Positive Fluorodeoxyglucose Positron Emission Tomography Research Articles

Longitudinally extensive transverse myelitis with trident sign and positive AQP4 antibody: a case report

BackgroundLongitudinally extensive transverse myelitis (LETM) is characterized by spinal cord lesions that affect at least three spinal cord segments. It can be associated with various inflammatory conditions. While imaging characteristics can aid in diagnosis, relying solely on them may lead to misinterpretation.Case presentationWe describe a 35-year-old woman who presented with subacute myelitis. Her cervical MRI (magnetic resonance imaging) revealed an extensive lesion from the area postrema down to the second thoracic level, with a trident sign observed in axial T1-weighted post-gadolinium imaging. The presence of a trident sign in MRI of patients with myelopathy is more commonly associated with sarcoidosis than other conditions. But our patient had positive (rechecked) AQP4 antibody and negative FDG-PET (fluorodeoxyglucose positron emission tomography) scan that shows trident sign could be seen in other inflammatory disorders such as NMO (neuromyelitis optica).ConclusionTrident sign is not pathognomonic for sarcoidosis, additional investigations are necessary to identify the diagnoses related to the trident sign.

Brentuximab Vedotin Administered To Platinum-Refractory Transplant Naïve Hodgkin Lymphoma Patients Can Increase The Proportion Achieving FDG-PET Negative Status

BackgroundClassical Hodgkin lymphoma (HL) is characterized by CD30-positive Reed-Sternberg cells and is frequently curable with initial therapy. The standard treatment for relapsed or refractory HL is multi-agent salvage chemotherapy, most commonly with platinum-based regimens followed by high dose chemoradiotherapy and autologous stem cell transplantation (ASCT) in patients with chemosensitive disease. Normalization of fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging prior to ASCT has been associated with improved outcomes (Moskowitz AJ et al., 2010) even when a second salvage therapy is employed (Moskowitz CH et al., 2012). Thus, achieving a FDG-PET negative state prior to ASCT is desirable. Brentuximab vedotin (BV), a CD30-directed antibody linked to the antitubulin agent monomethyl auristatin E, is a safe and well-tolerated therapy with favorable response rates in relapsed HL post-ASCT. Limited data exist regarding the use of BV as salvage therapy in transplant naive patients with persistently positive FDG-PET. We evaluated the role of BV in achieving FDG-PET negative status in patients with platinum-refractory HL prior to ASCT. MethodsPatients with relapsed or refractory HL treated at the Fred Hutchinson Cancer Research Center, Seattle Cancer Care Alliance, and University of Washington Medical Center between 2009 and 2013 were included in this retrospective analysis if they achieved less than a complete response with a persistently abnormal FDG-PET following platinum-based salvage therapy. All patients had CD30-positive tumors, received BV following the failed salvage regimen and had follow-up functional imaging. The primary endpoint of this study was the ability of BV to normalize FDG-PET scans. Secondary endpoints included disease response, response to subsequent therapy in BV failures, toxicity, ability to proceed to ASCT, and survival and progression-free status. ResultsWe identified 15 patients (10 male and 5 female) with platinum-refractory HL who met the above inclusion criteria. The median age at diagnosis was 30.8 years (range, 17- 64) and the numbers of patients with stage II, III, and IV disease were 6, 4, and 2 patients, respectively. 3 patients did not have staging data available. 11 patients had primary refractory disease and 4 patients had relapsed disease. Qualifying platinum-based salvage therapy included ICE/RICE (10); bendamustine, etoposide, carboplatin (2); gemcitibine, carboplatin, dexamethasone (2); and DHAP (1). The response to platinum-based therapy was partial response (PR), stable disease (SD), and progressive disease (PD), in 3, 9, and 3 patients, respectively. All patients had residual FDG-avid disease on PET with a median maximum bulk of 12.8 cm on CT. The median number of regimens received prior to BV was 2.5 (range, 2-4), and the best response to any prior chemotherapy was complete remission (CR) in 13% (2/15), PR in 33% (5/15), SD in 40% (6/15), and PD in 13% (2/15) of patients. A median of 4 BV cycles (range, 2 to 7) was administered at the standard dose of 1.8 mg/m2 every 3 weeks. 2 patients had a documented grade 2 or higher adverse event (peripheral neuropathy, allergic reaction), but BV was not discontinued in either patient.Treatment with BV converted 47% (7/15) of platinum-refractory patients to FDG-PET negative status, while 7% (1/15) achieved a PR. The overall response rate was 53% (8/15). At the time of analysis, 87% (13/15) of patients had proceeded to HDT/ASCT. For the 8 patients whose post-ASCT restaging scans are available, 50% (4/8) and 12.5% (1/8) of patients achieved CR and PR, respectively. At the time of analysis, 14/15 patients were alive and 8 patients were documented to be progression-free. The median follow-up since the last dose of BV and ASCT was 485 days and 491 days, respectively. FDG-PET negative CR rates to BV based on the response to platinum therapy were 67% (2/3), 56% (5/9), and 0% (0/3) in patients with PR, SD, and PD, respectively. ConclusionOur data suggest that BV can induce a FDG-PET negative CR in approximately half of all transplant naïve platinum-refractory HL patients and may be a particularly effective second-line salvage strategy for patients who have achieved at least SD or better. Further prospective studies are needed to confirm these findings and determine if BV-induced CRs predict the same post-ASCT outcomes as conventional salvage regimens. Disclosures:Holmberg:Seattle Genetics: Consultancy, Research Funding; Millennium: Research Funding; Merck: Research Funding; Otsuka: Research Funding; Sanofi: Research Funding; Educational Concepts: Speakers Bureau; Allos: Consultancy; Genzyme: Consultancy. Shustov:Seattle Genetics: Consultancy, Honoraria, Research Funding. Pagel:Seattle Genetics: Equity Ownership. Press:Roche/Genentech: Consultancy. Gopal:Seattle Genetics: Consultancy, Honoraria, Research Funding, Speakers Bureau; Millenium: Speakers Bureau.

