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Immunotherapy has revolutionized the treatment of malignant melanomas. Immunotherapy is associated with multi-system toxicities, which are referred to as immune-related adverse events (irAEs). Positron emission tomography (PET) with fluorodeoxyglucose (FDG) and CT is the preferred imaging modality to monitor disease progression in melanoma. FDG uptake by a sarcoid-like reaction (SLR) can mimic cancer progression, thereby posing a diagnostic and therapeutic dilemma. We present the case of a 39-year-old patient with malignant melanoma on immunotherapy who presented with PET scan findings of adenopathy with increased uptake. This case highlights the challenges in interpreting PET scan in the setting of an SLR.

Temporal artery biopsy will only detect (part of) the cranial forms of giant cell arteritis. For the large vessel variant of this type of vasculitis, FDG-PET is the technique of choice. Since treatment of large vessel vasculitis implies long-term treatment with steroids, it is important to have a firm diagnosis. I suggest performing a FDG-PET scan in every patient in whom large vessel vasculitis is suspected and in whom the temporal artery biopsy is negative. In the follow-up of giant cell arteritis patients, we can rely on clinical symptoms and inflammatory parameters to monitor disease activity and to adapt our treatment and do not need to repeat FDG-PET scan. In Takayasu arteritis, follow-up FDG-PET scans are probably necessary to assess ongoing inflammation, but prospective studies are lacking.

Morphine is the most commonly used drug for treating physical and psychological suffering caused by advanced cancer. Although morphine is known to elicit multiple supraspinal analgesic effects, its behavioral correlates with respect to the whole-brain metabolic activity during cancer-induced bone pain have not been elucidated. We injected 4T1 mouse breast cancer cells into the left femur bone marrow cavity of BALB/c mice. All mice developed limb use deficits, mechanical allodynia, and hypersensitivity to cold, which were effectively suppressed with morphine. Serial 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) was performed for each mouse before cancer induction (0 day), after cancer-induced bone pain was established (14 days), and during effective morphine treatment (16 days). The longitudinal FDG-PET imaging analysis demonstrated that cancer-induced bone pain increased glucose uptake in the insular cortex and hypothalamus and decreased the activity of the retrosplenial cortex. Morphine reversed the activation of the insular cortex and hypothalamus. Furthermore, morphine activated the amygdala and rostral ventromedial medulla and suppressed the activity of anterior cingulate cortex. Our findings of hypothalamic and insular cortical activation support the hypothesis that cancer-induced bone pain has strong inflammatory and affective components in freely moving animals. Morphine may provide descending inhibitory and facilitatory actions in the treatment of cancer-induced bone pain in a clinical setting.

To evaluate the effect of pre-scan blood glucose levels (BGL) on standardized uptake value (SUV) in 18F-FDG-PET scan. A literature review was performed in the MEDLINE, Embase, and Cochrane library databases. Multivariate regression analysis was performed on individual datum to investigate the correlation of BGL with SUVmax and SUVmean adjusting for sex, age, body mass index (BMI), diabetes mellitus diagnosis, 18F-FDG injected dose, and time interval. The ANOVA test was done to evaluate differences in SUVmax or SUVmean among five different BGL groups ( 200 mg/dl). Individual data for a total of 20,807 SUVmax and SUVmean measurements from 29 studies with 8380 patients was included in the analysis. Increased BGL is significantly correlated with decreased SUVmax and SUVmean in brain (p 200 mg/dl had significantly lower SUVmax. If BGL is lower than 200 mg/dl no interventions are needed for lowering BGL, unless the liver is the organ of interest. Future studies are needed to evaluate sensitivity and specificity of FDG-PET scan in diagnosis of malignant lesions in hyperglycemia.

In the present review the reader will be led across the most relevant observations that prompted oncologists and haematologist to consider FDG-PET/CT as a new paradigm for FL management in clinical practice. The contribute of functional imaging for lymphoma staging, restaging, prognostication, and tumour burden definition before radio-chemo-immunotherapy will be reviewed in detail. Moreover, a special focus will be addressed to technical and practical aspects of PET scan reporting, which have been set during the last decade in order to ensure the reproducibility of the therapeutic results. Finally, the predictive role of PET/CT on long-term treatment outcome will be compared with other well-known prognosticator as minimal residual disease (MRD) detection by gene rearrangement assessment by molecular biology.

Background:Sarcoidosis is an unknown etiology multisystem inflammatory disease in which noncaseating granulomas (a collections of inflammatory cells) form and grow in various organs, involving predominantly lungs, intrathoracic lymph node, skin and eyes. It most commonly affects patients between 20 and 40 years old of age but it could be observed at any age (female predominance; rare in Asians). Discussion: The areas of the body usually affected by sarcoidosis are lungs, skin, or lymph nodes; pulmonary and mediastinal involvement is seen in over of 90% of patients. Less commonly eyes, liver, heart, and brain are involved. Any organ, however, can be affected. Early diagnosis of sarcoidosis can be difficult due to few signs and symptoms in its early stages, and when disease does occur, it may mimic other pathologies, and is made up with chest X-ray, Computed Tomography (CT)-High Resolution CT (HRCT), gallium scans. Fluoro-Deoxy Glucose– Positron Emission Tomography (FDG-PET) is another useful tool to assess the extent of disease and has a potential to evaluate the clinical management of patients responding or not to the treatment.Conclusion:In this review, we would summarize in brief the clinical indications of PDG-PET in sarcoidosis and report the imaging features of the main organs involved in this disease.

Background: The aim of this study was to determine whether selection with fluorine-18-deoxyglucose positron emission tomography (FDG-PET) imaging would result in an improved outcome in surgically treated patients with curative resection of colorectal liver metastases (CRLM), stratified by the clinical risk score (CRS) of Fong et al. [Ann Surg 1999;230:309-318]. Patients and Methods: Between January 2000 and December 2009, all patients who underwent resection for CRLM from two different university teaching hospitals in the Netherlands were analysed. Patients were stratified by the CRS. Results: In total 613 patients were eligible for analysis. There was no statistical difference in median disease-free survival (DFS) between patients with and without an FDG-PET scan in both low CRS [17 months (95% CI 12-22) vs. 14 months (95% CI 11-17), p = 0.332] and high CRS [14 months (95% CI 7-21) vs. 9 months (95% CI 8-10), p = 0.073]. There was no statistical difference in median overall survival (OS) between patients with and without an FDG-PET scan in both low CRS [64 months (95% CI 54-74) vs. 54 months (95% CI 42-66), p = 0.663] and high CRS [39 months (95% CI 23-55) vs. 41 months (95% CI 34-48), p = 0.903]. Conclusion: The present study could not demonstrate that patients selected by an FDG-PET scan before liver resection, and stratified by CRS, have an improvement in DFS or OS.

