F-fluorodeoxyglucose Positron Emission Tomography Scans Research Articles

Total Eclipse of FDG-PET Scan Caused by Hyperphysiological FDG Uptake of Masticatory Muscles Due to Chewing

In routine oncological 18F-fluorodeoxyglucose positron emission tomography (FDG-PET/CT) scan, the patients rest in a quite, dimly lit room for 60 minutes after intravenous (IV) injection of FDG and they are instructed not to move during this time (uptake phase) before FDG-PET/CT scanning to prevent and decrease unwanted FDG accumulations on muscle traces caused by muscle movements. In conditions of patient inconsistency, undesirable activities can be seen and reach high levels making difficult or even impossible to interpret the images. Different muscle groups form various physiological or over- physiological uptake patterns depending on their specific motion. Herein we represent a good didactic example to this phenomenon.

Modest utility of quantitative measures in 18F-fluorodeoxyglucose positron emission tomography scanning for the diagnosis of aortic prosthetic graft infection

The clinical dilemma in suspected aortic graft infection (AGI) is how to noninvasively obtain a reliable proof of infection. In addition to confirming the presence of infection, obtaining information regarding the extent of infection to select a proper strategy for reoperation is also necessary. Therefore, developing a more reliable noninvasive physiologic approach to detect infected prostheses is required. (18)F-fluorodeoxyglucose positron emission tomography scanning ((18)F-FDG PET) has been suggested to have a pivotal role in the detection of AGI. In this study, we assessed the contribution of two (semi) quantitative parameters-maximal standardized uptake value (SUVmax) and tissue-to-background ratio (TBR)-and of two visual parameters-fluorodeoxyglucose (FDG) distribution patterns and visual grading scale-in the final confirmation of the diagnosis of AGI. Patients with a central aortic prosthetic graft and symptoms clinically suggestive of AGI were gathered from a prospectively maintained database. Included were those who underwent (18)F-FDG PET scanning combined with computed tomography angiography and in whom periprosthetic samples were taken at some stage in the diagnostic process. AGI was considered proven in case of a positive culture and compared with a group with negative cultures. Positive predictive values (PPVs) and negative predictive values (NPVs) were calculated. Receiver operating characteristics curves were used to assess the ability of SUVmax and TBR to identify the presence and absence of AGI (ie, accuracy). In 37 of 77 patients with suspected AGI, (18)FDG-PET and perigraft material for culturing was obtained. The tissue culture was positive in 21 of these 37 patients (56.7%). Mean ± standard deviation SUVmax for proven infection was 8.1 ± 3.7 (range, 3.6-18.5) and TBR was 5.9 ± 2.7 (range, 1.7-13.0). The area under the curve for SUVmax was 0.78 (95% confidence interval, 0.63-0.93). A cutoff value of 8 yielded a PPV of 80% and a NPV of 54%. The area under the curve for TBR was 0.70 (95% confidence interval, 0.52-0.87). A cutoff value of 6 yielded a PPV of 73% and NPV of 52%. The PPVs for the visual grading scale and (18)F-FDG distribution patterns were 75% and 61%, respectively; the NPVs were 77% and 67%, respectively. Our study, performed in a small sample of patients suspected of AGI, showed that the diagnostic abilities of quantitative and visual (18)F-FDG PET parameters are modest.

Nutrient patterns and brain biomarkers of Alzheimer's disease in cognitively normal individuals.

