18F-fluorodeoxyglucose Positron Emission Tomography-computed Tomography Research Articles

Detection of Recurrent Cervical Cancer and Prediction of Its Patient Survival with Serum Squamous-Cell Carcinoma-Antigen and 2-[18F] Fluoro-2-Deoxy-d-Glucose-Positron Emission Tomography/Computed Tomography.

Aim: To evaluate the usefulness of serum squamous-cell carcinoma antigen (SCC-Ag) and 2-[18F]fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) for the detection of recurrent squamous-cell carcinoma (SqCC) of the uterine cervix, and its prediction of patient survival. Methods: FDG-PET/CT was performed for patients with serum SCC-Ag levels elevated to ≥1.5 ng/mL (Group 1) and those with suspicious recurrences without any increase in serum SCC-Ag levels (Group 2). The results were analyzed on the basis of histological data, disease progression and/or clinical follow-up. Recurrence was defined as evidence of recurrent lesions within 6 months of FDG-PET/CT. The outcome was determined using medical records. Results: In total, 88 consecutive patients with cervical SqCC cancer with suspected recurrence (62 in Group 1 and 26 in Group 2) were enrolled. Recurrences were observed in 55 patients (77.4% (48/62) in Group 1 vs. 26.9% (7/26) in Group 2, p < 0.001). The overall sensitivity, specificity and accuracy of serum SCC-Ag were 87.3%, 57.6% and 76.1%, respectively, and those of FDG-PET/CT were 98.2%, 90.9% and 95.5%, respectively; the corresponding values were 97.9%, 92.9% and 96.8% for Group 1 and 100%, 89.5% and 92.3% for Group 2. Surgical resection was performed for 16 patients. At the end of the study, 40.3% (25/62) of Group 1 patients and 88.5% (23/26) of Group 2 patients were alive (p < 0.001). The survival of patients who underwent surgical resection for recurrent tumors was higher than that of patients who did not undergo resection (62.5% (10/16) vs. 17.9% (7/39), p = 0.001). Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) derived from FDG-PET/CT showed significantly different in-patient survival. Conclusions: Serum SCC-Ag could predict tumor recurrence and the survival of patients with SqCC cervical cancer. As such, the surgical resection of limited recurrent disease, as determined using FDG-PET/CT, might improve the survival of patients with cervical cancer. MTV and TLG may serve as a prognostic biomarker of survival in patients with recurrent cervical cancer.

Association between the Onset of Idiopathic Normal Pressure Hydrocephalus Symptoms and Reduced Default Mode Network Connectivity

Objective: The aim was to examine the association between connectivity changes in the default mode network (DMN) and the progression of idiopathic normal pressure hydrocephalus (iNPH). Methods: We retrospectively recruited cases of preclinical and clinical iNPH from 2,196 patients who had received whole-body ¹⁸F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) scanning. We included 31 cases with asymptomatic ventriculomegaly with features of iNPH on MRI (AVIM; reported as preclinical iNPH) and 12 with iNPH. We performed a voxel-based analysis of the brain FDG-PET images of the AVIM and iNPH groups as well as for each background-matched normal control (NC) group, using Statistical Parametric Mapping 12. Volume of interest (VOI)-based analysis was also performed. We set the VOI as the region from the precuneus to the posterior cingulate cortices (PCC), and compared the mean regional standardized uptake value ratio (SUVR) between the AVIM and iNPH group FDG-PET/CT images and each corresponding NC group. Results: The voxel-based analysis showed a greater decreased FDG uptake in the PCC in the iNPH group than in the AVIM group. The VOI-based analysis revealed no significant difference in the mean SUVR of the AVIM group and the corresponding NC group, but that of the iNPH group was significantly lower than that of its corresponding NC group. Conclusions: DMN connectivity was reduced in the clinical iNPH group but not in the preclinical group. These data suggest that alterations in the functional connectivity of the DMN are related to the onset of iNPH symptoms.