Management of rectal cancer has become multidisciplinary and is driven by the stage of the disease, with increased focus on restaging rectal cancer after neoadjuvant therapy.The purpose of this study was to assess the relative impact of restaging after preoperative chemoradiation with FDG-PET scan, CT, and MRI in the management of patients with rectal cancer.This was a retrospective study from a single institution.This study was conducted at a tertiary cancer center.A total of 199 patients met the inclusion criteria: patients with rectal adenocarcinoma; staged with positron emission tomography, CT, and MRI; T2 to T4, N0 to N2, M0 to M1; treated with neoadjuvant chemoradiation 50.4 Gy and infusional 5-fluorouracil; and restaged 4 weeks after chemoradiation before surgery between 2003 and 2013.Comparisons of the tumor stage among different imaging modalities before and after neoadjuvant chemoradiation were performed. The impact of restaging on the management plan was assessed.The stage at presentation was T2, 8.04%; T3, 65.33%; T4, 26.63%; N0, 17.09%; N1, 47.74%; N2, 34.67%; M0, 81.91%; and M1, 18.09%. Changes in disease stage postneoadjuvant chemoradiation were observed in 99 patients (50%). The management plans of 29 patients (15%) were changed. The impact of each restaging modality on management for all of the patients was positron emission tomography, 11%; CT, 4%; and MRI, 4%. In patients with metastatic disease at primary staging, the relative impact of each restaging modality in changing management was positron emission tomography, 32%; CT, 18%; and MRI, 6%.This study was limited by its single-center and retrospective design. Operations were performed 4 weeks after restaging.Changes in the extent of disease after long-course chemoradiotherapy result in changes of management in a significant percentage of patients. Positron emission tomography has the most significant impact in the change of management overall, and its use in restaging advanced rectal cancer should be further explored.

Flourine-18 fluoro-2-deoxy-glucose (18F-FDG) positron emission tomography combined with computed tomography (PET/CT) is a useful test for the management of malignant conditions. Inflammatory and infectious processes, however, can cause increased uptake on PET scanning, often causing diagnostic dilemmas. This knowledge is important to the rheumatologist not only because of the inflammatory conditions we treat but also because certain rheumatic diseases impose an increased risk of malignancy either due to the disease itself or as a consequence of medications used to treat the rheumatic diseases. There is an increasing body of evidence investigating the role of PET scans in inflammatory conditions. This paper describes a patient with rheumatoid arthritis who developed pulmonary nodules that showed increased uptake on PET/CT scan and reviews the use of PET scanning in the diagnosis and management of rheumatoid arthritis.

Introduction. The authors evaluated the application of 18 Ffluoro-2-deoxy-D: -glucose positron emission tomography/computed tomography to diagnose the activity in patients with chronic sarcoidosis. Material and Methods. The study sample included 71 patients (48 females and 23 males, their mean age being 47±3 years) with biopsy-proven sarcoidosis of chronic course. Results. All patients underwent 18 F-fluoro-2-deoxy-D: -glucose positron emission tomography/computed tomography, which detected inflammation in 65 patients (91.5%) (maximum standardized uptake value, 8.1 ± 3.9). Angiotensin-converting enzyme levels were significantly higher in the patients with positive than in those with negative 18 F-fluoro-2-deoxy-D: -glucose positron emission tomography/ computed tomography results. Conclusion. 18 F-fluoro- 2-deoxy-D: -glucose positron emission tomography/computed tomography revealed the functional inflammatory active localizations in chronic sarcoidosis. The obtained results contribute to the adequate therapeutic option. [Projekat Ministarstva nauke Republike Srbije, br. 175046 i br. 175081]

Purpose: To evaluate the patterns of recurrence when selective mediastinal node irradiation based on FDG-PET scan data is used in patients with non-small-cell lung cancer (NSCLC). Methods and Materials: A prospective Phase I/II study was undertaken on 44 patients with NSCLC without detectable distant metastases on CT and FDG-PET scan, delivering either 61.2 Gy in 34 fractions over 23 days or 64.8 Gy in 36 fractions over 24 days (1.8 Gy b.i.d. with 8-h interval). Only the primary tumor and the positive mediastinal areas on the pretreatment FDG-PET scan were irradiated. Isolated nodal failure was defined as recurrence in the regional nodes outside of the clinical target volume, in the absence of in-field failure. Results: The CT and FDG-PET stage distribution was as follows: Stage I: 8 patients (18%) and 13 patients (29%); Stage II: 6 patients (14%) and 10 patients (23%); Stage IIIA: 15 patients (34%) and 7 patients (16%); Stage IIIB: 15 patients (34%) and 14 patients (32%), respectively. After a median follow-up time of 16 months (95% confidence interval [CI], 11–21 months) postradiotherapy, 11 patients (25%) developed a local recurrence. Only 1 patient (crude rate, 2.3%; upper bound of 95% CI, 10.3%), with a Stage II tumor on both CT and PET, developed an isolated nodal failure. The median actuarial overall survival was 21 months (95% CI, 14–28 months), and the median actuarial progression-free survival was 18 months (95% CI, 12–24 months). Conclusions: Selective mediastinal node irradiation based on FDG-PET scan data in patients with NSCLC results in low isolated nodal failure rates. In the Phase I component of this trial, radiation dose escalation up to 64.8 Gy in 36 fractions over 24 days is feasible.

Author, An F-FDG-PET with CT scan was performed to stage a tongue cancer, revealing the hypermetabolic region in the thoracic vertebra. This corresponded to a benign lesion seen on MRIs and CT.Although these findings suggested a vertebral hemangioma, "hot" vertebra in FDG-PET was atypical. The final diagnosis was confirmed capillary hemangioma by the scopic biopsy and this lesion was no change at 1 year later.Careful interpretation of metabolic (FDG-PET) and anatomic (CT and MRI) images should be performed to accurately characterize the foci of increased FDG uptake.

FDG-PET has recently emerged as an important tool for the management of Hodgkins lymphoma. Although its use for initial staging and response evaluation at the end of treatment is well established, the place of interim PET for response assessment and subsequent treatment tailoring is still quite controversial. The use of interim PET after a few cycles of chemotherapy may allow treatment reduction for good responders, leading to lesser treatment toxicities as well as early treatment adaptation for bad responders with a potential higher chance for cure. Interpretation of interim PET is a rapidly moving field. Actually, visual interpretation is preferred over quantitative interpretation in this situation. The notion of minimal residual uptake emerged for faint persisting FDG uptake, but has evolved during the recent years. Guidelines using mediastinum and liver as references have been proposed at the expert meeting in Deauville 2009. Actually, several trials are ongoing both for localised and advanced disease to evaluate the FDG-PET potential for early treatment monitoring and tailoring. Until the results of these prospective randomized trials become available, treatment changes according to the interim PET results should remain inappropriate and limited to well-conducted clinical trials.

