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A 58-year-old man, known case of muscle invasive high-grade urinary bladder cancer, underwent radical cystectomy with extended pelvic lymph node dissection and ileal conduit diversion 2 years ago. Histopathology showed urothelial cancer with detrusor muscle invasion, grade 2, all margins, prostate

Objective To analyse the available literature on the prognostic value of preoperative 18F-FDG PET/CT metabolic parameters and their usefulness in risk stratification in patients with endometrial cancer (EC). Material and methods Pubmed searches used “(endometr* OR uter*) AND (PET OR FDG)” as keywords from January-2000 to June-2020. References in included articles were checked for possible publications not included in the first search. Studies evaluating the prognostic value of preoperative 18F-FDG PET/CT and its role for risk stratification in patients with EC were included. Non-original articles (reviews, editorials, letters, legal cases, interviews, case reports, etc.) were not included. Results Twenty-six studies (1918 patients) were selected according to the inclusion criteria in this review. Thirteen studies (939 patients) related to the prognostic role of preoperative 18F-FDG PET/CT and 14 studies (1036 patients) related to its role in risk stratification were included. Parameters such as SUVmax, metabolic tumour volume (MTV) and total lesion glycolysis (TLG) of the primary tumour were analysed. Conclusions Preoperative SUVmax is useful for non-invasive diagnosis and for deciding the appropriate therapeutic strategy, as it could be used as an independent prognostic marker for recurrence and survival in EC. In addition, both preoperative VTM and GTL could be independent prognostic factors for predicting recurrence and survival, but there is still insufficient scientific evidence. The usefulness of SUVmax for risk stratification is limited (there is insufficient literature that 18F-FDG PET/CT can replace surgical staging), although VTM and GTL are more accurate and have a valuable role in risk stratification of EC. However, larger multicentre studies with adequate follow-up time are needed to confirm these findings.

Background The assumption that increased [18F] fluoro-2-deoxy-d-glucose (FDG) uptake in hilar nodes on PET/CT imaging is indicative of distant metastasis can result in palliative rather than curative care in patients with esophageal cancer. This study aims to determine the significance of increased FDG uptake in hilar nodes in patients with potentially curable, locally advanced disease at initial staging. Methods We included patients with biopsy-proven esophageal carcinoma who had pretreatment FDG-PET/CT at initial staging, and follow-up imaging >1 year. We excluded patients with distant hematogeneous metastases. Hilar nodes were considered concerning for metastatic disease when SUV max was >2.5 or FDG uptake was visually > mediastinal background were examined. Results We reviewed FDG-PET CT scans from 806 patients treated for esophageal cancer from 2010-2018 and identified 42 patients with FDG avid hilar adenopathy. Thirteen patients underwent histological assessment and 29 were followed with imaging. None of the 42 patients were found to have distant metastatic disease on initial work up and all were treated curatively. In follow up, 2/42 patients eventually manifested hilar nodal metastases after treatment; one who had a biopsy-negative hilar node at initial staging and another who did not have a biopsy of the hilar node. Conclusions Increased FDG uptake in hilar nodes in patients with localized esophageal cancer was not indicative of non-regional nodal metastasis. Patients in these situations should be approached with curative intent. The need for biopsy of FDG avid hilar nodes in this cohort should be carefully considered due to the low diagnostic utility.

