The term extranodal disease refers to lymphomatous infiltration of anatomic sites other than the lymph nodes. Almost any organ can be affected by lymphoma, with the most common extranodal sites of involvement being the stomach, spleen, Waldeyer ring, central nervous system, lung, bone, and skin. The prevalence of extranodal involvement in non-Hodgkin lymphoma and Hodgkin disease has increased in the past decade. The imaging characteristics of extranodal involvement can be subtle or absent at conventional computed tomography (CT). Imaging of tumor metabolism with 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) has facilitated the identification of affected extranodal sites, even when CT has demonstrated no lesions. More recently, hybrid PET/CT has become the standard imaging modality for initial staging, follow-up, and treatment response assessment in patients with lymphoma and has proved superior to CT in these settings. Certain PET/CT patterns are suggestive of extranodal disease and can help differentiate tumor from normal physiologic FDG activity, particularly in the mucosal tissues, bone marrow, and organs of the gastrointestinal tract. Familiarity with the different extranodal manifestations in various locations is critical for correct image interpretation. In addition, a knowledge of the differences in FDG avidity among the histologic subtypes of lymphoma, appropriate timing of scanning after therapeutic interventions, and use of techniques to prevent brown fat uptake are essential for providing the oncologist with accurate information.

SummaryAim: To investigate the prevalence of smoking in the general population and in specific population sub-groups in Northern Greece. Methods: A cross-sectional study was conducted during the period 1999-2001 on a 5% sample (23,840) of those people aged between 21 to 80 out of a total general population of 653,249. 21,854/23,840 general population subjects were interviewed. In addition, we interviewed 9,276 high school students, 1,072 medical students, 597 medical doctors within the National Health System, 825 teachers, and 624 subjects who regularly exercised in a privately-owned gym. A specially modified ICRF study group questionnaire was used. Results: 34.4% of the general population sample were current smokers (47.8% of males and 21.6% of females). Smoking prevalence rates in the population sub-groups were: 29.6% of high school students; 40.7% of medical students; 44.9% of medical doctors; 46.4% of teachers; and 36.9% of the gym group. Conclusion: The prevalence of smoking in Northern Greece is high. High school and medical students present with high smoking rates, and the same situation is observed in medical doctors and teachers. An intensification of preventive antismoking measures is required.

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Oncologic 18 F-FDG PET/CT is rapidly gaining acceptance in clinical practice. However, the referring physician's attitude toward the usefulness of this diagnostic modality is unknown. This survey was undertaken to collect information regarding the current perspective of referring physicians on oncologic PET/CT. Methods: We conducted a prospective worldwide, Web-based survey of physicians who manage cancer patients. A total of 963 referring physicians completed a 20-question survey focused on their experience with oncologic 18 F-FDG PET/CT. Attention was directed toward their confidence about indications, their satisfaction with related educational resources, the quality of interaction with interpreting physicians, and practical problems encountered. The respondents included oncologists (38.5%, n 5 371), hematologists (16.4%, n 5 158), radiation oncologists (9.0%, n 5 87), surgeons (30.3%, n 5 292), and other physicians (5.7%, n 5 55). Results: Only 25.2% of respondents considered the oncologic 18 F-FDG PET/ CT indications to be well established and defined. Frequent uncertainty about the need for a PET scan was indicated by 62.3% of the respondents. High cost and overinterpretation of findings were the most commonly reported concerns (47.0% and 40.9%, respectively). The experience and skill level of the interpreting physician was considered very important by 96.8% of the surveyed physicians. Conclusion: Referring physicians expressed considerable uncertainty about the appropriate use of oncologic PET/CT. Additional major concerns are procedure costs and quality of interpretation. The responses suggest a strong need for efforts to educate referring and interpreting physicians about the appropriate use of 18 F-FDG PET/CT in oncology.

