Research progress on medical imaging techniques for diagnosis of breast tumors / 中国辐射卫生

Breast cancer is the most common malignancy and the fifth leading cause of cancer-associated mortality in the world, which has become a major global health concern with huge economic, social, and disease burdens. Early diagnosis is crucial for effective treatment and favorable prognosis of breast cancer. Medical imaging techniques can provide a variety of clinical information on the morphology, structure, metabolism, and function of tumor tissues in real-time, tissue damage-free, and minimally invasive manners, which have been widely used and hold great value for breast tumor screening and early diagnosis. This review summarizes the advances on the diagnostic value of medical imaging tools for breast tumors, including ultrasonography, computed tomography, magnetic resonance imaging, positron emission tomography/computed tomography, and breast-specific gamma imaging.

Evaluation of early efficacy of neoadjuvant chemotherapy in patient with breast cancer based on dynamic contrast-enhanced MRI via comparing with 18F-FDG PET/CT / 实用放射学杂志

Objective To investigate the predictive value of early efficacy of neoadjuvant chemotherapy(NAC)in patient with breast cancer via full quantitative parameters of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI).Methods Forty patients with breast cancer were selected.The 18 fluorodeoxyglucose positron emission tomography/computed tomography(18F-FDG PET/CT)and DCE-MRI were performed before and after two cycles of NAC.According to the decrease rate of maximum standardized uptake value(ΔSUVmax)of PET/CT before and after two cycles of NAC,all patients were divided into two groups,including good response group(24 cases)(ΔSUVmax>40%)and general response group(16 cases)(ΔSUVmax≤40%).The changes of full quantitative parameters of DCE-MRI between the two groups were observed and analyzed.Results There were statistically significant differences in changes of Ktrans and Kep between the two groups(P<0.05),however,there was no significant difference in the change of Ve between the two groups(P>0.05).There was a significant positive correlation between ΔKtrans and ΔSUVmax(r=0.850,P<0.001).There was a high positive correlation between ΔKtrans and ΔKep(r=0.727,P<0.001).Conclusion The full quantitative parameters of DCE-MRI are helpful to evaluate the early efficacy of NAC in breast cancer,which can reflect the changes of microcirculation in the lesion,further reflect the therapeutic effect of NAC,guide the clinical optimization of treatment plan in time,and achieve accurate evaluation and individualized treatment.

18F-FDG PET/CT combined with CT three-dimensional reconstruction in the differentiation of benign and malignant pulmonary nodules: A retrospective cohort study / 中国胸心血管外科临床杂志

@#Objective     To investigate the accuracy of 18F-FDG positron emission tomography/computed tomography (PET/CT) combined with CT three-dimensional reconstruction (CT-3D) in the differential diagnosis of benign and malignant pulmonary nodules. Methods     The clinical data of patients who underwent pulmonary nodule surgery in the Department of Thoracic Surgery, Northern Jiangsu People's Hospital from July 2020 to August 2021 were retrospectively analyzed. The preoperative 18F-FDG PET/CT and chest enhanced CT-3D and other imaging data were extracted. The parameters with diagnostic significance were screened by the area under the receiver operating characteristic (ROC) curve (AUC). Three prediction models, including PET/CT prediction model (MOD PET), CT-3D prediction model (MOD CT-3D), and PET/CT combined CT-3D prediction model (MOD combination), were established through binary logistic regression, and the diagnostic performance of the models were validated by ROC curve. Results     A total of 125 patients were enrolled, including 57 males and 68 females, with an average age of 61.16±8.57 years. There were 46 patients with benign nodules, and 79 patients with malignant nodules. A total of 2 PET/CT parameters and 5 CT-3D parameters were extracted. Two PET/CT parameters, SUVmax≥1.5 (AUC=0.688) and abnormal uptake of hilar/mediastinal lymph node metabolism (AUC=0.671), were included in the regression model. Among the CT-3D parameters, CT value histogram peaks (AUC=0.694) and CT-3D morphology (AUC=0.652) were included in the regression model. Finally, the AUC of the MOD PET was verified to be 0.738 [95%CI (0.651, 0.824)], the sensitivity was 74.7%, and the specificity was 60.9%; the AUC of the MOD CT-3D was 0.762 [95%CI (0.677, 0.848)], the sensitivity was 51.9%, and the specificity was 87.0%; the AUC of the MOD combination was 0.857 [95%CI (0.789, 0.925)], the sensitivity was 77.2%, the specificity was 82.6%, and the differences were statistically significant (P<0.001). Conclusion     18F-FDG PET/CT combined with CT-3D can improve the diagnostic performance of pulmonary nodules, and its specificity and sensitivity are better than those of single imaging diagnosis method. The combined prediction model is of great significance for the selection of surgical timing and surgical methods for pulmonary nodules, and provides a theoretical basis for the application of artificial intelligence in the pulmonary nodule diagnosis.

