Prognostic role of metabolic 18F?FDG PET/CT parameters and hematological prognostic indicators in patients with colorectal cancer

Background: The aim of this study is to evaluate the role of preoperative 18F?fluorodeoxyglucose (FDG) positron emission tomography朿omputed tomography (PET/CT) parameters, including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), hematologic prognostic indicators in patients with colorectal cancer (CRC) in terms of predicting prognosis. Methods: One hundred and one patients who had undergone 18F?FDG PET/CT for initial staging were evaluated retrospectively. Patient data including pathologic stage at presentation, histology, tumor location, and overall survival (OS) were analyzed. Neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), serum carcinoembryonic antigen (CEA) (ng/mL), CA?125 (cancer antigen 125) (U/mL), and CA19?9 (U/mL) levels, which were obtained within 2 weeks of the PET/CT examination, were used for hematological data. Results: The TNM Classification of Malignant Tumors stage and PET/CT parameters, including SUVmax, MTV, and TLG, were found to be correlated with survival rate in univariate analysis (P < 0.05). All hematological markers excluding PLR were also significantly associated with survival time. Receiver operating characteristics (ROC) analysis revealed that the optimal SUVmax cutoff value for predicting survival time in patients with CRC was >17.9 (Area under curve (AUC) = 0.625; P < 0.05). The calculated sensitivity and specificity values for this cutoff were 60% and 65.7%, respectively. To predict the survival time in these patients, the optimal MTV cutoff value was >34.29 (AUC = 0.775; P < 0.001; sensitivity = 85%; specificity = 62.3%). The optimal TLG cutoff value for predicting survival time was >270.4 (AUC = 0.790; P < 0.001; sensitivity = 77.5%; specificity = 68.9%). Conclusions: FDG PET/CT metabolical parameters are useful for predicting the prognosis in patients with CRC. High preoperative NLR and high tumor markers were also shown to be negative independent prognostic factors in these patients

Evaluation of 18FDG PET-CT-positive mediastinal-hilar lymph nodes in extrathoracic malignancies by EBUS-TBNA; correlation of SUVmax, and short-axis diameter with the final diagnosis

Introduction: Intrathoracic lymph node metastasis from extrathoracic neoplasms are rare. Primary malignancies that metastasize to mediastinal-hilar lymph nodes are head and neck , carcinoma breast ,and genitourinary. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA)/endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is currently the preferred modality for mediastinal lymph node sampling. Methods: Fifty seven patients with extrathoracic malignancies with maximum standardized uptake value (SUVmax) of mediastinal-hilar lymph nodes greater than or equal to 2.5 were taken up for EBUS-TBNA. The histo-cytopathological results obtained from EBUS-TBNA were compared with SUVmax value and short-axis diameter of a lymph node as noted on EBUS. Results: Out of 74 sampled nodes, 49 (66.2%) were benign and 25 (33.8%) were malignant. The SUVmax range of benign nodes was 2.8� as compared to 3� of malignant nodes. The size range of malignant and benign nodes were 8� mm and 8� mm, respectively. The mean size of abnormal nodes (metastatic + granulomatous) was 17.5 (8� mm) and the mean SUVmax was 9.1 (3.4�), and it was a statistically significant difference when compared to reactive (normal) nodes. At SUVmax cut-off 7.5, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) were 78.5%, 81.2%, 84.6%, and 74.2%, respectively for detecting abnormal nodes. At 13 mm size cut-off, sensitivity, specificity, PPV, NPV were 75.5%, 65%, 75%, and 72%, respectively, for detecting abnormal nodes. Conclusion: The majority of mediastinal-hilar nodes with increased metabolic activity are benign in nature. Size and SUVmax are poor predictors of metastasis in tuberculosis endemic region. There should be a restrictive attitude toward invasive diagnostic testing for mediastinal-hilar nodes in extrathoracic malignancies.

