Research progress of FAPI PET/CT in the diagnosis of malignant liver tumors / 中华肝脏病杂志

Malignant liver tumors have a high incidence and mortality rate. Therefore, it is of great significance to promptly learn about tumor advancement status through relevant examinations for patients' follow-up, diagnosis, and therapy as well as the improvement of the five-year survival rate. The primary lesions and intrahepatic metastases of malignant liver tumors have been better demonstrated in the clinical study with the use of various isotope-labeled fibroblast activating protein inhibitors because of their low uptake in liver tissues and high tumor/background ratio, which provides a new method for early diagnosis, precise staging, and radionuclide therapy. In light of this context, a review of the research progress of fibroblast-activating protein inhibitors for the diagnosis of liver malignant tumors is presented.

Application of PET-LINAC in Biology-guided Radiotherapy / 中国医疗器械杂志

Biology-guided radiotherapy (BgRT) is a novel technique of external beam radiotherapy, combining positron emission tomography-computed tomography (PET-CT) with a linear accelerator (LINAC). The key innovation is to utilize PET signals from tracers in tumor tissues for real-time tracking and guiding beamlets. Compared with a traditional LINAC system, a BgRT system is more complex in hardware design, software algorithm, system integration and clinical workflow. RefleXion Medical has developed the world's first BgRT system. Nevertheless, its actively advertised function, PET-guided radiotherapy, is still in the research and development phase. In this review study, we presented a number of issues related to BgRT, including its technical advantages and potential challenges.

Research hotspots of prostate cancer at the international conferences on urology in 2022 / 浙江大学学报·医学版

The American Urological Association (AUA), European Association of Urology (EUA) and International Urological Society (SIU) annual meetings were held in 2022. Studies on prostate cancer reported in the meetings mainly focus on the advances of diagnostic biomarkers (such as α-2, 3-1inked sialylation of terminal N-glycan on free PSA density, SelectMDx) and imaging techniques [such as multiparametric magnetic resonance imaging, prostate specific membrane antigen(PSMA)-PET/CT], the new method for prostate biopsy, the new treatments of prostate cancer including [177Lu] Ludotadipep and DROP-IN PSMA probe, and the prognosis assessment of prostate cancer (such as AR-V7). This article provides an overview on the research hotspots of three international academic meetings.

Causes of False-Positive Results in 68Ga-Labeled Fibroblast Activation Protein Inhibitor PET/CT Imaging / 中国医学科学院学报

Objective To investigate the causes of false-positive results in the 68Ga-labeled fibroblast activation protein inhibitor (68Ga-FAPI-04) PET/CT imaging. Methods The imaging data of 547 patients undergoing 68Ga-FAPI-04 PET/CT examination in the Department of Nuclear Medicine of the Affiliated Hospital of Southwest Medical University from September 2020 to May 2021 were retrospectively collected.Two experienced nuclear medicine diagnostic physicians analyzed the clinical data,relevant imaging examinations,laboratory examinations,pathological results and follow-up results of the patients with false-positive results. Results The 68Ga-FAPI-04 PET/CT imaging of 547 patients showed false-positive results in 99 (18.1%) patients,including 56 males and 43 females.The postoperative pathological examination confirmed false-positive results in 13 patients,including 1 patient of thyroiditis,2 patients of pulmonary tuberculosis,1 patient of bone tuberculosis,2 patients of pulmonary inflammatory pseudotumor,1 patient of pulmonary sarcoidosis,1 patient of pulmonary benign fibroma,1 patient of organic pneumonia,2 patients of renal angiomyolipoma,1 patient of mass pancreatitis,and 1 patient of pancreatic mucinous cystadenoma.The medical history,relevant imaging examination,and long-term follow-up confirmed false-positive results in 86 patients.Specifically,the false-positive uptake in the neck,chest,abdomen,bone joint,and skin occurred in 8 (9.3%),13 (15.1%),5 (5.8%),57 (66.3%),and 3 (3.5%) patients,respectively.Inflammation-related uptake appeared in 83 (83.8%) patients with false-positive imaging results,of which arthritis (23 patients) and osteophyte (29 patients) were the most common.Sixteen (16.2%) patients showed the false-positive uptake related to fibroblasts. Conclusion 68Ga-FAPI-04 PET/CT imaging will show non-malignant tumor false-positive results,which are mainly associated with inflammation and fibroblasts.