Evolução da Captação Miocárdica de 18F-FDG em Paciente com Diagnóstico de Cardiotoxicidade / Progression of Myocardial 18F-FDG Uptake in a Patient with Cardiotoxicity

Resumo O objetivo deste relato é mostrar a evolução da cardiotoxicidade (CTX) por quimioterápicos em paciente com linfoma por exames de imagens, destacando a importância da captação miocárdica de flúor-18 fluordeoxiglicose (18F-FDG) pela tomografia por emissão de pósitrons, acoplada à tomografia computadorizada (PET/CT). Feminino, 43 anos, com linfoma uterino, submetida a histerectomia, três esquemas de quimioterapia (QT), sucessivamente, e radioterapia. Apresentou episódios de insuficiência cardíaca aguda dois anos após QT. Ecocardiograma mostrou redução da fração de ejeção do ventrículo esquerdo (FEVE). Análise retrospectiva do 18F-FDG PET/CT observou elevação da captação miocárdica em todos os exames durante o seguimento oncológico. Apesar da remissão oncológica, a paciente desenvolveu IC com FEVE reduzida. Durante a QT, ocorreu aumento difuso e significativo da captação miocárdica de 18F-FDG, que precedeu a queda do desempenho cardíaco, e pareceu refletir alterações metabólicas nos cardiomiócitos relacionadas à CTX. A análise da captação miocárdica de 18F-FDG modificaria o desfecho cardiológico da paciente? Esse questionamento é relevante, visto que outros pacientes podem se beneficiar desse método como marcador precoce de CTX. Os exames de imagem são imprescindíveis no acompanhamento de pacientes com risco de CTX. O ecocardiograma permanece como principal auxílio diagnóstico, porém o 18F-FDG PET/CT pode estar surgindo como uma poderosa ferramenta para um diagnóstico mais precoce dessa condição clínica.

Abstract The objective of this case report was to present the progression of chemotherapy-induced cardiotoxicity in a patient with lymphoma, highlighting the importance of myocardial fluor-18-fluorodeoxyglucose (18F-FDG) uptake by positron emission tomography coupled with computed tomography (PET/CT). 43-year-old female patient with uterine lymphoma, who underwent hysterectomy followed by three chemotherapy regimens and radiotherapy. The patient had episodes of acute heart failure two years after chemotherapy. Echocardiogram revealed a reduction in left ventricular ejection fraction (LVEF). A retrospective analysis of 18F-FDG PET/CT showed an increase in myocardial uptake in all tests performed during oncologic treatment. Despite disease remission, the patient developed heart failure with reduced LVEF. During chemotherapy, there was a diffuse, significant increase in myocardial 18F-FDG uptake, which preceded the decrease in myocardial performance and seemed to reflect metabolic changes in cardiomyocytes, related to cardiotoxicity. Would an analysis of myocardial 18F-FDG uptake yield a different cardiac outcome in this patient? This question is relevant, considering that other patients may benefit from the use of PET as an early marker of cardiotoxicity. Imaging tests are essential in the follow-up of patients at risk of cardiotoxicity. Although echocardiography remains the main imaging test in the diagnosis of cardiotoxicity, 18F-FDG PET/CT may be a powerful tool for the early diagnosis of this condition.

