A region-level contrastive learning-based deep model for glomerular ultrastructure segmentation on electron microscope images / 南方医科大学学报

OBJECTIVE@#We propose a novel region- level self-supervised contrastive learning method USRegCon (ultrastructural region contrast) based on the semantic similarity of ultrastructures to improve the performance of the model for glomerular ultrastructure segmentation on electron microscope images.@*METHODS@#USRegCon used a large amount of unlabeled data for pre- training of the model in 3 steps: (1) The model encoded and decoded the ultrastructural information in the image and adaptively divided the image into multiple regions based on the semantic similarity of the ultrastructures; (2) Based on the divided regions, the first-order grayscale region representations and deep semantic region representations of each region were extracted by region pooling operation; (3) For the first-order grayscale region representations, a grayscale loss function was proposed to minimize the grayscale difference within regions and maximize the difference between regions. For deep semantic region representations, a semantic loss function was introduced to maximize the similarity of positive region pairs and the difference of negative region pairs in the representation space. These two loss functions were jointly used for pre-training of the model.@*RESULTS@#In the segmentation task for 3 ultrastructures of the glomerular filtration barrier based on the private dataset GlomEM, USRegCon achieved promising segmentation results for basement membrane, endothelial cells, and podocytes, with Dice coefficients of (85.69 ± 0.13)%, (74.59 ± 0.13)%, and (78.57 ± 0.16)%, respectively, demonstrating a good performance of the model superior to many existing image-level, pixel-level, and region-level self-supervised contrastive learning methods and close to the fully- supervised pre-training method based on the large- scale labeled dataset ImageNet.@*CONCLUSION@#USRegCon facilitates the model to learn beneficial region representations from large amounts of unlabeled data to overcome the scarcity of labeled data and improves the deep model performance for glomerular ultrastructure recognition and boundary segmentation.

Multimodal assessment in polymicrobial infective endocarditis with silent spondylodiscitis and cerebral embolism / Evaluación multimodal en endocarditis infecciosa polimicrobiana con espondilodiscitis silenciosa y embolia cerebral

Abstract Infective endocarditis (IE) is a rare but severe disease, due to an infection of the endocardial surface of the heart. The annual incidence ranging from 3 to 7 per 100 000 person-years, with an overall mortality rates of 25%. Staphylococci and Streptococci accounted for approximately 80% of IE cases. Enterococci are the third leading cause accounted for approximately 5-18% of all cases and are increasingly linked to health-care contact. The increasing number of cardiovascular electronic devices, prosthetic valves implants along with frequent invasive diagnostic or therapeutic procedures performed in elderly, may also contribute to the rise of IE in this population. Blood cultures and echocardiographic findings are the cornerstone of the IE diagnosis, confirmed or rejected according to modified Duke criteria. Other imaging modalities as Cardiac Computed Tomography, Cardiac Magnetic Resonance Imaging and 18Ffluorodeoxyglucose Positron Emission Tomography - Computed Tomography (18FDG-PET/CT) can determine a more correct diagnosis and identify many of the endocarditis-related complications. Here, we describe a patient with aortic prosthetic valve and Enterococcus faecalis (EF) IE. Cerebral and spinal MRI and 18FDG-PET/CT, performed during the hospitalization, showed multi-organ silent periferic embolization. Furthermore, the cultural examination of the valvular surgical specimen revealed a methicillin-sensitive Staphylococcus aureus suggestive for polymicrobial endocarditis. Some Authors demonstrated a possible false-positive valve culture due to a postoperative contamination. Since contaminated cultures usually yield microorganisms compatible with endocarditis, such as coagulase-negative Staphylococci, viridans group Streptococcus species, may be difficult for the physician not to treat the patient. This case represents need for high level of suspicion to diagnose IE. Multimodality assessment improves the diagnosis and allows the detection of the complications. Moreover, a multidisciplinary team and specialized centers determine a better patient’s outcome.