Long-Term Results of the Treatment of Persons with Hodgkin's Lymphoma in a Resource-Constrained Setting: Real-World Data from a Single Center

Background: Hodgkin's lymphoma (HL) is the model of curative care with radiation therapy, combination chemotherapy, staging approaches, peripheral blood stem cell transplantation, and immunotherapy. However, the value of the novel anti cancer drugs has been recently analyzed and questioned in view of the results in the real improvement of overall survival (OS). Material and methods: All consecutive patients seeking medical care after 1986 in our institution as a result of HL and followed for at least 3 months were entered in the study. A diagnosis of HL was based on the histological study of a pathology specimen, mainly a lymph node; the same pathologist analyzed all the specimens and defined the histological subtype. Clinical stage was defined according to the Ann Arbor classification. Bone marrow biopsies were done only in patients with clinical stages III or IV. Computed tomography (CT) scans were done in all cases, prior to starting the treatment. Fluorodeoxyglucose positron emission tomography (FDG-PET) scans were performed since 2002. Between 1986 and 1997, patients were treated with MOPP, and after 1997 with ABVD as frontline therapy. For stages I and II, four cycles of chemotherapy were delivered and a computerized tomography (CT) scan was performed; if lymph node enlargement were present at this point in time, four additional cycles were given, whereas two additional cycles were given if the CT scan was negative. For stages III and IV, the CT scans were performed at the end of six cycles and two or four more cycles. Mediastinal radiotherapy was delivered only to persons with a positive FDG-PET scan at the end of the treatment. Patients showing activity after these treatments were considered as refractory and treated with four courses of ICE (ifosfamide, carboplatin and etoposide). Autologous or allogeneic peripheral blood hematopoietic stem cell transplants (HSCT) were given to refractory patients after achieving a complete remission (CR): High-dose melphalan (200mg/m2) was employed in autologous transplants, whereas cyclophosphamide, fludarabine and busulfan were employed in allogeneic transplants, all of them from HLA-identical siblings. After the completion of the treatment, patients were every two months for one year and every four months later on. No FDG-PET scans were done during the follow up, unless clinically indicated. Results: Among 91 patients with HL identified between 1986 and 2020, 88 were followed three months or more and were included in the analysis. There were 37 females and 51 males. The median age was 29years (range5-73years). There were 62 patients with nodular sclerosing HL (70%), 19 mixed cellularity (HL), 2 lymphocyte depleted HL, and one lymphocyte predominant HL; in 4 cases the histologic variant could not be defined. According to Ann Arbor classification, 5 patients were found in stage I, 48 in stage II, 19 in stage III and 16 in stage IV. Ten patients presented with a mediastinal mass larger than 10 cm. in the chest X-ray film. Three cases presented with relapsed disease. Patients have been followed for a median of 114 months (range4-402). 44 patients are alive, 10 have died and 34 were lost to follow-up. Median OS for all the patients has not been reached, being above 402 months, the OS at 310 months is 88% and at 402 months 77%. Median OS has not been reached and is above 94, 109, 90 and 98 months for stages I, II, III and IV, respectively (p=0.2). The 310-month OS was 83% for patients treated with MOPP and 88% for those treated with ABVD (HR:0.76, 95% CI 0.2-2.8; p=0.6).Sixteen patients (18%) were refractory to the treatment and 9 (10%) relapsed; they were treated with ICE followed by HSCT (autologous 15 patients and allogeneic 10 patients). Patients who underwent auto-HSCT had a median survival of 329.1 months and an OS of 92.3%, whereas those given allo-HSCT had a median survival of 59.3 months and an OS of 45.7% (HR0.2, 95%CI 0.04-1.3, p=0.057). The OS of patients given or not HSCT was 73.5% and 92.9% at 266 and 404 months, respectively (HR4.09, 95%CI 1.0-16.6, p=0.01). The OS was similar. The causes of death were breast carcinoma in 2 cases, liver carcinoma in one and uncontrolled lymphoma activity in the remaining. Conclusion: HL may be less aggressive in Mexican population than in Caucasians. Combined chemotherapy renders acceptable results, irrespective of clinical stage. Disclosures No relevant conflicts of interest to declare.