Inguinal lymph node metastases from prostate cancer: clinical, pathology, and multimodality imaging considerations / Metástases de linfonodos inguinais de câncer de próstata: considerações clínicas, patológicas e de imagem multimodalidade

Abstract Objective: To investigate clinical, pathology, and imaging findings associated with inguinal lymph node (LN) metastases in patients with prostate cancer (PCa). Materials and Methods: This was a retrospective single-center study of patients with PCa who underwent imaging and inguinal LN biopsy between 2000 and 2023. We assessed the following aspects on multimodality imaging: inguinal LN morphology; extrainguinal lymphadenopathy; the extent of primary and recurrent tumors; and non-nodal metastases. Imaging, clinical, and pathology features were compared between patients with and without metastatic inguinal LNs. Results: We evaluated 79 patients, of whom 38 (48.1%) had pathology-proven inguinal LN metastasis. Certain imaging aspects— short-axis diameter, prostate-specific membrane antigen uptake on positron-emission tomography, membranous urethra involvement by the tumor, extra-inguinal lymphadenopathy, and distant metastases—were associated with pathology-proven inguinal LN metastases (p < 0.01 for all). Associations with long-axis diameter, fatty hilum, laterality, and uptake of other tracers on positronemission tomography were not significant (p = 0.09-1.00). The patients with metastatic inguinal LNs had higher prostate-specific antigen levels and more commonly had castration-resistant PCa (p < 0.01), whereas age, histological grade, and treatment type were not significant factors (p = 0.07-0.37). None of the patients had inguinal LN metastasis in the absence of locally advanced disease with membranous urethra involvement or distant metastasis. Conclusion: Several imaging, clinical, and pathology features are associated with inguinal LN metastases in patients with PCa. Isolated metastasis to inguinal LNs is extremely rare and unlikely to occur in the absence of high-risk imaging, clinical, or pathology features.

Resumo Objetivo: Investigar achados clinicopatológicos e de imagem associados a metástases linfonodais inguinais em pacientes com câncer de próstata (CaP). Materiais e Métodos: Estudo retrospectivo de uma única instituição de pacientes com CaP submetidos a exames de imagem e biópsia inguinal de linfonodos em 2000-2023. A imagem multimodalidade foi avaliada para morfologia inguinal do linfonodo, linfadenopatia fora da região inguinal, extensão do CaP primário/recorrente e sítios metastáticos não nodais. Características de imagem e clinicopatológicas foram comparadas entre pacientes com e sem linfonodos inguinais metastáticos pela patologia. Resultados: Entre 79 pacientes estudados, 38 (48,1%) apresentaram metástase inguinal de linfonodo comprovada patologicamente. Certos achados de imagem - diâmetro do eixo curto, captação do antígeno de membrana prostático específico na tomografia por emissão de pósitrons, envolvimento da uretra membranosa pelo tumor, linfadenopatia fora da região inguinal e metástases a distância - foram associados com metástases inguinais no linfonodo pela patologia (p < 0,01). Diâmetro de eixo longo, hilo gorduroso, lateralidade, captação em outros traçadores de tomografia por emissão de pósitrons não foram significativos (p = 0,09-1,00). Clinicopatologicamente, os pacientes com linfonodos inguinais metastáticos apresentaram maior antígeno prostático específico e foram mais resistentes à castração (p < 0,01); idade, grau histológico e tipo de tratamento não foram estatisticamente significantes (p = 0,07-0,37). Nenhum paciente apresentou metástase inguinal isolada no linfonodo na ausência de doença localmente avançada com envolvimento da uretra membranosa ou metástase a distância. Conclusão: Várias características de imagem e clinicopatológicas foram associadas a metástases em LNs inguinais em pacientes com CaP. A metástase isolada para os LNs inguinais é extremamente rara e é improvável que ocorra na ausência de características de imagem e clinicopatológicas de alto risco.

Evaluation of 18F-FDG PET/CT myocardial metabolism image quality / 中国医师杂志

Objective:To evaluate the value of 18F-fluorodeoxyglucose positron emission computed tomography ( 18F-FDG PET/CT) myocardial metabolic image quality by the ratio of the maximum standard uptake value (M/B) of left ventricular myocardium to cardiac blood pool. Methods:The clinical data of 145 non diabetes patients with coronary heart disease who were admitted to the First Affiliated Hospital of Xinjiang Medical University from January 2016 to August 2022 were retrospectively selected. All patients received intravenous injection of 18F-FDG for myocardial glucose metabolism imaging. According to the visual (qualitative) analysis, the image was divided into three categories: the best, the second best and the worst. Group A was the best image quality group, while Group B was the second best and the worst image quality group. The left ventricular myocardium, cardiac blood pool and descending aorta were semi-quantitatively analyzed, and M/B was calculated. Results:All 145 patients underwent image fusion analysis. Image visual (qualitative) analysis showed that the myocardial metabolic image quality of 111 patients was evaluated as the best (111 patients in Group A), 19 patients as the second best, and 15 patients as the worst (34 patients in Group B). The SUVmax value of the descending aorta in the two groups was lower than that of the left ventricle, with statistically significant difference (all P<0.05). The M/B value of group A was higher than that of group B, with statistically significant difference ( P<0.05). Conclusions:For the evaluation of image quality and the reliability of image interpretation, M/B value may be a good evaluation index, which reduces the interference of image quality evaluation due to high 18F-FDG uptake in some heart blood pools (background), and improves the accuracy of evaluation of myocardial viability.