Prognostic Value of Preoperative Imaging

18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) increases the sensitivity for preoperative detection of lymph nodes and distant metastases in endometrial cancer. The objective of this investigation was to determine the prognostic value of preoperative PET-CT compared with computed tomography (CT) alone for high-risk endometrial carcinoma. We performed a retrospective review of high-risk histology endometrial cancer from 2008 to 2015. Clinical variables including surgical procedure, preoperative imaging modality, and outcome were collected. Survival analysis was performed utilizing the Kaplan-Meier and Cox proportional hazards methodologies. Of the 555 women treated for high-risk histology endometrial cancer, 88 (16%) had preoperative PET-CT, and 97 (17%) CT without PET available. PET-CT demonstrated positive findings in 37 women (42%) compared with 33 (30%) with preoperative CT alone. PET-CT had a positive predictive value of 96% for nodal metastasis compared with 60% for CT alone. The median follow-up time for the entire cohort was 59 months (range, 12 to 96 mo). Patients with a negative preoperative PET-CT (n=54) had a median progression-free survival (PFS) that was not reached, whereas the median PFS in the PET-CT positive group was 13 months (n=34). Women with a negative PET-CT had a longer median overall survival (OS) not yet reached compared with 34 months in the PET-CT positive cohort (hazard ratio, 2.4; P<0.001). CT findings did not associate with PFS or OS. PET-CT demonstrated superior sensitivity for lymph node metastasis and detecting distant disease compared with CT. Preoperative PET-CT, whether positive or negative, offered OS and PFS prognostic value not observed with CT alone.

18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography Metabolic Parameters Before and After Neoadjuvant Chemotherapy Can Predict the Postoperative Prognosis of Locally Advanced Gastric Cancer.

Objective: To explore the value of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) metabolic parameters before and after neoadjuvant chemotherapy in predicting histopathological response and prognosis of locally advanced gastric cancer. Materials and Methods: A total of 56 patients with locally advanced gastric cancer underwent 18F-FDG PET/CT before and after neoadjuvant chemotherapy. The maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the lesions were measured before and after neoadjuvant chemotherapy. The percentage changes in the maximum standardized uptake value (ΔSUVmax%), mean standardized uptake value (ΔSUVmean%), metabolic tumor volume (ΔMTV%), and total lesion glycolysis (ΔTLG%), which were derived from 18F-FDG PET/CT, were calculated, and the cutoff values were determined by receiver operating characteristic curve analysis. Differences in progression-free survival (PFS) and overall survival (OS) between groups dichotomized by these cutoffs were analyzed using the Kaplan-Meier method and Cox proportional hazards regression model. Results: The patients were divided into histopathological responders and nonresponders according to the following cutoff values: 58.8% SUVmax reduction, 45.8% SUVmean reduction, 36.9% MTV reduction, and 57.8% TLG reduction. The differences in PFS and OS between groups dichotomized by these cutoffs were significant (all p < 0.01). Multivariate analysis suggested that a ΔTLG% > 57.8% was an independent postoperative risk factor for PFS (hazard ratio [HR] 0.348, 95% confidence interval [CI] 0.131-0.926, p = 0.035) and OS (HR 0.107, 95% CI 0.023-0.498, p = 0.004). Conclusions: The metabolic parameters before and after neoadjuvant chemotherapy of 18F-FDG PET/CT accurately reflected the chemotherapy effect, and ΔTLG% was the only independent postoperative predictive factor of PFS and OS for locally advanced gastric cancer.

18F-FDG PET/CT SUVmax and serum CEA levels as predictors for EGFR mutation state in Chinese patients with non-small cell lung cancer.

The epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) contribute to an increased response rate, compared with chemotherapy, in patients with inhibitor-sensitive EGFR mutations. The present study evaluated the association between the maximum standardized uptake value (SUVmax) of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT), as well as serum carcinoembryonic antigen (CEA) levels and EGFR mutations prior to treatment, in patients with non-small cell lung cancer (NSCLC). Patients with histologically confirmed NSCLC (n=167), who underwent an 18F-FDG PET/CT scan, EGFR mutation analysis and a serum CEA test participated in the present study. Multivariate logistic regression analysis was used to analyze predictors of EGFR mutations. Receiver-operating characteristic (ROC) curve analysis was performed to determine the efficient cut-off value. Survival rate analysis was evaluated according to SUVmax and EGFR mutation status. A decreased SUVmax and an increased CEA level was observed in patients with EGFR-mutations, compared with patients with wild-type primary lesions and metastatic lymph nodes. The exon 19 EGFR mutation was associated with increased SUVmax, compared with the exon 21 L858R mutation. The ROC analysis indicated that an 18F-FDG PET/CT uptake SUVmax >11.5 may be a predictor of the wild-type EGFR genotype and increased CEA levels (CEA >9.4 ng/ml) were associated with EGFR mutations. Furthermore, patients with no smoking history, low SUVmax of the primary tumor, metastatic lymph nodes and a high CEA level were significantly associated with EGFR mutation status. The results of the present study indicated that patients with advanced NSCLC, particularly Chinese patients, with decreased SUVmax and increased CEA levels are associated with EGFR mutations, which may serve as predictors for the EGFR-TKI therapeutic response.