Epidemiological evidence linking diet, one of the most important modifiable lifestyle factors, and risk of Alzheimer's disease (AD) is rapidly increasing. However, there is little or no evidence for a direct association between dietary nutrients and brain biomarkers of AD. This study identifies nutrient patterns associated with major brain AD biomarkers in a cohort of clinically and cognitively normal (NL) individuals at risk for AD. Cross-sectional study. Manhattan (broader area). Fifty-two NL individuals (age 54+12 y, 70% women, Clinical Dementia Rating=0, MMSE>27, neuropsychological test performance within norms by age and education) with complete dietary information and cross-sectional, 3D T1-weighted Magnetic Resonance Imaging (MRI; gray matter volumes, GMV, a marker of brain atrophy), 11C-Pittsburgh compound-B (PiB; a marker of fibrillar amyloid-β, Aβ) and 18F-fluorodeoxyglucose (FDG; a marker of glucose metabolism, METglc) Positron Emission Tomography (PET) scans were examined. Dietary intake of 35 nutrients associated with cognitive function and AD was assessed using the Harvard/Willet Food Frequency Questionnaire. Principal component analysis was used to generate nutrient patterns (NP) from the full nutrient panel. Statistical parametric mapping and voxel based morphometry were used to assess the associations of the identified NPs with AD biomarkers. None of the participants were diabetics, smokers, or met criteria for obesity. Five NPs were identified: NP1 was characterized by most B-vitamins and several minerals [VitB and Minerals]; NP2 by monounsaturated and polyunsaturated fats, including ω-3 and ω-6 PUFA, and vitamin E [VitE and PUFA]; NP3 by vitamin A, vitamin C, carotenoids and dietary fibers [Anti-oxidants and Fibers]; NP4 by vitamin B12, vitamin D and zinc [VitB12 and D]; NP5 by saturated, trans-saturated fats, cholesterol and sodium [Fats]. Voxel-based analysis showed that NP4 scores [VitB12 and D] were positively associated with METglc and GMV, and negatively associated with PiB retention in AD-vulnerable regions (p<0.001). In addition, both METglc and GMV were positively associated with NP2 scores [VitE and PUFA], and negatively associated with NP5 scores [Fats] (p<0.001), and METglc was positively associated with higher NP3 scores [Anti-oxidants and Fibers] (p<0.001). Adjusting for age, gender, ethnicity, education, caloric intake, BMI, alcohol consumption, family history and Apolipoprotein E (APOE) status did not attenuate these relationships. The identified 'AD-protective' nutrient combination was associated with higher intake of fresh fruit and vegetables, whole grains, fish and low-fat dairies, and lower intake of sweets, fried potatoes, high-fat dairies, processed meat and butter. Specific dietary NPs are associated with brain biomarkers of AD in NL individuals, suggesting that dietary interventions may play a role in the prevention of AD by modulating AD-risk through its effects on Aβ and associated neuronal impairment.

Cost-Effectiveness of Initial Diagnostic Strategies for Pulmonary Nodules Presenting to Thoracic Surgeons

Patients presenting to thoracic surgeons with pulmonary nodules suggestive of lung cancer havevaried diagnostic options including navigation bronchoscopy (NB), computed tomography-guided fine-needleaspiration (CT-FNA), (18)F-fluoro-deoxyglucose positron emission tomography (FDG-PET) and video-assisted thoracoscopic surgery (VATS). We studied the relative cost-effective initial diagnostic strategy for a 1.5-to 2-cm nodule suggestive of cancer. A decision analysis model was developed to assess the costs and outcomes of four initial diagnostic strategies for diagnosis of a 1.5- to 2-cm nodule with either a 50% or 65% pretest probability of cancer. Medicare reimbursement rates were used for costs. Quality-adjusted life years were estimated using patient survival based on pathologic staging and utilities derived from the literature. When cancer prevalence was 65%, tissue acquisition strategies of NB and CT-FNA had higher quality-adjusted life years compared with either FDG-PET or VATS, and VATS was the most costly strategy. In sensitivity analyses, NB and CT-FNA were more cost-effective than FDG-PET when FDG-PET specificity was less than 72%. When cancer prevalence was 50%,NB, CT-FNA, and FDG-PET had similar cost-effectiveness. Both NB and CT-FNA diagnostic strategies are more cost-effective than either VATS biopsy or FDG-PET scan to diagnose lung cancer in moderate- to high-risk nodules and resulted in fewer nontherapeutic operations when FDG-PET specificity was less than 72%. An FDG-PET scan for diagnosis of lung cancer may notbe cost-effective in regions of the country where specificity is low.

Functional imaging: A necessary prerequisite to neuropsychological assessment

After traumatic brain injury, neuropsychological testing may be insensitive in documenting functional brain injury. Imaging with single-photon emission computed tomography (SPECT) and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) scanning may identify brain injury that is missed on neuropsychological testing. A 27-year-old man had loss of consciousness after hydrogen sulfide exposure and a fall; he had markedly impaired function (short-term memory, sequential thinking, attention, and initiative), but neuropsychological testing showed only mild to moderate impairments. A 37-year-old woman had a whiplash injury and head trauma after an automobile accident; she had apprehension, dysphoria, word finding problems, impaired memory and concentration, and slowed thinking; neuropsy- chological testing was normal. In the man, SPECT scan showed decreased activity in the striatum, amygdala, and hippocampus bilaterally (decreased more in the right than left hemisphere); an FDG-PET scan showed markedly decreased metabolism in the left thalamus, heterogeneous abnormal uptake in the basal ganglia, and abnormally decreased metabolism in both temporal and inferior parietal lobes. In the woman, FDG-PET scan showed several regions of abnormal metabolic activity not restricted to single vascular territories and decreased activity in the left frontal lobe, left thalamus, and left caudate nucleus. Repeat neuropsychiatric testing in both patients showed cognitive and motor impairments that seriously limited routine activities of daily living. In summary, after traumatic brain injury associated with neuropsychological symptoms, SPECT and FDG-PET scanning may be more sensitive than neuropsychological testing in detecting objective signs of brain injury.