Diagnostic and prognostic value of bone marrow biopsy in patients with extranodal NK/T-cell lymphoma based on PET-CT staging / 中华放射肿瘤学杂志

Objective:To analyze the diagnostic and prognostic value of routine bone marrow examination in patients with extranodal NK/T-cell lymphoma (ENKTCL) based on PET-CT staging.Methods:Clinical data of 186 patients who received bone marrow biopsy and bone marrow aspiration in Fujian Medical University Union Hospital from 2013 to 2021 were retrospectively analyzed. All patients were divided into bone marrow biopsy + bone marrow aspiration group ( n=186) and PET-CT + bone marrow biopsy group ( n=139). The sensitivity, specificity, positive and negative predictive values were compared between two groups. The data were analyzed and plotted. Survival analysis was performed using Kaplan-Meier method and log-rank test. Results:In the whole cohort, 45 patients were positive for bone marrow biopsy, and 30 of them were positive for bone marrow aspiration. A total of 141 patients who were negative for bone marrow biopsy also achieved negative results for bone marrow aspiration. A total of 139 patients completed PET-CT staging and bone marrow biopsy. And 30 patients were diagnosed with positive bone marrow by PET-CT, in which 22 of them were confirmed positive by bone marrow biopsy. Among 109 patients diagnosed with negative bone marrow by PET-CT, 5 of them were confirmed positive by bone marrow biopsy. All these cases were classified as stage Ⅳ due to distant metastases. PET-CT had a diagnostic sensitivity of 81.5%, a specificity of 92.9%, a positive predictive value of 73.3%, and a negative predictive value of 95.4%. Among early stage (Ⅰ-Ⅱ stage) patients diagnosed with PET-CT, all of them were negative for bone marrow biopsy (the negative predictive value was 100%). In stage Ⅳ patients ( n=55), the 1-year overall survival of patients with bone marrow involvement by bone marrow biopsy or PET-CT ( n=35) compared with their counterparts with the involvement of other organs ( n=20) was 28.7% vs.42.0% ( P=0.13), and 1-year progression free survival rates was 23.2% vs. 23.3% in ( P=0.94). Conclusions:Routine bone marrow biopsy does not change the original staging of patients with early stage ENKTCL based on PET-CT staging. Advanced stage patients with positive bone marrow biopsy tend to obtain worse prognosis, indicating that bone marrow biopsy still has certain value.

Clinical and molecular biological characterization of patients with accelerated chronic lymphocytic leukemia / 中华血液学杂志

Objective: To investigate the clinical and molecular biological characteristics of patients with accelerated chronic lymphocytic leukemia (aCLL) . Methods: From January 2020 to October 2022, the data of 13 patients diagnosed with aCLL at The First Affiliated Hospital of Nanjing Medical University were retrospectively analyzed to explore the clinical and molecular biological characteristics of aCLL. Results: The median age of the patients was 54 (35-72) years. Prior to aCLL, five patients received no treatment for CLL/small lymphocytic lymphoma (SLL), while the other patients received treatment, predominantly with BTK inhibitors. The patients were diagnosed with aCLL through pathological confirmation upon disease progression. Six patients exhibited bulky disease (lesions with a maximum diameter ≥5 cm). Positron emission tomography (PET) -computed tomography (CT) images revealed metabolic heterogeneity, both between and within lesions, and the median maximum standardized uptake value (SUVmax) of the lesion with the most elevated metabolic activity was 6.96 (2.51-11.90). Patients with unmutated IGHV CLL accounted for 76.9% (10/13), and the most frequent genetic and molecular aberrations included +12 [3/7 (42.9% ) ], ATM mutation [6/12 (50% ) ], and NOTCH1 mutation [6/12 (50% ) ]. Twelve patients received subsequent treatment. The overall response rate was 91.7%, and the complete response rate was 58.3%. Five patients experienced disease progression, among which two patients developed Richter transformation. Patients with aCLL with KRAS mutation had worse progression-free survival (7.0 month vs 26.3 months, P=0.015) . Conclusion: Patients with aCLL exhibited a clinically aggressive course, often accompanied by unfavorable prognostic factors, including unmutated IGHV, +12, ATM mutation, and NOTCH1 mutation. Patients with CLL/SLL with clinical suspicion of disease progression, especially those with bulky disease and PET-CT SUVmax ≥5, should undergo biopsy at the site of highest metabolic uptake to establish a definitive pathological diagnosis.