Diagnostic Efficacy of 18F-FDG PET/CT in Detecting Bone Marrow Infiltration in Patients with Newly Diagnosed Diffuse Large B-Cell Lymphoma / 生物医学与环境科学（英文）

OBJECTIVE@#Diffuse large B-cell lymphoma (DLBCL) is often associated with bone marrow infiltration, and 2-deoxy-2-(18F) fluorodeoxyglucose positron emission tomography/computed tomography ( 18F-FDG PET/CT) has potential diagnostic significance for bone marrow infiltration in DLBCL.@*METHODS@#A total of 102 patients diagnosed with DLBCL between September 2019 and August 2022 were included. Bone marrow biopsy and 18F-FDG PET/CT examinations were performed at the time of initial diagnosis. Kappa tests were used to evaluate the agreement of 18F-FDG PET/CT with the gold standard, and the imaging features of DLBCL bone marrow infiltration on PET/CT were described.@*RESULTS@#The total detection rate of bone marrow infiltration was not significantly different between PET/CT and primary bone marrow biopsy ( P = 0.302) or between the two bone marrow biopsies ( P = 0.826). The sensitivity, specificity, and Youden index of PET/CT for the diagnosis of DLBCL bone marrow infiltration were 0.923 (95% CI, 0.759-0.979), 0.934 (95% CI, 0.855-0.972), and 0.857, respectively.@*CONCLUSION@#18F-FDG PET/CT has a comparable efficiency in the diagnosis of DLBCL bone marrow infiltration. PET/CT-guided bone marrow biopsy can reduce the misdiagnosis of DLBCL bone marrow infiltration.

Evaluation of PET Mainstream Scattering Correction Methods / 中国医疗器械杂志

OBJECTIVE@#Current mainstream PET scattering correction methods are introduced and evaluated horizontally, and finally, the existing problems and development direction of scattering correction are discussed.@*METHODS@#Based on NeuWise Pro PET/CT products of Neusoft Medical System Co. Ltd. , the simulation experiment is carried out to evaluate the influence of radionuclide distribution out of FOV (field of view) on the scattering estimation accuracy of each method.@*RESULTS@#The scattering events produced by radionuclide out of FOV have an obvious impact on the spatial distribution of scattering, which should be considered in the model. The scattering estimation accuracy of Monte Carlo method is higher than single scatter simulation (SSS).@*CONCLUSIONS@#Clinically, if the activity of the adjacent parts out of the FOV is high, such as brain, liver, kidney and bladder, it is likely to lead to the deviation of scattering estimation. Considering the Monte Carlo scattering estimation of the distribution of radionuclide out of FOV, it's helpful to improve the accuracy of scattering distribution estimation.

Clinical Analysis of Pulmonary Lymphoma / 中国实验血液学杂志

OBJECTIVE@#To study the clinical, imaging, and pathological features of pulmonary lymphoma.@*METHODS@#Patients with pulmonary lymphoma diagnosed by lung biopsy in Zhongda Hospital Affiliated to Southeast University from November 2013 to December 2020 were collected and divided into secondary pulmonary lymphoma (SPL) group and primary pulmonary lymphoma (PPL) group according to the primary site of lymphoma. The clinical characteristics, stages, imaging features, diagnostic methods and pathological types of the two groups were analyzed.@*RESULTS@#A total of 22 patients were included, 10 cases were PPL and 12 cases were SPL. The main symptoms of the two groups were cough, dyspnea and chest pain. The proportion of stage III/IV patients and international prognostic index (IPI) in SPL group were significantly higher than those in PPL group (P<0.05). Chest high-resolution computed tomography (HRCT) mainly showed masses, nodules and consolidation in both groups. The proportions of single mass and air bronchial sign in PPL group were significantly higher than those in SPL group, while the proportions of multiple nodules, mediastinal/hilar lymphadenopathy and pleural effusion were significantly lower (P<0.05). The max standardized uptake value (SUVmax), peak standardized uptake value (SUVpeak), total lesion glycolysis (TLG) and metabolic tumor volume (MTV) of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in PPL group were lower than those in SPL group, but the differences were not statistically significant (P>0.05). In PPL group, 8 cases were diagnosed by transbronchial lung biopsy (TBLB) and 2 cases by percutaneous lung puncture. In SPL group, 4 cases were diagnosed by TBLB, 7 cases by percutaneous lung puncture, and 1 case by surgery. 95.5% patients were diagnosed by non-surgical methods. The main pathological type of PPL was mucosa-associated lymphoid tissue (MALT) lymphoma, while that of SPL was diffuse large B-cell lymphoma (P<0.05).@*CONCLUSION@#The clinical symptoms of pulmonary lymphoma are nonspecific, but the chest HRCT has characteristic manifestations, which can also help to distinguish between SPL and PPL. 18F-FDG PET/CT is also a potential method to distinguish between SPL and PPL. TBLB and percutaneous lung puncture biopsy are reliable methods for the diagnosis of lung lymphoma. The main pathological type of PPL is MALT lymphoma, while that of SPL is diffuse large B-cell lymphoma.