Resumen La endocarditis infecciosa (EI) es una enfermedad poco frecuente pero severa, dada por una infección del endocardio. La incidencia anual oscila entre 3 y 7 por cada 100 000 personas-año, con una tasa de mortalidad general del 25%. Los estafilococos y los estreptococos representaron aproximadamente un 80% de los casos de EI. Los enterococos son la tercera causa, aportando aproximadamente 5% a 18% de todos los casos, y se vinculan cada vez más al contacto con la atención médica. El número creciente de dispositivos electrónicos cardiovasculares e implantes de válvulas protésicas, junto con los frecuentes procedimientos invasivos diagnósticos o terapéuticos en las personas ancianas, también podrían contribuir al incremento de EI en esta población. Los hemocultivos y los hallazgos ecocardiográficos son la piedra angular del diagnóstico de EI, confirmado o rechazado de acuerdo con los criterios modificados de Duke. Otras modalidades de imagenología tales como la Tomografía Computarizada Cardíaca (TCC), la Resonancia Magnética Cardíaca (RMC) y la Tomografía por Emisión de Positrones - Tomografía Computarizada con 18F-fluorodeoxiglucosa (18F-FDG PET/TC) pueden determinar un diagnóstico más preciso e identificar muchas de las complicaciones asociadas a la endocarditis. Aquí describimos un paciente con una válvula aórtica protésica y EI por EF. Una RM del cerebro y la columna vertebral y una 18F-FDG PET/TC practicadas durante la hospitalización evidenciaron embolia periférica multiorgánica silenciosa. Además, el examen por cultivo de la muestra quirúrgica valvular reveló Staphylococcus aureus sensible a la meticilina (SASM), sugestivo de endocarditis polimicrobiana. Algunos autores demostraron un posible falso positivo del cultivo valvular dado por contaminación postoperatoria. Ya que los cultivos contaminados generalmente producen microorganismos compatibles con la endocarditis, tales como estafilococos coagulasa negativos y estreptococos del grupo viridans, le puede resultar difícil al médico no tratar al paciente. Este caso representa la necesidad de tener un alto nivel de sospecha para diagnosticar la EI. La valoración multimodal mejora el diagnóstico y permite detectar complicaciones. Además, un equipo multidisciplinario y los centros especializados determinan un mejor desenlace para el paciente.

Design and Test of Automatic Dispensing and Injecting System for Positron Radiopharmaceuticals / 中国医学科学院学报

Objective To design a novel automatic dispensing and injecting system of positron radiopharmaceuticals,for precise dose dispensing,simplified operation,and reduction of occupational radiation exposure. Methods The automatic dispensing and injecting system was fabricated with tungsten alloy as the shielding material.The performance and radiation protection of the device were assessed. Results The total time of injection using the automatic dispensing and injecting system was about 60 s.The ratio of successful injection in stability test was 100%.The deviation of the dispensing dose with the system was ≤3%.With the tungsten alloy shield(40 mmPb of the cabinet,60 mmPb of the countertop,15 mmPb of the protective shield,and 50 mmPb of the inbuilt jar for radiopharmaceuticals),the average dose rate at 30 cm from the device was 1.44 μSv/h,and the radiation dose at the operator's extremity was reduced by 99%. Conclusions This automatic dispensing and injecting system of positron radiopharmaceuticals is easy to operate with precise dispensing dose.It is safe and meets the requirements of radiation protection.

Progress in enhancing electron transfer rate between exoelectrogenic microorganisms and electrode interface / 生物工程学报

Exoelectrogenic microorganisms are the research basis of microbial electrochemical technologies such as microbial fuel cells, electrolytic cells and electrosynthesis. However, their applications are restricted in organic degradation, power generation, seawater desalination, bioremediation, and biosensors due to the weak ability of biofilm formation and the low extracellular electron transfer (EET) efficiency between exoelectrogenic microorganisms and electrode. Therefore, engineering optimization of interaction between exoelectrogenic microorganisms and electrode interface recently has been the research focus. In this article, we review the updated progress in strategies for enhancing microbe-electrode interactions based on microbial engineering modifications, with a focus on the applicability and limitations of these strategies. In addition, we also address research prospects of enhancing the interaction between electroactive cells and electrodes.