Place actuelle de l'imagerie non invasive des artères de gros calibre dans l'artérite à cellules géantes: du diagnostic au suivi

Large vessel involvement in giant cell arteritis has long been described, although its right frequency and potential prognostic value have only been highlighted for two decades. Large vessel involvement not only is associated with a high incidence of late aortic aneurysms, but also might cause greater resistance to glucocorticoids and longer treatment duration, as well as worse late cardiovascular outcomes. These data were brought to our attention, thanks to substantial progress recently made in large vessel imaging. This relies on four single, often complementary, approaches of varying availability: colour Doppler ultrasound, contrast-enhanced computed tomography with angiography and, magnetic resonance imaging, which all demonstrate homogeneous circumferential wall thickening and describe structural changes; 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET/CT), which depicts wall inflammation and assesses many vascular territories in the same examination. In addition, integrated head-and-neck PET/CT can accurately and reliably diagnose cranial arteritis. All four procedures exhibit high diagnostic performance for a large vessel arteritis diagnosis so that the choice is left to the physician, depending on local practices and accessibility; the most important is to carry out the chosen modality without delay to avoid false or equivocal results, due to early vascular oedema changes as a result of high dose glucocorticoid treatment. Yet, ultrasound study of the superficial cranial and subclavian/axillary arteries remains a first line assessment aimed at strengthening and expediting the clinical diagnosis as well as raising suspicion of large-vessel involvement. In treated patients, vascular imaging results are poorly correlated with clinical-biological controlled disease so that it is strongly recommended not to renew imaging studies unless a large vessel relapse or complication is suspected. On the other hand, a structural monitoring of aorta following giant cell arteritis is mandatory, but uncertainties remain regarding the best procedural approach, timing of first control and spacing between controls. Individuals at greater risk of developing aortic complication, e.g. those with classic risk factors for aneurysm and/or visualised aortitis, should be monitored more closely.

Clinical Impact of F-18 FDG PET-CT on Biopsy Site Selection in Patients with Suspected Bone Metastasis of Unknown Primary Site.

We investigated the clinical role of F-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) in the identification of the primary site and the selection of the optimal biopsy site in patients with suspected bone metastasis of unknown primary site. The patients with suspected bone metastasis who underwent PET-CT for evaluation of primary site were enrolled in this study. The primary sites were identified by the histopathologic or imaging studies and were classified according to the FDG uptake positivity of the primary site. To evaluate the guiding capability of PET-CT in biopsy site selection, we statistically analyzed whether the biopsy site could be affected according to the presence of extra-skeletal FDG uptake. Among 74 enrolled patients, 51 patients had a metastatic bone disease. The primary site was identified in 48 of 51 patients (94.1%). Forty-six patients were eligible to test the association of clinical choice of biopsy site with PET positivity of extra-skeletal lesion. The extra-skeletal biopsies were done in 42 out of 43 patients with positive extra-skeletal uptake lesions. Bone biopsies were inevitably performed in the other three patients without extra-skeletal uptake lesions. The association came out to be significant (Fisher's exact test, P < 0.001). F-18 FDG PET-CT significantly contributed not only to identify the primary site but also to suggest optimal biopsy sites in patients with suspected bone metastasis.

Diagnostic and Predictive Values of 18F-FDG PET/CT Metabolic Parameters in EGFR-Mutated Advanced Lung Adenocarcinoma.