Rituximab is a chimeric anti-CD20 monoclonal antibody widely used in the treatment of B-cell non-Hodgkin lymphomas (NHL). Most adverse effects are due to infusion-related reactions, and severe respiratory complications are rare. We retrospectively reviewed clinical data and serial imaging studies of five patients with NHL treated with rituximab-containing chemotherapy who developed new pulmonary abnormalities on routine follow-up FDG-PET/CT imaging. None of the patients had pulmonary lymphoma or other pulmonary disease before therapy and all remained asymptomatic during follow-up. New pulmonary interstitial FDG-uptake was detected on follow-up FDG-PET/CT between 1 and 3 months post-treatment, preceded computed tomography abnormalities in one case, and persisted for several months. FDG uptake was linear, subpleural with maximum Standardized uptake value (SUV) from 2.0 to 5.84. Rituximab-containing chemotherapy for NHL may be associated with asymptomatic late pulmonary toxicity characterised by a distinct FDG uptake pattern. Awareness of this finding is important and should not be confused with lymphoma.

Our analysis revealed an association between sIL-2R levels and spleen 18F-FDG uptake and size, whereas all other serum biomarkers were not significantly associated with each other or with PET 18F-FDG uptake. Our results suggest that splenic inflammation may be related to the systemic inflammatory response in sarcoidosis that may be associated with elevated sIL-2R levels.

Because only pathologic examination can confirm the presence or absence of malignant disease in cancer patients, a certain rate of misinterpretation in any kind of imaging study is inevitable. For the accuracy of interpretation to be improved, determination of the nature, causes, and magnitude of this problem is needed. This study was designed to collect pertinent information from physicians referring patients for oncologic 18F-FDG PET/CT. Methods A total of 662 referring physicians completed an 11-question survey focused on their experience with the interpretation of oncologic 18F-FDG PET/CT studies. The participants were oncologists (36.1%; n = 239), hematologists (14.5%; n = 96), radiation oncologists (7.4%; n = 49), surgeons (33.8%; n = 224), and other physicians (8.2%; n = 54). Questions were aimed at determining the frequency, nature, and causes of scan misinterpretations as well as potential solutions to reduce the frequency of misinterpretations. Results Perceived misinterpretation rates ranged from 5% to 20%, according to most (59.3%) of the participants; 20.8% of respondents reported rates of less than 5%. Overinterpretation rather than underinterpretation was more frequently encountered (68.9% vs. 8.7%, respectively). Limited availability of a patient’s history and limited experience of interpreters were the major contributors to this phenomenon, according to 46.8% and 26.7% of the participants, respectively. The actions most commonly suggested to reduce misinterpretation rates (multiple suggestions were possible) were the institution of multidisciplinary meetings (59.8%), the provision of adequate history when ordering an examination (37.4%), and a discussion with imaging specialists when receiving the results of the examination (38.4%). Conclusion Overinterpretation rather than underinterpretation of oncologic 18F-FDG PET/CT studies prevails in clinical practice, according to referring physicians. Closer collaboration of imaging specialists with referring physicians through more multidisciplinary meetings, improved communication, and targeted training of interpreting physicians are actions suggested to reduce the rates of misinterpretation of oncologic 18F-FDG PET/CT studies.

BackgroundThere are studies showing the utility of the 18-fluorodeoxyglucose positron emission tomography (18FDG PET) scan in the management of patients with thymic epithelial tumors. It seems to be a correlation between the standard uptake value (SUVmax) of thymic epithelial tumors and the histological type and the stage. This study aims to use the ratio of the SUVmax of the lesion to the SUVmax of the adjacent mediastinal tissues in order to guide the choice of the surgical access.MethodsAll patients who presented an anterior mediastinal lesion with a high suspicion of being of thymic origin were included in a prospective database. A ratio inferior to 1 could predict a benign nature and less aggressive behavior, and a minimally invasive approach was performed. A ratio superior to 1 suggested a malignant and aggressive behavior, and a median sternotomy (or a thoracotomy) was performed.ResultsThere were 15 male (mean age 44.6 ± 16.26 years, range 25–73) and 15 female patients (mean age 50.1 ± 16.94 years, range 25–76). When the ratio is inferior to 1, it predicts benign disease in 80% of cases. When it is superior to 1, it predicts in half of cases advanced histological types (high risk thymomas and thymic carcinomas). On the contrary, it can quite accurately predict advanced Masaoka–Koga stages.ConclusionsThe protocol of this study is in accordance with the current literature showing the utility of 18FDG PET scan in the treatment of thymic epithelial tumors. This study goes one step further since the choice of surgical access is based on the SUVmax values. The ratio SUVmax of the lesion/SUVmax of the mediastinal tissues could be a new marker, more pertinent than absolute SUVmax values.