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

Can FDG-PET/CT replace blind bone marrow biopsy of the posterior iliac crest in Ewing sarcoma?

ObjectiveTo determine and compare the value of 18F–fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT) to blind bone marrow biopsy (BMB) of the posterior iliac crest in detecting metastatic bone marrow involvement in newly diagnosed Ewing sarcoma.Materials and methodsThis retrospective study included 20 patients with newly diagnosed Ewing sarcoma who underwent pretreatment FDG-PET/CT and a total of 38 blind BMBs (two unilateral and 18 bilateral) of the posterior iliac crest. FDG-PET/CT scans were evaluated for bone marrow involvement, both in the posterior iliac crest and other sites, and compared to blind BMB results.ResultsFDG-PET/CT was positive for bone marrow involvement in 7/38 posterior iliac crests, whereas BMB was positive in 5/38 posterior iliac crests. FDG-PET/CT and BMB results in the posterior iliac crest agreed in 36/38 cases (94.7%, 95% confidence interval [CI]: 82.7–98.5%). On a patient level, FDG-PET/CT was positive for bone marrow involvement in 4/20 patients, whereas BMB of the posterior iliac crest was positive in 3/20 patients. On a patient level, FDG-PET/CT and BMB results agreed in 19/20 patients (95.0%, 95% CI: 76.4–99.1%). The only discrepancies between FDG-PET/CT and BMB were observed in two BMBs of one patient. Both BMBs in this patient were negative, whereas FDG-PET/CT indicated bilateral posterior iliac crest involvement and also extensive bone marrow involvement elsewhere.ConclusionsFDG-PET/CT appears to be a valuable method for metastatic bone marrow assessment in newly diagnosed Ewing sarcoma. The routine use of blind BMB of the posterior iliac crest should be reconsidered when FDG-PET/CT is available.

Molecular Imaging for the diagnosis of infective endocarditis: A systematic literature review and meta-analysis

BackgroundInfective endocarditis (IE) is a serious, potentially life-threatening condition. Currently, the modified Duke criteria is used to assist with the diagnosis of IE, but it can still remain difficult. Growing data supports the potential use of molecular imaging to assist in the diagnosis of IE. Our objective was to understand the potential utility of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT), 67Ga citrate and radiolabeled white blood cell (WBC) scintigraphy in the diagnosis of IE. Methods and resultsA systematic review of the literature and meta-analysis on the use of all 3 modalities in IE was conducted. The literature search identified 2753 articles. A total of 14 studies met the inclusion criteria (10 for 18F-FDG, 3 for WBC and 1 for both modalities). No 67Ga citrate study met the inclusion criteria. Pooled sensitivity of 18F-FDG studies with adequate cardiac preparation for the diagnosis of IE was 81% (95% CI, 73%–86%) and pooled specificity was 85% (95% CI, 78%–91%). There was good overall accuracy with an area under the curve (AUC) of 0.897. Pooled sensitivity of WBC for the diagnosis of IE was 86% (95% CI, 77%–92%) and pooled specificity was 97% (95% CI, 92%–99%). The overall accuracy of WBC was excellent with an AUC of 0.957. ConclusionsBoth 18F-FDG and WBC have good sensitivity, specificity and accuracy for the diagnosis of IE. Both modalities are useful in the investigation of IE, and should be considered in cases where the diagnosis is uncertain.

P2.14-005 Determination of Optimal Cut off SUV Threshold for Auto-Contouring of GTV Using PETCT for Early Stage NSCLC

18F-Fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG-PET-CT) has the potential to increase the precision in contouring of gross tumor volume (GTV). However, detection of tumor edge in the halo around the tumor has been a problem. A surgical histopathological examination is the current gold standard for tumor size estimation in NSCLC. The aim of this study was to determine an optimal cut-off of standardized uptake value (SUV) on FDG-PET-CT images that correlates best with tumor size on surgical histopathology examination.

The potential usefulness of the Response Index in positron emission tomography assessing the therapeutic effect of pre-operative chemotherapy for advanced colorectal cancer.

