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.
PSMA-1007 ; Positron Emission Tomography Computed Tomography

OBJECTIVE: To explore the diagnostic value of ¹⁸F-FDG PET/CT in bone marrow infiltration (BMI) of newly diagnosed diffuse large B-cell lymphoma (DLBCL), compared with the results of bone marrow biopsy (BMB) and investigate whether the BMI diagnosed by ¹⁸F-FDG PET/CT and other factors have independent prognostic values. METHODS: Ninety-four newly diagnosed DLBCL patients who underwent PET/CT in Clinical Medical College of Shanghai General Hospital of Nanjing Medical University were included. BMB was performed within 2 weeks before or after PET/CT, and standardized treatment was performed after PET/CT. The manifestations of bone marrow (BM) FDG uptake were recorded. The diagnostic criteria of BMI were BMB positive or focal BM FDG uptake confirmed by imaging follow-up. The relationship between clinical features and BM FDG uptake and the values of PET/CT and BMB in the diagnosis of BMI was analyzed. The progression-free survival (PFS) was analyzed by Kaplan-Meier survival curves, log-rank test was used to compare PFS rate, and Cox regression model was used to analyze the independent risk factors affecting PFS. RESULTS: Among 94 DLBCL patients, 34 patients showed focal BM uptake (fPET), 7 patients showed super BM uptake (sBMU), 11 patients showed diffuse homogenous uptake higher than liver (dPET), and the other 42 patients had normal BM uptake (nPET) (lower than liver). BMB positive was found in all sBMU patients, in 20.6%(7/34) of fPET patients, and in 27.3% (3/11) of dPET patients. All nPET patients had negative BMB results. dPET patients were associated with lower hemoglobin level and leukocyte count compared with nPET group (P < 0.001, P =0.026). Compared with fPET patients, sBMU patients were more likely to have B symptoms and elevated lactate dehydrogenase (LDH). A total of 44 patients were diagnosed BMI, including 17 cases with BMB⁺. The sensitivity and specificity of BMB in the diagnosis of BMI was 38.6% (17/44) and 100% (50/50), respectively. Using fPET and sBMU as criteria of PET BMI, the diagnostic sensitivity and specificity of PET/CT was 93.2% (41/44) and 100% (50/50), respectively. Kaplan-Meier analysis showed that there was no significant difference in 2-year PFS rate between nPET and dPET patients (P >0.05), while sBMU patients had lower 2-year PFS rate compared with fPET patients (P < 0.001). Multivariate analysis showed that higher Ann Arbor stage (HR=9.010, P =0.04) and sBMU (HR=3.964, P =0.002) were independent risk factors affecting PFS. CONCLUSIONS Increased BM FDG uptake of DLBCL can be manifested as dPET, fPET and sBMU. fPET and sBMU can replace BMB to diagnose BMI. Although dPET cannot completely exclude the possibility of BMI, it does not affect the prognosis, so it can be diagnosed as PET BMI negative. sBMU is an independent prognostic risk factor.
Humans ; Positron Emission Tomography Computed Tomography/methods* ; Fluorodeoxyglucose F18 ; Prognosis ; Bone Marrow/pathology* ; Retrospective Studies ; China ; Positron-Emission Tomography/methods* ; Lymphoma, Large B-Cell, Diffuse/pathology* ; Biopsy