How we treat Richter syndrome

Richter syndrome (RS) is defined as the transformation of chronic lymphocytic leukemia (CLL) into an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (DLBCL). RS occurs in approximately 2% to 10% of CLL patients during the course of their disease, with a transformation rate of 0.5% to 1% per year. A combination of germline genetic characteristics, clinical features (eg, advanced Rai stage), biologic (ζ-associated protein-70(+), CD38(+), CD49d(+)) and somatic genetic (del17p13.1 or del11q23.1) characteristics of CLL B cells, and certain CLL therapies are associated with higher risk of RS. Recent studies have also identified the crucial role of CDKN2A loss, TP53 disruption, C-MYC activation, and NOTCH1 mutations in the transformation from CLL to RS. An excisional lymph node biopsy is considered the gold standard for diagnosis of RS; a (18)F-fluorodeoxyglucose positron emission tomography scan can help inform the optimal site for biopsy. Approximately 80% of DLBCL cases in patients with CLL are clonally related to the underlying CLL, and the median survival for these patients is approximately 1 year. In contrast, the remaining 20% of patients have a clonally unrelated DLBCL and have a prognosis similar to that of de novo DLBCL. For patients with clonally related DLBCL, induction therapy with either an anthracycline- or platinum-based regimen is the standard approach. Postremission stem cell transplantation should be considered for appropriate patients. This article summarizes our approach to the clinical management of CLL patients who develop RS.

Adult-Onset Still Disease

We conducted a retrospective observational study to describe a cohort and identify the prognostic factors in adult-onset Still disease (AOSD). Patients enrolled in this retrospective chart review fulfilled either Yamaguchi or Fautrel criteria. Candidate variables were analyzed with logistic unadjusted and adjusted regression models.Fifty-seven patients were seen in the internal medicine (75%) and rheumatology (25%) departments over a mean period of 8.4 years. The median time to diagnosis was 4 months. The course of AOSD was monocyclic in 17 patients, polycyclic in 25, and chronic in 15. The assessment of glycosylated ferritin (GF) in 37 patients was correlated with early diagnosis. Nine 18F-fluorodeoxyglucose positron emission tomography (18FDG-PET) scans identified the lymph nodes and glands as the main sites of hypermetabolism. Complications were frequent (n = 19), including reactive hemophagocytic syndrome (n = 8). None of the 3 deaths could be attributed to AOSD. Corticosteroid dependence, as predicted by a low GF level, occurred in 23 patients (45%). A quarter of the patients received tumor necrosis factor-α blockers or anakinra with good tolerance. Fever >39.5°C was predictive of monocyclic AOSD, while arthritis and thrombocytopenia were associated with chronic and complicated AOSD, respectively. The youngest patients had the highest risks of resistance to first-line treatments.AOSD remains difficult to diagnose. Mortality is low despite frequent complications. GF and 18FDG-PET scans were of value in the diagnostic approach. The condition in highly symptomatic patients evolved to systemic AOSD, whereas more progressive patterns with arthritis predicted chronic AOSD.

Maximum Standardized Uptake Value on FDG-PET Is a Strong Predictor of Overall and Disease-Free Survival for Non–Small-Cell Lung Cancer Patients after Stereotactic Body Radiotherapy