PurposeThe clinical implications of the metabolic parameters of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) in epidermal growth factor receptor (EGFR)-mutated lung cancer are not fully understood. The aim of this study was to evaluate the diagnostic and prognostic utility of the parameters in EGFR-mutated lung cancer patients.Patients and MethodsWe retrospectively enrolled 134 patients with advanced lung adenocarcinoma (72 EGFR-negative and 62 EGFR-positive). We evaluated the correlation between EGFR mutational status and the maximum standardized uptake value (SUVmax), as well as the associations between treatment outcomes in EGFR-mutated patients and various metabolic parameters of primary tumors. For the best predictive parameters, we calculated the metabolic tumor volume (MTV) and total lesion glycolysis (TLG) using two SUV cutoffs: 1.5 (MTV1.5, TLG1.5) and 2.5 (MTV2.5, TLG2.5).ResultsMean SUVmax was lower for EGFR-mutated tumors compared with EGFR wild-type (6.11 vs 10.41, p < 0.001) tumors. Low SUVmax was significantly associated with positive EGFR mutation (odds ratio = 1.74). Multivariate analysis for survival demonstrated that high MTV1.5, TLG1.5, MTV2.5, and TLG2.5 were independently associated with shorter progression-free survival (PFS) and overall survival (OS), and the highest hazard ratios were found in TLG1.5 (3.26 for PFS and 4.62 for OS).ConclusionSUVmax may be predictive for EGFR mutational status, and MTV and TLG of primary tumors may be promising prognostic parameters; 18F-FDG PET/CT has potential utility for the risk stratification of EGFR-mutated patients treated with targeted therapy.

CT Imaging of Left Ventricular Assist Devices and Associated Complications

The purpose of this paper is to review the current role of computed tomography (CT) in the imaging of left ventricular assist devices (LVAD). Recent studies have highlighted the prognostic role of measuring skeletal muscle CT attenuation in predicting adverse LVAD outcomes. CT is also useful for evaluation of inflow cannula malposition, and outflow graft complications such as obstruction and kinking. In addition, 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) has been shown to be of value in evaluation of suspected LVAD infection. Newer CT techniques such as dual-energy CT and metal artifact reduction algorithms can potentially generate better quality CT images, though currently there is no high-quality published literature on their use in LVAD imaging. CT is a useful technique as part of a multi-modality approach in the evaluation of LVADs and associated complications.

Long-Term Outcomes After Sublobar Resection Versus Lobectomy in Patients With Clinical Stage IA Lung Adenocarcinoma Meeting the Node-Negative Criteria Defined by High-Resolution Computed Tomography and [18F]-Fluoro-2-Deoxy-d-Glucose Positron Emission Tomography

PurposeTo evaluate long-term outcomes after sublobar resection for patients with clinical stage IA lung adenocarcinoma who met our proposed node-negative (N0) criteria, namely solid component size < 0.8 cm on high-resolution computed tomography (HRCT) or a maximum standardized uptake value (SUVmax) of < 1.5 on [18F]-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT). Patients and MethodsBetween April 2006 and December 2010, a total of 347 patients with clinical stage IA lung adenocarcinoma underwent complete resection in two medical centers. Long-term outcomes of patients with disease that met the N0 criteria after sublobar resection were evaluated. ResultsThe disease of 201 patients (57.9%) met the N0 criteria. Meeting N0 criteria was significantly associated with low-grade adenocarcinoma subtype (P < .001) and absence of lymphatic invasion (P < .001), vascular invasion (P < .001), and pleural invasion (P < .001). One patient (0.5%) had lymph node metastasis. The median follow-up period was 86.1 months. There was a significant difference in the overall survival (OS) rates between patients with disease that met the N0 criteria (5-year OS, 93.9%; 10-year OS, 90.3%) and disease that did not (5-year OS, 81.5%; 10-year OS, 64.3%; P < .001). Among patients with disease that met the N0 criteria, there was no significant difference in the OS between those who underwent lobectomy (5-year OS, 94.3%; 10-year OS, 92.6%) and those who underwent sublobar resection (5-year OS, 93.8%; 10-year OS, 89.3%; P = .64). ConclusionsSublobar resection of clinical stage IA lung adenocarcinoma is feasible in selected patients with disease that meets the N0 criteria, with excellent long-term survival.

Predicting EGFR mutation subtypes in lung adenocarcinoma using 18F-FDG PET/CT radiomic features.

