Value of 18FDG PET scan in staging of ocular adnexal lymphomas: a large single-center experience

Fluorine 18 deoxyglucose positron emission tomography ((18)FDG PET) is widely used in staging of non-Hodgkin's lymphomas (NHL), but very few studies have focused on its role in the initial staging of patients with ocular adnexal lymphoma (OAL). The aim of this study was therefore to evaluate the role of (18)FDG PET in the diagnosis of ophthalmologic lymphoma. A retrospective review of all imaging records, including computed tomography (CT), magnetic resonance imaging (MRI), and FDG PET, was performed. Forty-one OAL patients were included in the study. A pathologic review according to the World Health Organization classification showed 32 low-grade lymphoma patients (78%), including 26 mucosa-associated lymphoid tissue lymphomas (63%). Ophthalmologic sites were intra-orbital + lacrimal gland in 24 patients (59%), conjunctival in 13 patients (32%), multiple in 4 cases, and bilateral in 6 patients. (18)FDG PET was positive in orbital and conjunctival sites in 68 and 35% of cases, respectively. (18)FDG PET positivity was correlated with pathologic sites detected by MRI in 22/30 patients (73%); (18)FDG PET positivity was correlated with pathologic sites detected by CT in 25/34 patients (73%). This study shows that (18)FDG PET has a lower sensitivity than MRI to detect ophthalmologic lymphoma, particularly in non-conjunctival sites.     

Use of integrated FDG PET/CT imaging in pulmonary carcinoid tumours

BACKGROUND: Integrated positron emission tomography (PET)/computed tomography (CT) scanners have been recently introduced in the diagnostic work-up of suspected pulmonary malignancy and demonstrate encouraging results in the staging of nonsmall-cell lung cancer. OBJECTIVE: To evaluate the usefulness of integrated FDG PET/CT in pulmonary carcinoid tumours. SETTING: University hospital. METHODS: We studied 13 patients (mean age +/- 1 SD, 57 +/- 11 years) with pulmonary carcinoid tumours. All patients demonstrated a single pulmonary lesion. Integrated PET/CT scan and surgical resection were performed in all patients. RESULTS: The pulmonary lesion size ranged from 1.1 to 5.0 cm. Final histological diagnosis confirmed 12 typical and one atypical pulmonary carcinoid. Mean proliferation rate of the typical carcinoids was 1.7 +/- 1.4%. None of the patients had recurrent carcinoid disease or died during follow-up (864 +/- 218 days). Mean standardized uptake value (SUV) of (18)F-fluorodeoxyglucose (FDG) in typical carcinoids was 3.0 +/- 1.5 (range 1.2 - 6.6); SUV in the atypical carcinoid was remarkably high with a value of 8.5. The SUV was lower than 2.5 in 6 of 12 patients (50%). Mediastinal lymph node metastases or extrathoracic metastases were not detected in any patient. CONCLUSIONS: (18)F-fluorodeoxyglucose PET/CT imaging improves accurate localization of metabolic activity and thus the interpretation of pulmonary lesions on CT. FDG uptake in pulmonary carcinoid tumours is often lower than expected for malignant tumours. Therefore, surgical resection or biopsy of lesions suspected to be carcinoids should be mandatory, even if they show no hypermetabolism on FDG PET images.     

Comparison of the diagnostic value of 3-deoxy-3-18F-fluorothymidine and 18F-fluorodeoxyglucose positron emission tomography/computed tomography in the assessment of regional lymph node in thoracic esophageal squamous cell carcinoma: a pilot study