To assess the role of flourodeoxyglucose-positron-emission tomography (FDG-PET) scan in staging patients with nonsmall cell lung cancer (NSCLC).We prospectively studied 400 patients with NSCLC. Each patient underwent a computed tomography (CT) scan of the chest and upper abdomen, other conventional staging studies and had a FDG-PET scan within 1 month before surgery. All suspicious N2 lymph nodes by either chest CT or by FDG-PET scan were biopsied. Patients that were N2 and M1 negative underwent pulmonary resection and complete thoracic lymphadenectomy.The FDG-PET had a higher sensitivity (71% vs 43%, p0.001), positive predictive value (44% vs 31%, p0.001), negative predictive value (91% vs 84%, p = 0.006), and accuracy (76% vs 68%, p = 0.037) than CT scan for N2 lymph nodes. Similarly, FDG-PET had a higher sensitivity (67% vs 41%, p0.001), but lower specificity (78% vs 88%, p = 0.009) than CT scan for N1 lymph nodes. FDG-PET led to unnecessary mediastinoscopy in 38 patients. FDG-PET was most commonly falsely negative in the subcarinal (#7) station and the aortopulmonary window lymph node (#5, #6) stations. It accurately upstaged 28 patients (7%) with unsuspected metastasis and it accurately downstaged 23 patients (6%).The FDG-PET scan allows for improved patient selection. It more accurately stages the mediastinum, however there are many false positives lymph nodes and it may be more likely to miss N2 disease in the #5, #6, and #7 stations. A positive FDG-PET scan means a tissue biopsy is indicated in that location.

Objectives: We report a single institution experience with gastric diffuse large B-cell lymphoma (DLBCL) in an attempt to evaluate the roles of different treatment modalities, to assess the value of pretreatment positron emission tomography (PET) scan, and to identify potential prognostic factors. Methods: Among 384 patients diagnosed with DLBCL between 1995 and 2008, 75 patients had primary gastric DLBCL and were reviewed and analyzed. Results: The median age was 66. International prognostic index (IPI) risk was low in 52%, low-intermediate in 23%, high-intermediate in 9%, and high in 16%. Pretreatment PET scan was highly sensitive in detecting gastric lesions except stage I gastric DLBCL without detectable mass by CT or gastroscopy. As a general rule, patients with limited-stage disease were treated with three times of CHOP (with or without rituximab) and radiotherapy, and those with advanced-stage disease were treated with eight cycles of CHOP (with or without rituximab), and radiotherapy was given to residual diseases after chemotherapy. Three-year overall survival (OS) rate was 78%. Multivariate analysis revealed that low albumin, hemoglobin

Patients presenting with frequent ventricular arrhythmias can have underlying myocardial inflammation as an inciting factor. We seek to determine whether the site of origin (SOO) of ventricular arrhythmias on 12 lead EKG correlate with areas of inflammation on FDG PET cardiac imaging in patients

F-18 Fluorodeoxyglucose Positron Emission Tomography imaging (F-18 FDG PET) detects malignancies depending on the uptake profile of glycolysis of tumors; however, the role of FDG PET is limited in the evaluation of primary renal malignancy because of low FDG uptake by renal cell carcinoma and also because normal urinary excretion of FDG seen in the images. A patient with renal cell carcinoma whose FDG PET imaging study incidentally shows a photon-deficient mass in the upper pole of the right kidney is present here. The diagnosis is also validated by the histopathological findings of tumor necrosis, hemorrhage, and scars.

In this report we describe a case of pulmonary epithelioid hemangioendothelioma (PEH) in a young woman. The neoplasm manifested with dry cough, chest pain, finger clubbing, and multiple bilateral pulmonary nodules on chest x-ray and computed tomographic (CT) scan. She underwent thoracoscopy, and the histological features of the lung biopsies were initially interpreted as consistent with a not-well-defined interstitial lung disease. Our patient was clinically and radiologically stable over a period of four years, after which the disease progressed to involve not only the lung but also mediastinal lymph nodes, liver and bone. Fiberoptic bronchoscopy showed subtotal occlusion of the right middle and lower lobe bronchi. The histologic examination of bronchial biopsies revealed a poorly differentiated neoplasm immunohistochemically positive for vimentin and vascular markers CD31, CD34 and Factor VIII. A diagnosis of malignant hemangioendothelioma was made. Positron emission tomography (PET) is more sensitive than CT scan and bone scintigraphy in detecting PEH metastases. Furthermore, 18-fluorodeoxyglucose (FDG) uptake seems to be related to the grade of malignancy of PEH lesions. Therefore, we suggest that FDG-PET should be included in the staging system and follow-up of PEH.

FDG-PET検査の肺癌診断への臨床応用は病変の良・悪性鑑別において重要であるといわれている．われわれは同検査での定量指標であるStandardized uptake value（SUV）にこだわらず，胸部X線やCT検査結果を踏まえた定性的評価，すなわち視覚診断をおこなっている．今回，当科で手術した26例を対象に，CT検査上径3cm以下の肺結節性病変（Clinical T1症例）のFDG-PET検査について検討した．病理診断は悪性22例，良性4例で，それぞれのSUV値は3.62±3.88，2.33±1.49であった．SUV≧2.5を悪性とした場合のPETSUV診断およびわれわれのPET視覚診断の感度，特異度，正診率は，45％，75％，50％および86％，25％，77％で，感度，正診率においてPET視覚診断が有意に高い値を示した．Clinical T1症例の場合，FDG-PET検査において定量指標のSUVのみで良・悪性の鑑別をおこなうのは困難で，胸部X線やCT検査結果を併せたFDG-PET検査の視覚的診断である定性的評価を要すると考えられた．