Pre-operative chemotherapy is an option for patients with local advanced rectal cancer, but the response rate to pre-operative chemotherapy with oxaliplatin is still low. If the therapeutic effect of pre-operative chemotherapy could be assessed, we may be able to convert to surgery early. The purpose of the present study was to validate the correlation between the maximum standardized uptake value (SUVmax) in 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) of the primary tumor and the therapeutic effect of pre-operative chemotherapy in advanced colorectal cancer. Retrospective cohort study from January 2011 to October 2015. We examined 28 patients with pathologically confirmed sigmoid or rectal cancer that underwent pre-operative chemotherapy and surgery. The correlation between Response Index (RI), calculated as (SUVmax after chemotherapy)/(SUVmax before chemotherapy), and the therapeutic effect on the primary tumor in advanced colorectal cancer. The degree of differentiation (p = 0.04), SUVmax in the primary tumor after chemotherapy (p = 0.02), and RI (p = 0.008) were significant predictors of the therapeutic effect in univariate analysis. The areas under the ROC curve constructed with RI and therapeutic effect was 0.77. The optimal cut-off values for the RI in the responder group was < 0.32. RI calculated as (SUVmax after chemotherapy)/(SUVmax before chemotherapy) in the primary tumor significantly correlated with the therapeutic effect of chemotherapy on advanced colorectal cancer. Thus, RI is potentially useful for predicting the therapeutic effect in advanced colorectal cancer.

Quantitative Metabolic Volumetric Product on 18Fluorine-2fluoro-2-deoxy-D-glucose-positron Emission Tomography/Computed Tomography in Assessing Treatment Response to Disease-modifying Antirheumatic Drugs in Rheumatoid Arthritis: Multiparametric Analysis Integrating American College of Rheumatology/European League Against Rheumatism Criteria.

The purpose of this study was to assess the role of fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) in the evaluation of treatment response evaluation to disease-modifying antirheumatic drug (DMARD) therapy in patients of rheumatoid arthritis (RA). A total of ten patients with proven diagnosis of RA as per the 2010 American College of Rheumatology/European League against Rheumatism (EULAR) criteria were prospectively evaluated. All patients underwent clinical and biochemical evaluation and a baseline FDG-PET/CT with assessment of maximum standardized uptake value and metabolic volumetric product (MVP) values. DMARD therapy was started with a combination of hydroxychloroquine and sulfasalazine. On follow-up at 3 and 6 months, the response to treatment was assessed by clinical, biochemical, and FDG-PET/CT parameters. These parameters were analyzed in a combined manner, and the patients were grouped into 4 categories as per response to DMARD therapy - complete response, good response, mixed response, and no response. Evaluation of treatment response in ten patients at 3rd month and in nine patients at 6 months showed (a) agreement for MVP, biochemical parameters with clinical symptomatic assessment in all patients, (b) while agreement for EULAR score was noted in only three patients and disagreement in seven patients with clinical symptoms Response EULAR (rEULAR) (0.37) and at 6 months in only three patients and disagreement in six patients, rEULAR (0.52). The correlation factors at 3rd month and 6th months were, respectively, as follows: rMVP (0.67 and 0.75), response RA factor (0.54 and 0.74), response erythrocyte sedimentation rate (0.81 and 0.73), response C-reactive protein (0.78 and 0.51), and response anti-cyclic citrullinated peptide antibodies (0.33 and 0.54). The overall response to DMARD therapy at 3 months was assessed with results showing good response by four cases (40%), mixed response by 1 (10%), no response by 5 (50%), and complete response by none (0%). Step-up therapy at 3 months was initiated in four patients showing nonresponse/progression on clinical symptomatic assessment; of these, two patients showed a good response, one mixed response, and the remaining one continued to show nonresponse at 6 months follow-up. One patient who had a minimal response at 3 months on PET-CT (only 5.96% reduction of MVP) was continued on the same DMARD in view of clinical symptomatic good response (at 3 months) but ultimately had disease progression in all scales and worsening of symptom (at 6 months). FDG-PET/CT-based assessment of inflammatory activity noted in the joints of RA with quantitative parameters can be a promising approach for the whole body assessment of RA disease activity and treatment response assessment, especially in inconclusive cases and correlates well with other parameters. MVP can be used as a useful objective and adjunct parameter for assessing response to treatment.