We used pathological examination as golden standard to determine whether 3-deoxy-3-(18)F-fluorothymidine positron emission tomography/computed tomography (FLT PET/CT) can detect regional lymph node metastasis in untreated thoracic esophageal squamous cell carcinoma and additionally performed (18)F-fluorodeoxyglucose (FDG) PET/CT for direct comparison with that of FLT. Twenty-two patients with thoracic esophageal squamous cell carcinoma underwent dual-tracer PET/CT examinations before surgery. The results of reviewing CT images and side-by-side FDG PET and FLT PET images for the diagnosis of locoregional lymph node metastasis were compared prospectively in relation to pathologic findings. All patients underwent esophagectomy and lymphadenectomy. Pathologic examination confirmed nodes positive for metastasis in 16 patients and 47 of 424 excised nodes. The uptake of FDG (median SUVmax, 5.4; range, 2.4-10.6) in locoregional lymph nodes metastases was significantly higher than that of FLT (median SUVmax, 2.8; range, 1.3-4.6). There were 14 false-positive nodes in FDG PET/CT and only 3 in FLT PET/CT; 8 false-negative nodes in FDG PET/CT, while there were 12 false negative nodes in FLT PET/CT. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FLT PET/CT were 74.47%, 99.20%, 96.46%, 92.11%, and 96.89%, respectively, whereas those of FDG PET/CT were 82.98%, 96.29%, 94.81%, 82.98%, and 96.29%, respectively. P-values were 0.450, 0.014, 0.313, 0.050, and 0.555, respectively. FLT uptake in regional lymph nodes of esophageal carcinoma is significantly lower compared with FDG uptake. FLT PET/CT has fewer false-positive findings and higher specificity compared with FDG PET/CT.     

Diagnostic and prognostic value of 18-fluorodeoxyglucose positron emission tomography in adrenocortical carcinoma: a prospective comparison with computed tomography

OBJECTIVE: Patients with adrenocortical cancer are submitted to multiple imaging procedures for diagnosis of recurrence and staging. The aim of this prospective study was to evaluate the diagnostic and prognostic values of fluorodeoxyglucose (FDG) using a combined positron emission tomography and computed tomography (PET/CT) modality, compared with thoracoabdominopelvic computed tomography (TAP-CT). METHODS: Twenty-eight consecutive patients with adrenocortical cancer referred from November 2003 to December 2004 to the Institut Gustave Roussy were included. Mean time between PET/CT and TAP-CT was 16 d. Independent readers analyzed images of each modality. The gold standard was progression on follow-up TAP-CT or pathology. RESULTS: A total of 269 lesions in 57 organs were depicted in 22 patients. The sensitivities for the detection of distinct lesions and the diagnosis of metastatic organs were 90 and 93% for PET/CT and 88 and 82% for TAP-CT, respectively. Twelve percent of the lesions were seen on PET/CT only and 10% on TAP-CT only. Eighteen percent of the metastatic organs were diagnosed with PET/CT only and 7% with TAP-CT only. Thirty-eight percent of the local relapses were seen only with PET/CT. PET/CT depicted three false-positive lesions. Treatment modalities were modified by PET/CT findings in five cases among which one was falsely positive. Tumor size and mitotic rate were significantly associated with FDG uptake. The intensity of FDG uptake (maximum standardized uptake value > 10) and the volume of FDG uptake (>150 ml) were significant prognostic factors for survival. CONCLUSIONS: We show that FDG-PET/CT is complementary to TAP-CT and of special interest in the diagnosis of local relapses.     

Repetitive 18F-fluorodeoxyglucose positron emission tomography in giant cell arteritis: a prospective study of 35 patients

OBJECTIVE: To study fluorodeoxyglucose (FDG) uptake in the different vascular beds and in the large joints of patients with giant cell arteritis (GCA) at diagnosis, during steroid treatment, and at relapse. METHODS: All consecutive patients admitted to our department with a diagnosis of GCA underwent FDG-positron emission tomography (PET) scan before treatment with methylprednisolone was started. PET scans were repeated at 3 and 6 months, if the initial PET scans showed vascular FDG uptake. PET scans were scored at 7 different vascular areas and a total vascular score (TVS) was calculated, ranging from 0 to 21. RESULTS: A total of 35 patients entered the study. At diagnosis, vascular FDG uptake was noted in 29 patients (83%), especially in the subclavian arteries (74%), but also in the aorta (>50%) and up to the femoral arteries (37%). TVS decreased from a mean +/- SD score of 7.9 +/- 5.5 at baseline to 2.4 +/- 3.5 on repeat PET scan at 3 months (P < 0.0005), but did not further decrease at 6 months. The patients who relapsed had similar earlier decreases of TVS compared with those who did not relapse. FDG uptake in the shoulders at diagnosis correlated significantly with the presence of polymyalgia rheumatica (P = 0.005). CONCLUSION: FDG uptake in the large vessels is a sensitive marker for GCA, which can involve the larger thoracic, abdominal, and peripheral arteries. Polymyalgia rheumatica symptoms in patients with GCA correlate with (peri)synovitis of the shoulders. Relapses of GCA cannot be predicted by results of former PET scintigraphies.     