BackgroundIdentification of epidermal growth factor receptor (EGFR) mutation types is crucial before tyrosine kinase inhibitors (TKIs) treatment. Radiomics is a new strategy to noninvasively predict the genetic status of cancer. In this study, we aimed to develop a predictive model based on 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) radiomic features to identify the specific EGFR mutation subtypes.MethodsWe retrospectively studied 18F-FDG PET/CT images of 148 patients with isolated lung lesions, which were scanned in two hospitals with different CT scan setting (slice thickness: 3 and 5 mm, respectively). The tumor regions were manually segmented on PET/CT images, and 1,570 radiomic features (1,470 from CT and 100 from PET) were extracted from the tumor regions. Seven hundred and ninety-four radiomic features insensitive to different CT settings were first selected using the Mann white U test, and collinear features were further removed from them by recursively calculating the variation inflation factor. Then, multiple supervised machine learning models were applied to identify prognostic radiomic features through: (I) a multi-variate random forest to select features of high importance in discriminating different EGFR mutation status; (II) a logistic regression model to select features of the highest predictive value of the EGFR subtypes. The EGFR mutation predicting model was constructed from prognostic radiomic features using the popular Xgboost machine-learning algorithm and validated using 3-fold cross-validation. The performance of predicting model was analyzed using the receiver operating characteristic curve (ROC) and measured with the area under the curve (AUC).ResultsTwo sets of prognostic radiomic features were found for specific EGFR mutation subtypes: 5 radiomic features for EGFR exon 19 deletions, and 5 radiomic features for EGFR exon 21 L858R missense. The corresponding radiomic predictors achieved the prediction accuracies of 0.77 and 0.92 in terms of AUC, respectively. Combing these two predictors, the overall model for predicting EGFR mutation positivity was also constructed, and the AUC was 0.87.ConclusionsIn our study, we established predictive models based on radiomic analysis of 18F-FDG PET/CT images. And it achieved a satisfying prediction power in the identification of EGFR mutation status as well as the certain EGFR mutation subtypes in lung cancer.

First-line immunochemotherapy for follicular lymphoma in the GALLIUM study: Prognostic value of PET-CT status after long-term follow-up.

8025 Background: The prognostic value of 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) response assessment following first-line immunochemotherapy for advanced-stage symptomatic follicular lymphoma (FL) was previously demonstrated for patients (pts) enrolled in the Phase III GALLIUM study (NCT01332968; Trotman et al. ICML 2017). Here, we evaluated the association between PET complete metabolic response (CMR) and survival after longer follow-up in this patient population. Methods: In the GALLIUM study, 1202 pts with previously untreated FL were randomized 1:1 to induction therapy of 1000mg obinutuzumab (G; Days 1, 8, 15 of Cycle 1 then Day 1 of subsequent cycles) or 375mg/m2 rituximab (R; Day 1 of each cycle), in combination with chemotherapy (CHOP, CVP, or bendamustine) (Marcus et al. New Engl J Med 2017). PET-CT scans were mandatory, where available, at baseline and end-of-induction (EOI) for the first 170 pts enrolled, and optional thereafter. For this response analysis, the Lugano 2014 criteria were applied by an independent review committee (IRC) (Cheson et al. J Clin Oncol 2014). Associations between EOI PET complete metabolic response (PET-CMR) status and progression-free survival (PFS) and overall survival (OS) were evaluated, with hazard ratios (HR) stratified according to chemotherapy regimen and FL International Prognostic Index. Results: Of the 609 pts with a baseline PET scan, 595 (98%) had detectable lesions. Of these, 519 pts had an EOI PET evaluable by Lugano 2014 criteria. At EOI, per IRC assessment, 450/595 (76%) pts had achieved CMR. Pts with non-available scans were considered as non-responders and were excluded from the landmark (LM) analyses. Pts who died or progressed (CT-based progression assessment) before or at EOI were excluded from the PFS LM analysis; pts who died before EOI were excluded from the OS LM analysis. After a median follow-up of 76.5 months, EOI PET status was highly prognostic for both longer investigator-assessed PFS (non-CMR vs CMR: HR 3.40; 95% CI: 2.33–4.97; p &lt; 0.0001) and longer OS (HR 3.34; 95% CI: 1.81–6.17; p &lt; 0.0001). Six-year investigator-assessed PFS from EOI was 62.6% (95% CI: 57.0–67.6) for CMR pts compared with 23.4% (95% CI: 12.2–36.7) for non-CMR pts; the corresponding OS was 91.3% (95% CI: 88.1–93.6) vs 79.6% (95% CI: 68.0–87.4). Conclusions: With more than 6 years of follow-up, this analysis confirms that after first-line chemoimmunotherapy for FL, achieving CMR on PET-CT is an early and strong predictor of increased PFS and OS. Clinical trial information: NCT01332968 .