The maximum standardized uptake value (SUVmax) on F-fluorodeoxyglucose positron emission tomography is a predictor for overall survival (OS) in non-small-cell lung cancer (NSCLC) after resection. We investigated the association between SUVmax and outcomes in NSCLC after stereotactic body radiotherapy. Between 2005 and 2012, 283 patients with early NSCLC (T1a-2N0M0) were treated with stereotactic body radiotherapy; the total doses were 40 to 60 Gy in five fractions. Patients who underwent staging F-fluorodeoxyglucose positron emission tomography scans by a single scanner and were followed up for more than or who died within 6 months were eligible. The optimal threshold SUVmax was calculated for each outcome. Outcomes were analyzed using the Kaplan-Meier method and log-rank test. Prognostic significance was assessed by univariate and multivariate analyses. One hundred fifty-two patients were eligible. Median follow-up was 25.3 (range, 1.3-77.4) months. Local, regional, and distant recurrences, cancer-specific deaths, and deaths from other reasons occurred in 14, 11, 27, 21, and 31 patients, respectively. The optimal threshold SUVmax for local, regional, and distant recurrences, and disease-free survival (DFS), cancer-specific survival, and OS were 2.47 to 3.64. Outcomes of patients with SUVmax lower than each threshold were significantly better than those with higher SUVmax (all p<0.005): 3-year DFS rates were 93.0% versus 58.3% (p<0.001) and 3-year OS rates were 86.5% versus 42.2% (p<0.001), respectively. By multivariate analysis, higher SUVmax was a significantly worse predictor for DFS (p<0.01) and OS (p=0.04). SUVmax was a predictor for DFS and OS. A high SUVmax may be considered for intensive treatment to improve outcomes.

Physical Activity, Mediterranean Diet and Biomarkers-Assessed Risk of Alzheimer's: A Multi-Modality Brain Imaging Study.

Increased physical activity and higher adherence to a Mediterranean-type diet (MeDi) have been independently associated with reduced risk of Alzheimer’s disease (AD). Their association has not been investigated with the use of biomarkers. This study examines whether, among cognitively normal (NL) individuals, those who are less physically active and show lower MeDi adherence have brain biomarker abnormalities consistent with AD.MethodsForty-five NL individuals (age 54 ± 11, 71% women) with complete leisure time physical activity (LTA), dietary information, and cross-sectional 3D T1-weigthed MRI, 11C-Pittsburgh Compound B (PiB) and 18F-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) scans were examined. Voxel-wise multivariate partial least square (PLS) regression was used to examine the effects of LTA, MeDi and their interaction on brain biomarkers. Age, gender, ethnicity, education, caloric intake, BMI, family history of AD, Apolipoprotein E (APOE) genotype, presence of hypertension and insulin resistance were examined as confounds. Subjects were dichotomized into more and less physically active (LTA+ vs. LTA−; n = 21 vs. 24), and into higher vs. lower MeDi adherence groups (n = 18 vs. 27) using published scoring methods. Spatial patterns of brain biomarkers that represented the optimal association between the images and the groups were generated for all modalities using voxel-wise multivariate Partial Least Squares (PLS) regression.ResultsGroups were comparable for clinical and neuropsychological measures. Independent effects of LTA and MeDi factors were observed in AD-vulnerable brain regions for all modalities (p < 0.001). Increased AD-burden (in particular higher Aβ load and lower glucose metabolism) were observed in LTA− compared to LTA+ subjects, and in MeDi− as compared to MeDi+ subjects. A gradient effect was observed for all modalities so that LTA−/MeDi− subjects had the highest and LTA+/MeDi+ subjects had the lowest AD-burden (p < 0.001), although the LTA × MeDi interaction was significant only for FDG measures (p < 0.03). Adjusting for covariates did not attenuate these relationships.ConclusionLower physical activity and MeDi adherence were associated with increased brain AD-burden among NL individuals, indicating that lifestyle factors may modulate AD risk. Studies with larger samples and longitudinal evaluations are needed to determine the predictive power of the observed associations

Interim and Post-Treatment Positron Emission Tomography-Computed Tomography Scan Status Is Highly Predictive Of Outcome In Diffuse Large Cell Lymphoma Patients Treated With R-CHOP21