Bone marrow 18F‐fluoro‐2‐deoxy‐d‐glucose positron emission tomography/computed tomography cannot replace bone marrow biopsy in diffuse large B‐cell lymphoma

This study aimed to investigate whether visual and quantitative ¹⁸F‐fluoro‐2‐deoxy‐d ‐glucose positron emission tomography/computed tomography (FDG‐PET/CT)‐based bone marrow assessment can replace blind bone marrow biopsy (BMB) in newly diagnosed diffuse large B‐cell lymphoma (DLBCL). This retrospective study included 78 patients with newly diagnosed DLBCL who had undergone both FDG‐PET/CT and BMB. FDG‐PET/CT images were visually evaluated for bone marrow involvement. Patient‐based sensitivity of visual FDG‐PET/CT assessment was calculated using BMB as the reference standard. Metabolically active volume, maximum standardized uptake value, 3D partial volume corrected mean standardized uptake value, and 3D partial volume corrected mean metabolic volume product (cMVP_mean) of FDG‐avid bone marrow lesions were measured. Cox regression analysis was used to determine the influence of (potential) prognostic factors (BMB status, visual [dichotomous] FDG‐PET/CT bone marrow status, metabolically active volume, maximum standardized uptake value, 3D partial volume corrected mean standardized uptake value, 3D partial volume corrected mean metabolic volume product, and International Prognostic Index score) on progression‐free survival and overall survival. FDG‐PET/CT detected bone marrow involvement in 34 (43.6%) cases and BMB in 16 (20.5%) of 78 cases, of whom 11 were also detected by FDG‐PET/CT, resulting in a patient‐based sensitivity of 68.8% (95% confidence interval = 44.2%–86.1%) for FDG‐PET/CT. In the multivariate Cox proportional hazards model, only BMB status was an independent predictive factor of progression‐free survival (P = 0.016) and overall survival (P = 0.004). In conclusion, FDG‐PET/CT misses bone marrow involvement that has been detected by BMB in a non‐negligible proportion of patients. Furthermore, both visual and quantitative FDG‐PET/CT‐based bone marrow assessments are prognostically inferior to BMB. Therefore, FDG‐PET/CT cannot replace BMB in newly diagnosed DLBCL. Am. J. Hematol. 89:726–731, 2014. © 2014 Wiley Periodicals, Inc.     

Direct comparison of 18F-fluorodeoxyglucose coincidence gamma camera tomography with gallium scanning for the staging of lymphoma

BACKGROUND: The present study compared the performance of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) using a coincidence dual-head gamma camera (FDG Co-PET) with 67gallium scinti graphy (GS) in pretreatment staging of lymphoma. METHODS: A total of 46 patients underwent FDG Co-PET, computed tomography (CT) scanning and GS for pretreatment staging of lymphoma (40 newly diagnosed and recurrence) between November 1997 and December 1999. RESULTS: Histological subgroups comprised low grade (8 patients), intermediate grade (25) high-grade (3) non-Hodgkin's lymphoma and Hodgkin's disease (10). Based on clinical assessment, CT scan findings and biopsy, 100 nodal sites and 15 extra-nodal sites were deemed positive. FDG Co-PET was superior to GS in nodal site positivity rate (97%vs 79%, P < 0.0001). Compared with GS, FDG Co-PET detected 39 more abnormal sites in 22 patients (48%), of which 28 sites were validated by biopsy, CT and/or progress FDG Co-PET scanning. There was only one proven false negative FDG site in the spleen. CT + FDG Co-PET led to upstaging in 2 patients (4%), compared to CT + GS. CONCLUSION: FDG Co-PET shows potential for providing an accurate means for pretreatment staging of lymphoma and can detect extra sites of disease activity compared to GS.     