PET-CT in Vascular Graft Infections

18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET-CT) exhibits high diagnostic accuracy in the detection of vascular graft infections. Therapy control in vascular graft infection with FDG-PET-CT appears to be useful, as a significant impact on patient management has been described; however, supplemental data from large outcome studies are still pending.

18F-fluorodeoxyglucose positron emission tomography-computed tomography as a screening tool for second primary cancers in cancer patients.

BackgroundWe performed a meta-analysis to evaluate the value of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18FDG PET-CT) for the detection of second primary cancers in cancer patients.ResultsThis present study analyzed a total of 6 selected studies (1374 patients). The sensitivity and specificity of PET-CT were 0.84 (95% confidence interval [CI] = 0.66 to 0.93), and 0.98 (95% CI = 0.97 to 0.98). Area under the curve was 0.98 (95% CI = 0.96 to 0.99).MethodsStudies were systematically searched for relevant PET-CT original articles in the MEDLINE and EMBASE databases. We calculated the pooled sensitivity, specificity, and likelihood ratios for 18FDG PET-CT. We also constructed the summary receiver-operating characteristic curve for 18FDG PET-CT.Conclusions18FDG PET-CT has high sensitivity and specificity for the detection of second primary cancers in cancer patients.

The Incidence of Totally Implantable Venous Access Devices Insertion and the Associated Abnormalities in Patients With Cancer Revealed in 18F-FDG PET-CT Imaging

The purpose of this retrospective study was to evaluate the incidence of totally implantable venous access devices, also called ports, implantation and the associated abnormalities in 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography-computed tomography (PET-CT) images for patients with cancer, and to determine the percentage of abnormalities identified in the original reports. The study aimed to perform a retrospective review of all FDG PET-CT imaging in a 3-year period. Cases of port-associated abnormalities found on the FDG PET-CT images were identified and then correlated with X-ray reports and clinical treatment or follow-up. In total, 2442 FDG PET-CT scans were retrospectively reviewed. Among them, 897 (897 of 2442, 36.7%) demonstrated port implantation. Abnormalities, including 22 port fractures (22 of 897, 2.45%), 14 malposition (1.56%), one infection (0.11%), and one embraced by a fibrin sheath or tumor (0.11%) were found. Only the infectious one had clinical symptoms. Among the 22 fractured ports, eight fractured catheters migrated and became dislodged. All of the malpositioned ports, except two in the contralateral subclavian vein, were found in the ipsilateral jugular vein. Both the port infection and the port embraced by a fibrin sheath or tumor occurred at the tips of the devices, which demonstrated FDG uptake in the mediastinal region. Only seven of the 38 (18.42%) images of port abnormalities had been identified in the original reports. Based on this study, we recommend that the interpretation of FDG PET-CT scans should include a checklist to record all metallic device implantations and to interpret the whole-body X-ray topography as a standard part of PET-CT image report.

Comparison of biological target volume metrics based on FDG PET-CT and 4DCT for primary non-small-cell lung cancer.

Fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) and four-dimensional CT (4DCT) are used in several methods for defining the biological target volume (BTV) in primary non-small cell lung cancer (NSCLC). Disagreements between the assessments using these methodologies make the use of BTV for radiotherapy planning controversial. In this study, we compared existing methods with our proposed internal biological target volume (IBTV) metric, derived by combining internal target volume (ITV) and BTV metrics. We defined the IBTV from ITV (IBTVi) or BTV (IBTVb) based on ITV or BTV with symmetrical margin expansion. We detected large differences between IBTV, IBTVi and IBTVb (p < 0.001), but no difference between ITV and BTV. A margin expansion of about 13 mm was necessary for ITV or BTV to encompass > 95% IBTV. The conformity index correlated negatively with IBTV/ITV, IBTV/BTV, IBTVi/ITV, and IBTVb/BTV volume ratios (p < 0.05). VR also increased the margins of IBTVi and IBTVb. Indeed, IBTV was much smaller than IBTVi or IBTVb, suggesting that using IBTV for radiotherapy planning could improve treatment by minimizing the radiation exposure of healthy tissue and organs surrounding tumors.

The clinical outcome correlations between radiation dose and pretreatment metabolic tumor volume for radiotherapy in head and neck cancer: A retrospective analysis.

This study was to investigate the clinical outcomes between radiation dose and pretreatment metabolic tumor volume (MTV) in patients with head and neck cancer treated with definitive chemoradiotherapy.Thirty-four patients received pretreatment 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET/CT) were recruited for this study. The CT-based volume (gross tumor volume of the primary [GTVp]) and 4 types of MTVs were measured on the basis of either a maximal standardized uptake value (SUVmax) of 2.5 (MTV2.5), 3.0 (MTV3.0), or a fixed threshold of 40% (MTV40%), 50% (MTV50%). 18F-FDG PET-CT images before treatment, and data including response to treatment, local recurrence, death due to the cancer, disease-free survival (DFS) and primary relapse-free survival (PRFS), were collected for analysis.The Wilcoxon rank test showed that all values determined by the different delineation techniques were significantly different from the GTVp (P < .05). Tumor volume and the homogeneity of target dose of MTV2.5, MTV3.0, MTV40%, and MTV50% were significantly different between the 2 groups of patients through treatment outcomes (P < .05).The survival curves for DFS and PRFS demonstrated that the homogeneity of the target dose in MTVs was a good indicator. The homogeneity of target dose in the tumor is a potential indicator of DSF and PRFS in patients with head and neck cancer who underwent radiotherapy.

Comparison of standardized uptake value of 18F-FDG-PET-CT with 21-gene recurrence score in estrogen receptor-positive, HER2-negative breast cancer

BackgroundWe investigated the relationship between 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG-PET-CT) standardized uptake value (SUV) and 21-gene recurrence score (RS) in estrogen receptor (ER)-positive/HER2-negative breast cancer.Materials and methodsOne hundred sixty-seven patients were identified among those who underwent preoperative 18F-FDG-PET-CT and had RS. Maximum SUV was obtained from 18F-FDG-PET-CT; the cut-off point was 4.ResultsThe continuous RS and SUV correlated positively (Pearson’s R = 0.555; P < 0.001). An inverse correlation was found between progesterone receptor (PR) expression by reverse transcriptase-polymerase chain reaction, and SUV (Pearson’s R = -0.408; P < 0.001). Good agreement between dichotomized RS (<26 vs. ≥26) and SUV (<4 vs. ≥4) was observed in 137 of 167 patients (82.0%; 95% confidence interval [CI], 76.2–87.9). Among patients with low SUV, 114 of 115 (99.1% [95% CI, 97.4–100.0]) had tumors with lower RS (<26). Although 23 of 52 women (44.2% [95% CI, 30.7–57.7]) with high SUV had higher RS (≥26), all 13 women with high RS (≥31) had high-SUV tumors. Most cases with disagreements between SUV and RS (n = 30) were classified as high SUV/lower RS (n = 29). The discordant group had higher grade or elevated Ki67 expression (≥20%) compared with the low SUV/lower RS group (n = 109), but higher PR expression compared with the high SUV/higher RS group (n = 23). Multiple logistic regression analysis showed that high SUV were associated with higher RS (≥26).ConclusionsSUV, as a biologic parameter represented using a continuous variable, was found to associate with RS in ER-positive, HER2-negative breast cancer. Further studies may reveal the biology underlying the discordance between the markers.