BackgroundTaking a step forward from the international prognostic index, attention is focused on the role of 18F-fluorodeoxyglucose positron-emission tomography-Computed Tomography scan (PET) as a tool for guidance in risk stratification in patients with diffuse large B-cell lymphoma (DLBCL). Here, we analyzed the predictive value of interim and post-treatment PET in patients with DLBCL. MethodsIn our retrospective study, we analyzed a homogeneous cohort of newly diagnosed DLBCL patients treated with R-CHOP21 who underwent PET scan at diagnosis, after three cycles of chemotherapy and at the end of treatment. For interim PET, images were interpreted by computing maximum standardized uptake value between PET performed at baseline and after three cycles of immuno-chemotherapy (¦¤SUVmax). The images of post-treatment PET were interpreted visually according to the International Harmonization Project criteria. The primary study endpoints were progression-free survival (PFS) and overall survival (OS). ResultsThirty-eight patients with DLBCL with PET data were identified. The median follow-up was 28 months. At interim PET evaluation, optimal cutoff to predict progression was 66% for ¦¤SUVmax. ¦¤SUVmax analysis (≥66% vs< 66%) identified patients with significantly different 2-year PFS (90.7% vs 38.9%; P =.000) and 2-year OS (95.5% vs 62%; P=.016) (Fig1). Post-treatment PET status (negative vs positive) was statistically significantly associated with 2-year PFS (91% vs 45.5%; P =.001) and 2-year OS (100% vs 72.7%; P =.012) (Fig2). [Display omitted] [Display omitted] ConclusionsThese data support the prognostic utility of PET in interim and post-treatment settings in patients with DLBCL treated with R-CHOP21. An interim PET scan after three cycles of treatment can effectively predict the outcome by using quantitative assessment of ¦¤SUVmax and allows clinicians to design a risk-adapted therapeutic strategy. A positive PET after the completion of therapy identifies a patient subset with an inferior PFS and OS. Disclosures:No relevant conflicts of interest to declare.

An Oncocytic Variant of Intraductal Papillary Neoplasm of the Bile Duct that Formed a Giant Hepatic Cyst

Intraductal papillary neoplasms of the bile duct (IPNB) is the collective term used to refer to papillary bile duct tumors, mucin producing bile duct tumors, and cystic bile duct tumors. Pathologically, these tumors may be considered a highly differentiated adenocarcinoma or a tumor of borderline malignant potential. IPNB is classified into one of four variants based on cell differentiation. The rarest, oncocytic, is characterized by oxyphilic granular cytoplasm and no mucous cell differentiation. The patient, a 59-year old man, was admitted with a complaint of abdominal fullness and a 30×25 cm cystic mass in the right hepatic lobe demonstrated on computed tomography (CT). The mass had no malignant features on CT or magnetic resonance imaging; however, a portion was FDG avid on 18F-fluorodeoxyglucose positron emission tomography scan (FDG-PET). A fenestration operation was performed for the presumed diagnosis of a hepatic cyst. Pathological examination of the cyst contents demonstrated some atypical cells suspicious for malignancy. After eight months of observation, abnormal FDG uptake was again observed at the residual cyst. A partial hepatectomy was performed to excise the cyst. Pathological examination demonstrated adenocarcinoma in situ derived from an oncocytic IPNB variant. Following the resection, the patient remained disease free for 40 months. This is an extremely rare case of an oncocytic variant of IPNB that was difficult to distinguish clinically from a solitary hepatic cyst.

Glucose corrected standardized uptake value (SUVgluc) in the evaluation of brain lesions with 18F-FDG PET

To retrospectively assess the utility of (18)F fluorodeoxyglucose (FDG) positron emission tomography (PET) images of standardized uptake values corrected for blood glucose (SUV(gluc)), and to compare this to various quantitative methods to identify the presence or absence of high grade malignancy. A retrospective review in 42 patients, found 81 central nervous system (CNS) lesions. Fifty one were malignant and 30 were benign or post treatment changes based on pathology (n = 32) and on clinical outcome (n = 49). Dynamic FDG PET scans were processed to generate parametric images of SUV(gluc), SUV, glucose metabolic rate (GMR), and lesion to cerebellum ratios (SUV(Rc)), and contralateral white matter ratios (SUV(Rw)). The SUV(gluc) was calculated from SUV(max) * BG/[100 mg/dl], where SUV(max) is the maximum SUV and BG is the blood glucose level (mg/dL). Using a malignant threshold for SUV(gluc) of 4.5 and GMR of 13.0 μmole/min/100 g, the accuracies were similar for the SUV(gluc) (80%) and GMR (81%) and were higher than the conventional SUV(max) (73%). The area under the receiver operating characteristic (ROC) curve for the SUV(gluc) (0.8661) was better than that for the SUV(max) (0.7955) (p < 0.02) and was similar to those of the GMR (0.8694), SUV(Rc) (0.8278), and SUV(Rw) (0.8559). These results suggest that the SUV(gluc) may assist in the interpretation of FDG PET brain images in patients with CNS lesions. The SUV(gluc) method avoids the complexity of kinetic modeling and the definition of a reference region.