In vivo imaging of abdominal aortic aneurysms: increased FDG uptake suggests inflammation in the aneurysm wall

PURPOSE: To study the potential of integrated positron emission tomography and computed tomography (PET/CT) to identify aneurysm wall inflammation. METHODS: The level of F18-fluorodeoxyglucose (FDG) uptake was studied in aneurysmal and normal-sized aortas of 34 male patients [17 with abdominal aortic aneurysm (AAA) and 17 age-matched controls] identified in a database of 278 consecutive patients evaluated for staging of primary lung cancer. The maximal standardized uptake value (SUV) was calculated to quantify FDG uptake in the AAA wall. RESULTS: AAAs showed significantly higher FDG uptake than the normal-sized aorta in age-matched controls (SUV 2.52+/-0.52 versus 1.78+/-0.45, respectively; p<0.001). The level of FDG uptake did not correlate with maximal aneurysm diameter (r=0.09; 95% CI -0.42 to 0.56; p=0.7). CONCLUSION: FDG-PET/CT is a promising technique to identify inflammation of the aneurysm wall. Irrespective of aneurysm diameter, asymptomatic AAAs show more FDG uptake and more inflammatory activity in the wall than the non-dilated abdominal aorta of sex/age-matched controls. Future studies will be directed at the predictive value of increased FDG uptake for aneurysm wall strength, rupture risk, and the utility of FDG-PET/CT in assessing the effect of medical interventions.     

Thyroid incidentaloma identified by ¹⁸F-fluorodeoxyglucose positron emission tomography with CT (FDG-PET/CT): clinical and pathological relevance

Objective The percentage of patients with thyroid cancer incidentally diagnosed during a ¹⁸F‐fluorodeoxyglucose Positron Emission Tomography with computed tomography (CT) (FDG‐PET/CT) for nonthyroid diseases ranges between 26% and 50%. Design Retrospective assessment of the clinical and pathological features of thyroid incidentalomas at FDG‐PET/CT, aiming to identify potential predictors of malignancy. Patients Fifty‐two patients with incidental thyroid uptake at FDG‐PET/CT were retrospectively included [38 W, age 64·1 ± 12·5 years (mean ± SD)]. An arbitrary cut‐off level of 5·0 for the ‘maximum standardized uptake value’ (SUV max) was chosen to differentiate benign from malignant tumours. Complete thyroid function, neck ultrasonography (US) features, and cyto‐histological results were reported for all cases. Results In our institution, the prevalence of incidental thyroid ¹⁸F‐fluorodeoxyglucose (¹⁸F‐FDG) uptake was nearly 1·76%. The prevalence of focal uptake correlated with greater risk of malignancy (P < 0·01). In particular, the euthyroidism (P < 0·003) and a SUV max >5·0 (P < 0·0001) were associated with the diagnosis of thyroid cancer. Diffusely increased FDG‐PET/CT uptake in the thyroid was related to benign conditions. Conclusions The presence of focal uptake with high SUV max and euthyroidism correlate with high likelihood of malignancy. Performing a neck US would have to be recommended in all patients with euthyroidism and an incidental FDG‐PET/CT focal thyroid uptake. We do not suggest to use FDG‐PET/CT as a screening tool for thyroid cancer in the general population, because of both its high cost and low incidence of thyroid incidentaloma at FDG‐PET/CT.     

Different Scoring Methods of FDG PET/CT in Giant Cell Arteritis: Need for Standardization

