Project description:PurposeThis study aimed to evaluate the clinical utility of 18F-PSMA-1007 positron emission tomography (PSMA PET)/magnetic resonance imaging (MRI) imaging in patients with suspected or defined prostate cancer.MethodsIn the pilot study, we retrospectively investigated 62 patients who underwent PSMA-PET/MRI for suspected or defined PCa between June 2019 and June 2020. Patients were grouped into three subgroups: (1) suspected PCa without histological evidence, (2) primary PCa, (3) biochemical recurrent prostate cancer (BRPCa). Two nuclear physicians independently interpreted the results of PSMA-PET/MRI. Management strategies before PSMA-PET/MRI were retrospectively reported, and the management strategy was re-evaluated for each patient considering the PSMA-PET/MRI result. The changes in strategies were recorded. Besides, the correlation between prostate specific antigen (PSA) level and management changes was also accessed by Fisher exact test, and two-side p < 0.05 was assumed as statistical significance.ResultsThere were 28 patients in the suspected PCa group (group 1), 12 in the primary PCa group (group 2), and 22 in the BRPCa group (group 3). Overall, the intended decisions were changed in 26 (41.9%) of 62 patients after PSMA-PET/MRI, including 11/28 (39.3%) in suspected PCa group, 1/12 (8.4%) in primary PCa group, and 14/24 (63.6%) in BCR group. In group 1, the main impact on subsequent management included decreased active surveillance (from 20 to 9) and increased prostate biopsy (from 8 to 19). PSA levels were not significantly associated with management changes in suspected PCa patients (p = 0.865). In group 2, the main impact on subsequent management included decreased radical surgery (from 8 to 7), and multimodal therapy appearance (n = 1). Only in the category of PSA levels of ≥20 ng/ml, the management of primary PCa was changed. In group 3, the main impact on subsequent management included decreased salvage radiotherapy (from 5 to 2), increased systemic therapy (from 6 to 7), and increased multimodal therapy (from 11 to 13). The highest proportion of management changes occurred in BCR patients with 0.5≤PSA<1 ng/ml.ConclusionFrom our preliminary experience, PSMA-PET/MRI may be a valued tool for defining PCa lesions and changing management. The biggest impact of management intent was in patients with BRPCa, especially in patients with 0.5≤PSA<1 ng/ml. However, further studies are needed to confirm our pilot findings.
Project description:BackgroundThe diagnosis of cardiac implantable electronic device (CIED) infection is challenging because of its variable presentations. We studied the value of 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in the detection of CIED infection.Methods and resultsThirty patients with suspected CIED infection underwent 18F-FDG-PET/CT. The control group was ten patients with asymptomatic CIED who underwent cancer-related 18F-FDG-PET/CT. 18F-FDG-PET/CT was evaluated visually, semiquantitatively as maximum standardized uptake value (SUVmax) and target-to-background ratio (TBR). Final diagnosis of CIED infection was based on clinical and bacteriological data. 18F-FDG-PET/CT was visually positive in all 9 patients with recent (≤ 8 weeks) implantation of CIED, but only 4 had confirmed CIED infection. 18F-FDG-PET/CT was true positive in 9 out of 21 cases with remote implantation of CIED and false positive in 3 (14.3%) cases. 18F-FDG-PET/CT was also false positive in 3 (30%) cases of control group. The SUVmax of the pocket area was significantly higher in patients with CIED infection than in the control group (4.8 ± 2.4 vs 2.0 ± .8, P < .001). By using the cut-off value of TBR ≥ 1.8, sensitivity of 18F-FDG-PET/CT for the diagnosis of CIED infection in patients with remote implantation was 90% and specificity 73%, PPV 75%, and NPV 89%.Conclusions18F-FDG-PET/CT is a sensitive but nonspecific method in the diagnosis of CIED infection.
Project description:ObjectivesComputed tomography (CT) can perform comprehensive cardiac imaging. We compared CT coronary angiography (CTCA) and CT myocardial perfusion (CTP) with 15O-water positron emission tomography (PET) and invasive coronary angiography (ICA) with fractional flow reserve (FFR).Methods51 patients (63 (61-65) years, 80 % male) with known/suspected coronary artery disease (CAD) underwent 320-multidetector CTCA followed by "snapshot" adenosine stress CTP. Of these 22 underwent PET and 47 ICA/FFR. Obstructive CAD was defined as CTCA stenosis >50 % and CTP hypoperfusion, ICA stenosis >70 % or FFR <0.80.ResultsPET hyperaemic myocardial blood flow (MBF) was lower in obstructive than non-obstructive territories defined by ICA/FFR (1.76 (1.32-2.20) vs 3.11 (2.44-3.79) mL/(g/min), P < 0.001) and CTCA/CTP (1.76 (1.32-2.20) vs 3.12 (2.44-3.79) mL/(g/min), P < 0.001). Baseline and hyperaemic CT attenuation density was lower in obstructive than non-obstructive territories (73 (71-76) vs 86 (84-88) HU, P < 0.001 and 101 (96-106) vs 111 (107-114) HU, P 0.001). PET hyperaemic MBF corrected for rate pressure product correlated with CT attenuation density (r = 0.579, P < 0.001). There was excellent per-patient sensitivity (96 %), specificity (85 %), negative predictive value (90 %) and positive predictive value (94 %) for CTCA/CTP vs ICA/FFR.ConclusionCT myocardial attenuation density correlates with 15O-water PET MBF. CTCA and CTP can accurately identify obstructive CAD.Key points•CT myocardial perfusion can aid the assessment of suspected coronary artery disease. • CT attenuation density from "snapshot" imaging is a marker of myocardial perfusion. • CT myocardial attenuation density correlates with 15 O-water PET myocardial blood flow. • CT attenuation density is lower in obstructive territories defined by invasive angiography. • Diagnostic accuracy of CTCA+CTP is comparable to invasive angiography + fractional flow reserve.
