Functional imaging with PET is playing an increasingly important role in the diagnosis and staging of malignant disease, image-guided therapy planning, and treatment monitoring. PET with the labeled glucose analogue fluorine 18 fluorodeoxyglucose (FDG) is a relatively recent addition to the medical technology for imaging of cancer, and FDG PET complements the more conventional anatomic imaging modalities of CT and MRI. CT is complementary in the sense that it provides accurate localization of organs and lesions, while PET maps both normal and abnormal tissue function. When combined, the two modalities can help both identify and localize functional abnormalities. Attempts to align CT and PET data sets with fusion software are generally successful in the brain; other areas of the body is more challenging, owing to the increased number of degrees of freedom between the two data sets. These challenges have recently been addressed by the introduction of the combined PET/CT scanner, a hardware-oriented approach to image fusion. With such a device, accurately registered anatomic and functional images can be acquired for each patient in a single scanning session. Currently, over 800 combined PET/CT scanners are installed in medical institutions worldwide, many of them for the diagnosis and staging of malignant disease and increasingly for monitoring of the response to therapy. This review will describe some of the most recent technologic developments in PET/CT instrumentation and the clinical indications for which combined PET/CT has been shown to be more useful than PET and CT performed separately.LUNG CANCER
Background: Airway mucus hypersecretion plays an important role in the pathogenesis of asthma, and is associated with the induction of MUC5AC expression in airway secretion. The MUC5AC gene is highly polymorphic; however, there are few studies about the association between the polymorphisms of the MUC5AC gene and asthma susceptibility or asthma phenotypes. We have investigated the association of MUC5AC promoter polymorphisms with the risk of asthma and asthma phenotypes. Methods: We determined the genotypes of the MUC5AC promoter (-1274G>A) in 78 asthma patients and in 78 age, sex-matched control individuals in the Korean population. Genomic DNAs from blood were analyzed by PCR and RFLP (restriction fragment length polymorphism) determination. We examined FEV1, total eosinophil count, serum IgE level, PC20 and the presence of atopy (by a skin test) in asthma patients. Results: The mean age of the patients was 47.7 ± 16.1 years and 38.5% were men, and the mean FEV1 was 84.4 ± 22.3% of predicted in the asthma patients. The -1274G>A polymorphism of the MUC5AC promoter in asthma patients was not significantly different as compared with normal individuals (GG 57.7%, AG 34.6% and AA 7.7% in asthma patients vs. GG 56.4%, AG 38.5% and AA 5.1% in control subject, p = 0.752, Cod). Several clinical parameters in asthma patients such as FEV1, total eosinophil count, serum IgE level, PC20 and the presence of atopy, were not associated with the -1274G>A polymorphism of the MUC5AC promoter. Conclusion: The -1274G>A single nucleotide polymorphism (SNP) frequency of the MUC5AC promoter was not associated with asthma in a Korean population. (Tuberc Respir Dis 2007; 63: 235-241)
Background: Abnormal angiogenesis can induce hypoxia within a highly proliferating tumor mass, and these hypoxic conditions can in turn create clinical problems, such as resistance to chemotherapy. However, the mechanism by which hypoxia induces these changes has not yet been determined. Therefore, this study was conducted to determine how hypoxia induces changes in cell viability and extracellular microenvironments in an in vitro culture system using non-small cell lung cancer cells. Methods: The non-small cell lung cancer cell line, A549 was cultured in DMEM or RPMI-1640 media that contained fetal bovine serum. A decrease in the oxygen tension of the media that contained the culture was then induced in a hypoxia microchamber using a CO2-N2 gas mixture. A gas analysis and an MTT assay were then conducted. Results: (1) The decrease in oxygen tension was checked the anaerobic gas mixture for 30 min and then reoxygenation was induced by adding a 5% CO2-room air gas mixture to the chamber. (2) Purging with the anaerobic gas mixture was found to decrease the further oxygen tension of cell culture media. (3) The low oxygen tension resulted in a low pH, lactic acidosis and a decreased glucose concentration in the media. (4) The decrease in glucose concentration that was observed as a result of hypoxia was markedly different when different types of media were evaluated. (5) The decrease in oxygen tension inhibited proliferation of A549 cells. Conclusion: These data suggests that tumor hypoxia is associated with acidosis and hypoglycemia, which have been implicated in the development of resistance to chemotherapy and radiotherapy. (Tuberc Respir Dis 2007; 63: 242-250)