Introduction The Pentoxifylline, Tocopherol and Clodronate protocol (PENTOCLO) showed promising results for jaw osteoradionecrosis (ORN) management. However, the clinical and radiological improvements are often delayed, leading to unwanted long-term treatment, with potential loss of opportunity for more radical surgical treatments. Our objective was to assess the diagnosis performance of 18F-FDG PET/CT to early predict ORN response to the PENTOCLO protocol. Materials and methods All patients from our center who were treated with the PENTOCLO protocol and with a 18F-FDG PET/CT performed at diagnosis and three months after the end of antibiotherapy were retrospectively included. The PENTOCLO protocol was always combined with prior appropriate antibiotherapy for six weeks. The healing endpoint was divided into healing, stability or worsening, according to the combination of clinical and radiological assessments at the date of last follow-up. For each patient, the difference between the maximal standardized uptake value (ΔSUVmax) of the ORN lesion at three months and baseline were computed. Diagnostic performance of 18F-FDG PET/CT was evaluated by sensitivity, specificity and the area under the receiver operating characteristic curve (ROC-AUC) of ΔSUVmax. Results 24 patients were included with an average follow-up of 29.3 months. The healing, stability and worsening rate were 25%, 62.5% and 12.5% respectively. The AUC for discriminating worsening vs stability or healing was 0.92 (IC95 [0.81-1.00]). A ΔSUVmax greater than or equal to 0 was predictive of a worsening with a sensitivity and specificity of 84 and 66% respectively. Conclusion 18F-FDG PET/CT imaging could be useful for early prediction of PENTOCLO treatment resistance with appropriate antibiotherapy.

Introduction and objectives The human immunodeficiency virus [HIV] is a lentevirus, primarily infects certain cells of the immune system, thereby greatly weakens the body’s own defenses against diseases. This study was aimed to explore the value and significance of 18F-FDG PET/CT in the assessment of patients with HIV infection and to examine the presence of quantitative alterations in 18F-FDG uptake among patients with HIV-related infections or malignant diseases in HIV-positive patients. Patients and methods Forty patients with HIV infection were scanned on PET/CT system. The data were registered according to immune status, antiretroviral therapy, and definitive diagnosis. All pathologic lesions and disease related areas were described, 18F-FDG uptake patterns were evaluated. Semiquantitative analysis of 18F-FDG uptake was performed and SUVmax were calculated. Results Twenty-eight patients [70%] were diagnosed with HIV-related infection or malignant diseases. The sensitivity of PET/CT was shown to be 100% and the specificity 92% for concomitant diseases requiring additional treatment to antiretroviral therapy. The SUVmax and CD4 counts were not statistically different between HIV-related reactive lymphadenopathy, HIV-related malignancy, and HIV-related infections. Conclusions The pattern of distribution of nodal/extranodal uptake on 18F-FDG PET/CT may facilitate distinction between HIV-related generalized lymphadenopathies, HIV-related opportunistic infections, and malignancies. In this context, 18F-FDG PET/CT should be preferred for routine use in the management of patients infected with HIV.

Diagnosis of infective endocarditis can be challenging for clinicians, especially when involving prosthetic valves. Recent data suggest that 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) could be a useful diagnostic tool in this setting. Here, we report a case of a patient with an aortic biological prosthesis who presented with a history of fever and fatigue. Echocardiograms were negative for vegetations. The 18F-FDG PET/CT revealed an infective process of the valve and serological tests were positive for chronic Coxiella burnetii infection. Specific treatment for chronic Q fever endocarditis was, therefore, started and the response was monitored using 18F-FDG PET/CT. This case highlights the challenges and pitfalls clinicians face when confronted with prosthetic valve endocarditis and the use of 18F-FDG PET/CT for diagnosis and follow-up.

In this article, a three-dimensional detection framework for detecting non-small cell lung cancer (NSCLC) in 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) images and guided by a multi-modality attention fusion is proposed. A total of 250 18F-FDG PET/CT scans between January 1, 2015 and December 31, 2019 of patients who had histopathologically proven NSCLC were acquired. A customized dual-path 3D CenterNet is used for NSCLC detection. Moreover, we propose a multi-modality attention module that adaptively refines the multi-modality feature map fusion. Since the 3D convolutional neural network (CNN) requires many graphic memories and sliding windows, a 384×384×32 patch size is designed and used for training and testing. Five-fold cross-validation is applied for this study. The sensitivity and false positive per scan (FPPS) obtained by our proposed method are 0.96 and 1.04, respectively. Our method significantly outperforms 3D CenterNet in terms of sensitivity (P =.031). This module demonstrates the potential to be implemented in other multi-modality applications. Our result performs competitively against other lung cancer detections. Furthermore, case studies show that the proposed method can detect difficult-to-diagnose NSCLCs. Our result shows the proposed method can help radiologists and medical physicists diagnose NSCLC.