Potential of electron transfer and its application in dictating routes of biochemical processes associated with metabolic reprogramming / 医学前沿

Metabolic reprogramming, such as abnormal utilization of glucose, addiction to glutamine, and increased de-novo lipid synthesis, extensively occurs in proliferating cancer cells, but the underneath rationale has remained to be elucidated. Based on the concept of the degree of reduction of a compound, we have recently proposed a calculation termed as potential of electron transfer (PET), which is used to characterize the degree of electron redistribution coupled with metabolic transformations. When this calculation is combined with the assumed model of electron balance in a cellular context, the enforced selective reprogramming could be predicted by examining the net changes of the PET values associated with the biochemical pathways in anaerobic metabolism. Some interesting properties of PET in cancer cells were also discussed, and the model was extended to uncover the chemical nature underlying aerobic glycolysis that essentially results from energy requirement and electron balance. Enabling electron transfer could drive metabolic reprogramming in cancer metabolism. Therefore, the concept and model established on electron transfer could guide the treatment strategies of tumors and future studies on cellular metabolism.

Application of Virtual Monochromatic Images Reconstructed by Dual-energy Computed Tomography in Radiotherapy Treatment Planning System / 中国医疗器械杂志

Virtual monochromatic images (VMI) that reconstructed on dual-energy computed tomography (DECT) have further application prospects in radiotherapy, and there is still a lack of clinical dose verification. In this study, GE Revolution CT scanner was used to perform conventional imaging and gemstone spectral imaging on the simulated head and body phantom. The CT images were imported to radiotherapy treatment planning system (TPS), and the same treatment plans were transplanted to compare the CT value and the dose distribution. The results show that the VMI can be imported into TPS for CT value-relative electron density conversion and dose calculation. Compared to conventional images, the VMI varies from 70 to 140 keV, has little difference in dose distribution of 6 MV photon treatment plan.

Two-Dimensional Electron Beam Radiotherapy Planning System with Modeling Function / 中国医疗器械杂志

In order to adapt to different target shapes and protect the surrounding normal tissues, the design of two-dimensional electron beam radiotherapy planning requires additional lead blocks. But the Pinnacle treatment planning system can not directly shape the lead block conformity to the size of the beam field given by the doctor. Every time, physicists need to manually drag the lead block to form the required beam field. When meeting a two-dimensional electron beam treatment planning with the same field parameters as before, physicists need to rearrange the field for dose calculation, which greatly reduces the design efficiency of the two-dimensional electron beam treatment planning. In this study, we independently developed a two-dimensional electron beam radiotherapy planning system based on Qt Creator. The system can quickly design a two-dimensional electron beam radiotherapy plan, which reduces the repeated work of physicists.

Common Troubles of Vacuum Components in Elekta Linear Accelerator and Fast Solutions / 中国医疗器械杂志

The transportation of electron is inseparable from vacuum environment. The maintenance of the vacuum system of Elekta linear accelerator depends on two sputtering ionic pumps at the gun end and the target end. The traveling wave acceleration were used in Elekta linear accelerators. And the design of the electron gun filament is detachable. Because of these two reasons, the vacuum stability is relatively weak. Only two vacuum values are used to reflect the operation state of the whole vacuum system, which causes a few failures but will not trigger a the machine interlock. Considering the complexity of whole vacuum system, the problem of vacuum caused by the failure of various components in vacuum system is analyzed in this paper. It is hoped that some useful repairing experience and suggestions for the maintenance engineers of linear accelerator to solve the vacuum fault and rebuild the vacuum can be provided quickly.