Adjunctive role of dual time point imaging in evaluating bone lesions with increased 18F-PSMA-1007 uptake

Background@#Non-specific focal uptake in the skeleton is a diagnostic pitfall on 18F-PSMA-1007 PET/CT, but adjunctive measures to aid interpretation of these lesions are currently lacking. We present two cases where dual time point imaging provided additional information. @*Case Presentation@#The first patient had a PI-RADS 3 lesion on MRI. No PSMA-avid abnormality was seen on PET, save for focal uptake in the right pubis with no anatomic correlate. Additional imaging showed a decrease in lesion SUV, and this was interpreted as benign. Another patient, diagnosed with prostate cancer, had multiple PSMA-avid pelvic foci. Two suspiciously malignant bone lesions had increasing SUV trend after dual time point imaging despite only faint sclerosis on CT. In contrast, one faint PSMA-avid lesion with no anatomic abnormality was read as benign after a decrease in SUV. A decrease in lesion SUV may point to a benign etiology, while an increase would heighten suspicion for malignancy. One possible molecular explanation is that a true PSMA-overexpressing lesion would bind to the tracer for a longer period than a false positive.@*Conclusion@#Dual time point imaging provides additional information that may be useful in the interpretation of non-specificskeletal lesions with increased 18F-PSMA-1007 uptake.

Use of PET/CT as a diagnostic tool in various clinical scenarios related to systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a systemic disease mediated by immune complexes of unknown aetiology that generates excessive production of autoantibodies against components of the cell nucleus, generating multisystemic involvement affecting organs or systems such as the central nervous, cardiovascular, haematolymphoid, musculoskeletal, kidney, serous, skin and subcutaneous tissue cells, among others. 2-Fluoro-2-deoxyglucose (FDG) is a glucose analogue that has been shown to be a useful diagnostic tool to establish the initial systemic involvement of this disease and response to the various treatments used.

El lupus eritematoso sistémico (LES) es una enfermedad sistémica mediada por inmunocomplejos de etiología desconocida, la cual genera una producción excesiva de autoanticuerpos contra componentes del núcleo celular. Esto último conlleva un compromiso multisistémico que afecta a órganos o sistemas como el nervioso central, el cardiovascular, el hematolinfoide, el musculoesquelético, el rinón, las serosas, la piel y el tejido celular subcutáneo, entre otros. La 2-fluoro-2-desoxiglucosa (FDG) es un análogo de la glucosa que ha mostrado ser una herramienta diagnostica útil para establecer el compromiso sistémico inicial de esta enfermedad y la respuesta a los diversos tratamientos.

Condroma pulmonar y paraganglioma carotídeo como manifestaciones de la tríada de Carney: reporte de un caso / Pulmonary chondroma and carotid paraganglioma as expressions of Carney's triad: report of a case