PurposeTo comparatively evaluate the diagnostic performances of total-body 18F-FDG PET/CT with fast 2-min acquisition and conventional PET/CT in liver cancer patients.Methods This study included 156 patients with liver tumours. Seventy-eight patients underwent total-body PET/CT. PET raw data were reconstructed using acquisition durations of 2 min (G2) and 15 min (G15). Another 78 patients with liver lesions (control patients) underwent conventional uMI780 PET/CT (G780). All patients were evaluated based on TNM staging. The maximum tumour standardized uptake value (tumour SUVmax), mean normal liver SUV (SUVmean), and tumour SUVmax-to-liver SUVmean ratio (TLR) were determined for all patients. G15 data were used as the reference in the lesion detectability analysis. The diagnostic performances of PET/CT in terms of visual parameters and of PET in terms of semi-quantitative parameters such as SUVmax and TLR were evaluated. Receiver operating characteristics (ROC) curve analysis of SUVmax and TLR at G2 was performed. Pathologic findings of surgical specimens served as the gold standard for all patients.Results The lesions found in G15 were also noted in G2; three lymph nodes were missed in G2; however, no significant difference was found in the TNM stage among G2, G15, and G780. For benign and malignant lesions, the liver SUVmean in G2 and G15 was higher than that in G780 (all P < 0.05). The tumour SUVmax and TLR in G2 were equivalent to those in G15 and G780 regardless of whether the lesions were benign or malignant. ROC curve analysis (SUVmax cut-off: 4.34, TLR cut-off: 1.34) demonstrated that G2 also had good sensitivity in detecting liver cancer. Conclusion The diagnostic performance of total-body PET/CT in G2 was comparable to that in G15 among liver cancer patients. Further, the diagnostic efficiency of total-body PET/CT imaging with fast 2-min acquisition and conventional PET/CT was similar.

PurposeTo assess the diagnostic performance of 68Ga-FAPI-04 (68Ga-FAPI) PET/MR for primary as well as metastatic lesions in pancreatic cancer patients and to compare the results with those of 18F-FDG PET/CT.MethodsProspectively, we evaluated 31 patients suspected to have pancreatic malignancy. Within one week, each patient underwent both 18F-FDG PET/CT and 68Ga-FAPI PET/MR. Comparisons of the detection abilities and the standardized uptake values (SUVs) for primary tumors, lymph nodes, as well as hepatic metastases were conducted for the two imaging approaches.ResultsTwenty-eight pancreatic cancer patients and three pancreatitis ones were enrolled. 68Ga-FAPI and 18F-FDG exhibited equivalent (100%) detection rates for primary tumors. The SUVs of primary tumors on 68Ga-FAPI PET were markedly higher than those on 18F-FDG (p < 0.05). Fifteen pancreatic cancer patients were accompanied by pancreatic parenchymal uptake, whereas 18F-FDG PET images showed parenchymal uptake in 3 patients only (53.57% vs. 10.71%, p < 0.001). The number of positive lymph nodes detected was higher for 68Ga-FAPI than for 18F-FDG PET (31 vs. 26), led to N upstaging in 27.27% (3/11) of patients, however, the difference was not statistically significant (p = 0.053). 18F-FDG PET was able to detect more liver metastases than 68Ga-FAPI, and 68Ga-FAPI uptake of metastatic tumors was significantly lower than 18F-FDG (6.13 ± 1.63 vs. 8.09 ± 1.68, p < 0.001). In larger liver metastatic lesions, 68Ga-FAPI tended to distribute around the periphery of the lesions. In addition, multiple sequence MR imaging was helpful for finding more micrometastases.Conclusion68Ga-FAPI PET demonstrated equivalent detection rate with 18F-FDG for primary tumors of pancreatic cancer, and its percentage of pancreatic parenchymal uptake caused by inflammation was higher. It might be better in the detection of suspicious lymph node metastases. The MR multiple sequence imaging of integrated PET/MR was helpful for detecting tiny liver metastases.