18F-fluorodeoxyglucose positron emission tomography in the staging and prognosis of T cell lymphoma

We previously reported that 18F-fluorodeoxyglucose positron emission tomography scan (FDG-PET) is almost universally positive in patients with T cell lymphoma. In the present analysis we examined the impact of FDG-PET on the initial staging of peripheral T cell lymphomas (PTCLs), and the prognostic value of interim FDG-PET. This retrospective analysis identified patients with mature T or natural killer (NK) lymphomas who had PET scans as part of initial staging or staging at relapse [(n = 95) (staging cohort)] in the PTCL database at Memorial Sloan-Kettering Cancer Center. A subset of these patients had repeat PET for interim restaging during initial therapy with curative intent [(n = 50) (interim restaging cohort)]. The frequency of specific T cell histologies included in this analysis were: PTCL not otherwise specified (NOS) (n = 35); angioimmunoblastic T cell lymphoma (AITL) (n = 17); anaplastic large cell lymphoma (ALCL), ALK-1+ (n = 11) and ALK-1− (n = 12); adult T cell lymphoma/leukemia (ATLL) (n = 7); NK/T cell lymphoma (NKTCL) (n = 10); and enteropathy-associated T cell lymphoma (EATL) (n = 3). In the staging cohort, 77 patients were newly diagnosed, and 18 had relapsed disease. Pretreatment FDG-PET was positive in 96% of patients. PET identified additional disease sites in 47/95 patients (50%) when added to conventional staging. Most frequently identified additional sites were: other nodal (n = 24); bone (n = 10); skin (n = 8); nasopharynx (n = 4); spleen (n = 3); and lung (n = 2). However, FDG-PET modified computed tomography (CT)-based staging in only 5/95 patients (5.2%): two patients were upstaged and three patients were downstaged. FDG-PET-based staging did not alter planned treatment for any patient. Interim restaging with PET was performed after a median of 4 cycles of chemotherapy. In this cohort, treatment regimens included cyclophosphamide, doxorubicin, vincristine and prednisone CHOP (n = 19); CHOP/ifosfamide, carboplatin and etoposide (ICE) (n = 26); and other (n = 7). Subsequently, 29 patients were consolidated with either autologous (n = 22) or allogeneic (n = 7) stem cell transplant. After a median follow-up of 3.4 years for surviving patients, those with negative interim PET had superior progression-free survival (PFS) compared to patients with positive interim PET (p = 0.03). There were no differences in overall survival (OS). In PTCL, FDG-PET commonly identifies additional sites of disease but infrequently impacts CT-based staging and does not influence therapy. Interim FDG-PET may predict for PFS. FDG-PET should be integrated into prospective trials to confirm these findings.

Interrelationship between Liver Hemodynamics and Tumor Metabolism in Liver Metastases: Diagnostic Value of Doppler Perfusion Index Revisited

It should be expected that the hepatic blood flow increase in the cases with liver metastasis. We aimed to find out if there is a correlation between Doppler parameters and hepatic metabolic activity in oncology patients. 35 patients with hepatic metastases who were identified by 18F-fluorodeoxyglucose positron emission tomography scan and assessed with Doppler ultrasound were included in this prospective study. Patients with hepatic disease, cardiac dysfunction, dehydration, history of alcoholism, intake of antihypertensive or vasoactive medication were excluded. Volume flow of the proper hepatic artery and the portal vein were measured in the hepatoduodenal ligament by Doppler sonography. Doppler perfusion index (the ratio of the hepatic artery flow to the total liver blood flow) and flow volumes of 31 age matched subjects were compared. Both flow of the proper hepatic artery and portal vein were found to be significantly higher in patients with liver metastasis. The mean Doppler perfusion index value was 0.2 ± 0.13 in hepatic metastases whereas 0.13 ± 0.05 in control group. Doppler perfusion index was significantly higher in liver metastases (p=0.008). A positive correlation was found between the maximum standardized uptake value of the liver and flow volume of the proper hepatic artery (r=0.774, p=0). Blood flow of the proper hepatic artery and Doppler perfusion index correlates with hepatic standardized uptake value. Flow measurements of the liver may become an important parameter for selecting patients for further positron emission tomography scan and following-up the response after systemic and local therapeutic procedures.