Progress in application of positron emission tomography/computed tomography (PET/CT) imaging in tumor screening / 中国辐射卫生

@#Worldwide, the incidence of cancer is greatest in China. Tumor screening is effective to achieve early diagnosis, improve prognosis, increase the quality of life, and reduce mortality among cancer patients. Positron emission tomography/computed tomography (PET/CT) imaging provides metabolic data to support initial staging, treatment planning, and response evaluation in tumor screening, as well as tumor follow-up. The progressive integration of PET/CT imaging in radiotherapy has its basic principle in the biological heterogeneity of inter- and intra-tumor malignant lesions, and the radiation dose is required to be adjusted to achieve effective local tumor control among cancer patients. In addition, PET/CT imaging provides data on the biological features of tumor lesions, such as metabolism, hypoxia, and proliferation, which is useful to identify radiation-resistant regions and optimize treatment plans. These data are effective to reduce the uncertainty and variability in the anatomic description of tumor sites. This review summarizes the application of PET/CT imaging in common tumors.

How much exposure dose does a patient receive in PET/CT examination? / 中国辐射卫生

@#Positron emission tomography/computed tomography (PET/CT) scanner is an irreplaceable instrument in clinical diagnosis. The exposure dose that a patient receives is the sum of the doses caused by PET and CT examination. This study discussed the exposure dose level that a patient received during PET/CT examination according to the research data. Like other radiological diagnostic methods, PET/CT examination brings benefits outweighing its radiation risk. It is not advisable to exaggerate or ignore the exposure dose. The patient’s exposure dose caused by PET/CT examination should be controlled as much as possible under the premise of meeting clinical needs.

18F-FDG PET/CT Metabolic Parameters and Circulating Tumour DNA Mutation Abundance in Diffuse Large B-Cell Lymphoma: Correlation and Survival Analysis / 中国实验血液学杂志

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.

Application of interim PET-CT in first-line treatment decision-making for lymphoma / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Recent advances in lymphoma treatment have significantly improved the survival of patients; however, the current approaches also have varying side effects. To overcome these, it is critical to implement individualized treatment according to the patient's condition. Therefore, the early identification of high-risk groups and targeted treatment are important strategies for prolonging the survival time and improving the quality of life of patients. Interim positron emission tomography-computed tomography (PET-CT) has a high prognostic value, which can reflect chemosensitivity and identify patients for whom treatment may fail under this regimen. To date, many prospective clinical studies on interim PET (iPET)‍-adapted therapy have been conducted. In this review, we focus on the treatment strategies entailed in these studies, as well as the means and timing of iPET assessment, with the aim of exploring the efficacy and existing issues regarding iPET-adapted treatment. It is expected that the improved use of PET-CT examination can facilitate treatment decision-making to identify precise treatment options.

Configuration and type-selection of PET/CT and PET/MR equipment during the period of National 14th Five-Year Plan / 中国医学装备

Objective:To explore the configuration conditions and type-selections of positron emission tomography/computed tomography(PET/CT)and positron emission tomography/magnetic resonance(PET/MR)system under the national new policies during the 14th Five-Year Plan period,so as to provide references for configuration and type-selection of PET/CT and PET/MR equipment of medical institutions.Methods:According to the management polices of relevant configurations of PET/CT and PET/MR,which included configuration licensing,use management and configuration plan,and which were issued by China 14th Five-Year Plan,as well as the development trend and characteristics of PET/CT and PET/MR new techniques,the configuration conditions and type-selection plan of PET/CT and PET/MR equipment were analyzed.Results:Under the new polices during national 14th Five-Year Plan,medical institutions should configure PET/CT and PET/MR depended on the condition of institutions,personnel condition,work basis,the supporting facilities and other conditions,and should select the type of PET/CT and PET/MR which can meet the requirements of medical institutions depended on the technique parameters and performance indicators of PET/CT and PET/MR.Conclusions:Since the 14th Five-Year Plan,there were significant changes in the new policies related to the configurations of PET/CT and PET/MR compared to previous policies.The medical institutions should apply configurations and use PET/CT and PET/MR as new requirement,and configure the PET/CT and PET/MR equipment and conduct type-selection of them as various requirements of each institution.