Objective This retrospective study aimed to evaluate the role of metabolic parameters of 18F-FDG PET/CT in pediatric lymphoblastic lymphoma (LBL). Methods Thirty patients with LBL underwent 42 scans. Metabolic parameters including maximum standardized uptake value (SUVmax), total metabolic tumor volume (TMTV), and total lesion glycolysis (TLG) were measured at baseline PET/CT. Univariate and multivariate analysis for survival were performed to assess their prognostic value. Twelve patients underwent PET/CT after reinduction regime, and the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT for predicting relapse were calculated. Results Patients with stage Ⅳ had a higher TMTV than those with stage III (p = 0.031). Besides, patients with T-LBL or mediastinal involvement had a high TMTV and TLG (p 0.05). Children with a low TMTV ( Conclusions Metabolic parameters of baseline PET/CT were not predictive of outcomes in children with LBL. PET/CT done after the reinduction regime had better sensitivity and NPV than CT alone, and a negative scan could be a reliable indicator for sustained remission.

BACKGROUND To compare the rate, time and, pattern of recurrence of cervical cancer between patients with and without HIV infection and to determine factors predicting cervical cancer recurrence in patients evaluated by 18F-FDG-PET/CT. METHODS We reviewed the 18F-FDG-PET/CT images of patients with histologically proven cervical carcinoma who were presenting with suspected recurrence. We extracted epidemiologic data, previous treatment, histologic subtype, HIV status, viral load and CD4 counts from the electronic laboratory database and the referral form for the 18F-FDG-PET/CT study. RESULTS We studied 303 women including 112 HIV-infected patients. FIGO stage III disease was present in 131 patients. Of 198 patients with recurrence, 74 were HIV-infected while 124 were not (p=0.849). HIV infected patients were younger (41.99 ± 9.30 years) compared to HIV-uninfected (50.19 ± 11.09), p

Rationale and Objective To assess the possibility of differentiating pulmonary carcinoids from hamartomas and typical from atypical carcinoids by means of 18F-FDG PET/CT. Materials and Methods We retrospectively reviewed 139 patients with pathologically proven pulmonary carcinoids and hamartomas who underwent 18F-FDG PET/CT before surgical resection. Receiver operating characteristics curves were calculated to determine the potential of SUVmax to discriminate between pulmonary carcinoids and hamartomas, typical and atypical carcinoids. The correlation between SUVmax and tumor size was analyzed by Spearman correlation analysis. Results SUVmax was significantly higher in pulmonary carcinoids than in hamartomas (p Conclusion 18F-FDG PET/CT might be a useful tool in the differential diagnosis of carcinoids and hamartomas, and can also distinguish atypical from typical carcinoids. This may facilitate improved selection of patients for surgical resection and radiological follow-up.

Background 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is a useful tool for identifying high-risk features in patients with newly diagnosed multiple myeloma (NDMM). This study evaluated the role of autologous stem cell transplantation (ASCT) in patients presenting with positive results on PET/CT scans. Materials and Methods The medical records of 210 patients who underwent PET/CT at diagnosis were retrospectively reviewed. Eligible patients for transplantation proceeded to upfront ASCT with high-dose chemotherapy (HDT) after induction therapy with novel agents. Results The presence of a number of focal lesions (FL) >3 and extramedullary disease (EMD) occurred in 111 and 35 patients, respectively. ASCT was performed in 54 patients. Among patients with FL > 3, those treated with ASCT showed a prolonged 2-year progression-free survival (PFS) and overall survival (OS) rates compared to those not treated with ASCT (PFS, 60.2% vs. 23.5%, P 3, Revised International Staging System (R-ISS), and upfront ASCT were independent prognostic factors for PFS and OS. Conclusion Presenting FL > 3 on baseline PET/CT represents a high-risk feature in patients with NDMM. Frontline ASCT with HDT prolonged the survival of patients with FL > 3.