Prognostic value of pretreatment 18F-FDG PET-CT for nasopharyngeal carcinoma patients.

Background:Nasopharyngeal carcinoma (NPC) is a special subtype of head and neck cancer (HNC). At present, there are no highly specific prognostic markers to aid in tumor grading and guide patient treatment modalities for NPC. The prognostic value of pretreatment 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-PET-CT) in NPC patients is controversial and no consensus exists as to its predictive capability.Methods:To analyze the predictive efficacy of 18F-PET-CT imaging in NPC patients, data from MEDLINE, EMBASE, the Cochrane library, CBM, CNKI, and VIP (inception to July 2016) were accessed. Results from prospective and retrospective observational studies that used 18F-FDG PET to predict disease prognosis in NPC patients were used for analysis. Two authors independently assessed study quality and extracted data. Event-free survival (EFS) was considered the primary endpoint and overall survival rate (OS) was considered the secondary endpoint.Results:Data from 14 studies and 1134 patients were included in our analysis. The hazard ratios (HRs) of maximum standardized uptake value of primary tumor (SUVmax-T), metabolic tumor volume of primary tumor (MTV-T), and total lesional glycolysis of primary tumor (TLG-T) for EFS were 1.31 (95% confidence interval [CI], 1.11–1.55, P = .001), 2.38 (95% CI 1.53–3.70, P < .001), and 1.65 (95% CI 0.76–3.59, P = .21), respectively. Among studies including TLG-T, those with a fixed SUV of 2.5 had an HR of 3.55 (95% CI, 1.42–8.84, P = .007). The HRs of SUVmax-T and MTV-T for OS were 2.19 (95% CI, 1.47–3.27, P < .001) and 2.69 (95% CI, 1.01–7.17, P = .05), respectively. Among studies including MTV-T, those with a fixed SUV of 2.5 had an HR of 4.07 (95% CI, 2.22–7.46, P < .001). Tests used for assessing predictive value of pretreatment SUVmax, MTV, and TLG of lymph nodes for EFS and OS showed that these parameters did not have significant predictive value (P>.05).Conclusion:Our results suggested that SUVmax, MTV, and TLG (with a fixed SUV of 2.5) of primary tumors before treatment initiation may be independent prognostic factors for NPC patients; however, SUVmax, MTV, and TLG of metastatic lymph nodes are not.

Impact and prognostic value of 18F-fluorodeoxyglucose positron emission tomography-computed tomography scan in the evaluation of residual head and neck cancer: Single-center experience from Pakistan.

Background:Overview of clinical impact of positron emission tomography-computed tomography (PET-CT) scans in patients with head and neck carcinomas at our center.Methods:Retrospective review of posttreatment 18F-fluorodeoxyglucose (18F-FDG) PET-CT scans in patients with head and neck carcinomas with risk of residual disease. Clinical outcome served as the reference standard.Results:This study included 93 patients (65.6% males, mean age: 48.8 years ± 17.2 standard deviation) with squamous cell carcinoma as most frequent histopathology (91.4%). PET-CT scans were performed on average 6 months posttreatment. Diagnostic accuracy, positive predictive value, and negative predictive value of PET-CT for disease were found to be 88%, 88%, and 92%, respectively. A median follow-up of 24 months was available for 91 patients. Kaplan–Meier curves showed significantly higher disease-free survival with negative PET-CT as compared to positive PET-CT (P = 0.01) and maximum standardized uptake values of <5.0 (P = 0.01).Conclusion:FDG PET-CT has diagnostic and prognostic implications in treated patient of head and neck cancers.

Can 18F-Fluoroestradiol Positron Emission Tomography Become a New Imaging Standard in the Estrogen Receptor-positive Breast Cancer Patient: A Prospective Comparative Study with 18F-Fluorodeoxyglucose Positron Emission Tomography?