Giant cell arteritis (GCA) is the most frequent form of vasculitis in persons older than 50 years. Cranial and systemic large vessels can be involved. [¹⁸F] fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is increasingly used to diagnose inflammation of the large arteries in GCA. Unfortunately, no consensus exists on the preferred scoring method. In the present study, we aim to define the optimal FDG PET/CT scoring method for GCA diagnosis using temporal artery biopsy and clinical diagnosis as the reference method.FDG PET/CT scans of GCA patients (12 glucocorticoid-naive, 6 on glucocorticoid treatment) and 3 control groups (inflammatory, atherosclerotic, and normal controls) were evaluated. We compared 2 qualitative visual methods (i.e. (1a) first impression and (1b) vascular uptake versus liver uptake) and 4 semiquantitative methods ((2a) SUVmax aorta, (2b) SUVmax aorta-to-liver ratio, (2c) SUVmax aorta-to-superior-caval-vein ratio, and (2d) SUVmax aorta-to-inferior-caval-vein ratio). FDG uptake pattern (diffuse or focal) and presence of arterial calcifications were also scored.Diagnostic accuracy of the visual method vascular versus liver uptake (1b) was highest when the cut-off point “vascular uptake higher than liver uptake” (sensitivity 83%, specificity 91%) was used. Sensitivity increased to 92% when patients on glucocorticoids were excluded from the analysis. Regarding the semiquantitative methods, the aorta-to-liver ratio (2b) with a cutoff of 1.03 had the highest diagnostic accuracy, with a sensitivity and specificity of 69% and 92%, respectively. Sensitivity increased to 90% when patients on glucocorticoids were excluded. The number of vascular segments with diffuse FDG uptake pattern was significantly higher in GCA patients without glucocorticoid use compared with all control patient groups. CRP was not significantly different between positive and negative FDG PET scans in the GCA group.Visual vascular uptake higher than liver uptake resulted in the highest diagnostic accuracy for the detection of GCA, especially in combination with a diffuse FDG uptake pattern. Of the semiquantitative methods, the aorta-to-liver SUVmax ratio (cutoff point = 1.03) had the highest diagnostic accuracy. The diagnostic accuracy increased when patients using glucocorticoids were excluded from the analyses.     

Whole-body fluorodeoxyglucose positron emission tomography/computed tomography in patients with active polymyalgia rheumatica: evidence for distinctive bursitis and large-vessel vasculitis

Objectives

To investigate fluorodeoxyglucose (FDG) accumulation in large joints, bursas, and large vessels in patients with polymyalgia rheumatica (PMR) using 18-FDG positron emission tomography/computed tomography (PET/CT) and to differentiate PMR from similar diseases.

Methods

Fourteen untreated patients with active PMR and 17 control patients with rheumatoid arthritis (n?=?11) or other active rheumatic diseases (n?=?6) underwent 18-FDG PET/CT. FDG uptake in large joints, bursas and vertebral spinous processes was evaluated by calculating maximum standardised uptake values and by visual scoring (scale 0–4). PET scan images were scored in seven vascular regions, and total vascular scores (range 0–21) were calculated.

Results

Polymyalgia rheumatica patients showed increased FDG uptake in ischial tuberosities, greater trochanters, and lumbar spinous processes. Positive results at two or more of these sites showed high sensitivity (85.7%) and specificity (88.2%) for the diagnosis of PMR, and shoulder or hip-joint involvement showed low disease specificity. High FDG accumulations were found in the aortas and subclavian arteries of two PMR patients who were asymptomatic for temporal arteritis and scanty synovium and perisynovium, based on FDG uptake. PET/CT images of the 12 PMR patients without apparent vascular involvement showed synovitis and/or perisynovitis.

Conclusions

Fluorodeoxyglucose-PET/CT may be useful for the detection of PMR lesions, which are difficult to identify using other methods.     

Incidental carcinomas detected by PET/CT scans in patients with malignant lymphoma

According to the international working group response criteria for malignant lymphoma revised in 2007, 18F-fluorodeoxyglucose positron emission tomography (¹⁸FDG-PET) combined with or without computed tomography (CT) is recommended for pre-treatment staging and response assessment among patients with diffuse large B-cell lymphoma and Hodgkin lymphoma. Recently, along with the widespread use of PET/CT, unexpected uptake and accumulation of ¹⁸FDG has been reported. Discussed in the present report are patients with malignant lymphoma and second primary carcinomas that were incidentally found by PET/CT. A total of 497 consecutive PET/CT were performed on 290 patients with malignant lymphoma in our institution from April 2008 through March 2010. Eight patients (2.8%) had pathologically confirmed second primary carcinomas consisting of 4 colon cancers, 3 lung cancers, and 1 pancreatic cancer. Two cases were diagnosed at the initial staging, and the others were detected after treatment for lymphoma. It is noteworthy that PET revealed high accumulations of ¹⁸FDG in 5 (62.5%) of the 8 patients without corresponding tumors in conventional CT. All of the 4 patients with colon carcinoma underwent curative surgery. The present study suggests that incidental findings by PET in malignant lymphoma can lead to early detection and successful treatment of second malignancies.     