Application of Statistical Process Control in Evaluation of Performance for Beam-matched Medical Electron Linacs / 中国医疗器械杂志

Clinically, beam matching can greatly improve the flexibility and efficiency of treating patients between different medical electron linacs. However, in addition to the regular quality assurance (QA) test of the machine performance of linacs, there is still a lack of comprehensive evaluation of the clinical radiotherapy performance of beam-matched linacs. In this paper, the performance of volumetric modulated arc therapy (VMAT) between three closely matched linacs was evaluated by statistical process control (SPC) technology. It was found that the average and median γ passing rates of the VMAT QA processes of the three linacs had little difference, but the process capability levels were at three different levels. The results show that SPC technology can effectively evaluate the performance of beam matching for medical electron linacs, improve the patient-specific VMAT QA processes, and guide clinical decision-making.

Recent progress of positron radionuclide labeled small molecule inhibitors of prostate specific membrane antigen for PET/CT imaging of prostate cancer / 生物医学工程学杂志

Prostate cancer is the most common tumor of the urinary system, and its mortality rate is second only to lung cancer. With the specific and high expression on the surface of prostate cancer cells, prostate-specific membrane antigen (PSMA) has been an ideal theranostic target of prostate cancer with great clinical significance and research value. Positron emission tomography/computed tomography (PET/CT), a new modality of molecular imaging combining functional metabolic information and anatomical structure, provides high diagnostic performance for cancer detection. This paper mainly reviewed recent progress of PSMA inhibitors labeled by positron-emitting radionuclides for early diagnosis, preoperative staging, response assessment, restaging and metastasis detection of prostate cancer.

Performance of F-18 Fluorocholine PET/CT for Detection of Hyperfunctioning Parathyroid Tissue in Patients with Elevated Parathyroid Hormone Levels and Negative or Discrepant Results in conventional Imaging

Comportamiento dosimétrico de un sistema de planificación mediante curvas de calibración de densidades electrónicas relativas / Dosimetric behaviour of a planning system through calibration curves of relative electron density

En esta investigación se planteó como objetivo la verificación del comportamiento dosimétrico del Sistema de Planificación de Tratamiento (TPS) de Radioterapia mediante las curvas de calibración de Densidades Electrónicas Relativas (DER). Este estudio se realizó en el Hospital de la Sociedad de Lucha Contra el Cáncer (SOLCA) Núcleo Loja, usando un fantoma antropomorfo CIRS 062M y un tomógrafo Toshiba Activion 16. Para determinar la nueva curva de calibración DER se tomaron los valores de densidades electrónicas especificadas en el manual del fantoma y las Unidades Hounsfield de la imagen tomográfica. Se realizó controles de calidad dosimétricos y verificación dosimétrica en tres casos clínicos: tórax, pelvis y cráneo; para realizar las pruebas dosimétricas se utilizó un acelerador CLINAC CX, cámara de ionización PTW tipo Farmer con volumen sensible de 0,6 cm3 y un electrómetro PTW UNIDOS E. Los resultados mostraron que las medidas para cada inserto del fantoma en ningún caso excedieron los límites establecidos de ± 20 UH, para el tomógrafo y el TPS; las pruebas de control de calidad no superaron el límite máximo de desviaciones en el cálculo de dosis absorbida por el TPS y la obtenida por medición de ± 4 % establecida por la IAEA y las verificaciones dosimétricas en tórax, pelvis y cráneo, determinaron que las desviaciones en el cálculo de la dosis absorbida por el TPS y la obtenida por medición no superaban la tolerancia del ± 5 % establecida por la ICRU.