Since its first proposal in the late 1980s FDG-PET scan (and later on FDG-PET/CT scan) and lymphoma have become an indissoluble binomial. FDG-PET scan proves a very useful tool for Hodgkin (HL) and non-Hodgkin (NHL) lymphoma staging, restaging and prognostication and is essential for radiotherapy planning and chemosensitivity assessment in HL; the last-born offspring of this synergy has been the PET response-adapted strategy in HL and diffuse large B cell lymphoma (DLBCL). Thanks also to the contribution of PET scan in all these important steps of lymphoma management, the longterm lymphoma survivorship has increased overtime in the last two decades also in lymphoma subsets (elderly patients and HL) in which no major advances in treatment effectiveness could have account for this improvement. Onco-haematologists and nuclear medicine experts joined their efforts in several informal and international workshops dedicated to PET scan in lymphoma to standardize interim and end-of therapy PET scan reporting, proposing the so-called ‘‘Deauville five-point scale’’ or ‘‘Deauville rules’’, from the venue hosting the first meeting. The latter, in turn, has been incorporated in the lastborn criteria for lymphoma staging and restaging, the socalled Lugano criteria, which have definitely included FDG-PET scan in the armamentarium of the necessary imaging tools for assessing the tumour spread in FDG-avid lymphoma. In agreement with the organization committee of the International Conference on Malignant Lymphoma (ICML), which is held every other year in Lugano, the PET in lymphoma workshop is held every other year in Menton (France), interspersed with Lugano meetings. The cooperation between haematologists and nuclear medicine experts has been further tightened in the organization of dedicated courses for PET reporting in clinical trials based on PET imaging. The technological evolution of PET scanning equipment, the implementation of new software able to perform a semi-automatic reading of FDG concentrating lesions, the new metrics for quantitative PET scan (Q-PET) reading with SUV and derived parameters such as metabolic tumour volume (MTV) and total lesion glycolysis (TLG) have further widened the interdisciplinary cooperation, involving other categories of imaging experts: the medical physicists, the bioinformatics and the statisticians. The progress of bioinformatics has eased the imaging exchange for central review of scans and central handling and computing of Q-PET parameters. This in turn has opened new frontiers for international cooperation among cooperative groups in lymphoma, in the context of PETbased multicentre clinical trials. Finally, the new trends in personalized medicine have spurred the search for newer, more accurate tools for prognostication on a single-patient basis, and biomarkers have been recently integrated with imaging for the setup of newer prognostic model. For this reason, the galaxy of the expanding knowledge revolving around imaging has spurred an interdisciplinary approach needing dedicated channels of information. & Alberto Biggi biggi.a@ospedale.cuneo.it

A 2-year, 6-month-old Saudi male with infantile Krabbe's disease was studied with fluorine-18-labeled-2-fluoro-2-deoxyglucose positron emission tomography (FDG PET) scan. The patient presented with a gradual loss of developmental milestones, irritability, and crying. At the advanced stage of the disease, he developed tonic-clonic seizures and became a microcephalic, extremely irritable, blind, spastic quadriplegic child, with no deep tendon reflexes. Laboratory studies revealed normal blood chemistry, muscle enzymes, very long chain fatty acids, and acylcarnitines. No abnormal urinary organic acids were detected. The cerebrospinal fluid protein concentration was increased. Magnetic resonance imaging of the brain revealed mild brain atrophy and white matter disease mainly in the centrum semiovale. Electroretinography was normal; however, electroencephalography and visual-evoked potentials were abnormal. Peripheral nerve conduction studies documented a demyelinating neuropathic process. The FDG PET study of the brain demonstrated a marked decrease in the metabolism of the left cerebral cortex and no uptake in the caudate heads. Normal glucose uptake was observed in the thalami, lentiform nuclei, and cerebellum. The patient did not present for subsequent clinic visits and is presumed dead.

Neuroacanthocytosis syndromes (NA) include autosomal recessive chorea-acanthocytosis and X-linked McLeod syndrome consisting of a choreatic movement disorder, psychiatric manifestations and cognitive decline, and additional multi-system features including myopathy and axonal neuropathy. Fluor 18 -2-fluoro-2-deoxyglucose (F-18-FDG-PET) positron emission tomography (PET) and technetium 99m-d, l-hexamethyl-propylene amine oxime (99mTc-HMPAO) brain single photon emission computed tomography (SPECT) have been increasingly used for the detection of neurologic disorders, such as dementia, epilepsy, and movement disorders. In this case report, we report two patients with neuroacanthocytosis syndromes with the imaging features of brain metabolism by PET and brain perfusion by SPECT. Brain PET and brain SPECT findings of patients with neuroacanthocytosis syndromes were also reviewed.

Positron emission tomography with 2-deoxy-2-[fluorine-18]fluoro- D-glucose (18F-FDG-PET) has an important role in the management of lymphoma, but it is important to keep in mind that not only lymphoma but also a number of other pathologic and non-pathologic processes can cause increased tissue FDG uptake. Our case is a rare example when a uterine fibroid caused differential diagnostic problem.

女性生殖器以外の腫瘍を原発巣とする転移性子宮腫瘍は頻度が少なく,また大腸癌からの転移は極めて稀である.我々は直腸癌の腹腔内再発及び子宮体部転移をきたした症例を経験したので報告する.患者は3年前に直腸癌の切除を受けており,術後経過観察中に血清CEA値の上昇を認めた.MRI,CTにて子宮体部に腫瘍を認め,術前のFDG-PETにて直腸癌からの子宮体部転移と判断した.切除標本の病理組織検査では中分化腺癌を認め直腸癌の子宮体部転移と考えた.転移性子宮腫瘍に対しては確立した診断法は無く,また転移性子宮腫瘍の患者は診断の時点で他臓器の転移があることが多い.転移性子宮腫瘍に対して手術を行う前に他臓器への転移の有無を確認することが重要であろう.本症例では転移性子宮腫瘍の診断と他臓器の遠隔転移の除外においてFDG-PETが有用であった.

The clinical data and the imaging findings of the positron emission tomography (PET) and the magnetic resonance imaging (MRI) studies in five patients, previously diagnosed to have propionic acidemia, were retrospectively reviewed. The patients were all normal at birth. The first clinical signs, typically hypotonia and failure to thrive, appeared during the first 2 years of life. With progression of the disease, the neurological findings consisted of variable degrees of dementia and extrapyramidal symptoms, notably dystonia, choreoathetosis and rigidity of variable degrees. Initial cerebral PET and MRI studies were normal. Follow-up MRI examinations showed progressive basal ganglia degeneration, with evidence of atrophy and signal abnormalities within the caudate nuclei and the putamina. The thalamic structures were normal. The PET studies demonstrated increased uptake in the basal ganglia and thalami, followed by decreased uptake in the basal ganglia at a later stage of the disease. The structural (MRI) and the functional (PET) studies of the brain were found to be complementary in the evaluation of propionic acidemia, and were in good correlation with the clinical findings.