Circulating Human Papillomavirus DNA as a Biomarker of Response in Patients With Locally Advanced Cervical Cancer Treated With Definitive Chemoradiation.

To determine whether plasma human papillomavirus (HPV) DNA predates clinical recurrence and compare its accuracy with 3-month fluorodeoxyglucose positron emission tomography (FDG-PET) in locally advanced cervical cancer. This prospective multicenter study accrued 23 women with stage IB to IVA cervical cancer planned for definitive chemoradiation therapy (CRT). Plasma HPV DNA was measured serially by digital polymerase chain reaction, and FDG-PET was performed at 3 months post-CRT. Of the 19 women with HPV+ cervical cancer included in this analysis, 32% were stage IB, 58% IIB, and 10% IIIB/IVA. Median follow-up was 24 months (range, 18 to 30 months). All patients had detectable plasma HPV DNA before treatment. Six patients had detectable plasma HPV DNA at the end of CRT, and three of them developed metastases at 3 months. Of the 13 patients with undetectable plasma HPV DNA at end of CRT, to date, only one has developed recurrence. Six of those 13 patients had a positive 3-month FDG-PET with no definite residual disease on subsequent imaging or clinical examination to date, and four of these six had undetectable plasma HPV DNA at 3 months. Patients with undetectable plasma HPV DNA at end of CRT had significantly higher 18-month progression-free survival than those with detectable plasma HPV DNA (92% v 50%; P = .02). The area under the receiver operating characteristic curve (accuracy) of 3-month plasma HPV DNA and 3-month FDG-PET imaging for predicting recurrence at 18 months were 77% and 60%, respectively (P = .008). Detectable plasma HPV DNA at end of CRT predates the clinical diagnosis of metastases and is associated with inferior progression-free survival. Moreover, 3-month plasma HPV DNA level is more accurate than 3-month FDG-PET imaging in detecting residual disease. The clinical utility of plasma HPV DNA detection for guiding adjuvant/salvage therapy should be evaluated in future studies.

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.

The role of FDG-PET imaging as a prognostic marker of outcome in primary mediastinal B-cell lymphoma.

Primary mediastinal B-cell lymphoma (PMBL) is a subtype of diffuse large B-cell lymphoma (DLBCL) that arises in the mediastinum from B-cells of thymic origin. Optimal management of patients with PMBL remains controversial. The present study evaluates outcomes of 27 PMBL patients treated with R-CHOP with or without radiation therapy (RT). It investigates the role of both interim and posttreatment fluorodeoxyglucose-positron emission tomography (FDG-PET) as prognostic markers of outcome. Additionally, it assesses postprogression therapies in the six patients who had progressive disease. At a median follow-up of 41.5 months (range: 6.1–147.2 months), OS was 95.5% (95% CI = 71.9–99.4) and progression-free survival (PFS) was 70.4% (95% CI = 49.4–83.9) for the entire cohort. The negative predictive values of interim and posttreatment FDG-PET scans were both 100%. Patients who failed initial therapy and were treated with salvage regimens and autologous stem cell transplantation (ASCT) all achieved and maintained CR. PMBL patients can achieve excellent outcomes with minimal toxicities when treated with R-CHOP with or without RT. Negative interim and negative posttreatment FDG-PET results identified PMBL patients who achieve long-term remission. However, the significance of both positive interim and positive posttreatment FDG-PET results needs to be better defined. Those who failed initial therapy were successfully treated with salvage regimens and ASCT.