Whole-body fluorodeoxyglucose positron emission tomography/computed tomography in patients with active polymyalgia rheumatica: evidence for distinctive bursitis and large-vessel vasculitis

Abstract

Objectives To investigate fluorodeoxyglucose (FDG) accumulation in large joints, bursas, and large vessels in patients with polymyalgia rheumatica (PMR) using 18-FDG positron emission tomography/computed tomography (PET/CT) and to differentiate PMR from similar diseases.

Methods Fourteen untreated patients with active PMR and 17 control patients with rheumatoid arthritis (n = 11) or other active rheumatic diseases (n = 6) underwent 18-FDG PET/CT. FDG uptake in large joints, bursas and vertebral spinous processes was evaluated by calculating maximum standardised uptake values and by visual scoring (scale 0–4). PET scan images were scored in seven vascular regions, and total vascular scores (range 0–21) were calculated.

Results Polymyalgia rheumatica patients showed increased FDG uptake in ischial tuberosities, greater trochanters, and lumbar spinous processes. Positive results at two or more of these sites showed high sensitivity (85.7%) and specificity (88.2%) for the diagnosis of PMR, and shoulder or hip-joint involvement showed low disease specificity. High FDG accumulations were found in the aortas and subclavian arteries of two PMR patients who were asymptomatic for temporal arteritis and scanty synovium and perisynovium, based on FDG uptake. PET/CT images of the 12 PMR patients without apparent vascular involvement showed synovitis and/or perisynovitis.

Conclusions Fluorodeoxyglucose-PET/CT may be useful for the detection of PMR lesions, which are difficult to identify using other methods.     

Clinical implication of FDG uptake of bone marrow on PET/CT in gastric cancer patients with surgical resection

AIM To determine the relationship between F-18 fluorodeoxyglucose(FDG) uptake of bone marrow(BM) on positron emission tomography/computed tomography(PET/CT) and clinical factors and to assess the prognostic value of FDG uptake of BM in gastric carcinoma.METHODS We retrospectively enrolled 309 gastric cancer patients who underwent staging FDG PET/CT and curative surgical resection. FDG uptake of primary tumor was visually classified as positive or negative FDG uptake. Mean FDG uptake of BM(BM SUV) and BM-to-liver uptake ratio(BLR) were measured. The relationships of BM SUV or BLR with clinical factors were evaluated. The prognostic values of BM SUV, BLR, and other clinical factors for predicting recurrence-free survival(RFS) and overall survival(OS) were assessed.RESULTS Of 309 patients, 38 patients(12.3%) experienced cancer recurrence and 18 patients(5.8%) died. Patients with advanced gastric cancer, positive FDG uptake, and recurrence had higher values of BM SUV and BLR than those with early gastric cancer, negative FDG uptake, and no recurrence(P 0.05). BM SUV and BLR were significantly correlated with hemoglobin level, neutrophil-to-lymphocyte ratio, and platelet-tolymphocyte ratio(P 0.05). On multivariate analysis, multiple tumors, T stage, lymph node metastasis, tumor involvement of resection margin, and BLR were significantly associated with RFS(P 0.05). T stage, lymph node metastasis, hemoglobin level, and BLR were significantly associated with OS(P 0.05). CONCLUSION BLR on PET/CT was an independent prognostic factor for RFS and OS in gastric cancer patients with curative surgical resection.     

18F-FDG PET/CT显像在进展期前列腺癌诊断和分期中的应用

目的探讨^18F-FDG PET/CT显像在进展期前列腺癌诊断和分期中的临床价值.方法20例临床进展期前列腺癌患者行^18F-FDG PET/CT全身显像,同时行B超和骨扫描检查.结果①9例未经治疗者中^18F-FDG PET/CT确诊8例;全雄激素阻断治疗（MAB）后前列腺特异性抗原（PSA）值较稳定者及逐渐升高者共5例,PET/CT均准确显示;6例MAB反应良好者,^18F-FDG PET/CT示其病灶均无放射性浓聚（即阴性）.②6例盆腔淋巴结转移和6例骨转移者中^18F-FDG PET/CT分别发现5例和4例,假阴性者均为MAB后反应良好患者.结论^18F-FDG PET/CT显像是评估进展期前列腺癌激素治疗效果的无创性检查方法,有利于未治疗、激素治疗有部分反应及激素难治性进展期前列腺癌的诊断和临床分期.     