Please see the Editorial Comment by Javier Villanueva-Meyer discussing this article. Background: Pegfilgrastim administration after chemotherapy increases bone marrow and spleen FDG uptake. Consens...

Objective This study aimed to determine the prognostic role of baseline maximum standardized uptake value (SUVmax) obtained by pretreatment PET/CT and the change in SUVmax (ΔSUVmax [%]) in patients with axillary lymph node–positive breast cancer receiving neoadjuvant chemotherapy (NAC). Methods One hundred and eighty patients with baseline SUVmax and 121 patients with SUVmax measurement after treatment were evaluated in the study. The baseline SUVmax value of the breast (SUVmaxBI) and axilla (SUVmaxAI) and the change in the SUVmax of the breast (ΔSUVmaxB) and axilla (ΔSUVmaxA) were measured. The optimal cut-off value of SUVmax and ΔSUVmax were determined by ROC curve analysis. Disease-free survival (DFS) and overall survival (OS) were calculated using Kaplan–Meier curves. Results ΔSUVmaxB, pCRB, pCRA, and pCR parameters were found to be associated with relapse (P Conclusion The results showed that ΔSUVmaxB was an independent prognostic factor for relapse and mortality in patients with axillary lymph node–positive breast cancer who received NAC.

68Ga-conjugated fibroblast activation protein inhibitor (68Ga-FAPI) has become an attractive agent for positron emission tomography (PET). This study aimed to compare 68Ga-FAPI-46 PET/computed tomography (CT) with 18F-fluorodeoxy-D-glucose (18F-FDG) PET/CT for detecting primary cancer and metastatic lesions in patients with head and neck squamous cell carcinoma (HNSCC). Methods: Twelve patients and twenty-eight patients with HNSCC underwent 68Ga-FAPI-46 and 18F-FDG PET/CT for initial staging and recurrence detection, respectively. Concordance and diagnostic accuracy of both tracers were analyzed. Semiquantitative parameters, including the maximum and mean of standardized uptake value (SUVmax and SUVmean) and tumor-to-background ratio (T/B) were compared. FAP expression tumor volume (FTV) and total lesion FAP expression (TLF) of 68Ga-FAPI-46 were compared with metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of 18F-FDG, respectively. Differences between semiquantitative parameters were analyzed using paired t-tests. Results:68Ga-FAPI -46 PET/CT was 83.3% and 96.4% concordant with 18F-FDG PET/CT for initial staging and recurrence detection, respectively. Eighteen lesions had histopathological validation and both tracers displayed 100% sensitivity, 50% specificity, and 94.4% accuracy for lesion-based analysis. FTV was greater than MTV (P < 0.05), but no significant differences were observed for the other parameters. Conclusion:68Ga-FAPI-46 PET/CT showed good concordance and comparable diagnostic performance compared with 18F-FDG PET/CT for initial staging and recurrence detection in patients with HNSCC.

Please see the Editorial Comment by John F. Bruzzi discussing this article. BACKGROUND. Lymphovascular invasion (LVI) is an adverse prognostic indicator in non–small cell lung cancer (NSCLC) and se...