Visibility Of Bone Lesions In Relapsed Multiple Myeloma Can Be Improved By FDG-PET Scanning

Osseous involvement is one the predominant features of patients with multiple myeloma (MM). Whole body X-ray (WBX) is the standard method for detecting skeleton abnormalities but has limited value in relapsing disease since it cannot make a distinction between old and new active skeleton lesions. Therefore changes in metabolic activity might be a more useful method to detect new skeleton lesions in MM. This can be assessed by [F-18] fluorodeoxyglucose positron emission tomography (FDG-PET) imaging. Consequently WBX and FDG-PET was studied in relapsing MM prior to treatment. In addition immunohistochemical staining on bone marrow biopsies was performed for glucose transport protein (GLUT) 3 expression, micro vessel density (MVD), and vascular endothelial growth factor (VEGF) to demonstrate whether these parameters might be predictive for the in vivo scanning results. This study included 44 patients (median age 62 yr (range 48-78)) with a median of 3.5 (range 2-12) relapses. Thus far 86% of the patients were treated with autologous stem cell transplantation in combination with bortezomib (78%) or lenalidomide (65%). New lesions on FDG-PET were more frequently demonstrated than new lesions on WBX (p=0.00001). In 78% of the patients FDG-PET demonstrated a median of 4 lesions (range 0-22) per patient with a median standard uptake value (SUV) max of 5.7 (range 0-24). In 42% of the patients new X-ray lesions (median 0 (range 0-7)) were demonstrated and these were concordant with the results of FDG-PET. In 5 % of the patients new X-ray lesions were observed without FDG-PET lesions. For the relapsing patients treatment consisted of dexamethasone in combination with bortezomib (65%) or lenalidomide (50%). CR was obtained in 27% of the patients, PR in 39% and progressive disease in 22%. Average time to next treatment (TTNT) was 11.7 months (2-43). However FDG-PET positivity was not predictive for PFS (p =0.55) and OS (p=0.40) neither if PET positivity was defined as more than 3 lesions nor if the cut off value of SUV max > 4.2 was applied. Immunohistochemical staining on bone marrow biopsies (n=20) with CD34 demonstrated a significant increased MVD of 39 ± 54 (mean ± SD, normal bone marrow MVD 3.5 ± 2.9), in particular when clusters of plasma cells were present. These enhanced MVD was associated with a significant increased expression of VEGF and GLUT-3. However MVD (p = 0.16), VEGF (p = 0.70) or GLUT-3 (p =0.70) expression were not predictive for having a positive or negative FDG-PET. In summary, our results demonstrate that FDG-PET is more informative than WBX for detecting skeleton lesions in relapsing MM patients. However, and in contrast to what was previously shown in patients with newly diagnosed MM, FDG-PET it is not predictive for treatment outcome. This might be due to heterogeneity in studied patients and treatments. Disclosures:No relevant conflicts of interest to declare.

Diagnosis of the jejunoileal lymphoma by double-balloon endoscopy

To investigate the feasibility of double-balloon endoscopy (DBE) to detect jejunoileal lymphoma, compared with fluorodeoxyglucose positron emission tomography (FDG-PET). Between March 2004 and January 2011, we histologically confirmed involvement of malignant lymphoma of the jejunoileum in 31 patients by DBE and biopsy. In 20 patients of them, we performed with FDG-PET. We retrospectively reviewed the records of these 20 patients. Their median age was 64 years (range 50-81). In the 20 patients, the pathological diagnosis of underlying non-Hodgkin's lymphoma (NHL) comprised follicular lymphoma (FL, n = 12), diffuse large B cell lymphoma (DLBCL, n = 4), mantle cell lymphoma (MCL, n = 2), enteropathy associated T cell lymphoma (ETL, n = 1) and anaplastic large cell lymphoma (ALCL, n = 1). Ten cases showed accumulation by FDG-PET (50%). FDG-PET was positive in 3 of 12 FL cases (25%) while in 7 of 8 non-FL cases (88%, P < 0.05). Intestinal FL showed a significantly lower rate of positive FDG-PET, in comparison with other types of lymphoma. Cases with endoscopically elevated lesions (n = 10) showed positive FDG-PET in 2 (20%), but those with other type NHL did in 8 of 10 (80%, P < 0.05). When the cases having elevated type was compared with those not having elevated type lesion, the number of cases that showed accumulation of FDG was significantly smaller in the former than in the latter. In a significant proportion, small intestinal involvement cannot be pointed out by FDG-PET. Especially, FL is difficult to evaluate by FDG-PET but essentially requires DBE.

The evaluation of FDG-PET imaging for epileptogenic focus localization in patients with MRI positive and MRI negative temporal lobe epilepsy