In this research, the aim was to verify the dosimetric behavior of the Radiotherapy Treatment Planning System (TPS) using the Relative Electron Density (DER) calibration curves. This study was carried out at the SOLCA (Society of Fight Against Cancer) hospital in Loja, using an CIRS model 062M anthropomorphic phantom and a Toshiba Activion 16 tomograph. To determine the new DER calibration curve, the values of the electron densities specified in the manual of the phantom and the Hounsfield Units of the tomographic image were taken. Dosimetric quality controls were made in the location of three clinical cases: thorax pelvis and skull; used a CLINAC CX accelerator was used to perform the dosimetric tests, PTW ionization chamber type Farmer with sensitive volume of 0.6 cm3 and a PTW UNIDOS E electrometer. The results showed that the measurements for each insert of the phantom in no case exceeded the established limits of ± 20 UH, for the tomograph and the TPS; the quality control tests did not exceed the maximum limit of deviations in the calculation of dose absorbed by the TPS and the one obtained by measurement of ± 4% established by the IAEA and the clinical planning in the thorax, pelvis and skull, determine that the deviations in the calculation of the dose absorbed by the TPS and that obtained by measurement, they do not exceed the tolerance of ± 5% established by the ICR.

Metastasis of Rhabdomyosarcoma to the Male Breast: a Case Report with Magnetic Resonance Imaging Findings

Metastasis of rhabdomysarcoma to the breast is a very rare manifestation in adult males. Herein, we report a case of metastasis from embryonal rhabdomyosarcoma in the left hypothenar muscle that presented as a breast mass in a 38-year-old man, who four months later expired because of multiple bone metastases related to pancytopenia. We describe the various imaging findings, including mammograms, ultrasonography, computerized tomography (CT), positron emission tomography-computed tomography (PET-CT), and magnetic resonance imaging (MRI) of this rare disease. The various imaging findings of this lesion could be helpful for future diagnosis of male breast lesions.

Quantitative Feasibility Evaluation of ¹¹C-Methionine Positron Emission Tomography Images in Gamma Knife Radiosurgery : Phantom-Based Study and Clinical Application

OBJECTIVE: The functional information of ¹¹C-methionine positron emission tomography (MET-PET) images can be applied for Gamma knife radiosurgery (GKR) and its image quality may affect defining the tumor. This study conducted the phantom-based evaluation for geometric accuracy and functional characteristic of diagnostic MET-PET image co-registered with stereotactic image in Leksell GammaPlan® (LGP) and also investigated clinical application of these images in metastatic brain tumors.METHODS: Two types of cylindrical acrylic phantoms fabricated in-house were used for this study : the phantom with an array-shaped axial rod insert and the phantom with different sized tube indicators. The phantoms were mounted on the stereotactic frame and scanned using computed tomography (CT), magnetic resonance imaging (MRI), and PET system. Three-dimensional coordinate values on co-registered MET-PET images were compared with those on stereotactic CT image in LGP. MET uptake values of different sized indicators inside phantom were evaluated. We also evaluated the CT and MRI co-registered stereotactic MET-PET images with MR-enhancing volume and PET-metabolic tumor volume (MTV) in 14 metastatic brain tumors.RESULTS: Imaging distortion of MET-PET was maintained stable at less than approximately 3% on mean value. There was no statistical difference in the geometric accuracy according to co-registered reference stereotactic images. In functional characteristic study for MET-PET image, the indicator on the lateral side of the phantom exhibited higher uptake than that on the medial side. This effect decreased as the size of the object increased. In 14 metastatic tumors, the median matching percentage between MR-enhancing volume and PET-MTV was 36.8% on PET/MR fusion images and 39.9% on PET/CT fusion images.CONCLUSION: The geometric accuracy of the diagnostic MET-PET co-registered with stereotactic MR in LGP is acceptable on phantom-based study. However, the MET-PET images could the limitations in providing exact stereotactic information in clinical study.

The importance of 18F-fluorodeoxyglucose positron emission tomography and carbohydrate antigen 19-9 in patients with periampullary tumors

No abstract available.