Clinical implication of F-18 FDG PET/CT in patients with secondary hemophagocytic lymphohistiocytosis

The contribution that F-18 fluoro-2-deoxyglucose positron emission tomography/computed tomography (F-18 FDG) PET/CT makes to the diagnosis of malignancy in patients with hemophagocytic lymphohistiocytosis (HLH) is still uncertain. The aim of this study was to evaluate the diagnostic performance of F-18 FDG PET/CT for the detection of underlying malignancy, to investigate the correlation between PET and laboratory parameters, and to identify prognosis-related factors in patients with secondary HLH. We enrolled 14 patients who were diagnosed with HLH and referred for F-18 FDG PET/CT to exclude malignancy. The diagnostic performance of F-18 FDG PET/CT for malignancy detection was assessed. The correlations between PET and laboratory parameters were determined. The prognostic significance of the following factors was evaluated: PET and laboratory parameters, age in years, presence of underlying malignancy, and fever and splenomegaly. Six of the 14 patients had malignancies (four with lymphoma, one with multiple myeloma, and one with colonic malignancy). Sensitivity, specificity, and diagnostic accuracy of F-18 FDG PET/CT for malignancy detection were 83, 62.5, and 71.4 %, respectively. F-18 FDG uptake in the bone marrow and spleen was positively correlated with neutrophil count and C-reactive protein. All of the PET parameters, but none of the clinical or laboratory parameters, were significantly associated with patient outcome, as determined by univariate analysis. Given the small sample size, F-18 FDG PET/CT was useful for detecting underlying malignancy, and PET parameters correlated with laboratory parameters that reflected inflammatory status. F-18 FDG PET/CT might provide prognostic information for the management of patients with secondary HLH.     

FDG PET/CT for evaluating systemic arterial inflammation induced by anthracycline-based chemotherapy of Hodgkin lymphoma: A retrospective cohort study

To evaluate arterial fluorodeoxyglucose (FDG) uptake as a marker of arterial inflammation in multiple vascular beds in patients treated with anthracycline-based chemotherapy for Hodgkin lymphoma (HL).We used maximum standardized uptake value (SUVmax) and target-to-background ratio (TBR) to quantify arterial FDG uptake in the carotid artery, ascending aorta, abdominal aorta, and femoral artery obtained on positron emission tomography/computed tomography (PET/CT) imaging performed at baseline before chemotherapy and after completion of chemotherapy in patients with HL treated with an anthracycline-containing regimen. We compared the SUVmax and TBR obtained at baseline with that obtained post-chemotherapy for each arterial bed to evaluate the effect of anthracycline-based chemotherapy. We evaluated the effect of cardiovascular risk factors such as human immunodeficiency virus (HIV) infection, smoking, hypertension, and diabetes on the changes in SUVmax and TBR seen in the different arterial beds after anthracycline-based chemotherapy.Fifty-two patients were included with a mean age of 34.56 ± 10.19 years. There were 33 males, and 18 patients were HIV-infected. The mean interval between completion of chemotherapy and follow-up flourine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scan was 65 weeks. We found no significant difference in arterial FDG uptake measured by SUVmax and TBR in all arterial beds between the pre- and post-chemotherapy FDG PET/CT. There was no significant impact of HIV infection, smoking, and hypertension on the changes in arterial FDG uptake following treatment with anthracycline-based chemotherapy.In patients with HL who were treated with anthracycline-based chemotherapy, we found no significant increase in arterial inflammation measured by FDG PET/CT after an average follow-up period of about 65 weeks since completion of chemotherapy.     