We studied the contribution of interictal FDG-PET ([18F] fluorodeoxyglucose-positron emission tomography) in epileptic focus identification in temporal lobe epilepsy patients with positive, equivocal and negative magnetic resonance imaging (MRI). Ninety-eight patients who underwent surgical treatment for drug resistant temporal lobe epilepsy after neuropsychological evaluation, scalp video EEG monitoring, FDG-PET, MRI and/or long-term intracranial EEG and with >12months clinical follow-up were included in this study. FDG-PET findings were compared to MRI, histopathology, scalp video EEG and long-term intracranial EEG monitoring. FDG-PET lateralized the seizure focus in 95% of MRI positive, 69% of MRI equivocal and 84% of MRI negative patients. There was no statistically significant difference between the surgical outcomes among the groups with Engel class I and II outcomes achieved in 86%, 86%, 84% of MRI positive, equivocal and negative temporal lobe epilepsy patients, respectively. The patients with positive unilateral FDG-PET demonstrated excellent postsurgical outcomes, with 96% Engel class I and II. Histopathology revealed focal lesions in 75% of MRI equivocal, 84% of MRI positive, and 23% of MRI negative temporal lobe epilepsy cases. FDG-PET is an accurate noninvasive method in lateralizing the epileptogenic focus in temporal lobe epilepsy, especially in patients with normal or equivocal MRIs, or non-lateralized EEG monitoring. Very subtle findings in MRI are often associated with histopathological lesions and should be described in MRI reports. The patients with negative or equivocal MRI temporal lobe epilepsy are good surgical candidates with comparable postsurgical outcomes to patients with MRI positive temporal lobe epilepsy.

Pulmonary aspergilloma: a potential cause of false positive fluorodeoxyglucose positron emission tomography scan

Pulmonary aspergilloma is a fungus ball developed in a pre-existing lung cavity, generally in the superior lobes. Its size remains stable in most cases and it is usually asymptomatic. Herein, we present a case of a 64-year-old male with pulmonary aspergilloma, which was developed in an emphysematous cyst of the right inferior lobe, increased in size, and fluorodeoxyglucose positron emission tomography scan was positive. There are only a few reported cases of pulmonary aspergilloma with a false positive fluorodeoxyglucose positron emission tomography scan.

Comparing 18F-Fluorodeoxyglucose Positron Emission Tomography and Video-assisted Thoracoscopic Surgery in the Evaluation of Small Pulmonary Nodules in Patients with a History of Malignancy

BackgroundThe aims of the study were to determine the accuracy of fluorodeoxyglucose positron emission tomography (FDG-PET) in detecting pulmonary metastasis through video-assisted thoracoscopic surgery (VATS), a technique that allows the excisional biopsy of small pulmonary nodules in patients with known malignancies.Materials and MethodsBetween October 2007 and April 2010, 28 patients with known malignancies and small pulmonary nodules underwent VATS excisional biopsies. All patients were in follow-up for a previously treated malignancy. The malignancies included the following: colorectum (9), breast (6), head and neck (5), stomach (3), lymph (1), ovary (1), uterus (1), bladder (1), and liver (1).ResultsThere were 16 men and 12 women whose mean age was 56.7 years old (range, 38 to 77 years). The sizes of the mean nodules removed were 11.3 mm (range, 7 to 21 mm). Diagnoses included metastatic (11), bronchioloalveolar carcinoma (1), primary adenocarcinoma (1), pulmonary tuberculosis (6), fibrosis (5), organizing pneumonia (3), lymphoid hyperplasia (1). Among these lesions, 46.4% were malignant.ConclusionTrue positive FDG-PET was 39.2%. FDG-PET is not a sensitive test in the evaluation of patients with a history of an extrathoracic malignancy and newly diagnosed small pulmonary nodules. VATS excision allows the early diagnosis of small pulmonary nodules, with low morbidity, in patients with known malignancies.

FDG-Positron Emission Tomography in T-Cell Lymphoma

Abstract 1614 Background:Few data are available on the role of fluoro-deoxy-glucose positron emission tomography (FDG-PET) in T-cell non Hodgkin Lymphoma (NHL). We compared standard contrast-enhanced computerized tomography (CECT) and FDG-PET for initial staging and restaging after treatment in T-cell NHL. Methods:We reviewed 58 FDG-PET scans performed in 29 patients (pts) affected by T-cell NHL and we focused on the 42 cases for which a simultaneous standard CECT was available for comparison. The specific T-cell histology was Peripheral T-Cell Lymphoma Not Otherwise Specified in 12 pts, Angioimmunoblastic T-Cell Lymphoma in 4 pts, Anaplastic Large Cell Lymphoma in 10 pts, other T-NHL hystologies in 3 pts. Twelve pts were males and median age at diagnosis was 57 years (range: 25–77). Baseline FDG-PET scans were 20, while FDG-PET performed for disease reassessment were 22. Results:FDG-PET performed at baseline was positive in all cases. In 6 cases (30%) FDG-PET identified fewer disease sites than CECT, while in 14 cases (70%) FDG-PET identified additional disease sites. New sites identified by FDG-PET were: other nodal sites (11 pts), spleen (2 pts), nasopharynx (1 pt) and testicles (1 pt). Different disease extent evaluation according to FDG-PET modified clinical stage in 10 pts (50%): one pt was downstaged and 9 pts were upstaged. FDG-PET-based stage was not considered for therapeutic decision. FDG-PET scans performed at restaging were negative in 16 cases (72%) and positive in the remaining 6 cases (28%). In 13/16 (81%) negative cases CECT was concordant and showed a complete remission, while in the remaining 3 cases CECT showed a residual nodal disease. In the 6 FDG-PET positive cases, CECT was as follows: abnormal in the same site of FDG-PET in 1 case, abnormal in fewer sites than FDG-PET in 3 cases and abnormal in more sites than FDG-PET in 2 cases. With a median follow-up of 32 months, the median overall survival (OS) of the 6 positive FDG-PET cases at restaging was 26 months. With a median follow-up of 23 months, the median OS of the 16 negative FDG-PET cases at restaging was not reached. Conclusion:FDG-PET can be useful in the initial staging of T-cell NHL, since it can allow a more accurate disease extension evaluation: in our experience it could identify additional sites, both nodal and extra-nodal, in 70% of pts. A change in clinical stage according to FDG-PET was observed in 50% of cases, with an upstaging in the majority of pts. We could confirm the high sensitivity of baseline FDG-PET in T-cell NHL. A high level of concordance was observed between PET and CECT at restaging. However, independently on CECT result, the worse OS of FDG-PET positive cases confirms the role of FDG-PET as prognostic factor for survival. Larger prospective trials are needed to confirm the utility of FDG-PET in baseline staging, reassessment after chemotherapy and treatment planning. Disclosures:No relevant conflicts of interest to declare.