Summary Background Clearance of viable tumour cells in mediastinal lymph nodes (MLN) by induction chemotherapy (IC) – so-called MLN downstaging – is an important aspect of combined-modality treatment of N2-NSCLC. Reassessment of MLN after IC by CT is far from accurate, while re-mediastinoscopy is often technically difficult. Based on our previous results with FDG-PET in the initial staging of N2 disease, we investigated whether PET after IC could be helpful in predicting MLN downstaging and therapeutic outcome. Patients and methods Patients underwent a first PET before IC. After three cycles of platinum-based IC, a second PET was performed before locoregional therapy, either surgery or radiotherapy. PET results were correlated with pathology of the MLN when available, and with survival. Results Fifteen surgically staged N2-NSCLC patients were prospectively included. Locoregional therapy after IC consisted of surgery in nine and radiotherapy in six. Correlation with pathology of the nine resection specimens revealed that the accuracy of PET in predicting MLN downstaging was 100% (six true negatives; three true positives), whereas for CT it was only 67% (two false pos; one false neg). Reassessment with PET after IC was correlated with the outcome after the entire combined modality treatment. Survival was significantly better in patients with mediastinal clearance (P = 0.01) or with a greater than 50% decrease in the Standardised Uptake Value (SUV) of the primary tumour (P = 0.03) after IC. Conclusions Mediastinal PET after IC accurately assesses pathologic MLN downstaging in N2-NSCLC. The data suggest a possible correlation of early survival with mediastinal clearance and an important decrease of SUV in the primary tumour. Confirmation of these preliminary findings would establish PET as a useful non-invasive tool to select patients for intensive locoregional treatment after IC.

Exact localisation of thoracic lymph nodes (LNs) on fluorine-18 fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) can be hampered by the paucity of anatomical landmarks. In non-small cell lung cancer (NSCLC) patients referred for locoregional LN staging, we prospectively examined to what extent localisation of LNs at PET reading could be improved by visual correlation with computed tomography (CT), or by anatometabolic PET+CT fusion images. Fifty-six patients with potentially operable NSCLC underwent CT, PET and surgical staging. Prospective reading was performed for CT, PET without CT, PET+CT visual correlation and PET+CT fusion. Reading was blinded to surgical pathology data and noted on a standard LN map. Surgical staging was available for 493 LN stations. In the evaluation per individual LN station, CT was accurate in 87%, PET in 91% and visual correlation and fusion in 93%. In the identification of the nodal stage, CT was correct in 28/56 patients (50%), PET in 37/56 (66%), visual correlation in 40/56 (71%), and fusion in 41/56 (73%). It is concluded that in the exact localisation of metastatic thoracic LNs, the accuracy of reading of PET is increased if the PET images can be visually correlated with CT images. PET+CT anatometabolic fusion images add only a marginal benefit compared with visual correlation.

胸部異常陰影で受診した76歳の女性.胸部CTで左S6に胸膜嵌入像を伴った直径約10mmの腫瘤影を認めた.18F fluorodeoxy glucose positron emission tomography (FDG-PET) 検査では, 腫瘤影に一致して高い集積像を示し, 肺癌が疑われた.胸腔鏡下肺部分切除を行った結果, 原発性肺クリプトコッカス症と診断された.術後は髄膜炎の予防のために抗真菌薬を12ヵ月にわたって投与された.FDG-PETは肺癌の診断に有効な検査であるが, 孤立性の腫瘤を形成した原発性肺クリプトコッカス症では, 偽陽性を示すことがあり, 肺癌との鑑別がしばしば困難である.

A positive scan in pretransplantation fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has been shown to be associated with a poor prognosis in patients with lymphoma undergoing high-dose chemotherapy followed by autologous stem cell transplantation (ASCT). For those with a positive FDG-PET scan, treatment that includes allogeneic stem cell transplantation (allo-SCT) may be an alternative. However, it is uncertain whether allo-SCT can overcome a poor prognosis. Therefore, we conducted a retrospective analysis of 14 patients with lymphoma who had undergone FDG-PET scan within one month before allo-SCT at our institution. Eleven patients were FDG-PET-positive and three were negative. With a median follow-up of 17 months (range: 6-44) after allo-SCT, the cumulative incidence of progression was 29.3% in FDG-PET-positive patients and 0% in the FDG-PET-negative patients. Four of the 11 patients who had post-transplantation FDG-PET showed FDG-avid lesions on the first post-transplantation scan. In two of the four, regression of the lesions was observed during the scheduled reduction of immunosuppressant without donor lymphocyte infusion and remained without progression at the last follow-up (34 and 8 months). Durable responses after allo-SCT, at least with conventional conditioning regimens, can be expected in patients with FDG-PET-positive lesions before transplantation. Thus, conventional allo-SCT could be an attractive modality compared to ASCT for patients with positive FDG-PET after the completion of conventional salvage chemotherapy, and particularly for patients with T and NK-cell lymphomas.

Study objective: To compare the performance of CT, radio-labeled F-18-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) blinded to CT, and FDG-PET visually correlated with CT, in the detection of N2 metastatic mediastinal lymph nodes (MLN) in patients with non-small cell lung cancer (NSCLC) and to hypothesize how PET could influence our actual mediastinal staging procedures. Setting: Tertiary university hospital. Patients and methods: In 50 patients with potentially operable NSCLC, thoracic CT, PET, and invasive surgical staging were performed. Blinded prospective interpretation was performed for each test and compared with surgical pathology results. Abnormalities on each of these staging examinations were recorded on a standard MLN map. Results: The sensitivity, specificity, and accuracy in detecting N2 disease of CT was 67%, 59%, and 64%, respectively. Results of PET blinded to CT were significantly better (p = 0.004): 67%, 97%, and 88%, respectively. For PET visually correlated with CT, this was 93%, 97%, and 96%, respectively. In 22 patients, both CT and PET were normal, and this was correct in all cases. Conclusions: PET was significantly more accurate than CT in the MLN staging in NSCLC, Both examinations were complementary, since visual correlation with the anatomic information on CT improved the reader's ability to discriminate between hilar vs subaortic MLN FDG uptake, and between paramediastinal tumor vs tracheobronchial MLN FDG uptake. If the results can be confirmed in larger numbers of patients, PET could reduce the need for invasive surgical staging remarkably.

Background The use of positron emission tomography with fluoro-deoxy-glucose (FDG PET) in Hodgkin's disease (HD) is continuing to expand worldwide, with response assessment after completion of therapy being its most widely utilized application. A positive scan has been associated with high relapse rates and disease progression. Methods A decision analysis was performed to determine the long-term impact of FDG PET restaging both with and without computed tomography (CT) in terms of the 5-year progression-free survival (5yrPFS). Outcomes and utilities were based on published data. The first strategy involved CT restaging after first-line therapy, with or without subsequent FDG PET, while the second strategy used FDG PET scan alone. All positive test required histological examination. Upon histological confirmation of active lymphoma, patients were considered candidates for autologous transplantation and long-term outcomes were retrieved. The expected clinical benefit of the two strategies was calculated and depicted, along with the mean costs. One-way and two-way sensitivity analyses were performed to ensure the validity of the results. Results CT restaging plus FDG PET when residual mass is detected, results in a 2% benefit at 5yrPFS at baseline compared to FDG PET-alone restaging and remains positive for a wide range of probabilities. This strategy reduces the average cost by €1863 per patient, including costs of biopsy and autologous transplantation. Conclusion A more conservative approach that includes CT restaging after first-line therapy and FDG PET scan only on residual mass, is the preferred strategy in HD. Furthermore it appears to confer the maximal diagnostic yield along with a substantial reduction in the mean cost.