OBJECTIVE: To investigate the correlation between ¹⁸Fluoro-deoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) metabolic parameters and peripheral blood circulating tumour DNA (ctDNA) in patients with diffuse large B-cell lymphoma (DLBCL), and the prognostic value of these two types of parameters in predicting progression-free survival (PFS). METHODS: Clinical, PET/CT and ctDNA data of DLBCL patients who underwent peripheral blood ctDNA testing and corresponding PET/CT scans during the same period were retrospectively analyzed. At the time of ctDNA sampling and PET scan, patients were divided into baseline and relapsed/refractory (R/R) groups according to different disease conditions. CtDNA mutation abundance was expressed as variant allele frequency (VAF), including maximum VAF (maxVAF) and mean VAF (meanVAF). Total metabolic tumour volume (TMTV) and total lesion glycolysis (TLG) were obtained by the 41% maximum normalized uptake value method, and the distance between the two farthest lesions (Dmax) was used to assess the correlation between PET parameters and ctDNA mutation abundance using Spearman correlation analysis. The receiver operating characteristic (ROC) curves were used to obtain the optical cut-off values of those parameters in predicting PFS in the baseline and R/R groups, respectively. Survival curves were outlined using the Kaplan-Meier method and log-rank test was performed to compare survival differences. RESULTS: A total of 67 DLBCL patients ［28 males and 39 females, median age 56.0(46.0, 67.0) years］ were included and divided into baseline group (29 cases) and R/R group (38 cases). Among these PET parameters, baseline TMTV, TLG, and Dmax were significantly correlated with baseline ctDNA mutation abundance, except for maximum standardized uptake value (SUVmax) (maxVAF vs TMTV: r=0.711; maxVAF vs TLG: r=0.709; maxVAF vs Dmax: r=0.672; meanVAF vs TMTV: r=0.682; meanVAF vs TLG: r=0.677; meanVAF vs Dmax: r=0.646). While in all patients, these correlations became weaker significantly. Among R/R patients, only TMTV had a weak correlation with meanVAF (r=0.376). ROC analysis showed that, the specificity of TMTV, TLG and Dmax in predicting PFS was better than mutation abundance, while the sensitivity of ctDNA mutation abundance was better. Except R/R patients, TMTV, TLG, Dmax, and VAF were significantly different at normal/elevated lactate dehydrogenase in baseline group and all patients (all P<0.05). Survival curves indicated that high TMTV (>109.5 cm³), high TLG (>2 141.3), high Dmax (>33.1 cm) and high VAF (maxVAF>7.74%, meanVAF>4.39%) were risk factors for poor PFS in baseline patients, while only high VAF in R/R patients (both maxVAF and meanVAF >0.61%) was a risk factor for PFS. CONCLUSION PET-derived parameters correlate well with ctDNA mutation abundance, especially in baseline patients. VAF of ctDNA predicts PFS more sensitively than PET metabolic parameters, while PET metabolic tumour burden with better specificity. TMTV, TLG and VAF all have good prognostic value for PFS. PET/CT combined with ctDNA has potential for further studies in prognostic assessment and personalized treatment.
Male ; Female ; Humans ; Middle Aged ; Positron Emission Tomography Computed Tomography ; Fluorodeoxyglucose F18 ; Circulating Tumor DNA/genetics* ; Retrospective Studies ; Positron-Emission Tomography ; Survival Analysis ; Lymphoma, Large B-Cell, Diffuse/metabolism* ; Prognosis

BACKGROUND: In recent years, immunotherapy represented by programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) immunosuppressants has greatly changed the status of non-small cell lung cancer (NSCLC) treatment. PD-L1 has become an important biomarker for screening NSCLC immunotherapy beneficiaries, but how to easily and accurately detect whether PD-L1 is expressed in NSCLC patients is a difficult problem for clinicians. The aim of this study was to construct a Nomogram prediction model of PD-L1 expression in NSCLC patients based on 18F-fluorodeoxy glucose (18F-FDG) positron emission tomography/conputed tomography (PET/CT) metabolic parameters and to evaluate its predictive value. METHODS: Retrospective collection of 18F-FDG PET/CT metabolic parameters, clinicopathological information and PD-L1 test results of 155 NSCLC patients from Inner Mongolia People's Hospital between September 2016 and July 2021. The patients were divided into the training group (n=117) and the internal validation group (n=38), and another 51 cases of NSCLC patients in our hospital between August 2021 and July 2022 were collected as the external validation group according to the same criteria. Then all of them were categorized according to the results of PD-L1 assay into PD-L1+ group and PD-L1- group. The metabolic parameters and clinicopathological information of patients in the training group were analyzed by univariate and binary Logistic regression, and a Nomogram prediction model was constructed based on the screened independent influencing factors. The effect of the model was evaluated by receiver operating characteristic (ROC) curve, calibration curve and decision curve analysis (DCA) in both the training group and the internal and external validation groups. RESULTS: Binary Logistic regression analysis showed that metabolic tumor volume (MTV), gender and tumor diameter were independent influences on PD-L1 expression. Then a Nomogram prediction model was constructed based on the above independent influences. The ROC curve for the model in the training group shows an area under the curve (AUC) of 0.769 (95%CI: 0.683-0.856) with an optimal cutoff value of 0.538. The AUC was 0.775 (95%CI: 0.614-0.936) in the internal validation group and 0.752 (95%CI: 0.612-0.893) in the external validation group. The calibration curves were tested by the Hosmer-Lemeshow test and showed that the training group (χ2=0.040, P=0.979), the internal validation group (χ2=2.605, P=0.271), and the external validation group (χ2=0.396, P=0.820) were well calibrated. The DCA curves show that the model provides clinical benefit to patients over a wide range of thresholds (training group: 0.00-0.72, internal validation group: 0.00-0.87, external validation group: 0.00-0.66). CONCLUSIONS The Nomogram prediction model constructed on the basis of 18F-FDG PET/CT metabolic parameters has greater application value in predicting PD-L1 expression in NSCLC patients.
Humans ; Carcinoma, Non-Small-Cell Lung/drug therapy* ; Positron Emission Tomography Computed Tomography ; Lung Neoplasms/drug therapy* ; Fluorodeoxyglucose F18/therapeutic use* ; Nomograms ; Retrospective Studies ; B7-H1 Antigen/metabolism* ; Glucose/therapeutic use* ; Positron-Emission Tomography/methods*