Preoperative evaluation of prostate cancer by 68Ga-PMSA positron emission tomography/computed tomography: comparison with magnetic resonance imaging and with histopathological findings / Avaliação pré-operatória do câncer de próstata pela tomografia por emissão de pósitrons/tomografia computadorizada com PSMA-68Ga: comparação com ressonância magnética e com achados histopatológicos

Abstract Objective: To evaluate the accuracy of preoperative positron emission tomography/computed tomography with 68Ga-labeled prostate-specific membrane antigen (68Ga-PSMA PET/CT) for staging prostate cancer and compare it with magnetic resonance imaging (MRI) using histopathology of surgical specimens as the gold standard. Materials and Methods: In this retrospective study, 65 patients with prostate cancer were analyzed. Results: The accuracy of 68Ga-PSMA PET/CT for tumor detection was 95%, and that of MRI was 91%. There was no difference between 68Ga-PSMA PET/CT and MRI regarding localization of the lesion. The sensitivity of 68Ga-PSMA PET/CT for detecting extraprostatic extension was quite low (14%). For detection of seminal vesicle invasion, 68Ga-PSMA PET/CT showed a sensitivity of 57% and accuracy of 91%. There was a moderate correlation between the maximum standardized uptake value (SUVmax) and the serum level of prostate-specific antigen (p < 0.01; ρ = 0.368) and between the SUVmax and the International Society of Urological Pathology (ISUP) grade (p < 0.01; ρ = 0.513). Conclusion: 68Ga-PSMA PET/CT is a promising tool for detecting and evaluating the primary tumor, which can alter the staging and management of the disease.

Resumo Objetivo: Avaliar a acurácia da tomografia por emissão de pósitrons/tomografia computadorizada com PSMA (PET-PMSA) pré-operatória para estadiamento do câncer de próstata e compará-la com a ressonância magnética (RM) utilizando o histopatológico cirúrgico como padrão ouro. Materiais e Métodos: Neste estudo retrospectivo foram analisados 65 pacientes com câncer de próstata. Resultados: A acurácia da PET-PSMA para a detecção tumoral foi de 95% e a da RM foi de 91%. Não houve diferença entre a PET-PSMA e a RM quanto à localização da lesão. A PET-PSMA apresentou baixa sensibilidade (14%) para detecção de extensão extraprostática em comparação ao histopatológico. Para detecção de invasão de vesícula seminal, a PET-PSMA apresentou sensibilidade de 57% e acurácia de 91% em comparação ao histopatológico. Houve correlação moderada entre o SUVmax e o PSA (p < 0,01; ρ = 0,368) e entre o SUVmax e o ISUP (p < 0,01; ρ = 0,513). Conclusão: A PET-PSMA é uma ferramenta promissora para detecção e avaliação do tumor primário, alterando o estadiamento e a conduta do paciente.

Musculoskeletal pitfalls in 68Ga-PSMA PET/CT / Pitfalls do sistema musculoesquelético na PET/CT com 68Ga-PSMA

Abstract Prostate-specific membrane antigen (PSMA) is a transmembrane protein expressed in normal prostate cells and overexpressed in prostate cancer. Consequently, it is an important tool in the evaluation of prostate cancer, including the staging of high-risk patients and the assessment of biochemical recurrence. Despite the "specific" designation, benign musculoskeletal conditions, such as fractures, osteodegenerative changes, and fibrous dysplasia, can also show PSMA uptake, which can lead to misinterpretation of the imaging findings. Therefore, radiologists must be aware of these potential pitfalls, understand their causes, and fully analyze their morphologic features on unfused computed tomography (CT) and magnetic resonance imaging scans to correctly interpret the examination. In this pictorial essay, we review the basic characteristics of the 68Ga-PSMA positron-emission tomography/CT (PET/CT) radiotracer, discuss potential causes of false-positive findings on 68Ga-PSMA PET/CT in the musculoskeletal system, and illustrate the corresponding imaging findings.