Background: The causes of the pleural effusion are remained unclear in a the substantial number of patients with exudative effusions determined by an examination of the fluid obtained via thoracentesis. Among the various tools for diagnosing exudative pleural effusions, thoracoscopy has a high diagnostic yield for cancer and tuberculosis. Medical thoracoscopy can also be carried out under local anesthesia with mild sedation. The aim of this study was to determine diagnostic accuracy and safety of medical thoracoscopy. Methods: Twenty-five patients with exudative pleural effusions of an unknown cause underwent medical thoracoscopy between October 2005 and September 2006 in Konyang University Hospital. The clinical data such as age, gender, preoperative pulmonary function, amounts of pleural effusion on lateral decubitus radiography were collected. The vital signs were recorded, and arterial blood gas analyses were performed five times during medical thoracoscopy in order to evaluate the cardiopulmonary status and acid-base changes. Results: The mean age of the patients was 56.8 years (range 22-79). The mean depth of the effusion on lateral decubitus radiography (LDR) was 27.49 mm. The medical thoracoscopic pleural biopsy was diagnostic in 24 patients (96.0%), with a diagnosis of tuberculosis pleurisy in 9 patients (36%), malignant effusions in 8 patients (32%), and parapneumonic effusions in 7 patients (28%). Medical thoracoscopy failed to confirm the cause of the pleural effusion in one patient, who was diagnosed with tuberculosis by a pericardial biopsy. There were no significant changes in blood pressure, heart rate, acid-base and no major complications in all cases during medical thoracoscopy (p>0.05). Conclusions: Medical thoracoscopy is a safe method for patients with unknown pleural effusions with a relatively high diagnostic accuracy. (Tuberc Respir Dis 2007; 63: 261-267)
A tuberculous pleural effusion may be a sequel to a primary infection or represent the reactivation of pulmonary tuberculosis. It is believed to result from a rupture of a subpleural caseous focus in the lung into the pleural space. It appears that delayed hypersensitivity plays a large role in the pathogenesis of a tuberculous pleural effusion. We encountered a 52 years old man with pleural effusion that developed several days after a CT guided percutaneous needle biopsy of a solitary pulmonary nodule. He was diagnosed with TB pleurisy. It is believed that his pleural effusion probably developed due to exposure of the parenchymal tuberculous focus into the pleural space during the percutaneous needle biopsy. This case might suggest one of the possible pathogeneses of tuberculous pleural effusion. (Tuberc Respir Dis 2007; 63: 268-272)
70세 남자가 내원 7일전 발생한 우측 흉부 통증, 고열 및 가래를 동반한 기침으로 입원하였다. 백혈구와 CRP(C reactive protein)의 상승, 흉부 방사선 소견상 우하엽에 폐렴을 시사하는 소견이 관찰되어 지역 사회 획득성 폐렴에 준한 경험적 항생제를 투여하였다. 처음 두 번의 연속적인 가래 배양 검사에서 항생제 감수성이 있는 Acinetobacter baumannii균이 동정 되었으며 항생제 치료 후 임상 증상 및 방사선 소견이 점차 호전되었다. Acinetobacter baumannii는 중환자실에서 주로 발생하는 병원 획득성 폐렴의 주요 균으로 알려져 있으며 지역 사회 획득성 폐렴의 흔한 원인균은 아니다. (Tuberc Respir Dis 2007; 63: 273-277)
Invasive aspergillus tracheobronchitis is uncommon manifestation of infection due to Aspergillus species, occurring in severely immunocompromised patients who are generally neutropenic with haematological diseases, AIDS, or after heart and lung transplantation. The pseudomembranous form is the most severe condition and is usually fatal despite treatment with antifungal agents. However, there are a few cases reported with no apparent severe compromise in the host defences. We encountered a pseudomembranous necrotizing bronchial aspergillosis in a 73-year old male patient, who was treated successfully with antifungal agents. (Tuberc Respir Dis 2007; 63: 278-282)
A gastrointestinal metastasis from lung cancer is rare and is quite often found during an autopsy. A 58-year-old man was admitted with left upper back pain and a mass in the left upper lobe on the chest radiograph. The transbronchial lung biopsy revealed an adenocarcinoma of the lung. A gastroduodenoscopy was carried out to evaluate the indigestion and epigastric discomfort. The duodenofibroscopy revealed bulging mucosa on the minor papilla of the duodenum. A metastasis to the duodenum from an adenocarcinoma of the lung was diagnosed by a duodenofibroscopic biopsy of the bulging lesion. We report this rare case of an adenocarcinoma of lung with a metastasis to the duodenum. (Tuberc Respir Dis 2007; 63: 283-288)
Lymphangioleiomyomatosis (LAM) is a rare disease that affects females of reproductive age. It is characterized by the abnormal proliferation of smooth muscle cells in the lung and along the axial lymphatics. We report a case of lymphangioleiomyomatosis presenting as a lung mass. The patient visited the emergency room because of dyspnea upon exertion. The chest X-ray showed a lung mass in the right lower lung field and a pneumothorax in the left lung. Chest computed tomography revealed a 5 x 3 cm sized mass in the right lower lobe and multiple thin-walled small cysts scattered in both lungs. Transbronchial biopsy of the lung mass was performed. The biopsy specimen showed atypical smooth muscle cell proliferation and cystic dilatation of the terminal bronchioles, which confirmed the diagnosis of lymphangioleiomyomatosis. To the best of our knowledge, this is the first case of lymphangioleiomyomatosis presenting as a lung mass. (Tuberc Respir Dis 2007; 63: 289-293)
Pulmonary alveolar proteinosis is a rare disorder that is characterized by the abundant accumulation of surfactant-derived material within the alveolar spaces and distal bronchioles. Although the findings of homogenous ground-glass opacities overlaid by thickened septa, which form a "crazy paving" pattern on high-resolution computed tomography, can assist in making a diagnosis, a lung biopsy is usually required. This disorder has a variable clinical course, from spontaneous resolution to respiratory failure and death. While a whole lung lavage has been the standard treatment since the early 1960s, GM-CSF therapy has been attempted based on the recently suggested pathogenetic mechanism. We report a case of pulmonary alveolar proteinosis that resolved spontaneously after an open lung biopsy. (Tuberc Respir Dis 2007; 63: 294-298)