The role of MRI and 18F-FDG PET/CT with respect to evaluation of pathological response in the rectal cancer patients after neoadjuvant chemoradiotherapy

Background: We aimed to evaluate the role of magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (FDG) positron emission tomography朿omputed tomography (PET-CT) in determining the correct stage and predicting the pathological response. Methods: Seventy one patients with pathologic proven rectal adenocarcinoma, clinical stage IIA-IVA, and neoadjuvant chemoradiotherapy (CRT) were evaluated retrospectively. Radiotherapy was delivered 45� Gy in 25 fractions with concomitant oral capecitabine. Pelvic MRI, colonoscopy, and 18F-FDG PET-CT were performed before the neoadjuvant treatment (NAT). After NAT, MRI and PET-CT were performed for re-evaluation. Results: The median follow-up time was 25 months (range: 3� months). Of the 71 patients who underwent NAT, 57 patients underwent surgery. Downstaging was recorded in 48 (84.2%) of 57 patients who underwent surgery. There was no statistically significant difference between both MRI and PET-CT with pathology results in terms of response evaluation. As a result of the comparison of MRI and PET-CT with pathological results; sensitivity and specificity were 91.6% (44/48) and 22.2% (2/9) for MRI, and 100% (47/47) and 12.5% (1/8) for PET-CT, respectively. Conclusion: PET-CT and MRI are effective in predicting response to NAT and predictive for the pathological response. A more accurate response can be judged when both PET-CT and MRI are executed together in restaging after NAT

Complete response in metastatic breast cancer with visceral crisis using a combination of cyclin-dependent kinase 4/6 inhibitor and aromatase inhibitor: A case report from the eastern region of India

Patients with metastatic breast cancer (MBC) in visceral crisis require systemic chemotherapy. However, a coexisting cardiac failure that contradicts the use of systemic chemotherapy often demands an alternative treatment. Here, we report a case of hormone-receptor-positive MBC with cardiological comorbidities. She was treated with a combination treatment of tablet Ribociclib (600 mg once daily for 21 days followed by 7 days gap) and tablet Letrozole (2.5 mg once daily). The patient had a complete metabolic response in 18-Fluorodeoxyglucose Positron Emission tomography-Computed Tomography (18F-FDG PET/CT), after 6 months of treatment. Combination treatment with Ribociclib and Letrozole is beneficial in postmenopausal females with hormone receptor-positive and human epidermal growth factor receptor 2 neu-negative MBC in visceral crisis who have a contraindication to chemotherapy.

Application of 18F-FDG PET-CT Simulation Localization in Radiotherapy of Recurrent Abdominal and Pelvic Tumors / 肿瘤防治研究

Objective To investigate the clinical application value of 18F-FDG PET-CT simulation localization in radiotherapy of recurrent abdominal and pelvic tumors. Methods 18F-FDG PET-CT was used to simulate positioning 38 patients with abdominal and pelvic tumors who relapsed after treatment.Based on both CT images and 18F-FDG PRT-CT, we drew up a systemic treatment plan and outlined the radiotherapy target area, and then compared the differences between the two methods. Results In 38 patients, 21.1%(3/8) of patients were found to have distal metastases outside the pelvic and abdominal cavity, and changed the systemic treatment plan.The radiotherapy target was altered in 34(89.5%) patients.The mean value of GTVPET-CT was 118.14cm3and the mean value of GTVCT was 148.53cm3(P=0.044). Conclusion For patients with recurrent abdominal and pelvic tumors, 18F-FDG PET-CT simulation localization treatment improves tumor re-staging, changes the integrated therapy for some patients, and makes the target area of radiotherapy more accurate.

Research Advances on Application of 18F-FDG PET/CT in Clinical Diagnosis and Treatment of Hepatocellular Carcinoma / 肿瘤防治研究

Hepatocellular carcinoma (HCC) has high mortality, low early diagnosis rate, relatively poor treatment outcomes and prognosis. 18F-FDG PET/CT has an important application value on the detection of HCC metastasis, early recurrence and treatment prognosis. This paper summarizes and reviews the research progress on the application of 18F-FDG PET/CT in HCC diagnosis, liver transplantation, surgical resection and local ablation, to provide references for clinicians to make rational use of 18F-FDG PET/CT imaging technology in accurate diagnosis and treatment of HCC.

Primary Malignant Melanoma of the esophagus in a 39-year-old Filipino male: A case report