Resumo O antígeno de membrana próstata específico (PSMA) é uma proteína transmembrana que apresenta expressão em células prostáticas normais e superexpressão em neoplasia da próstata. Dessa forma, é uma importante ferramenta na avaliação da neoplasia prostática, de utilidade no estadiamento de pacientes de alto risco e na análise de recorrência bioquímica. Apesar do termo "específico", condições musculoesqueléticas benignas podem demonstrar captação de PSMA, como fraturas, alterações osteodegenerativas e displasia fibrosa, podendo levar a uma avaliação equivocada dos achados de imagem. Assim, o radiologista deve conhecer esses potenciais pitfalls, compreender suas causas e analisar as características morfológicas nas imagens não fundidas de TC e RM para interpretar corretamente o exame. Neste ensaio iconográfico, revisaremos as características básicas do radiofármaco 68Ga-PSMA PET/CT, discutiremos possíveis causas de resultados falso-positivos na 68Ga-PSMA PET/CT no sistema musculoesquelético e ilustraremos os achados de imagem correspondentes.

Antimicrobial peptide for bacterial infection imaging: first case reported in Brazil

ABSTRACT Molecular imaging markers can be used to differentiate between infection and aseptic inflammation, determine the severity of infection, and monitor treatment responses. One of these markers is ubiquicidin(29-41) (UBI), a cationic peptide fragment that binds to the bacterial membrane wall and is labeled with gallium-68 (68Ga), a positron emitter radioisotope. The use of UBI in positron emission tomography (PET)/computed tomography (CT) for improved detection of lesions has been receiving considerable attention recently. Herein, we report the first case of 68Ga-UBI PET/CT performed in Brazil. The patient was a 39-year-old woman referred for a scan to confirm a clinical suspicion of chronic osteomyelitis of her fractured left tibia. PET images revealed radiotracer uptake near the posterior contour of the tibial fracture focus and the fixation plate, in the soft tissue around the distal half of the tibia, and in the non-consolidated fracture of the left distal fibula. Surgery for local cleaning was performed, and culture of a specimen collected from the surgical site confirmed the presence of Staphylococcus aureus. In the present case, 68Ga-UBI PET/CT, a non-invasive imaging modality, identified the infection foci in vivo, indicating its potential for clinical use.

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.

La intensidad de la captación intraprostática del PSMA como predictor de cáncer de próstata clínicamente significativo / The intensity of PSMA intraprostatic uptake as a predictor of clinically significant prostate cancer

Resumen Introducción: La tomografía por emisión de positrones (PET) con antígeno de membrana específico de próstata (PSMA) mejora la estadificación del cáncer de próstata. Además, la intensidad de captación intraprostática del PSMA puede predecir resultados oncológicos clínicamente relevantes. Nuestro objetivo fue evaluar si la intensidad de captación de PSMA se asocia con el cáncer de próstata clínicamente significativo y poder conocer qué valor de captación de PSMA discrimina mejor esta relación. Métodos: Se realizó un estudio de cohorte de 40 pacientes con cáncer de próstata comprobado por biopsia previo a la realización de radioterapia externa. Se evaluó correlación entre intensidad de captación del PSMA intraprostático y los resulta dos patológicos adversos en la biopsia prostática. Se estudió qué valor de captación de PSMA discrimina mejor el cáncer de próstata clínicamente significativo utilizando curvas ROC. Resultados: El 40% de los pacientes tuvieron un cáncer de próstata clínicamente significativo, el maximum standardized uptake value (SUV max) tuvo una media de 11.5 (DE ± 7). La muestra arrojó un coeficiente de correlación Spearman de 0.4 (p = 0.007). El área bajo la curva (AUC) fue de 0.73, mostrando el punto de corte un SUV max ≥ 9.5, sensibilidad 0.81 y especificidad 0.71 en la detección de cáncer de próstata clínicamente significativo. Conclusión: la intensidad de captación del PSMA intraprostático puede ser una nueva herramienta diagnóstica en la detección del cáncer de próstata clínicamente significativo. Una intensidad de captación ≥ 9.5 tuvo una buena correlación con el cáncer de próstata clínicamente significativo.