Diagnostic role of F-18 FDG PET/CT for preoperative lymph node staging in thyroid cancer patients; A systematic review and metaanalysis

PurposeAlthough ultrasonography (US) is a standard technique for the assessment of cervical lymph node (LN) metastasis, the role of F-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) is increasingly reported. The purpose of this study is to assess the diagnostic accuracy of F-18 FDG PET-CT for detection of cervical LN metastasis in thyroid cancer (TCa) patients through a meta-analysis. Patients and methodsThe PubMed, Cochrane Database, and Embase from the earliest available date of indexing through September 31, 2019, were searched for studies evaluating the diagnostic performance of F-18 FDG PET-CT for detection of LN metastasis in TCa. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR-), and constructed summary receiver operating characteristic curves. ResultsAcross 9 studies (759 patients), the pooled sensitivity for F-18 FDG PET-CT for all cervical LN metastasis in TCa was 0.30 (95% CI; 0.26–0.35) a pooled specificity of 0.94. For central LN metastasis, the pooled sensitivity was 0.28 (95% CI; 0.21–0.34) and a pooled specificity was 0.87 (95% CI; 0.83–0.90). For lateral LN metastasis, the pooled sensitivity was 0.56 (95% CI; 0.50–0.62) and a pooled specificity was 0.94. ConclusionsF-18 FDG PET-CT shows a low sensitivity and high specificity for the detection of metastatic LNs in patients with TCa. The current data suggests that F-18 FDG PET-CT is not indicated in the work up of patients with thyroid cancer or biochemical evidence of recurrent disease.

Translational large animal model of hibernating myocardium: characterization by serial multimodal imaging.

Nonrevascularizable coronary artery disease is a frequent cause of hibernating myocardium leading to heart failure (HF). Currently, there is a paucity of therapeutic options for patients with this condition. There is a lack of animal models resembling clinical features of hibernating myocardium. Here we present a large animal model of hibernating myocardium characterized by serial multimodality imaging. Yucatan minipigs underwent a surgical casein ameroid implant around the proximal left anterior descending coronary artery (LAD), resulting in a progressive obstruction of the vessel. Pigs underwent serial multimodality imaging including invasive coronary angiography, cardiac magnetic resonance (CMR), and hybrid 18F-Fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT). A total of 43 pigs were operated on and were followed for 120 ± 37days with monthly multimodality imaging. 24 pigs (56%) died during the follow-up. Severe LAD luminal stenosis was documented in all survivors. In the group of 19 long-term survivors, 17 (90%) developed left ventricular systolic dysfunction [median LVEF of 35% (IQR 32.5-40.5%)]. In 17/17, at-risk territory was viable on CMR and 14 showed an increased glucose uptake in the at-risk myocardium on 18FDG-PET/CT. The present pig model resembles most of the human hibernated myocardium characteristics and associated heart failure (systolic dysfunction, viable myocardium, and metabolic switch to glucose). This human-like model might be used to test novel interventions for nonrevascularizable coronary artery disease and ischemia heart failure as a previous stage to clinical trials.

A two-way comparison of whole-body 18FDG PET-CT and whole-body contrast-enhanced MRI for distant metastasis staging in patients with malignant tumors: a meta-analysis of 13 prospective studies