Diagnostic accuracy of PET/CT in patients with extranodal marginal zone MALT lymphoma

BACKGROUND: (18)Fluoro-2-deoxyglucose ((18)FDG) positron emission tomography (PET) is widely used for initial staging and follow-up in patients with malignant lymphoma. While earlier studies suggested a limited role for PET in extranodal marginal zone mucosa-associated lymphoid tissue (MALT) lymphoma patients due to their non-FDG avidity, more recent reports have suggested that the issue is controversial. In the present study, we evaluated the diagnostic accuracy of PET integrated with CT (PETCT) in patients with MALT lymphoma and assessed its reliability in clinical staging and monitoring response. METHODS: Thirty-three patients with biopsy proven MALT lymphoma in 37 sites, who underwent PET/CT at diagnosis, were enrolled. Medical records, PET/CT findings and data obtained by other diagnostic procedures were reviewed. RESULTS: Common sites of MALT lymphoma were the stomach (18), lung (5), orbit (4), and parotid gland (3). PET/CT detected active disease in 18 of 33 patients (54.5%) at diagnosis. Sensitivity in gastric MALT (38.9%) was lower when compared with non-gastric MALT (75%). PET/CT detected active disease in 100% patients with advanced disease (stage III-IV) but only in 42.3% with early stage disease (I-II). The incidence of gastric FDG uptake was higher in patients showing gastric ulcer on gastroscopy than in subjects with minimal or no macroscopic findings. Of the 33 patients in the study cohort, 12 had a follow-up PET/CT which detected relapse in three patients. CONCLUSIONS: These data suggest that PET/CT is a useful tool for both, initial staging and follow-up after therapy in patients with MALT lymphoma. Its sensitivity depends on disease location and stage at initial diagnosis.     

Pulmonary Sclerosing Pneumocytoma of the Lung: CT Characteristics in a Large Series of a Tertiary Referral Center

The purpose of this study is to describe the detailed clinical, chest computed tomography (CT), and ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG PET) characteristics of the tumor boundary for the diagnosis and investigate the outcome of pulmonary sclerosing pneumocytoma (PSP) using confirmed large data of a tertiary referral center.Confirmed 76 patients were included. We evaluated the findings of CT including 4 CT signs, FDG PET, and histopathology.Most patients had a single lesion (92.1%), smooth boundary (65.8%), and oval shape (65.8%) and the mean diameter was 22.7 mm. The CT signs included marginal pseudocapsule (50%), overlying vessel (26.3%), air gap (2.6%), and halo sign (17.1%). A predominantly solid was the most common histopathologic type. The mean maximum standardized uptake value on FDG PET of 17 patients was 1.8 (range, near 0 or normal tissue metabolism ∼2.9).PSP should be considered in middle-aged women whose CT features show incidental nodule(s), commonly with surrounding ground-glass opacity and characteristic CT signs of the tumor boundary, and hypometabolic uptake on FDG PET. Outcome of patients is excellent.     

Results of 188 whole-body fluorodeoxyglucose positron emission tomography scans in 137 patients with sarcoidosis

BACKGROUND: To study the role of whole-body 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) scans in the identification of occult biopsy sites and reversible granulomatous disease in patients with sarcoidosis. METHODS: A retrospective review was undertaken of 188 FDG PET scans performed in 137 patients with proven sarcoidosis. All patients had given a complete medical history and undergone a physical examination, standard chest radiograph, spirometry, diffusing capacity determination, and measurement of serum angiotensin-converting enzymes levels. RESULTS: One hundred thirty-nine whole-body scans had positive findings. The most common positive sites were mediastinal lymph nodes (54 scans), extrathoracic lymph nodes (30 scans), and lung (24 scans). The standardized uptake value (SUV) ranged from 2.0 to 15.8. Twenty occult disease sites were identified. Eleven repeat scans exhibited decreased SUV with corticosteroid therapy. The positive pulmonary FDG PET scan findings occurred in two thirds of patients with radiographic stage II and III sarcoidosis. Negative pulmonary FDG PET scan findings were common in patients with radiographic stage 0, I, and IV sarcoidosis. CONCLUSIONS: Whole-body FDG PET scans are of value in identifying occult and reversible granulomas in patients with sarcoidosis. However, a positive FDG PET scan finding, by itself, is not an indication for treatment.