We conducted a retrospective analysis of 50 lymphoma patients (Hodgkin's disease and non-Hodgkin's lymphoma) who had an 18F-fluoro-deoxyglucose positron emission tomography (FDG-PET) scan after at least two cycles of salvage chemotherapy and before autologous stem cell transplantation (ASCT) at our institution. The patients were categorized into FDG-PET negative (N = 32) and positive (N = 18) groups. The median follow-up after ASCT was 19 months (range: 3-59). In the FDG-PET-negative group, the median progression-free survival (PFS) was 19 months (range: 2-59) with 15 (54%) patients without progression at 12 months after ASCT. The median overall survival (OS) for this group was not reached. In the FDG-PET-positive group, the median PFS was 5 months (range: 1-19) with only one (7%) patient without progression at 12 months after ASCT. The median OS was 19 months (range: 1-34). In the FDG-PET-negative group, chemotherapy-resistant patients by CT-based criteria had a comparable outcome to those with chemotherapy-sensitive disease. A positive FDG-PET scan after salvage chemotherapy and prior ASCT indicates an extremely poor chance of durable response after ASCT.

We report the case of a 23-year-old woman who initially presented with Wegener's granulomatosis (WG) limited to the lungs, diagnosed on the basis of a biopsy of an upper left lobe nodule and elevated ANCA titers. Remission occurred under treatment with methylprednisolone and intravenous immunoglobulins. Later in the course of the disease, findings highly suggestive of Takayasu's arteritis (TA) appeared: murmur at the level of the left subclavian artery, thickening of the arterial wall of the aorta and pulmonary arteries on tomodensidometry, and abnormal uptake of the aortic arch and ascending aorta on FDG-PET scan. This latter exam also showed an increased uptake of an already known pulmonary nodule, due to WG. Although five cases of WG occurring together with TA have previously been reported, this is the only one in which TA was revealed by FDG-PET scan. In the specific setting of overlapping vasculitides, FDG-PET scan may be helpful in simultaneously evaluating the activity of the two diseases.

T-cell lymphomas represent a rare and heterogeneous group of non-Hodgkin lymphomas (NHLs) characterized by dismal prognosis. Current first line chemotherapeutic approaches have not significantly changed during the last 20 years, and several efforts have been made for early risk stratification of T-cell NHL patients with unsatisfactory results. Functional imaging with 2-deoxy-2-[fluorine-18]fluoro- D-glucose positron emission tomography scan (FGD-PET) has demonstrated improved outcome stratification and response evaluation in Hodgkin lymphoma and B-cell NHL, in comparison with computed tomography (CT) scan. Most T-cell lymphomas are FDG avid and FDG-PET is routinely used in clinical practice, however limited and conflicting data are available on the value of FDG-PET in response assessment at the end of treatment (FDG-PETend). With the aim of evaluating the prognostic value of FDG-PETend in T-cell lymphomas we performed a retrospective study evaluating all T-cell NHL patients treated at the European Institute of Oncology (IEO, Milan) over the past 20 years. Clinical data of all T-cell NHL patients treated at IEO from 1995 to 2015 were retrospectively collected. The back bone of first line therapy did not significantly change over time, being based on the administration of CHOP/CHOP-like chemotherapy eventually followed by treatment intensification with autologous stem cell transplantation (ASCT). Post first-line therapy FDG-PET scans were visually evaluated according to the criteria of the international Harmonization Project (positive vs negative). Ninety-eight consecutive patients (58 males, 40 females) with complete clinical data were considered in this analysis. FDG-PET was used for response evaluation starting from 2002, but only 18 patients considered in the present analysis were treated before 2002. Median age at diagnosis was 54 years (range 14-82). Fifty-two patients (53.1%) had Peripheral T-cell lymphomas not otherwise specified (PTCL-NOS), 23 (23.5%) had anaplastic large T-cell lymphoma (ALCL), 15 (15.3%) had acute lymphoblastic T-cell lymphoma (LAL-T), 8 (8.1%) had NK/T-cell lymphoma. Ten patients were diagnosed in stage I, 21 in stage II, 17 in stage III, 50 patients in stage IV. Thirty-two patients underwent ASCT during the study period. Median follow-up was 16 months (range 1-182). 42 patients were evaluated with FDG-PET at the end of first line therapy: 25 had negative (60%), and 17 (40%) positive PET scans. In 56 patients response was evaluated with CT scan only, and complete responses or complete responses unconfirmed (CR/CRu) were detected in 29 cases (51%). The 10-year progression free survival (PFS) and overall survival (OS) of the whole patient cohort were 22% and 32% respectively. To determine the prognostic value of FDG-PETend we first assessed the PFS of PET positive vs PET negative patients. Those patients who were PET positive at the end of treatment had a statistically inferior PFS compared to PET negative ones (5-year PFS: 29% vs 47% respectively; p Disclosures No relevant conflicts of interest to declare.

Extracapsular spread (ECS) to the cervical lymph nodes is a major adverse prognostic factor in oral cavity squamous cell carcinoma (OSCC). We prospectively examined the value of FDG PET immediately before postoperative radiotherapy/concurrent chemoradiotherapy (pre-RT/CCRT PET) to detect residual/relapsing disease in the early postsurgical follow-up period in high-risk OSCC patients with ECS.We examined 183 high-risk OSCC patients with ECS who underwent preoperative FDG PET/CT for staging purposes. Of these patients, 29 underwent a second pre-RT/CCRT FDG PET/CT scan. The clinical utility of the second FDG PET/CT was examined using Kaplan-Meier curve analysis.Patients who underwent the second FDG PET/CT scan had baseline clinicopathological characteristics similar to those who did not undergo a second scan. Of the patients who underwent the second scan, seven (24 %) had unexpected, newly discovered lesions. Five eventually died of the disease, and two had no evidence of recurrence after a change in RT field and dose. In an event-based analysis at 2 months, rates of neck control (6/29 vs. 6/154, p = 0.001), distant metastases (3/29 vs. 4/154, p = 0.046), and disease-free survival (7/29 vs. 10/154, p = 0.003) were significantly higher in patients who received a second PET scan than in those who did not. The second pre-RT/CCRT PET scan was of particular benefit for detecting new lesions in OSCC patients with both ECS and lymph node standardized uptake value (SUV) of ≥ 5.2 in the first PET scan.The present findings support the clinical value of pre-RT/CCRT FDG PET for defining treatment strategy in OSCC patients with both ECS and high nodal SUV, even when FDG PET had already been performed during the initial staging work-up.