Langerhans Cell Sarcoma of the Scalp with Concomitant Multiple Cervical Lymph Node and Adjacent Soft Tissue Involvement: A Case Report / 대한피부과학회지

Currently, the World Health Organization classifies Langerhans cell tumors into Langerhans cell histiocytosis and Langerhans cell sarcoma (LCS). LCS is a neoplastic proliferation of Langerhans cells showing malignant cytological features and aggressive clinical behavior with grave prognosis. Only a few cases have been reported in the available literature; therefore, to date, no definitive treatment has been established. A 64-year-old woman presented with a 1-year history of an asymptomatic, slow-growing erythematous nodule measuring 0.7 cm on her scalp. The patient also reported a 3-month history of a painful swelling on the right side of her neck. Histopathological examination of a scalp biopsy specimen revealed sheets of atypical cells with hyperchromatic nucleoli and clear cytoplasm. Immunohistochemical studies revealed malignant cells positive for CD1a, CD31, CD68, and S-100 expression. Additionally, positron emission tomography–computed tomography and fine-needle aspiration revealed LCS of the cervical lymph nodes and surrounding soft tissue. We recommended surgical excision and adjunctive chemotherapy; however, the patient refused treatment and died of the disease 28 months later.

Management of Arrhythmias Associated with Cardiac Sarcoidosis

Sarcoidosis is a multisystem granulomatous disorder of unknown etiology. The annual incidence of systemic sarcoidosis is estimated at 10–20 per 100,000 individuals. Owing to the recent advances in imaging modalities, cardiac sarcoidosis (CS) is diagnosed more frequently. The triad of CS includes conduction abnormality, ventricular tachycardia, and heart failure. Atrial and ventricular arrhythmias are caused by either inflammation or scar formation. Inflammation should be treated with immunosuppression and antiarrhythmic agents and scar formation should be treated with antiarrhythmics and/or ablation, in addition to implantable cardioverter defibrillator (ICD) implantation, if necessary. Ablation can provide a good outcome, but it might require bipolar ablation if the critical portion is located mid-myocardium. Late recurrence might be caused by reactivation of sarcoidosis, which would need to be evaluated by positron emission tomography-computed tomography imaging. Risk of sudden cardiac death (SCD) in patients with advanced atrioventricular block is not low, and ICD implantation could be considered instead of a pacemaker. For risk stratification for SCD, late gadolinium enhancement by cardiac magnetic resonance imaging or program stimulation is often used.

Quantitative Feasibility Evaluation of ¹¹C-Methionine Positron Emission Tomography Images in Gamma Knife Radiosurgery : Phantom-Based Study and Clinical Application

OBJECTIVE: The functional information of ¹¹C-methionine positron emission tomography (MET-PET) images can be applied for Gamma knife radiosurgery (GKR) and its image quality may affect defining the tumor. This study conducted the phantom-based evaluation for geometric accuracy and functional characteristic of diagnostic MET-PET image co-registered with stereotactic image in Leksell GammaPlan® (LGP) and also investigated clinical application of these images in metastatic brain tumors. METHODS: Two types of cylindrical acrylic phantoms fabricated in-house were used for this study : the phantom with an array-shaped axial rod insert and the phantom with different sized tube indicators. The phantoms were mounted on the stereotactic frame and scanned using computed tomography (CT), magnetic resonance imaging (MRI), and PET system. Three-dimensional coordinate values on co-registered MET-PET images were compared with those on stereotactic CT image in LGP. MET uptake values of different sized indicators inside phantom were evaluated. We also evaluated the CT and MRI co-registered stereotactic MET-PET images with MR-enhancing volume and PET-metabolic tumor volume (MTV) in 14 metastatic brain tumors. RESULTS: Imaging distortion of MET-PET was maintained stable at less than approximately 3% on mean value. There was no statistical difference in the geometric accuracy according to co-registered reference stereotactic images. In functional characteristic study for MET-PET image, the indicator on the lateral side of the phantom exhibited higher uptake than that on the medial side. This effect decreased as the size of the object increased. In 14 metastatic tumors, the median matching percentage between MR-enhancing volume and PET-MTV was 36.8% on PET/MR fusion images and 39.9% on PET/CT fusion images. CONCLUSION: The geometric accuracy of the diagnostic MET-PET co-registered with stereotactic MR in LGP is acceptable on phantom-based study. However, the MET-PET images could the limitations in providing exact stereotactic information in clinical study.