Neurosyphilis presenting with unusual hippocampal abnormalities on magnetic resonance imaging and positron emission tomography scans: a case report

IntroductionThe incidence of neurosyphilis has declined markedly since the introduction of penicillin therapy. While there are a number of case reports in the literature of neurosyphilis causing focal decreased 18F-fluorodeoxyglucose uptake on positron emission tomography/computed tomography scans, to the best of our knowledge this is the first published report of neurosyphilis presenting with intensely increased 18F-fluorodeoxyglucose uptake in the hippocampus.Case presentationA 55-year-old Caucasian man presented to our facility with acute collapse against a background of memory difficulties over the previous six months. The results of his initial physical examination were normal. He scored 24 out of 30 on the Montreal Cognitive Assessment test. A magnetic resonance imaging scan of his brain revealed high T2 signal intensity and atrophy within the right frontal area in addition to high T2 signal intensity in the bilateral mesial temporal areas. Blood and cerebrospinal fluid analysis revealed an active syphilis infection. An 18F-fluorodeoxyglucose positron emission tomography brain scan showed intensely increased 18F-fluorodeoxyglucose uptake limited to the head of the right hippocampus. He responded to penicillin treatment with an improvement in his cognition, which was further reflected in a complete resolution of the findings previously seen on magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography scans.ConclusionsDiagnosis of neurosyphilis can be difficult, as many patients are either asymptomatic or present with non-specific symptoms such as memory disturbance or seizures. This report highlights the importance of considering neurosyphilis in the differential diagnosis when mesiotemporal changes are seen on magnetic resonance imaging or 18F-fluorodeoxyglucose positron emission tomography scans.

Monitoring the Response of Stereotactic Body Radiation Therapy (SBRT) in Patients With Early-stage Lung Cancer Using Serial Positron Emission Tomography (PET)

To report on the utility and predictive value of serial 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) scan surveillance following stereotactic body radiation therapy for stage I non-small cell lung cancer (NSCLC).

The role of 18F‐fluorodeoxyglucose–positron emission tomography in the assessment of disease activity in patients with Takayasu arteritis

The assessment of disease activity in Takayasu arteritis (TA) is difficult in clinical situations because clinical symptoms and laboratory parameters do not always reflect the actual inflammation of the arterial wall. We undertook this study to comprehensively investigate the role of (18) F-fluorodeoxyglucose-positron emission tomography (FDG-PET) in the assessment of disease activity in patients with TA. We performed a retrospective chart review of 53 FDG-PET scans in 38 patients with TA. We measured (18) F-fluorodeoxyglucose ((18) F-FDG) accumulation in the vascular wall of the large vessel using semiquantitative (visual grade) and quantitative (standard uptake value intensity) analyses. Clinical disease activity was evaluated based on the National Institutes of Health criteria for active TA, and erythrocyte sedimentation rates (ESRs) and C-reactive protein (CRP) levels were measured. At baseline, active vascular (18) F-FDG uptake (visual grade ≥2) was observed in 18 of 24 patients with active disease and in 5 of 14 patients with inactive disease. There was a significant association between clinical disease activity and disease activity judged by FDG-PET (P = 0.008). Visual grade, standard uptake value intensity, and the number of vascular lesions with active (18) F-FDG uptake were significantly higher in patients with active disease and correlated well with the ESR and CRP levels. In 15 followup FDG-PET scans, the changes in visual grade, areas of active vascular (18) F-FDG uptake, and standard uptake value intensity reflected changes in clinical disease activity. (18) F-FDG uptake was associated with clinical disease activity and markers of inflammation, and FDG-PET reflected changes in clinical disease activity in patients with TA. FDG-PET may be a useful tool for aiding in the assessment of disease activity in patients with TA.

Severe olfactory dysfunction is a prodromal symptom of dementia associated with Parkinson's disease: a 3 year longitudinal study

Dementia is one of the most debilitating symptoms of Parkinson's disease. A recent longitudinal study suggests that up to 80% of patients with Parkinson's disease will eventually develop dementia. Despite its clinical importance, the development of dementia is still difficult to predict at early stages. We previously identified olfactory dysfunction as one of the most important indicators of cortical hypometabolism in Parkinson's disease. In this study, we investigated the possible associations between olfactory dysfunction and the risk of developing dementia within a 3-year observation period. Forty-four patients with Parkinson's disease without dementia underwent the odour stick identification test for Japanese, memory and visuoperceptual assessments, (18)F-fluorodeoxyglucose positron emission tomography scans and magnetic resonance imaging scans at baseline and 3 years later. A subgroup of patients with Parkinson's disease who exhibited severe hyposmia at baseline showed more pronounced cognitive decline at the follow-up survey. By the end of the study, 10 of 44 patients with Parkinson's disease had developed dementia, all of whom had severe hyposmia at baseline. The multivariate logistic analysis identified severe hyposmia and visuoperceptual impairment as independent risk factors for subsequent dementia within 3 years. The patients with severe hyposmia had an 18.7-fold increase in their risk of dementia for each 1 SD (2.8) decrease in the score of odour stick identification test for Japanese. We also found an association between severe hyposmia and a characteristic distribution of cerebral metabolic decline, which was identical to that of dementia associated with Parkinson's disease. Furthermore, volumetric magnetic resonance imaging analyses demonstrated close relationships between olfactory dysfunction and the atrophy of focal brain structures, including the amygdala and other limbic structures. Together, our findings suggest that brain regions related to olfactory function are closely associated with cognitive decline and that severe hyposmia is a prominent clinical feature that predicts the subsequent development of Parkinson's disease dementia.