Resumen Objetivos: Presentar caso clínico y revisión de la literatura sobre asociación de tumores poco frecuentes compatibles con diagnóstico de tríada de Carney. Paciente y Métodos: Revisión de ficha clínica de paciente de sexo femenino de 39 años de edad con antecedentes de asma, quien acude a servicio de urgencias por síntomas respiratorios. En estudio con imágenes se evidencia masa pulmonar en lóbulo superior derecho probablemente hamartoma y masa en la bifurcación carotídea izquierda compatible con posible paraganglioma. Se completó el estudio con endoscopia digestiva alta sin evidencia de tumor gástrico y PET-CT (tomografía de emisión de positrones-tomografía computarizada) que descartó otras lesiones. Resultados: La paciente fue sometida a resección quirúrgica de ambos tumores (pulmonar y carotídeo). En estudio histopatológico diferido, se plantean los diagnósticos de paraganglioma carotideo y hamartoma pulmonar, el cual, luego de una segunda revisión histopatológica, es corregido a condroma pulmonar. Discusión: La tríada de Carney se compone por la asociación de al menos 2 de 3 tumores: tumor estromal gastrointestinal (GIST), paraganglioma extra-adrenal y condroma pulmonar. Su expresión es variable, coexistiendo en forma completa en solo el 22% de los casos. Conclusión: Los pacientes con sospecha de tríada de Carney deben recibir evaluación multidisciplinaria, estudio completo en búsqueda de tumores asociados y seguimiento a largo plazo por posibles recurrencias o metástasis.

Objective: To present a clinical case and review of the literature on the infrequent association of pulmonary and extra thoracic tumors compatible with Carney's triad. Patient and Methods: Review of clinical records of a 39 years-old female patient with history of asthma who presented in the emergency department with respiratory symptoms. An imaging study showed a pulmonary mass in the right upper lobe with the aspect of hamartoma and a mass in the left carotid artery bifurcation compatible with a possible paraganglioma. Upper gastrointestinal endoscopy showed no evidence of gastric tumor and a PET-CT (Positron Emission Tomography - Computed Tomography) excluded other lesions. Results: Patient underwent surgical resection of both tumors (pulmonary and carotid). Diagnosis of carotid paraganglioma and pulmonary hamartoma were stated by histopathology. However, lung tumor after a second pathological analysis was confirmed to be a pulmonary chondroma. Discussion: Carney's triad is defined by the association of at least 2 of 3 tumors: Gastrointestinal Stromal Tumor (GIST), extraadrenal paraganglioma and pulmonary chondroma. Its expression is variable, coexisting completely in only 22% of cases. Conclusion: Patients with suspected Carney's triad should receive a multidisciplinary assessment, a complete study searching associated tumors and long-term follow-up for recurrences or metastases.

The impact of multimodality integrated positron emission tomography-computed tomography on improving the staging and management of head and neck malignancy: a cross- sectional study

ABSTRACT BACKGROUND: Clinical assessment of head and neck cancers is highly challenging owing to the complexity of regional anatomy and wide range of lesions. The diagnostic evaluation includes detailed physical examination, biopsy and imaging modalities for disease extent and staging. Appropriate imaging is done to enable determination of precise tumor extent and involvement of lymph nodes, and detection of distant metastases and second primary tumors. OBJECTIVE: To evaluate the initial staging discrepancy between conventional contrasted computed tomography (CT) and 18F-fluorodeoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) and its impact on management plans for head and neck malignancies. DESIGN AND SETTING: Prospective cross-sectional study in two tertiary-level hospitals. METHODS: This study included 30 patients with primary head and neck malignant tumors who underwent contrasted computed tomography and whole-body 18F-FDG PET/CT assessments. The staging and treatment plans were compared with the incremental information obtained after 18F-FDG PET/CT. RESULTS: 18F-FDG PET/CT was found to raise the stage in 33.3% of the cases and the treatment intent was altered in 43.3% of them, while there was no management change in the remaining 56.7%. 18F-FDG PET/CT had higher sensitivity (96% versus 89.2%) and accuracy (93% versus 86.7%) than conventional contrast-enhanced computed tomography. CONCLUSION: Our study demonstrated that 18F-FDG PET/CT had higher sensitivity and accuracy for detecting head and neck malignancy, in comparison with conventional contrast-enhanced computed tomography. 18F-FDG PET/CT improved the initial staging and substantially impacted the management strategy for head and neck malignancies.