Methionyl-tRNA Synthetase is a Useful Diagnostic Marker for Lymph Node Metastasis in Non-Small Cell Lung Cancer

PURPOSE: Identification of lymph node (LN) metastasis in non-small cell lung cancer (NSCLC) is critical for disease staging and selection of therapeutic modalities. Sometimes it is not possible to obtain LN core tissue by endobronchial ultrasound-guided transbronchial needle aspirate (EBUS-TBNA), resulting in low diagnostic yield. MATERIALS AND METHODS: In this study, 138 specimens were collected from 108 patients who underwent EBUS-TBNA under the suspicion of LN metastasis of NSCLC. Diagnostic yields of anti-CD45 and anti-methionyl-tRNA synthetase (MRS), immunofluorescent (IF) staining on cytology specimens were compared with those of conventional cytology and positron emission tomography-computed tomography (PET-CT). RESULTS: MRS was strongly expressed in NSCLC cells metastasized to LNs, but weakly expressed in cells at the periphery of the LN germinal center. The majority of cells were CD20 positive, although a few cells were either CD3 or CD14 positive, indicating that CD45 staining is required for discrimination of non-malignant LN constituent cells from NSCLC cells. When the diagnostic efficacy of MRS/CD45 IF staining was evaluated using 138 LN cellular aspirates from 108 patients through EBUS-TBNA, the sensitivity was 76.7% and specificity was 90.8%, whereas those of conventional cytology test were 71.8% and 100.0%, respectively. Combining the results of conventional cytology testing and those of PET-CT showed a sensitivity and specificity of 71.6% and 100%, and the addition of MRS/CD45 dual IF data to this combination increased sensitivity and specificity to 85.1% and 97.8%, respectively. CONCLUSION: MRS/CD45 dual IF staining showed good diagnostic performance and may be a good tool complementing conventional cytology test for determining LN metastasis of NSCLC.

Preoperative Risk Factors for Pathologic N2 Metastasis in Positron Emission Tomography-Computed Tomography–Diagnosed N0–1 Non-Small Cell Lung Cancer / 대한흉부외과학회지

BACKGROUND: Accurate mediastinal lymph node staging is vital for the optimal therapy and prognostication of patients with lung cancer. This study aimed to determine the preoperative risk factors for pN2 disease, as well as its incidence and long-term outcomes, in patients with clinical N0–1 non-small cell lung cancer. METHODS: We retrospectively analyzed patients who were treated surgically for primary non-small cell lung cancer from November 2005 to December 2014. Patients staged as clinical N0–1 via chest computed tomography (CT) and positron emission tomography (PET)-CT were divided into two groups (pN0–1 and pN2) and compared. RESULTS: In a univariate analysis, the significant preoperative risk factors for pN2 included a large tumor size (p=0.083), high maximum standard uptake value on PET (p<0.001), and central location of the tumor (p<0.001). In a multivariate analysis, central location of the tumor (p<0.001) remained a significant preoperative risk factor for pN2 status. The 5-year overall survival rates were 75% and 22.9% in the pN0–1 and pN2 groups, respectively, and 50% and 78.2% in the patients with centrally located and peripherally located tumors, respectively. In a Cox proportional hazard model, central location of the tumor increased the risk of death by 3.4-fold (p<0.001). CONCLUSION: More invasive procedures should be considered when pre-operative risk factors are identified in order to improve the efficacy of diagnostic and therapeutic plans and, consequently, the patient’s prognosis.