Interim 18f-PDGPET for Aggressive Non-Hodgking's Lymphoma: A Systematic Review and Meta-Analysis

Abstract 5183 Background:The advantage of using interim 18F-fluorodeoxyglucose (FDG) positron-emission tomography (PET) scan in the clinical work-up of patients with non-Hodgkin's lymphoma (NLH) is unclear. Data from meta-analyses are inconclusive, mainly because of the low number of patients evaluated and heterogeneity among studies. New clinical investigations, focused on this topic, have been recently published. We conducted an updated systematic review on the role of 18PDG-PET for the interim evaluation in patients with aggressive lymphomas. Materials and Methods:Medline, Embase, Scopus and Databases were searched for relevant studies through March 2011. We included studies that evaluated FDG-PET performed between the first and the fourth cycle of first-line chemotherapy. Patients were selected when they were evaluated for response assessment with interim 18FDG-PET. For each study, we constructed a 2 × 2 contingency table consisting of true positive (TP), false positive (FP), false negative (FN), and true negative (TN), where all patients were categorized according to whether they were PET positive or negative, and whether they experienced treatment failure. A meta-analysis of the prognostic accuracy was performed. Results:We selected 16 out of 46 studies, involving 1256 patients with aggressive NHLs (90% with Diffuse Large B-Cell Lymphoma); 1157 patients met our inclusion criteria and were considered for the final analysis. Interim18FDG-PET, performed after a median of 3 cycles of chemotherapy (range 1–6 cycles), gave true and false negative results in 641 (56 %) and 65 (6%) patients, respectively. Therefore, 18FDG-PET had an overall sensitivity of 0.80 (95% CI, 0.69 to 0.88) and a specificity of 0.84 (95% CI, 0.76 to 0.90) (figure). Heterogeneity among studies was substantial. Conclusion:Because of data heterogeneity, interim 18FDG-PET for aggressive NHL patients remains an unproven test for routine clinical practice. Its role should be further evaluated in clinical researches with homogeneous treatments and standardized imaging. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

FDG-PET metabolic response predicts outcomes in anal cancer managed with chemoradiotherapy

Background:The aim was to investigate the correlation between 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) metabolic response to chemoradiotherapy and clinical outcomes in squamous cell carcinoma (SCC) of the anus.Methods:A total of 48 patients with biopsy-proven anal SCC underwent FDG-PET scans at baseline and post chemoradiotherapy (54 Gy, concurrent 5-FU/mitomycin). Kaplan–Meier analysis was used to determine survival outcomes according to FDG-PET metabolic response.Results:In all, 79% patients (n=38) had a complete metabolic response (CMR) at all sites of disease, 15% (n=7) had a CMR in regional nodes but only partial response in the primary tumour (overall partial metabolic response (PMR)) and 6% (n=3) had progressive distant disease despite CMR locoregionally (overall no response (NR)). The 2-year progression-free survival (PFS) was 95% for patients with a CMR, 71% for PMR and 0% for NR (P<0.0001). The 5-year overall survival (OS) was 88% in CMR, 69% in PMR and 0% in NR (P<0.0001). Cox proportional hazards regression analyses for PFS and OS found significant associations for incomplete (PMR+NR) vs complete FDG-PET response to treatment only, (HR 4.1 (95% CI: 1.5–11.5, P=0.013) and 6.7 (95% CI: 2.1–21.6, P=0.002), respectively).Conclusion:FDG-PET metabolic response to chemoradiotherapy in anal cancer is significantly associated with PFS and OS, and in this cohort incomplete FDG-PET response was a stronger predictor than T or N stage.