Bronchial stump aspergillosis after lobectomy for lung cancer as an unusual cause of false positive fluorodeoxyglucose positron emission tomography and computed tomography: a case report

IntroductionBronchial stump aspergillosis is a rare entity characterized by cough and hemoptysis.Case presentationWe report the case of a 58-year-old Caucasian woman who developed bronchial stump aspergillosis two years after a left upper lobe resection for lung cancer. Bronchial stump aspergillosis was diagnosed as a result of a focus of increased fluorodeoxyglucose activity in a follow-up positron emission tomography and computed tomography scan. She was treated with oral antifungal therapy and presented with good evolution after three months of treatment.ConclusionBronchial stump aspergillosis is an unusual complication after pulmonary resection. Clinicians should be aware of it when a local recurrence of cancer around the bronchial stump is suspected based on a positive positron emission tomography and computed tomography finding.

FDG-PET in diagnostic work-up of pulmonary artery sarcomas

To the Editors: Pulmonary artery sarcomas (PAS) represent a group of rare tumours with a poor prognosis. In a recent review, the mean±sd survival of patients with this disease was 11±3 months when no curative resection was attempted, whereas patients undergoing curative resection had a survival of 36.5±20.2 months 1. Appropriate application and interpretation of different imaging modalities facilitates differentiation of PAS from chronic thromboembolism. Findings in chest computed tomography (CT) could be inhomogeneous attenuation, vascular distension or filling defects of the entire luminal diameter of a proximal or main pulmonary artery 2, 3. Extraluminal extension of the tumour can be a specific finding of PAS. Magnetic resonance imaging (MRI) aids the determination of the extent of masses and the relationship to adjacent structures, and during postoperative follow-up 4. The degree of contrast enhancement in MRI was shown to correlate with the degree of tumour differentiation, and contrast enhancement might be used to differentiate neoplasm from central pulmonary embolism 5. Single case reports have shown that fluorodeoxyglucose-positron emission tomography (FDG-PET) might be helpful in differentiating PAS from pulmonary thromboembolic disease, and helps decision-making when it is not possible to perform intraoperative biopsies for histological confirmation of PAS before attempting curative pneumonectomy 6, 7. In the current study, we present three cases of patients with PAS, in whom a presumptive diagnosis of PAS was made preoperatively based on clinical, CT and MRI findings and a positive FDG-PET scan. Case 1 was a 48-yr-old male nonsmoker with absence of previous medical history who presented with progressive dyspnoea. On spiral contrast-enhanced CT scan taken 4 months prior to presentation, a left-sided paracentral pulmonary embolism was suspected. No …

Negative Interim FDG-PET Scan Is Predictive of Superior Outcome in T Cell Lymphoma.