Correct staging is the most crucial for the treatment outcome in cancer management. Molecular imaging with 18F-fluoroestradiol (FES) positron emission tomography-computed tomography (PET-CT) targets estrogen receptor (ER) and may have a higher incremental value in diagnosis by aiding specificity. We enrolled 12 female breast cancer patients prospectively and did 18F-FES PET-CT and 18F-fluorodeoxyglucose (FDG) PET-CT within 1 week interval time. Lesion detection sensitivity was compared for a total number of lesions and for nonhepatic lesions only by McNemar test. 18F-FES PET-CT was taken as reference in case of indeterminate lesions. The incremental value reported by identifying 18F-FES exclusive lesions and by characterization of 18F-FDG indeterminate lesions. Spearman rank test was used to correlate ER expression and maximum standardized uptake value (SUVmax). Two ER-negative patients with no 18F-FES uptake were excluded. Ten ER-positive patients with 154 disease lesions were finally analyzed. 18F-FDG picked-up 142 lesions (sensitivity 92.21%), whereas 18F-FES picked-up 116 lesions (sensitivity 75.32%) and this difference was statistically significant. For nonhepatic lesions (n = 136) detectability, 18F-FDG picked-up 124 (sensitivity 91.18%), whereas 18F-FES picked-up 116 (sensitivity 85.29%) lesions and this difference was not statistically significant. Beside 12 exclusive lesions, 18F-FES characterized 41 (27.5%) 18F-FDG indeterminate lesions. Overall 18F-FES impacted 20% patient management. The positive trend was also seen with 18F-FES SUVmax with ER expression and negative with 18F-FDG SUVmax. We conclude, 18F-FDG has overall better sensitivity than 18F-FES PET-CT, however for nonhepatic metastasis difference was not significant. 18F-FES PET-CT better-characterized lesions and impacted 20% patient management. Therefore, 18F-FES PET-CT should be used with 18F-FDG PET-CT in strongly ER expressing patients for better specificity.

Evaluation of metabolic response with 18F-FDG PET-CT in patients with advanced or recurrent thymic epithelial tumors

BackgroundPatients with advanced or recurrent thymic epithelial tumors (TETs) often need several consecutive lines of chemotherapy. The aim of this retrospective monocentric study was to test whether 18F-Fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) is able to monitor standard chemotherapy efficacy in those patients and whether metabolic response correlates with morphovolumetric response as assessed by Response Evaluation Criteria in Solid Tumor (RECIST).MethodsWe evaluated 27 consecutive patients with advanced (16 patients) or recurrent (11 patients) TETs. All patients underwent 18F-FDG PET-CT before and after at least 3 cycles of chemotherapy. Maximum standardized uptake value (SUVmax) of all detected lesions was recorded and the most 18F-FDG avid lesion in each patient was selected for determination of percentage change of SUVmax (ΔSUVmax) in pre- and post-treatment scans. Tumor response was assessed by contrast-enhanced computed tomography (CE-CT) using RECIST criteria. Receiver operating characteristic (ROC) curve analysis was performed to define the optimal threshold of ΔSUVmax discriminating responders from non-responders.ResultsMetabolic response expressed as ΔSUVmax was significantly correlated with morphovolumetric response (Spearman’s rank correlation, r = 0.64, p = 0.001). ROC curve analysis showed that a ΔSUVmax value of -25% could discriminate responders from non-responders with a sensitivity of 88% and a specificity of 80%. Conversely, basal SUVmax values were not predictive of morphovolumetric tumor response.ConclusionsOur findings indicate that metabolic response assessed by 18F-FDG PET-CT, through evaluation of ΔSUVmax, may allow identification of responders and non-responders thus guiding adaptation of therapy in patients with advanced or recurrent TETs.