We performed a prospective study to assess the value of positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) in the prediction of local control in irradiated head and neck squamous cell carcinomas (HNSCCs). Forty-two patients with irradiated HNSCCs underwent 49 FDG-PET scans between 3 and 6 months after the end of radiotherapy. The mean follow-up time after the first FDG-PET scan was 17 months. The result of the FDG-PET scan was true-positive in 6 patients, false-positive in 7 patients, and true-negative in 29 patients. The sensitivity, specificity, positive predictive value, and negative predictive value of FDG-PET scanning were 100%, 81%, 46%, and 100%, respectively. We conclude that FDG-PET scanning is useful for prediction of therapy outcome in irradiated HNSCCs. No biopsy is needed for at least 1 year if an FDG-PET scan is negative. If the scan is positive and the biopsy is negative, decreased FDG uptake measured in a follow-up scan indicates that a local recurrence is unlikely.

Fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) scanning is useful in evaluating suspicious lesions of the lung. Our patient was a 65-year-old woman with a 45-pack-year smoking history who was referred for further evaluation because of a 3 cm × 3 cm solid lung nodule on computed tomography scan of the chest. FDG-PET scan revealed a standard uptake value of 3.2 suggestive of malignancy. The histology of the lung nodule was consistent with lipoid pneumonia, a benign condition frequently associated with inadvertent aspiration or inhalation of oily substances.

The utility of ([18F])fluoro-2-deoxy- d-glucose positron-emission tomography (FDG-PET) for predicting outcome after autologous stem cell transplantation (ASCT) for diffuse large B cell lymphoma (DLBCL) is uncertain - existing studies include a range of histological subtypes or have a limited duration of follow-up. Thirty-nine patients with primary-refractory or relapsed DLBCL with pre-ASCT PET scans were analysed. The median follow-up was 3 years. The 3-year progression-free survival (PFS) for patients with positive PET scans pre-ASCT was 35% vs. 81% for those who had negative PET scans (P = 0.003). The overall survival (OS) in these groups was 39% and 81% (P = 0.01), respectively. In a multivariate analysis, PET result, number of salvage cycles and the presence of relapsed or refractory disease were shown to predict a longer PFS; PET negativity (P = 0.04) was predictive of a longer OS. PET is useful for defining those with an excellent prognosis post-ASCT. Although those with positive scans can still be salvaged with current treatments, PET may useful for selecting patients eligible for novel consolidation strategies after salvage therapies.

A 32-year-old male had suffered from persistent dull epigastric pain, constipation, postprandial vomiting, and body-weight loss for 2 months. An abdominal computed tomography (CT) scan showed thickening of the proximal jejunal wall. He was also referred to our center for an fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) scan because his tumor marker CA19-9 was above 800 ng/mL and malignancy was suspected. The PET scan showed an FDG-avid lesion over the upper left abdomen. Endoscopy of the small intestine revealed focal thickening of the mucosal fold and skip ulcer lesions in the jejunum. Culture from the biopsy tissue proved the diagnosis of Mycobacterium tuberculosis infection. No evidence of pulmonary tuberculosis was detected during further evaluation.

Purpose : This study aimed to evaluate the F-2-fluoro-2-deoxyglucose positron emission tomography (F-18 FDG PET) findings of Loeffler's syndrome and to determine differential features between lung malignancy and Loeffler's syndrome. Materials and methods : F-18 FDG PET and low-dose chest CT scans were performed to screen for lung cancer. Eleven patients who showed pulmonary lesions on CT scan with peripheral blood eosinophilia were included. PET scans were evaluated by mean and maximum standardized uptake values (SUVs) of abnormalities. CT findings were reviewed and correlated with the PET findings. In all patients, follow-up CT scans and PET scans were done from 1 to 4 weeks after the initial study. Results : F-18 FDG PET scans identified metabolically active lesions in 9 of 11 patients. Maximum SUVs ranged from 2.8 to 10.6, and mean SUVs ranged from 2.2 to 7.2. The other 2 patients had maximum SUVs of 1.3 and 2.2. Follow-up PET scans showed a decreased degree of initially noted FDG uptakes or migration of the lesion. The CT scan showed nodular lesions with a peripheral halo (n = 6), ground-glass attenuation (n = 4), and consolidation (n = 1). Follow-up CT scans revealed decreased size and extent of the initial lesions in 7 patients and migration in 2 patients. The other 2, who had relatively mild F-18 FDG uptakes, showed complete radiographic resolution of the lesions. Conclusions : A single F-18 FDG PET study is not useful in differentiating benign and malignancy in patients with Loeffler's syndrome. Correlation and follow-up of PET and CT scan for the identification of abnormalities and their changes can be helpful for the differentiation between lung malignancy and Loeffler's syndrome.