Abstract 1956Poster Board I-979 Background:Fluoro-deoxy-glucose positron emission tomography (FDG-PET) is a required staging study for diffuse large B-cell lymphoma and Hodgkin lymphoma. Numerous studies have demonstrated that FDG-PET performed after one to four cycles of multiagent chemotherapy (interim restaging) is predictive of outcome, with relapse rates much higher in patients with positive FDG-PET scans at interim restaging. The prognostic role of FDG-PET in T-cell lymphoma however is unclear and has yet to be well defined. Small retrospective studies have demonstrated FDG-PET avidity of T-cell lymphoma. Our experience confirms that the great majority of patients with mature T or NK lymphomas have FDG-PET avid disease. We hypothesized that the interim FDG-PET (int FDG-PET) may have prognostic importance in patients with T-cell lymphomas as they do in diffuse large B-cell lymphoma and Hodgkin lymphoma. Methods:We reviewed our T-cell lymphoma database to identify patients with mature T or NK lymphomas who had FDG-PET scans as part of complete staging at initial diagnosis as well as repeat PET imaging as part of restaging. Inclusion criteria required FDG-PET avid disease at baseline and treatment administered with curative intent. Results:We reviewed fifty four patients who met the above criteria. Histologies were as follows: peripheral T-cell lymphoma NOS (N=18), angioimmunoblastic T-cell lymphoma (N=5), anaplastic large cell lymphoma ALK-1- (N=15), anaplastic large cell lymphoma ALK-1+ (N=3), and other subtypes (N=13). Patients received a variety of initial chemotherapy regimens including CHOP (N=18), EPOCH (N=6), CHOP/ICE (N=20) or other treatments provided with curative intent. Twenty two patients were consolidated with high dose therapy and either autologous (N=18), or allogeneic (N=4) SCT. Fifty nine percent were PET negative at interim restaging (32/54), 7.4% were positive (4/54), 22 % were not available (12/54), and 11% had equivocal scans (6/54). Median follow up was 17 months. Median PFS for the entire group was 15 months. Median OS for the entire group was 40 months. The median OS of patients with negative int FDG-PET has not been reached, compared to the OS of patients with positive int FDG-PET of 10.2 months (p<.001). Patients with equivocal int FDG-PET had a median OS of 62 months, which was statistically superior to patients with positive int FDG-PET (p=.02). There was no significant difference in median OS in patients with negative versus equivocal int FDG-PET. Similar to what was observed in OS, the median PFS of patients with negative int FDG-PET has not yet been reached, compared to the PFS of patients with a positive int FDG-PET of 4.8 months (p=<.001). Patients with equivocal int FDG-PET had a statistically improved PFS of 16 months when compared to those with a positive int FDG-PET (p<.01). Patients with equivocal int FDG-PET had similar outcomes to patients with a negative int FDG-PET, and superior to those with a positive int FDG-PET, whose results were very poor. Conclusions:In this dataset, interim PET scans are strongly predictive of outcome. Patients with negative int FDG-PET enjoyed significantly longer remissions and better overall survival. Patients with negative int FDG-PET were more likely to receive consolidative therapy, which may contribute to their superior outcomes. This may be a potentially confounding factor. Nonetheless, achievement of a negative int FDG-PET appears to be a reliable predictor of outcome in patients with T-cell lymphomas and may have similar prognostic importance in these patients as they do in diffuse large B-cell lymphoma and Hodgkin lymphoma. It is reasonable to consider int FDG-PET in the restaging of patients with T-cell lymphomas. Disclosures:Zelenetz:Millenium Advisory board: Membership on an entity's Board of Directors or advisory committees. Horwitz:Allos Therapeutics, Inc: Consultancy, Research Funding.

The role of FDG-PET imaging and involved field radiotherapy in relapsed or refractory diffuse large B-cell lymphoma

We examined the role of fluorodeoxyglucose-positron emission tomography (FDG-PET) and the addition of involved field radiotherapy (IFRT) as potential modifiers of salvage therapy. From January 2000 to June 2007, 83 patients with chemosensitive relapsed or primary refractory diffuse large B-cell lymphoma (DLBCL) underwent FDG-PET scans following second-line chemotherapy before high-dose therapy with autologous stem cell rescue (HDT/ASCR). We evaluated the prognostic value of having a negative FDG-PET scan before HDT/ASCR and whether IFRT improved the outcomes. Median follow-up was 45 months, and the 3-year PFS, disease-specific survival (DSS) and OS were 72, 80 and 78%, respectively. Multivariate analysis revealed that a positive FDG-PET scan had worse PFS (hazard ratio=(HR) 3.4; P=0.014), DSS (HR=7.7; P=0.001) and OS (HR=5.4; P=0.001), and that patients not receiving IFRT had worse PFS (HR=2.7; P=0.03) and DSS (HR=2.8, P=0.059). Patients who received IFRT had better local control with fewer relapses within prior involved sites compared with those that did not receive IFRT (P=0.006). These outcomes confirm the important prognostic value of FDG-PET scans before undergoing HDT/ASCR. It also suggests that the role of IFRT should be evaluated further.

Is F 18 Fluorodeoxyglucose Positron Emission Tomography Too Sensitive for the Diagnosis of Vascular Endograft Infection?