Project description:Primary mediastinal germ cell tumor (MGCT) is an uncommon tumor. Although it has histology similar to that of gonadal germ cell tumor (GCT), the prognosis for MGCT is generally worse than that for gonadal GCT. We performed visual assessment and quantitative analysis of [18F]fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG PET/CT) for MGCTs. A total of 35 MGCT patients (age = 33.1 ± 16.8 years, F:M = 16:19) who underwent preoperative PET/CT were retrospectively reviewed. The pathologic diagnosis of MGCTs identified 24 mature teratomas, 4 seminomas, 5 yolk sac tumors, and 2 mixed germ cell tumors. Visual assessment was performed by categorizing the uptake intensity, distribution, and contour of primary MGCTs. Quantitative parameters including the maximum standardized uptake value (SUVmax), tumor-to-background ratio (TBR), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and maximum diameter were compared between benign and malignant MGCTs. On visual assessment, the uptake intensity was the only significant parameter for differentiating between benign and malignant MGCTs (p = 0.040). In quantitative analysis, the SUVmax (p < 0.001), TBR (p < 0.001), MTV (p = 0.033), and TLG (p < 0.001) showed significantly higher values for malignant MGCTs compared with benign MGCTs. In receiver operating characteristic (ROC) curve analysis of these quantitative parameters, the SUVmax had the highest area under the curve (AUC) (AUC = 0.947, p < 0.001). Furthermore, the SUVmax could differentiate between seminomas and nonseminomatous germ cell tumors (p = 0.042) and reflect serum alpha fetoprotein (AFP) levels (p = 0.012). The visual uptake intensity and SUVmax on [18F]FDG PET/CT showed discriminative ability for benign and malignant MGCTs. Moreover, the SUVmax may associate with AFP levels.
Project description:Identification of primary tumors and metastasis sites is an essential step in cancer diagnostics and the following treatment. Positron emission tomography-computed tomography (PET/CT) is one of the most reliable methods for scanning the whole organism for malignancies. In this work, we synthesized an 11C-labeled oligonucleotide primer and hybridized it to an anti-cancer DNA aptamer. The 11C-aptamer was applied for in vivo imaging of Ehrlich ascites carcinoma and its metastases in mice using PET/CT. The imaging experiments with the 11C-aptamer determined very small primary and secondary tumors of 3 mm2 and less. We also compared 11C imaging with the standard radiotracer, 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG), and found better selectivity of the 11C-aptamer to metastatic lesions in the metabolically active organs than 18F-FDG. 11C radionuclide with an ultra-short (20.38 min) half-life is considered safest for PET/CT imaging and does not cause false-positive results in heart imaging. Its combination with aptamers gives us high-specificity and high-contrast imaging of cancer cells and can be applied for PET/CT-guided drug delivery in cancer therapies.
Project description:Response to primary treatment in diffuse large B-cell lymphoma (DLBCL) is highly predictive of long-term outcome. We evaluated the value of computed tomography (CT) findings relative to positron emission tomography (PET) findings, after the completion of chemotherapy. We retrospectively reviewed records from 491 patients with DLBCL at M. D. Anderson in 2001-2007; 22 patients were excluded for uncertain pathology and 169 for having received consolidative radiation, leaving 300 patients for the present analysis (median age, 61 years; 53% men, 47% women; 27% stage I-II, 73% stage III-IV; 73% completed 6-8 cycles of doxorubicin-based therapy). Factors associated with outcome on univariate analysis were response according to PET/CT and CT (p < 0.0001 for overall survival [OS], disease-specific survival [DSS] and progression-free survival [PFS]); number of chemotherapy cycles received (p < 0.0001 OS, p < 0.0001 DSS, p < 0.002 PFS); the combined presence of Ki-67 > 50%, PET SUV ? 13 and bulky (> 5 cm) disease (p = 0.005 OS, p = 0.001 DSS, p = 0.001 PFS); and International Prognostic Index (IPI) score (p = 0.004 OS, p = 0.005 DSS, p = 0.004 PFS). On multivariate analysis, PET/CT-negative, CT residual mass (> 2 cm) significantly influenced OS, DSS and PFS (p < 0.0001). The presence of a residual mass >2 cm on CT, coupled with negative findings on PET/CT, has prognostic value in DLBCL.