Perianal Paget's disease (PPD) is a rare malignant cutaneous tumor. This paper reported a case of PPD complicated by lung adenocarcinoma and anal canal cancer. The patient, a 76-year-old female, had been experiencing recurrent lower abdominal pain and perianal pruritus for the past 5 years. Upon physical examination, a cauliflower-like neoplasm in size of 5 cm×6 cm was observed on the right perianal skin, with local skin ulceration and a small amount of fluid discharge. The left perianal skin was also involved. In thoracoknee position, a hard mass was palpable in the rectal submucosa at 5-6 points 2 cm from the anal verge. Chest CT revealed multiple lesions in both lungs, indication of metastatic tumors. Further evaluation with fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET/CT) indicated multiple hypermetabolic nodules in the lungs, hypermetabolic lymph nodes throughout the body, early FDG uptake in a small patch of skin on the left hip, and increased FDG uptake in the anorectal region. Histopathological examination confirmed the diagnosis of lung adenocarcinoma. This resulted in the patient being diagnosed with PPD, lung adenocarcinoma, anal canal cancer, and systemic multiple lymph node metastasis. The combination of PPD with gastrointestinal tumors and other metachronous malignant tumors is highly prevalent. Colonoscopy, FDG-PET/CT, histopathology, and immunohistochemistry play crucial roles in early identification of local lymph node and distant involvement, facilitating the evaluation of potential malignant tumors and differential diagnosis. Treating methods for PPD are currently diverse, including postoperative combined or single chemotherapy, radiotherapy, targeted therapy, and photodynamic therapy. As trerapeutical options continue to develop, the extent and efficacy of surgery need to be reassessed.
Female ; Humans ; Aged ; Paget Disease, Extramammary/pathology* ; Fluorodeoxyglucose F18 ; Positron Emission Tomography Computed Tomography ; Adenocarcinoma of Lung/complications* ; Lung Neoplasms/complications*

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 (SUV_max), peak standardized uptake value (SUV_peak), 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.
Humans ; Positron Emission Tomography Computed Tomography ; Fluorodeoxyglucose F18 ; Lung Neoplasms/pathology* ; Lymphoma, Large B-Cell, Diffuse/pathology* ; Lymphoma, B-Cell, Marginal Zone/diagnosis* ; Prognosis ; Retrospective Studies

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.
Positron Emission Tomography Computed Tomography ; Scattering, Radiation ; Computer Simulation ; Brain ; Monte Carlo Method ; Phantoms, Imaging ; Image Processing, Computer-Assisted

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.
Humans ; Positron Emission Tomography Computed Tomography/methods* ; Fluorodeoxyglucose F18 ; Bone Marrow/pathology* ; Retrospective Studies ; Positron-Emission Tomography/methods* ; Lymphoma, Large B-Cell, Diffuse/pathology*

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.
Female ; Male ; Humans ; Gallium Radioisotopes ; Positron Emission Tomography Computed Tomography ; Angiomyolipoma ; Retrospective Studies ; Kidney Neoplasms ; Fibroblasts ; Inflammation ; Fluorodeoxyglucose F18 ; Quinolines

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.
Male ; Humans ; Urology ; Positron Emission Tomography Computed Tomography/methods* ; Prostatic Neoplasms/pathology* ; Multiparametric Magnetic Resonance Imaging/methods* ; Gallium Radioisotopes