The correct staging of distant metastasis is crucial in deciding an adequate course of therapy for cancer patients. This meta-analysis was carried out to produce an evaluation and comparison of the performances of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18FDG PET-CT) and contrastenhanced magnetic resonance imaging (MRI) in detecting distant metastasis in patients suffering malignant tumors. Systematic literature searches of the MEDLINE and Embase databases were conducted to identify relevant studies in the period from December 31, 1950 to August 1, 2019. We used the following search terms: MRI, magnetic resonance imaging, PET, positron emission tomography, staging, distant metastasis, and distant recurrence. The searches were carried out by two independent reviewers. We only included relevant studies that evaluated both 18FDG PET-CT and contrast-enhanced MRI in relation to distant metastasis detection in the same patients with malignant tumors. The two reviewers independently extracted relevant data from the eligible studies, and the quality of each study was determined with "Quality Assessment of Diagnostic Accuracy Studies-2". Using the bivariate model, we obtained pooled estimates for sensitivity and specificity. The area under the curve (AUC) of summary receiver operating characteristic (SROC) curves for 18FDG PET-CT and contrast-enhanced MRI was used to extra and synthesize, respectively. Pooled sensitivities and specificities, and the AUC of SROC curves for 18FDG PET-CT and contrast-enhanced MRI were used to measure the main outcomes, respectively. Across all 13 studies (1,465 patients), 18FDG PET-CT had similar sensitivity (0.84 vs. 0.85) and specificity (0.96 vs. 0.98) to contrast-enhanced MRI. In the 5 studies related to head and neck cancer (511 patients), 18FDG PET-CT had similar sensitivity (0.82 vs. 0.81) and specificity (0.97 vs. 0.98) to contrastenhanced MRI. In the 6 lung cancer-related studies (779 patients), sensitivity (0.72 vs. 0.85) and specificity (0.95 vs. 1.00) tended to be lower in 18FDG PET-CT than in contrast-enhanced MRI. :18FDG PET-CT and contrast-enhanced MRI both performed well as detectors of distant metastasis in the diagnosis of cancer patients. The subgroup analysis suggests that 18FDG PET-CT and contrast-enhanced MRI may possess different advantageous qualities for distant metastasis staging of patients with various types of tumor.

Pretreatment Photopenia on 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography Scans Predicts Poor Prognosis in Nasopharyngeal Cancer Patients Undergoing Concurrent Chemoradiotherapy.

ObjectivesTo investigate the influence of pretreatment primary tumor or nodal photopenia (PP) on 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT), an indicator of tumor ischemia, on survival results of nasopharyngeal cancers (NPCs) treated with concurrent chemoradiotherapy (C-CRT).MethodsThe pre-C-CRT FDG PET-CT scans of 104 patients with NPC (cT1-4 N0-3 M0) were retrospectively examined to determine the presence of PP (PP+). Our primary endpoint was the influence of PP+ on overall survival (OS), while the progression-free survival (PFS) and locoregional PFS (LRPFS) constituted the secondary endpoints.ResultsThe PP+ was detected in 29 (27.9%): nine (8.7%), seven (6.7%), and 13 (12.5%) in the primary tumor alone, primary tumor plus neck nodes, and neck nodes alone, respectively. Because the PP+ cases were small by count per location, all comparative analyses were performed according to overall PP+/ PP– status instead of per detected site. At a median follow-up of 67.8 months (range, 9 to 130 months), the median survival times were not reached (NR) for the entire population, while 5-year OS, LRPFS, and PFS rates were 73.3%, 68.2%, and 63.4%, respectively. Comparatively the PP+ patients exhibited significantly poorer median OS (49.8 months vs. NR, P<0.001), LRPFS (40.7 months vs. NR, P=0.001), and PFS (31.8 months vs. NR, P=0.002) durations than their PP– counterparts. Furthermore, the PP+ retained its independent prognostic significance in multivariate analysis (P<0.001).ConclusionPresent results uncovered the pre-C-CRT PP as an independent predictor of poor prognosis for NPC patients, which underscore the requirement for the fortification of the local and systemic treatments in hypoxic NPCs.

Diagnostic Performance and Prognostic Relevance of FDG Positron Emission Tomography/Computed Tomography for Patients with Extrahepatic Cholangiocarcinoma.

ObjectiveWe aimed to evaluate the diagnostic value and prognostic relevance of FDG positron emission tomography/computed tomography (PET-CT) in extrahepatic cholangiocarcinoma patients.Materials and MethodsThis study included 234 extrahepatic cholangiocarcinoma patients who underwent FDG PET-CT between June 2008 and February 2016. The diagnostic performance of FDG PEG-CT was compared to that of contrast-enhanced multidetector row CT (MDCT) and MRI. Independent prognosticators for poor survival were also assessed.ResultsThe sensitivity of FDG PET-CT for detecting primary tumor and regional lymph node metastases was lower than that of MDCT or MRI (p < 0.001), whereas the specificity and positive predictive value for detecting regional lymph nodes metastases was significantly better in FDG PET-CT compared to MDCT and MRI (all p < 0.001). There was no significant difference in the diagnostic yield of distant metastases detection among three diagnostic imaging techniques. In a multivariate analysis, maximum standardized uptake values (SUVmax) of the primary tumor (adjusted hazard ratio [HR], 1.75; 95% confidence interval [CI], 1.13–2.69) and of the metastatic lesions ≥ 5 (adjusted HR, 8.10; 95% CI, 1.96–33.5) were independent contributors to poor overall survival in extrahepatic cholangiocarcinoma patients. In a subgroup analysis of 187 patients with periductal infiltrating type of cholangiocarcinoma, an SUVmax of the primary tumor ≥ 5 was associated with an increased risk of regional lymph node (adjusted odds ratio [OR], 1.60; 95% CI, 0.55–4.63) and distant metastases (adjusted OR, 100.57; 95% CI, 3.94–2567.43) at diagnosis as well as with poor overall survival (adjusted HR, 1.81; 95% CI, 1.04–3.15).ConclusionFDG PET-CT showed lower sensitivity for detecting primary tumor and regional lymph node involvement than MDCT and MRI. However, the SUVmax of primary tumors and metastatic lesions derived from FDG PET-CT could have significant implications for predicting prognoses in extrahepatic cholangiocarcinoma patients.

