropancreatic neuroendocrine neoplasms, 18/32 (56.3%). All patients underwent GCI and 68 Ga-FAPI-04 PET/CT within median 4 days. Staging outcomes and subsequent treatment decisions were compared between GCI and 68 Ga-FAPI-04 PET/CT.Compared with GCI, 68 Ga-FAPI-04 PET/CT led to staging changes in 15/32 patients (46.9%). Among those, downstaging was recorded in 3/15 cases (20.0%) and upstaging in the remaining 12/15 patients (HCC, 4/12 [33.3%]; PDAC, 4/12 [33.3%]; neuroendocrine neoplasms, 3/12 [25%]; colon adenocarcinoma, 1/12 [8.3%]). Therapeutic management was impacted in 8/32 patients (25.0%), including 4 instances of major and 4 instances of minor therapeutic changes. The highest proportion of treatment modifications was observed in patients diagnosed with PDAC and HCC in 6/8 (75%).In patients affected with digestive system tumors, 68 Ga-FAPI-04 PET/CT resulted in staging changes in more than 46% and therapeutic modifications in 25% of the cases, in particular in patients with HCC and PDAC. In clinical routine, such findings may favor a more widespread adoption of FAP-directed imaging in those tumor types.
Purpose To compare radiation dose, subjective and objective image quality of 3 rd generation dual-source CT (DSCT) and dual-energy CT (DECT) with conventional 64-slice single-source CT (SSCT) for pulmonary CTA. Materials and Methods 180 pulmonary CTA studies were performed in three patient cohorts of 60 patients each. Group 1: conventional SSCT 120 kV (ref.); group 2: single-energy DSCT 100 kV (ref.); group 3: DECT 90/Sn150 kV. CTDIvol, DLP, effective radiation dose were reported, and CT attenuation (HU) was measured on three central and peripheral levels. The signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) were calculated. Two readers assessed subjective image quality according to a five-point scale. Results Mean CTDIvol and DLP were significantly lower in the dual-energy group compared to the SSCT group (p < 0.001 [CTDIvol]; p < 0.001 [DLP]) and the DSCT group (p = 0.003 [CTDIvol]; p = 0.003 [DLP]), respectively. The effective dose in the DECT group was 2.79 ± 0.95 mSv and significantly smaller than in the SSCT group (4.60 ± 1.68 mSv, p < 0.001) and the DSCT group (4.24 ± 2.69 mSv, p = 0.003). The SNR and CNR were significantly higher in the DSCT group (p < 0.001). Subjective image quality did not differ significantly among the three protocols and was rated good to excellent in 75 % (135/180) of cases with an inter-observer agreement of 80 %. Conclusion Dual-energy pulmonary CTA protocols of 3 rd generation dual-source scanners allow for significant reduction of radiation dose while providing excellent image quality and potential additional information by means of perfusion maps. Key Points: Citation Format
• The deep learning algorithm detected intracranial hemorrhage (ICH) with 91.0% accuracy (sensitivity 91.4% specificity 90.4%). • In comparison with the assigned radiologist, the deep learning algorithm was able to highlight presence of ICH significantly faster. • In ensemble, the algorithm and the radiologist detected presence of ICH with sensitivity of 100% in a small clinical cohort. We evaluate the performance of a deep learning-based pipeline using a Dense U-net architecture for detection of intracranial hemorrhage (ICH) in unenhanced head computed tomography (CT) scans. A balanced database was assembled retrospectively, comprising a total of 872 CT scans (362 with present ICH). Predictions by the algorithm were analyzed and compared to the radiology report (ground truth). Secondly, the algorithm's performance was tested in clinical environment: A total of 100 head CT scans (11 with present ICH) were analyzed simultaneously by the deep learning algorithm and a radiologist during clinical routine. The time until first temporary diagnosis of ICH was measured. Performances of the algorithm were evaluated in combination with the radiologist, when using it as triage tool. In the retrospectively assembled dataset the deep learning algorithm detected ICH with a sensitivity of 91.4%, specificity of 90.4% and overall accuracy of 91.0%. In clinical environment, the algorithm was significantly faster compared to the temporary report of the assigned radiologist (24 ± 2 s vs. 613 ± 658 s, p < 0.001). When using the algorithm as a triage tool additional to the report of the assigned radiologist, a sensitivity of 100% was achieved. These results and the short processing time demonstrate the immense potential of deep learning applications for the use as triage tool and for additional review of manual reports.
A key step in translational cardiovascular research is the use of large animal models to better understand normal and abnormal physiology, to test drugs or interventions, or to perform studies which would be considered unethical in human subjects. Ultrahigh field magnetic resonance imaging (UHF-MRI) at 7 T field strength is becoming increasingly available for imaging of the heart and, when compared to clinically established field strengths, promises better image quality and image information content, more precise functional analysis, potentially new image contrasts, and as all