We evaluated the prognostic value of metabolic parameters measured on pretreatment FDG PET/CT in patients with cervical neuroendocrine carcinomas (NECs).A total of 22 patients with cervical NECs who underwent pretreatment FDG PET/CT were retrospectively reviewed. The SUVmax, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary lesion were measured. The associations between prognostic factors and progression-free survival (PFS) and overall survival (OS) were investigated using the Kaplan-Meier method, log-rank test, and univariate and multivariate Cox proportional hazards model.Of the 22 patients, 12 developed disease progression, and 5 died during the follow-up period. Univariate analyses revealed that MTV, TLG, and the International Federation of Gynecology and Obstetrics stage were significantly associated with PFS (all P0.05), whereas SUVmax did not show a significant correlation with PFS. Kaplan-Meier survival curves revealed that patients with MTV31.9 cm3 (log-rank, P0.001), TLG154.3 (log-rank, P0.001), and higher International Federation of Gynecology and Obstetrics stage (log-rank, P = 0.026) had significantly shorter PFS. In the multivariate analyses, MTV (P = 0.017; hazard ratio [HR], 7.298; 95% confidence interval [CI], 1.427-37.316) and TLG (P = 0.003; HR, 15.175; 95% CI, 2.470-93.244) were independent prognostic factors, whereas for OS, the univariate analysis revealed that only TLG154.3 showed statistical significance (P = 0.043; HR, 9.821; 95% CI, 1.080-89.290).Metabolic tumor volume and TLG on FDG PET/CT were the significant prognostic factors of PFS in patients with cervical NECs. Patients with high MTV and TLG had worse clinical outcomes. In addition, TLG may also be a predictor of OS.

Background Brentuximab-vedotin (BV) monotherapy has shown high efficacy in heavily pre-treated patients with relapsed or refractory Hodgkin lymphoma (HL) after high-dose chemotherapy or autologous stem cell transplantation (ASCT). We retrospectively analyzed the outcomes of treatment with BV of HL patients and examined the predictive ability of PET-CT for response in this setting. Patients and methods Records of 49 HL patients (median age, 39 years, 55% male) treated with BV for relapse (71.4%) or consolidation (28.6%) post-ASCT were analyzed. Patients who did not reach complete response (CR) on PET/CT after 4 cycles (non-responders) discontinued BV and received the next treatment line. Overall survival (OS) and progression-free survival (PFS) were compared between responders and non-responders. Results After a median follow-up of 19.1 months, all consolidation patients were alive and none progressed. Median OS in 23 relapsed patients that did not achieve CR after 4 cycles and continued to the next treatment was 55.0 months, while all those in CR (n = 24) were alive (P = .0120). No statistically significant differences in OS were observed between responders and non-responders with relapsed HL (P = .1072). Median PFS evaluated after 4 BV cycles was significantly longer in responders compared to non-responders (47.9 vs. 1.5 months, P Conclusions HL patients treated with BV for relapse or consolidation who achieved CR by PET-CT after 4 cycles showed improved PFS and OS compared to non-responders. Non-responders treated for relapsed HL who proceeded to the next treatment line demonstrated comparable OS to responders.

Background Although there is increasing use of 18F-FDG PET/CT in the diagnostic procedure for IgG4-related disease (IgG4-RD), little is known about the quantification of 18F-FDG PET/CT. We aimed to evaluate the utility of the quantification of 18F-FDG PET/CT in the diagnosis of IgG4-RD by analyzing the relation between 18F-FDG PET/CT findings and histopathologic findings. Methods Twenty-one patients with IgG4-RD, in whom 18F-FDG PET/CT was performed at the time of diagnosis between November 2011 and July 2018, were enrolled. Tissue biopsy was performed at 24 sites in 21 patients. To perform quantitative analysis of 18F-FDG PET/CT imaging, the highest standardized uptake value (SUV) of the pixels (SUVmax) and the average SUV (SUVmean) within the biopsied lesion were measured. The SUVmean of the liver was also measured as a reference. Results The mean age at diagnosis was 64.6 ± 11.9 years, and the median serum IgG4 level was 650 mg/dl. Histological findings were consistent with IgG4-RD (histopathology-positive) at 19 out of 24 sites. Although there was no significant difference in the values of SUVmax between histopathology-positive and histopathology-negative tissues, the values of SUVmean were significantly higher in the histopathology-positive tissue than those in the histopathology-negative tissue (4.98 and 3.54, respectively P mean/liver were also higher in the histopathology-positive tissue (2.17 and 1.52, respectively P mean to determine which of multiple lesions should be biopsied, a receiver operating characteristic (ROC) curve was constructed. ROC curve analysis indicated SUVmean=4.07 or SUVmean/liver = 1.66 as a cut-off value that could discriminate IgG4-RD-related lesions. Conclusions Our present study suggested that quantitative analysis of 18FDG-PET/CT imaging might be useful for selecting the biopsy site in IgG4-RD. The calculation of SUVmean, not of SUVmax, is important for evaluating IgG4-RD-related lesions in 18F-FDG PET/CT imaging.