@#Primary malignant melanoma of the esophagus (PMME) is an exceptionally rare condition, representing a mere 0.1 to 0.2% of esophageal cancers, and accounting for just 0.1 to 0.5% of all melanomas. This case involves a 39 -year-old Filipino male who sought medical attention after an episode of choking. Subsequently, endoscopy with biopsy revealed a mass in the distal third of the esophagus, ultimately diagnosed as PMME based on histopathology and immunohistochemistry. FDG-PET/CT scan revealed a hypermetabolic distal esophageal mass and a confluent upper paratracheal lymphadenopathy. He was initially treated with Pembrolizumab, Nivolumab, and Ipilimumab immunotherapy. However, post-treatment FDG PET/CT scans unveiled metabolic progression of the esophageal mass with new hypermetabolic cervical lymph nodes, necessitating a shift to carboplatin and paclitaxel chemotherapy. After two cycles, there was a notable metabolic regression of the mass and paratracheal node with metabolic resolution of the cervical lymph node. An additional 2 cycles of chemotherapy were given, aimed to further reduce the size of the tumor, however, a succeeding follow-up study revealed metabolic progression of the mass. Surgical resection of both the esophageal mass and paratracheal nodes became imperative. The aggressive characteristics, metastasis at early diagnosis, and lack of effective treatment have contributed to the poor prognosis of PMME. Total esophagectomy is the preferred method of treatment. Chemotherapy and immunotherapy may be used in advanced diseases but with variable efficacy. The utilization of FDG PET/CT scans plays a crucial role in both the initial staging and the ongoing assessment of treatment response in patients diagnosed with PMME. This advanced imaging modality offers valuable insights into the extent of the disease and aids clinicians in evaluating the effectiveness of the chosen therapeutic interventions. Given the rarity and challenges associated with PMME, a multidisciplinary approach integrating surgical, medical, and imaging strategies is essential for comprehensive patient care.

Prognostic value of 18F-FDG PET/CT parameters and histopathologic variables in head and neck cancer / Valor prognóstico de parâmetros de PET/TC com 18F-FDG e variáveis histopatológicas em câncer de cabeça e pescoço

Abstract Introduction 18F-fluorodeoxyglucose positron emission tomography/computed tomography parameters such as; maximum standardized uptake values, standard metabolic tumor volume and otal lesion glycosis are important prognostic biomarkers in cancers. Objective To investigate the prognostic value of these parameters in patients with head and neck cancers. Methods We performed a retrospective study including 47 patients with head and neck cancer who underwent18F-fluorodeoxyglucose positron emission tomography/computed tomography prior to treatment. Standard metabolic tumor volume, otal lesion glycosis and standardized uptake were measured for each patient. The prognostic value of quantitative 18F-fluorodeoxyglucose positron emission tomography/computed tomography parameters and clinicopathologic variables on disease free survival and overall survival were analyzed. Results The median (range) standard metabolic tumor volume and otal lesion glycosis and standardized uptake were 7.63 cm3 (0.6-34.3), 68.9 g (2.58-524.5 g), 13.89 (4.89-33.03 g/mL), respectively. Lymph node metastases and tumour differentiation were significant variables for disease free survival and overall survival, however, all 18F-fluorodeoxyglucose positron emission tomography/computed tomography parameters were not associated with disease- free survival and overall survival. Conclusion Pretreatment quantities positron emission tomography parameters did not predict survival in head and neck cancer.

Resumo Introdução Os parâmetros da tomografia por emissão de pósitrons/tomografia computadorizada com 18F-fluordesoxiglicose, como os máximos valores de captação padronizados, o volume metabólico tumoral padrão e a glicólise total da lesão são importantes biomarcadores prognósticos de câncer. Objetivo Investigar o valor prognóstico desses parâmetros em pacientes com câncer de cabeça e pescoço. Método Fizemos um estudo retrospectivo que incluiu 47 pacientes com câncer de cabeça e pescoço e que foram submetidos à tomografia por emissão de pósitrons/tomografia computadorizada com 18F-fluordesoxiglicose antes do tratamento. Volume metabólico tumoral, glicólise total da lesão e valores de captação padronizados foram aferidos em cada paciente. O valor prognóstico de parâmetros quantitativos da tomografia por emissão de pósitrons/tomografia computadorizada com 18F-fluordesoxiglicose e das variáveis clínico-patológicas sobre a sobrevida livre de doença e a sobrevida geral foi analisado. Resultados A média (intervalo) de volume metabólico tumoral e glicólise total da lesão e valores de captação padronizados foram 7,63 cm3 (0,6-34,3), 68,9 g (2,58-524,5) e 13,89 g/mL (4,89-33,03), respectivamente. Metástase nos nódulos linfáticos e diferenciação tumoral foram variáveis significativas de sobrevida livre de doença e sobrevida geral; contudo, nenhum parâmetro da tomografia por emissão de pósitrons/tomografia computadorizada com 18F-fluordesoxiglicose estava associado a sobrevida livre de doença e sobrevida geral. Conclusão As quantidades dos parâmetros da tomografia por emissão de pósitrons pré-tratamento não previram a sobrevida em câncer de cabeça e pescoço.