We report a case of a false positive fluorodeoxyglucose positron emission tomography (FDG-PET) scan in a patient who presented with abdominal pain, and gastrointestinal bleeding accompanied by elevation of inflammatory markers, seven weeks after a proximal type I endoleak repair with a cuff extension. Aortoenteric fistula and endograft infection was ruled out by laparotomy. FDG-PET image may have a role in diagnosis of infection, but false positive results are possible and caution is necessary if other data are non-confirmatory.

Clinical Significance of Postradiotherapy [ 18F]-Fluorodeoxyglucose Positron Emission Tomography Imaging in Management of Head-and-Neck Cancer—A Long-Term Outcome Report

To determine the accuracy and prognostic significance of post-treatment [(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET) in head-and-neck squamous cell carcinoma after radiotherapy (RT). This was a retrospective study of 188 patients with head-and-neck squamous cell carcinoma who had undergone FDG-PET within 12 months after completing RT. All living patients had >/=1 year of follow-up after FDG-PET. All patients had undergone intensity-modulated RT, 128 with definitive and 60 with postoperative intensity-modulated RT. For all patients, the median follow-up after RT completion was 32.6 months and after FDG-PET was 29.2 months. For the neck, 171 patients had negative FDG-PET findings. Of these results, two were falsely negative. Seventeen patients had positive FDG-PET findings, of which 12 were true-positive findings. The sensitivity, specificity, positive predictive value, and negative predictive value for FDG-PET in the assessment of the treatment response in the neck was 86%, 97%, 71%, and 99%, respectively. For the primary site, 151 patients had negative FDG-PET findings, of which two were falsely negative. Thirty-seven patients had positive FDG-PET findings, of which 12 were true-positive findings. The sensitivity, specificity, positive predictive value, and negative predictive value for FDG-PET in the assessment of the treatment response in the primary site was 86%, 86%, 32.4%, and 98.7%, respectively. Patients with positive post-RT PET findings had significantly worse 3-year overall survival and disease-free survival. The results of our study have shown that the findings of post-RT FDG-PET have a high negative predictive value and are a significant prognostic factor. It can provide guidance for the management of head-and-neck cancer after definitive treatment.

Assessment of disease activity in alveolar echinococcosis: a comparison of contrast-enhanced ultrasound, three-phase helical CT and [18F]fluorodeoxyglucose positron-emission tomography

Objective of the present study was to assess activity or vascularization of focal liver lesions in alveolar echinococcosis (AE) using [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) in comparison with contrast enhanced ultrasound (CEUS) and three-phase helical computed tomography (CT). In this prospective study, 17 patients with confirmed AE of the liver were included (6 males, 11 females; average age: 59 +/- 16 years; average duration of disease: 10.5 years) and were then examined using FDG-PET, precontrast ultrasound (US), CEUS, and three-phase helical CT. We assessed metabolic activity (FDG-PET) and vascularization (CEUS and CT) of Echinococcus multilocularis specific hepatic lesions. FDG-PET identified increased metabolic activity in the corresponding lesions in seven patients (41.2%). A vascularization pattern of echinococcal lesions was visualized in 9 patients (52.9%) by CEUS and in 4 patients (23.5%) by CT. All positive FDG-PET findings were also positive at CEUS. There was association between findings of metabolic activity in AE at FDG-PET and vascularized lesions of the liver returned by CEUS. This suggests that CEUS may represent a cost-effective tool in the decision making to perform FDG-PET examination.

Powerful Prognostic Stratification By [18F]Fluorodeoxyglucose Positron Emission Tomography in Patients With Metastatic Breast Cancer Treated With High-Dose Chemotherapy

This study examines the use of [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) for the evaluation of the therapeutic response for patients treated with high-dose chemotherapy (HDC) with autologous stem cell transplantation for metastatic breast cancer (MBC) focusing on prognostic stratification. Forty-seven patients with MBC were treated with a maximum of three cycles of HDC. Therapeutic response was assessed with conventional imaging (CImg; including a computed tomography in all cases and ultrasound, mammography, and bone scanning as clinically indicated) and by FDG-PET study performed after the last cycle of HDC. Parameters analyzed for predicting survival were FDG-PET and CImg results, pattern of disease, prior treatment, and HDC regimen. Complete responses were observed in 16 patients (37%) with CImg and 34 patients (72%) with FDG-PET. The FDG-PET result was the most powerful and independent predictor of survival; patients with a negative post-treatment FDG-PET had a longer median survival than patients with a positive FDG-PET (24 months v 10 months; P < .001). By multivariate analysis the relative risk (RR) of death was higher in patients with FDG-PET-positive disease (RR, 5.3), prior anthracycline treatment (RR, 3.3), or with visceral metastasis (RR, 2.4). A single FDG-PET study performed after completion of HDC for MBC can powerfully stratify for survival. This may have implications for how we should assess outcome after conventional-dose therapy for MBC and warrants additional study.