18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET/CT) is not routinely recommended for the diagnosis of infective endocarditis (IE) due to the lack of clinical impact. Between January 2016 and January 2020, clinical data from patients with a possible diagnosis of IE were reviewed retrospectively to evaluate the value of 18F-FDG-PET/CT in the diagnosis of IE. 18F-FDG PET/CT scan was performed as an additional diagnostic tool in possible IE when echocardiography was inconclusive or in patients with definite IE to identify extracardiac complications. Cases were classified according to modified Duke criteria as rejected, definite or possible. 313 patients with suspected IE were included. 72 (23%) patients underwent 18F-FDG PET/CT. 18F-FDG PET/CT resulted in a reclassification of Duke criteria in 29/72 (40%) patients, from “possible” to “definite” (n, 10) and to “rejected” (n, 19). Patients who benefited from a Duke criteria reclassification following 18F-FDG PET/CT were more frequently classified as possible IE at inclusion or had a non-conclusive baseline echocardiography (100% vs 58%; p 0.001) and had more likely a prosthetic metallic valve replacement (59% vs 21%; p 0.001). Abnormal perivalvular uptake was identified in 46 patients (71% prosthetic vs 50% native; p 0.118). 18F-FDG PET/CT identified extracardiac uptake consistent with septic emboli in 14/72 (19%) patients. In addition, extracardiac uptake indicative of an alternative diagnosis was identified in 5 patients (2% prosthetic vs 17% native; p 0.039). The use of 18F-FDG-PET/CT has shown to be useful in the diagnosis of IE, particularly in prosthetic IE and may provide additional value in the detection of septic emboli and/or the identification of an alternative diagnosis different from IE.

To investigate minimal required sub milli-Sievert (mSv) ultra-low dose CT and corresponding tube current and voltage for reliable attenuation correction and semi- quantitation in 18F-FDG PET-CT in an effort for radiation dose reduction. Methods: We performed a PET-CT investigational study using a NEMA torso phantom containing six spheres (diameter: 10, 13, 17, 22, 28, 37 mm) filled with a fixed concentration of 60 kBq/ml and a background of 15 kBq/ml of 18F-FDG. Two sets of PET images, separated by 2 hours, were acquired for 3 minutes in a single bed position using 3-D mode with and without time-of-flight in a GE D-690 scanner. Several sets of CT images were acquired for attenuation correction with different combinations of tube voltage (80, 100, 120 kVp) and effective mAs (tube current-time product divided by pitch), using the maximum beam collimation (64 x 0.625 mm). The lowest CT acquisition technique available on this scanner is 10 mA, 0.4 s and 1.375 for the tube current, tube rotation time and pitch, respectively. The CT radiation dose was estimated based on the computed tomography dose index volume (CTDIvol) measurements performed following the standard methodology and the Imaging Performance Assessment of CT Scanners (ImPACT) calculator. Each of the CT techniques was used for attenuation correction to the same PET acquisition, using ordered-subset expectation maximum (OSEM) algorithm with 24 subsets and 2 iterations. The maximal and average radioactivity (kBq/ml) and standardized uptake values (SUV) of the spheres were measured. The minimal ultra-low dose CT for attenuation correction was determined by reproducible SUV measurements (±10%) compared to our reference CT protocol of 100 kVp and 80 mA for 0.5 s rotation. Results: The minimal ultra-low dose of CT for reproducible quantification in all spheres (

This research compared differences of dosimetric and biological parameters between PET/CT-guided isotoxic SIB-IMRT plans and conventional radiotherapy plans for patients with LA-NSCLC, and it also ...