Imágenes en endocarditis infecciosa: no todo es ecocardiografía / Imaging in infective endocarditis: not all is ultrasonography

Resumen La endocarditis infecciosa (EI) es una enfermedad de alta mortalidad, caracterizada por una infección endocárdica y frecuentes complicaciones multiorgánicas, que requiere un diagnóstico rápido y preciso, y un manejo agresivo, ya sea médico o quirúrgico. Su diagnóstico se realiza tomando en cuenta criterios bacteriológicos, clínicos y ecocardiográficos. Es objetivo de este artículo realizar una actualización del estudio imagenológico en paciente con EI, con especial énfasis en aquellos exámenes no ecocardiográficos disponibles en nuestro medio. En los últimos años, estudios de imagen avanzados han adquirido un rol creciente en su estudio inicial, particularmente la tomografía computada multicorte (TCMC) cardiaca y el positron emission tomography/computed tomography (PET/CT), y han sido recomendados como criterios diagnósticos en las guías recientes para el manejo de esta entidad. La TCMC cardiaca proporciona información anatómica detallada de las válvulas cardiacas y tejido perivalvular, identificando pseudoaneurismas, abscesos y dehiscencias valvulares. El PET/CT con F18-fluorodeoxiglucosa (F18-FDG) permite aumentar la sensibilidad en la detección de EI, y pesquisar con alta eficiencia fenómenos embólicos sistémicos, de elevada frecuencia en esta población. Ambos métodos prestan particular utilidad en EI de válvula protésica, donde la ecocardiografía presenta menor rendimiento diagnóstico. La resonancia magnética (RM) cerebral es el mejor método de imagen para descartar eventos isquémicos/embólicos del sistema nervioso central.

Abstract Infective endocarditis (IE) is an entity characterized by endocardial infection and frequent multiorgan complications, resulting in high mortality. It requires a rapid and accurate diagnosis, and a medical or surgical aggressive treatment. Currently, IE diagnosis rests on bacterial, clinical and ultrasonographic criteria. The objective of this article is to update the imaging study in patients with IE, with special emphasis on those non-echocardiographic examinations available in our environment. Last years, advanced imaging had achieved a growing role in IE diagnosis, especially cardiac multislice computed tomography (MSCT) and positron emission tomography/computed tomography (PET/CT), which have been recommended in recent clinical guidelines to be included as part of diagnostic criteria. Cardiac MSCT provides detailed anatomic information of cardiac valves and perivalve tissue, allowing identification of pseudoaneurysm, abscess and valve dehiscence. F18-FDG PET/CT increases sensitivity for IE detection and shows high accuracy in searching for extracranial systemic embolic events. Both MSCT and PET/CT have particular utility in cases of prosthetic valve endocarditis, where cardiac ultrasonography shows lower performance. Brain magnetic resonance imaging (MRI) is the best imaging method for evaluating ischemic/embolic events of central nervous system.

Chronic Periaortitis – Review and Presentations

Chronic periaortitis is a rare inflammatory condition predominantly affecting the abdominal segment of the aorta. This can present as IgG4 related inflammatory disease, idiopathic retroperitoneal fibrosis, perianeurysmal retroperitoneal fibrosis andinflammatory abdominal aortic aneurysm (IAAA). Aortitis can also be a manifestation of a number of rheumatological large vessel vasculitides such as Takayasu arteritis and giant cell arteritis (GCA). We present three interesting cases of chronic periaortitis and a literature review. The first case showsa classic picture ofIgG4 periaortitis. The second case illustrates periaortitis with retroperitoneal fibrosis, ureteric involvement and hydronephrosis, following abdominal aortic aneurysmal stenting. The final case presents as widespread periaortitis due to Takayasu's disease involving the entire aorta including the arch and root of the subclavian artery

Relationship between SUVmax in 18F-FDG PET/CT and PD-L1 expression in invasive lung adenocarcinoma / 中国胸心血管外科临床杂志