The Role of 18F‐fluorodeoxyglucose Positron Emission Tomography‐Computed Tomography for Predicting Pathologic Response After Induction Therapy for Thymic Epithelial Tumors

We investigated the role of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) in predicting the effect of induction therapy in patients with thymic epithelial tumors. Fourteen patients with thymic epithelial tumors who underwent PET-CT before and after induction therapy were retrospectively analyzed. The relationship between the change in the maximum standardized uptake value (SUVmax) in PET-CT, the response evaluation criteria in solid tumors and the pathologic response (Ef0, no necrosis of tumor cells; Ef1, some necrosis of tumor cells with more than one-third of viable tumor cells; Ef2, less than one-third of tumor cells were viable; and Ef3, no tumor cells were viable) was analyzed. The study cohort consisted of 5 males and 9 females. Nine of the patients had thymoma, and 5 had thymic carcinoma. The induction therapy included chemotherapy in 9 cases, chemoradiation therapy in 4 cases and radiation therapy in 1 case. Among the 8 patients with a pathologic response of Ef0/1, 5 were clinically evaluated as having stable disease (SD), while 3 were found to have had a partial response (PR). The SUVmax was elevated in 2 cases, unchanged in 1 and decreased in 5. On the other hand, 3 of the 6 patients with a pathologic response of Ef2, 3 were classified as having SD, while the other 3 had a PR. The SUVmax decreased in all of the patients. In comparison with CT, PET-CT seems to be useful for predicting the pathologic response to induction therapy in patients with thymic epithelial tumors.

Liver Transplantation for Hepatocellular Carcinoma Beyond the Milan Criteria.

Hepatocellular carcinoma is the most common primary liver malignancy. Liver transplantation has been a successful therapy for selected patients with hepatocellular carcinoma. Since 1996, Milan criteria have been universally recognized as the guidelines for selecting patients with hepatocellular carcinoma for orthotopic liver transplantation. However, the simple use of tumor size and number has been insufficient to indicate the biologic features of hepatocellular carcinoma and to predict the risk of tumor recurrence. The Milan criteria are quite strict because their rules can cause patients to be excluded from wait lists who could in fact benefit from transplant. Therefore, many expanded criteria are now incorporating different biologic markers, such as alpha-fetoprotein. 18F-fluorodeoxyglucose positron emission tomography-computed tomography could be a helpful diagnostic tool to decide the most suitable therapy, particularly for patients with hepatocellular carcinoma beyond the Milan criteria. Patients initially beyond Milan criteria can be downstaged to reduce tumor size to fulfill Milan criteria. Locoregional therapies are used for downstaging, including transarterial chemoembolization, radiofrequency ablation, and percutaneous ethanol injection. Good responses to downstaging therapy and then waiting at least 3 months after locoregional therapy to reevaluate the decision of liver transplantation for patients with hepatocellular carcinoma beyond Milan criteria can result in better survival rates in these patients. Sorafenib and mammalian target of rapamycin inhibitors are promising agents for reducing tumor recurrence rate after liver transplantation. With cautious patient selection criteria and the use of locoregional therapy before liver transplantation, good results can be obtained for patients beyond Milan criteria who had no better chance other than liver transplant.

TEP-FDG et pathologies infectieuses

Interests of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) have been demonstrated since many years. FDG physiopathology explains its use for infectious diseases, especially in infective endocarditis, cardiac electronic device infection, and in vascular graft infection, as well as in fever of unknown origin. FDG PET is very interesting to make the diagnostic and for the extension of these infectious diseases, thanks to the whole body acquisition. This synthesis article identifies and illustrates principal indications in this field of this imagery modality.

Lymphomatous Involvement of Male Breast in a Patient with Bilateral Gynecomastia: Demonstration with 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography.

Lymphomatous Involvement of Male Breast in a Patient with Bilateral Gynecomastia: Demonstration with 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography.

Primitive Neuroectodermal Tumor of Nasal Cavity on 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography.

Primitive neuroectodermal tumor is a malignant small round cell tumor of presumed neural crest origin, usually affecting the bony structures of the nasal cavity and its clinical and radiological features may be confused with those of infection and malignancy. I report a case with primitive neuroectodermal tumor of the nasal cavity showing increased tracer uptake on 18F-fluorodeoxyglucose positron emission tomography-computed tomography mimicking an another primary malignancy in a 17-year-old boy.