Prognostic parameters in recurrent colorectal cancer: A role of control or restaging by FDG-PET/CT

Background/Aim. Colorectal cancer ranks the third most frequent cancer in the world. Approximately 40% of the disease recurs after surgical resection. Determination of predictive parameters for recurrence may help in stratification of patients and contribute to patient management. There are still very few studies which sought factors to predict the recurrence of colorectal cancer. The aim of this study was to examine the predefined risk factors in metastatic development and evaluate clinical significance of 18Ffluorodeoxyglucose (FDG) uptake. Methods. The study was conducted with 56 patients for whom FDG-PET/CT (FDG-positron emission tomography/computed tomography) was requested for the suspicious recurrence or metastasis by routine conventional screening tests. Thirty three patients in whom recurrence/metastases were established with final histopathologic diagnosis formed the malignant group, and 23 patients with no recurrence/metastases formed the benign group. Risk factors [age, serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (Ca 19-9) levels, the maximum standardized uptake volume (SUVmax), tumor size (TS), CT/magnetic resonance imaging (MRI) findings, sex, primary tumor localization, lymphovascular invasion, perineural invasion (PNI), initial neoadjuvant therapy, lymph node initial metastasis (ILNM) excision, stage, tumor differentiation] were compared between these groups. Results. CEA, Ca 19-9, SUVmax, TS, PNI, ILNM, FDG uptake pattern, pattern of lesions on CT and tumor differentiation were found statistically significant by univariate analysis. After multivariate analysis, SUVmax and ILNM remained as the main risk parameters impacting recurrence/metastases. Mean SUVmax was 7.25 in the benign group, while it was 11.7 in the malignant group (p = 0.019). ILNM was present in 66.5% of patients in the malignant group, and in 30.5% of patients in the benign group (p = 0.015). For an estimated cut-off value of 6.3 and 12.5, respectively on ROC curve, the calculated specificities were 61% and 87%, respectively. Conclusion. ILNM and SUVmax are the main risk factors for recurrence of colorectal cancer and the patients with these factors must be followed up carefully. FDG-PET/CT is very sensitive for the detection of recurrence/metastases of colorectal cancer and SUVmax appears to improve its specificity.

Metastatic Thymic Carcinoma on Restaging 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography.

Thymic carcinoma is a rare thymic epithelial cancer which is not only locally invasive but also highly aggressive disease. The prognosis for this cancer is poor and the surgery remains the mainstay of treatment. Thymic carcinomas have been shown to metastasize to the lymph nodes, lung, and liver. A 63-year old male who was successfully treated for thymic cancer in 2015, presented with metastatic disease recurrence to the spinal cord. We share interesting images of the spinal cord lesions as well as pituitary metastases that were incidentally detected on restaging 18F-fluorodeoxyglucose positron emission tomography-computed tomography.

Recurrent Renal Carcinoma with Solitary Intramedullary Spinal Cord Metastasis.

We report a case of an elderly male who has undergone right radical nephrectomy for renal cell carcinoma (RCC). Six months later, he presented with gradually progressive low backache and mild lower limb weakness. 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET-CT) was done that revealed a suspected area of mild metabolic activity in the spinal cords at the L1–L2 vertebral level. Magnetic resonance imaging revealed intramedullary spinal cord metastasis (ISCM). Solitary ICSM is a rare presentation of RCC on FDG PET-CT, and only a few case reports exist in the literature. This case highlights that adequate clinical history and careful examination of the PET images may reveal it.