Aportes de la tomografía por emisión de positrones con 18F-fluorodesoxiglucosa/tomografía computada en el diagnóstico de compromiso extramedular por mieloma múltiple en Uruguay / 18F-fluorodesoxyglucose positron emission tomography/computed tomography in extramedullary multiple myeloma

BACKGROUND: 18F-fluorodesoxyglucose positron emission tomography/ computed tomography (PET-CT) has a high sensitivity and specificity to detect medullary and extramedullary lesions in multiple myeloma (MM). AIM: To describe the findings of PET-CT in extramedullary multiple myeloma (EMM) at diagnosis and at relapse, and correlate its results with clinical variables, response to treatment and survival. MATERIALS AND METHODS: Review of medical records and PET-CT reports of 39 patients with multiple myeloma (MM) who had at least one PET-CT study, treated between January 1, 2015, and January 1, 2019 at a clinical hospital. RESULTS: The Standard Uptake Values for each hypermetabolic lesion were not described in PET-CT reports. Fifteen patients had an EMM and in eight, without a previous clinical suspicion, PET-TC lead to the diagnosis. The mortality rate in the 39 patients with MM was 46%. Sixty seven percent of deaths occurred in patients with EMM. CONCLUSIONS: PET-TC was useful to diagnose EMM. However, a standardization in PETCT reports would be required to unify criteria. As previously reported, EMM had a greater aggressiveness and lower survival.

Value of 18F-FDG PET/CT Imaging in Secondary Extramedullary Infiltration of Multiple Myeloma / 中国实验血液学杂志

OBJECTIVE@#To investigate the characteristics of 18F-FDG PET/CT images of multiple myeloma secondary extramedullary infiltration in order to improve recognition.@*METHODS@#Twenty-one patients with multiple myeloma secondary extramedullary infiltration confirmed by pathology or follow-up from January 2012 to October 2020 in the First Affiliated Hospital of University of Science and Technology of China were retrospectively analyzed. All the patients underwent 18F-FDG PET/CT imaging before treatment, and the PET/CT characteristics of extramedullary infiltration and bone marrow were analyzed.@*RESULTS@#Twenty-one patients included 12 males and 9 females, aged from 41 to 77 years old, with an average of 58.3±10.0; 9 cases of extramedullary infiltration involving lymph nodes; lung, stomach, spleen, and kidney were involved respectively in 2 cases; retroperitoneal, right auricle, subcutaneous nodule, and spinal meninges involvement were reported in each one case respectively. The maximum SUVmax value of extra-medullary lesions was 21.2, the minimum value was 2.1, and mean was 7.7±5.3. The maximum SUVmax value of bone marrow was 33.5, the minimum was 2.4, and mean was 6.6±3.6. There was no statistically significant difference in SUVmax value between extra-medullary lesions and bone marrow (Z=-1.195, P=0.232).@*CONCLUSION@#18F-FDG PET/CT not only has a good diagnostic value for multiple myeloma, but also a good evaluation value for secondary extramedullary infiltration, which provides reference for clinical treatment and prognosis.

Correlation and Influencing Factors of SUVmax and Ki-67 in Non-Hodgkin Lymphoma / 中国实验血液学杂志

OBJECTIVE@#To investigate the influencing factors of maximum standard uptake value (SUVmax) of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) and nuclear antigen Ki-67 in non-Hodgkin lymphoma (NHL) and their correlation.@*METHODS@#The relationship between SUVmax, Ki-67 and gender, age, maximum lesion diameter, extranodal involvement, superficial and deep lymph node involvement, malignancy, B symptoms, clinical stage, lactate dehydrogenase (LDH) and international prognostic index (IPI) scores and their correlation were reviewed.@*RESULTS@#Among 185 NHL patients, 99 cases were aggressive B-cell NHL, 43 cases were indolent B-cell NHL, and 43 cases were T-cell NHL, respectively. Obviously, the SUVmax and Ki-67 of aggressive B-cell NHL were higher than those of indolent B-cell NHL and T-cell NHL (P<0.05), while indolent B-cell NHL were lower than those of T-cell NHL (P<0.05). SUVmax and Ki-67 were closely related to maximum lesion diameter, extranodal involvement, malignancy, LDH, and IPI scores (P<0.05). SUVmax was positively correlated with Ki-67 expression (r=0.615). According to the analysis of receiver operating characteristic (ROC), the results showed that the SUVmax and Ki-67 could reflect the aggressiveness of NHL accurately, with an AUC of 0.871 and 0.968.@*CONCLUSION@#SUVmax and Ki-67 are not affected by age, sex, B symptoms, clinical stage and so on, and are relatively objective quantitative parameters. SUVmax is positively correlated with Ki-67 expression in NHL. SUVmax and Ki-67 have certain value in clinical diagnosis of malignant degree of NHL.