A 63-year-old lady with a background of ischemic heart disease was referred for 18F-FDG PET/CT for multiple lytic bone lesions which showed disseminated FDG avid lesions in the skeleton, nodal stations as well as spleen simulating advanced malignancy such as diffuse lymphomatous disease. A diagnosis of sarcoidosis was pathologically confirmed with bone biopsy. Following treatment, repeat PET/CT revealed significant regression of FDG avid lesions, however prominent uptake in the lateral ventricular wall was suspicious for active cardiac sarcoidosis, particularly given recurrent chest pain. This was confirmed on cardiac MRI and correlation with PET enabled discrimination between ischemic and non-ischemic fibrosis.

While FDG PET/CT bears a high sensitivity and specificity for the staging of stage III and IV melanoma as well as for the purpose of melanoma recurrence detection, overall results tend to vary from one part of the body to another as well as for melanoma from cutaneous or choroidal origin. In this paper, organ or site-related differences in sensitivity and specificity in melanoma patients, both from cutaneous and choroidal origin, as well as their impact on clinical decision making are discussed. Furthermore, with the advent of immunotherapy for the treatment of malignant melanoma, post-treatment related potential false positive findings have emerged, the knowledge of which is essential for accurate treatment response assessment. These post-treatment related potential false positive findings are summarized in this paper so as to help the nuclear medicine physician in avoiding erroneous interpretation of acquired FDG PET/CT images in melanoma patients receiving immuntherapy.

Background Leydig cell tumors (LCTs) represent the most common form of stromal tumors. We reported the 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) findings of a patient with testicular LCT. Case presentation A 50-year-old man with a history of end-stage renal disease and renal transplantation 19 years ago. One year earlier, he started to have a chronic rejection. During the investigation to determine the cause of chronic rejection, a suspicious lesion in the graft with a collection around it was seen on ultrasound (US) images, raising the possibility of post-transplant lymphoproliferative disorder (PTLD). The patient was referred for further evaluation by whole body 18F-FDG PET/CT imaging. The image finding revealed an incidental hypermetabolic focal lesion in the right testicle—no other specific findings in the remaining parts of the body nor definitive FDG avid lymphadenopathy to suggest PTLD. Testicular US was requested and showed a well-defined right-sided heterogeneous hypoechoic intratesticular focal mass at the upper pole of the right testis with significant internal vascularity on the color Doppler imaging. The patient underwent a right radical orchidectomy, and the tumor was pathologically confirmed as an LCT. Conclusion In our case, 18F-FDG-PET/CT has been helpful in incidentally detecting this rare testicular tumor in a patient with suspected PTLD.

OBJECTIVES Reactive axillary lymph nodes (ALN) may occur post-COVID-19 vaccination. This may be confused with malignant nodal metastases on oncological imaging. We aimed to determine the reactive ALN incidence and duration on 18F-fluorodeoxyglucose positron emission tomography - computed tomography (18F-FDG PET-CT), and its relationship with gender, age and vaccine type. METHODS A retrospective study was performed. Two-hundred and four eligible patients had 18F-FDG PET-CT between 01 January 2021 and 31 March 2021, post-vaccination with Pfizer-BioNTech or Oxford-AstraZeneca vaccine. Image analysis was performed on dedicated workstations. SPSS was used for statistical analysis. RESULTS Thirty-six per cent of patients had reactive ALN until 10 weeks post-vaccination; reducing in frequency and intensity with time. Women were more likely to have reactive ALN compared with men. The frequency and intensity were higher in patients aged