Abstract Introduction: Positron emission tomography (PET) with prostate-specific membrane antigen (PSMA) improves prostate cancer staging. Furthermore, the intensity of intraprostatic uptake of PSMA can predict clinically relevant oncologic outcomes. The objective of this study is to evaluate whether the intensity of PSMA uptake is associated with clinically significant prostate cancer and to determine which value of PSMA uptake best dis criminates this relationship. Methods: A cohort study of 40 patients with biopsy-proven prostate cancer prior to external radiotherapy was conducted. The correlation between intraprostatic PSMA uptake intensity and adverse pathological findings in prostate biopsy was evaluated. Which PSMA uptake value better discriminates clinically significant prostate cancer was assessed using ROC curves. Results: Forty percent of the patients had a clinically significant prostate cancer and the maximum standardized uptake value (SUV max) had a mean of 11.5 (SD ± 7). The sample showed a Spearman correlation coefficient of 0.4 (p = 0.007). The area under the curve (AUC) was 0.73 and a SUV max ≥ 9.5 showed a sensitivity of 0.81 and a specificity of 0.71 in the detection of clinically significant prostate cancer. Conclusion: Intraprostatic PSMA uptake intensity can be a new diagnostic tool in the detection of clinically significant prostate cancer. An uptake intensity equal or greater than 9.5 is correlated with clinically significant prostate cancer.

Performance of 68Ga-labeled prostate-specific membrane antigen ligand positron emission tomography/computed tomography in the diagnosis of primary prostate cancer: a systematic review and meta-analysis

ABSTRACT Objective: To explore the feasibility of 68Ga-PSMA PET/CT in diagnosing primary prostate cancer. Materials and Methods: Embase, PubMed and Cochrane Library databases were searched for studies published before July 2020. The studies that used 68Ga-PSMA PET/CT for detecting primary prostate cancer, and pathological biopsy as the reference standard were included. The selecting process used preferred reporting items for systematic reviews and meta-analyses (PRISMA). The quality of enrolled studies was assessed by the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Results: According to our search strategy, 9 studies were included for analysis. A total of 547 patients with primary prostate cancer and 443 lesion segments that underwent 68Ga-PSMA PET/CT scans were included and their pathological biopsies were compared. The results of these studies showed some differences. For instance, the lowest sensitivity of 68Ga-PSMA PET/CT in diagnosing primary prostate cancer was 67%, while the highest sensitivity recorded was 97%. Conclusions: Compared with conventional imaging examinations, 68Ga-PSMA PET/CT had higher sensitivity and specificity in detecting primary prostate cancer. At present, most of the studies that used 68Ga-PSMA PET/CT for detecting prostate cancer are retrospective studies. Based on its advantage of high detection rate, the use of 68Ga-PSMA PET/CT in the detection of primary prostate cancer is worthy of promotion.

Patient with Rosai-Dorfman-Destombes disease:18F-FDG-PET/CT as a diagnostic tool

Rosai-Dorfman-Destombes disease (RDD) is a rare non-Langerhans cell histiocytosis, with sinus involvement and massive lymphadenopathy. RDD is usually self-limited; it can appear alone or related to other diseases. We present a 9-year-old male with biopsy of that lesion was taken, giving as result a benign histiocytosis, compatible with RDD. The patient was scanned with full body 18F-FDG PET/CT, the results of the study showed hypermetabolic focal lesions in the sphenoid sinus, ethmoid sinus, and bilateral nasal involvement with hypermetabolic focal injury in the middle third of the left tibia, findings in relation to high-grade expansive injury. The study of 18F-FDG PET/CT demonstrated avid FDG lesions at nodal and extranodal sites, and it also can be used in monitoring and/or evaluating response to treatment.

La enfermedad de Rosai-Dorfman-Destombes (RDD) es una rara histiocitosis de células no Langerhans, con compromiso de los senos nasales y linfadenopatías masivas. RDD es usualmente autolimitada, y puede aparecer sola o asociada a otras enfermedades. Se presenta el caso de un niño varón de 9 años cuyo resultado histopatológico mostró histiocitosis benigna compatible con RDD. El paciente se sometió a una Tomografía Computarizada/Tomografía de Emisión de Positrones con 18F-fluorodeoxyglucosa (18F-FDG-TEP/TC) de todo el cuerpo, que mostró lesiones focales hipermetabólicas en los senos esfenoidales, etmoidales, y nasales bilaterales, junto a una lesión focal hipermetabólica en el tercio medio de la tibia izquierda. El estudio con 18F-FDG-PET/CT pudo demostrar lesiones ávidas de glucosa en sitios nodales y extra-nodales, y también puede servir en la monitorización o evaluación de la respuesta al tratamiento.