68Ga-PSMA ligand PET/CT integrating indocyanine green-guided salvage lymph node dissection for lymph node metastasis after radical prostatectomy / 亚洲男科学杂志(英文版)

To efficiently remove all recurrent lymph nodes (rLNs) and minimize complications, we developed a combination approach that consisted of 68Gallium prostate-specific membrane antigen (PSMA) ligand positron emission tomography (PET)/computed tomography (CT) and integrated indocyanine green (ICG)-guided salvage lymph node dissection (sLND) for rLNs after radical prostatectomy (RP). Nineteen patients were enrolled to receive such treatment. 68Ga-PSMA ligand PET/CT was used to identify rLNs, and 5 mg of ICG was injected into the space between the rectum and bladder before surgery. Fluorescent laparoscopy was used to perform sLND. While extensive LN dissection was performed at level I, another 5 mg of ICG was injected via the intravenous route to intensify the fluorescent signal, and laparoscopy was introduced to intensively target stained LNs along levels I and II, specifically around suspicious LNs, with 68Ga-PSMA ligand PET/CT. Next, both lateral peritonea were exposed longitudinally to facilitate the removal of fluorescently stained LNs at levels III and IV. In total, pathological analysis confirmed that 42 nodes were rLNs. Among 145 positive LNs stained with ICG, 24 suspicious LNs identified with 68Ga-PSMA ligand PET/CT were included. The sensitivity and specificity of 68Ga-PSMA ligand PET/CT for detecting rLNs were 42.9% and 96.6%, respectively. For ICG, the sensitivity was 92.8% and the specificity was 39.1%. At a median follow-up of 15 (interquartile range [IQR]: 6-31) months, 15 patients experienced complete biochemical remission (BR, prostate-specific antigen [PSA] <0.2 ng ml-1), and 4 patients had a decline in the PSA level, but it remained >0.2 ng ml-1. Therefore, 68Ga-PSMA ligand PET/CT integrating ICG-guided sLND provides efficient sLND with few complications for patients with rLNs after RP.

Research progress on prostate-specific membrane antigen ligand positron emission tomography imaging of prostate cancer / 生物医学工程学杂志

Prostate cancer is the most common malignant tumor in male urinary system, and the morbidity and mortality rate are increasing year by year. Traditional imaging examinations have some limitations in the diagnosis of prostate cancer, and the advent of molecular imaging probes and imaging technology have provided new ideas for the integration of diagnosis and treatment of prostate cancer. In recent years, prostate-specific membrane antigen (PSMA) has attracted much attention as a target for imaging and treatment of prostate cancer. PSMA ligand positron emission tomography (PET) has important reference value in the diagnosis, initial staging, detection of biochemical recurrence and metastasis, clinical decision-making guidance and efficacy evaluation of prostate cancer. This article briefly reviews the clinical research and application progress on PSMA ligand PET imaging in prostate cancer in recent years, so as to raise the efficiency of clinical applications.

Consideration on Animal Experiment in PET/CT / 中国医疗器械杂志

PET/CT imaging can reflect the physiological metabolic process in living body which is the model experiment incapable to simulate. Animal experiment may be considered for systematic validation of PET/CT products. The obtained research data can be used to evaluate the feasibility, effectiveness and safety of PET/CT products, and be submitted as supporting documents for research data or clinical evaluation data when doing product registration or alteration registration. In this study, the functions and advantages of animal experiments were expounded, and relevant research cases were given as well as the issues that should be paid attention to. It can be a reference for the validation and review of PET/CT products.

Progressive massive fibrosis in pneumoconiosis is mimicking lung malignancy on (18)F-FDGPET-CT: two cases report / 中华劳动卫生职业病杂志

Occupational pneumoconiosis is one of the main occupational diseases in China. Progressive massive fibrosis in pneumoconiosis should be distinguished from lung cancer for their similar imaging features which is often identified by (18)F-FDG PET-CT in clinic. Here we reported two cases of pneumoconiosis. Both of them were suspected of carrying malignant tumors by preoperative PET-CT exam, however, nodules in these two patients were all proved to be benign by intraoperative pathology which suggested that there is false-positive possibility in the distinguishment of pneumoconiosis nodules by (18)F-FDG PET-CT.