Introduction: High standardized uptake value (SUV) on FDG PET scan in follicular lymphoma (FL) suggests aggressive disease and possible transformation to diffuse large B-cell lymphoma. Schoder et al, J Clin Oncol, 2005, reported that SUV >10 predicted aggressive lymphoma with >80% certainty and SUV >13 with >90% certainty. However, it is unknown whether the maximum SUV (SUVmax) on FDG PET scan at baseline, suggesting the possibility of focal aggressive or transformed disease, has prognostic value in FL. Here, we determined the prognostic value of SUVmax on baseline FDG PET scan in patients with advanced stage FL treated uniformly with R-CHOP chemoimmunotherapy at initial diagnosis. Methods: We reviewed medical records of all patients with stage III or IV FL who had FDG PET scan at initial diagnosis and were treated with R-CHOP chemoimmunotherapy at MD Anderson Cancer Center between January 2001 and December 2012. Patients with histological diagnosis of concurrent diffuse large B-cell lymphoma were excluded. Results: For the 225 patients studied, the median age was 57 years (range, 20-82). 83 (37%) patients were >= age 60, 137 (61%) had grade 1 or 2 FL, and 88 (39%) had grade 3A (n=57, 25%) or 3B (n=31, 14%). The Ki-67 score was 40% for 56 (40%) patients. FLIPI risk groups were 54 patients (24%) low, 74 (33%) intermediate, and 97 (43%) high. GELF criteria were met in 133 (59%) patients. Tumor bulk of >= 6 cm was seen in 97 (43%) patients. The absolute lymphocyte count (ALC) was normal or high in 155 (69%) patients and low in 70 (31%). Sixty-nine (31%) patients received rituximab maintenance. There was no correlation between baseline SUVmax on FDG PET scan and Ki-67 score (Pearson correlation co-efficient of 0.168). The overall and complete response rates were 96% and 87%, respectively. The median follow-up time was 66 months. At 5 years, progression-free survival (PFS) was 85% and overall survival (OS) was 90%. Male gender, stage IV, high risk FLIPI, presence of GELF criteria, high beta-2 microglobulin, and low ALC were associated with significantly inferior PFS and OS (p= 60 was associated with inferior OS but not PFS. Rituximab maintenance was associated with improved PFS but not OS. On baseline FDG PET scan, median SUVmax was 13.7 and the SUVmax range was 1.5-42.1. 105 (47%) patients had SUVmax 13. Patient characteristics including age, gender, histological grade, Ki-67 score, and FLIPI risk groups were not significantly different between the two SUVmax populations (p>0.05). The overall response rates were 94% and 96% for the SUVmax 13 groups, respectively. The complete response rate was 87% in both groups. At 5 years, the PFS and OS were not significantly different between the low and high SUVmax groups (61% vs 63% for PFS, p=0.98 and 90% vs 89% for OS, p=0.63). PFS and OS were not significantly different even when the patients were grouped into SUVmax 10 (p=0.9 and 0.61, respectively) or when other cut-offs were used. SUVmax was also not predictive of PFS and OS when only the patients meeting GELF criteria were analyzed. Conclusions: In this large cohort of advanced stage FL patients treated uniformly with R-CHOP chemoimmunotherapy, SUVmax on baseline FDG PET scan was not predictive of clinical outcome or correlated with other features. It is possible that the doxorubicin-based chemotherapy regimen may have benefited patients with high SUVmax who may have underlying aggressive or undiagnosed transformed disease. It remains to be determined whether SUVmax is predictive of clinical outcome in FL patients treated with other commonly used therapies such as rituximab monotherapy, rituximab and bendamustine, or R-CVP. Figure 1 Figure 1. Disclosures Wang: Pharmacyclics, Janssen: Honoraria, Research Funding. Westin:Novartis: Research Funding.

Background An increased 18-fluoro-deoxyglucose (FDG) uptake has been described in the large vessels of the thorax and legs in patients with giant cell arteritis (GCA) and/or polymyalgia rheumatica (PMR),1,2 using positron emission tomography (PET). This reflects increased glucose metabolism in these inflamed vessels. Objectives We wanted to expand the FDG-PET technology to other patients with biopsy-proven vasculitis. We wondered if vasculitis could also be visualised in patients with other types of large vessel vasculitis, in patients with medium-sized vessel vasculitis and in patients with different forms of small vessel vasculitis. Methods Patients with biopsy-proven vasculitis, different from GCA/PMR, who were admitted to the General Internal Medicine Department of the University Hospital Gasthuisberg, Leuven, Belgium underwent FDG-PET scan before eventual treatment with steroids was started. One hour before imaging, 6.5 Mbq/kg FDG were injected intravenously. Results A total of 18 patients were included: 2 patients had large vessel vasculitis (1 Takayasu’s arteritis, 1 periaortitis), 3 patients had medium-sized vessel inflammation (2 Churg-Strauss syndrome, 1 polyarteritis nodosa or PAN) and 13 patients had small vessel vasculitis (7 Wegener’s granulomatosis, 2 Henoch-Schonlein purpura, 2 cutaneous polyarteritis, 1 relapsing polychondritis and 1 microscopic polyangiitis). Aortic FDG-uptake was very intense in periaortitis and rather discrete, but persistent under steroid treatment in Takayasu’s arteritis. There was no increased vascular FDG-uptake in patients with PAN or Churg-Strauss syndrome. Increased FDG-uptake in the lungs was seen in Wegener’s granulomatosis patients with lung involvement, as well as in the patient with microscopic polyangiitis and lung involvement. Cutaneous involvement of the legs in small vessel vasculitis is also reflected on FDG-PET scan, as well as bowel involvement in Henoch-Schonlein purpura. (Para) nasal involvement in Wegener’s granulomatosis also produces a hot focus on FDG-PET scan. Conclusion Apart from GCA/PMR, FDG-PET scan can also be used to visualise the inflamed thoracic arteries in those other – but much less frequent – large vessel vasculitides as there are Takayasu’s arteritis and periaortitis. In medium-sized vasculitis, FDG-PET scan seems to be of much less value. In small vessel vasculitis, internal organ involvement can be visualised, especially in the lungs. However, FDG-PET scan can not distinguish pulmonary vasculitic involvement from pulmonary infection, since both conditions induce more local FDG metabolism. References Blockmans, et al. New arguments for a vasculitic nature of polymyalgia rheumatica using positron emission tomography. Rheumatology 1999;38:444–7 Blockmans, et al. Positron emission tomography in giant cell arteritis and polymyalgia rheumatica: evidence for inflammation of the aortic arch. Am J Med. 2000;108:246–9

A case is presented of detection of a secondary thyroid cancer arising from a pulmonary adenocarcinoma by fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET). The need to investigate thyroidal hypermetabolic foci detected incidentally on PET scans is well established so as not to miss a primary thyroid cancer. However, as our case illustrates, the possibility of metastatic thyroid cancer, even though less common, should be considered.

Early diagnosis of intravascular large B-cell lymphoma (IVLBCL) is difficult, but is critical for longer survival for the patients. We report a case of IVLBCL that was diagnosed with the help of FDG-PET. A 76-year-old woman was referred to us for the evaluation of her elevated serum LDH. She presented with general malaise and high fever. There were no skin lesions or neurological involvement. FDG-PET imaging showed increased uptake of FDG in the vertebra, bilateral femurs, sternum, and iliac bones. A diagnosis of IVLBCL was made by bone marrow biopsy. She was successfully treated with rituximab and modified CHOP therapy.

Central necrosis in lymphoma lesions as demonstrated in [(18)F] fluoro-2-deoxyglucose positron emission tomography (FDG-PET) studies is a rare phenomenon, and the clinical significance of this observation has not been described in the literature. The role of FDG-PET in the management of peripheral T cell lymphoma (PTCL) is also still unclear at this time. We present a case of a patient newly diagnosed with PTCL who underwent both computed tomography (CT) and FDG-PET examinations prior to and following therapy. CT showed pulmonary cavitary lesions in both lungs, and PET demonstrated multiple large confluent masses with intense FDG uptake in the corresponding lung fields with central photopenia suggestive of necrosis. Post-treatment FDG-PET images showed a significant improvement in the previously described lesions with some residual, recurrent, and new lesions. Central necrosis shown by PET may be associated with the advanced stage of the disease and may have prognostic implications because of central necrosis caused by hypoxia.