@#Objective    To investigate the relationship between the expression of programmed cell death ligand-1 (PD-L1) and the maximal standardized uptake value (SUVmax) in 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and the correlation of clinical factors between SUVmax values and PD-L1. Methods    The clinical data of 84 patients with invasive lung adenocarcinoma diagnosed pathologically in West China Hospital, Sichuan University from August 2016 to November 2018 were analyzed retrospectively, including 38 males and 46 females, aged 60 (32-85) years. The tumor was acinar-predominant in 37 patients, papillary in 20, lepidic in 19, solid in 5 and micropapillary in 3. Multivariate analysis of the relationship between SUVmax value and other clinicopathological features was performed by linear regression. Logistic regression analysis was used to analyze the relationship between PD-L1 protein expression and other pathological features. Results    The SUVmax of the PD-L1 expression group was significantly higher than that of the non-PD-L1 expression group in the whole invasive lung adenocarcinoma group (P=0.002) and intermediate-grade histologic subtype (P=0.016). The SUVmax cut-off value of PD-L1 expression in the whole invasive lung adenocarcinoma group and intermediate-grade histologic subtype was 5.34 (AUC: 0.732, P=0.002) and 5.34 (AUC: 0.720, P=0.017), respectively. Multivariate analysis showed that pleura involvement, vascular tumor thrombus and the increase of tumor diameter could cause the increase of the SUVmax value, while the SUVmax value decreased in the moderately differentiated tumor compared with the poorly differentiated tumor. The SUVmax cut-off value between low-grade histologic subtype and intermediate-grade histologic subtype, intermediate-grade histologic subtype and high-grade histologic subtypes was 1.54 (AUC: 0.854, P<0.001) and 5.79 (AUC: 0.889, P<0.001), respectively. Multivariate analysis of PD-L1 expression showed pleura involvement (P=0.021, OR=0.022, 95%CI 0.001 to 0.558) and moderate differentiation (opposite to poor differentiation) (P=0.004, OR=0.053, 95%CI 0.007 to 0.042) decreased the expression of PD-L1. Conclusion    The SUVmax of the PD-L1 expression group is significantly higher than that of the non-PD-L1 expression group in the whole invasive lung adenocarcinoma group and intermediate-grade histologic subtype. The level of SUVmax and the expression of PD-L1 in invasive lung adenocarcinoma are related to many clinical factors.

Tomografía por emisión de positrones con 18F-fluordeoxiglucosa-tomografía computarizada en el diagnóstico del tumor primario de origen desconocido / Value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography ın the diagnosis of carcinoma of unknown primary origin

Introducción: La incidencia de tumores primarios de origen desconocido en pacientes oncológicos es del 0,5 al 7 por ciento en el momento del diagnóstico con una supervivencia a los 3 y 5 años de 11 y 6 por ciento, respectivamente. Objetivo: valorar la utilidad de la técnica PET/CT-FDG (Tomografía por emisión de positrones con 18F-Fluordeoxiglucosa) en el diagnóstico de tumor primario de origen desconocido (TOD). Material y método: Se analizaron retrospectivamente los estudios PET/CT-FDG realizados en pacientes con el diagnóstico de TOD para la búsqueda de tumor primario, con estudios convencionales previos negativos, entre noviembre de 2017 y junio de 2018. El diagnóstico final se estableció mediante confirmación histológica y/o seguimiento clínico/radiológico por 8 meses. Resultados: 42 pacientes fueron estudiados, en 19 estudios PET/CT se evidenciaron focos de captación sugestivos de tumor primario, de los cuales 9 se confirmaron histológicamente como verdaderos positivos y sólo 1 correspondió a un falso positivo. De los 23 pacientes con PET/CT negativos para tumor primario, todos continuaron con diagnóstico de TOD a pesar de las múltiples pruebas diagnósticas. Conclusiones: La técnica PET/CT permitió identificar el 45,2 por ciento de los tumores primarios en la muestra de pacientes, lo que la convierte en una herramienta útil para el diagnóstico en pacientes con metástasis de origen desconocido. Se considera que el PET/CT-FDG debe ser incluido de manera precoz en los algoritmos diagnósticos en Cuba, permitiendo orientar la realización de pruebas complementarias subsiguientes(AU)

Introduction: The incidence of carcinoma of unknown primary origin in oncologic patients is from 0,5 percent to 7 percent at the time of diagnosis with an overall 3-year and 5-year survival of 11 percent and 6 percent, respectively. Objective: To assess the effectiveness of 18 F-FDG-PET/CT (18F-fluorodeoxyglucose posıtron emıssıon tomography) in the diagnosis of carcinoma of unknown primary origin (CUP). Material and Methods: F-FDG-PET/CT studies were conducted in patients with CUP in the search for primary tumor with negative previous conventional studies carried out from November, 2017 to June 2018. The final diagnosis was established by histological confirmation and/or clinical/radiological follow-up during 8 months. Results: A total of 44 patients were studied. There were evidences of suggestive CUP in 19 patients; 9 of them were histologically confirmed as true-positive and only 1 was a false-positive. Of the 23 patients with negative F-FDG-PET/CT studies for primary tumor, all of them continued with the diagnosis of CUP in spite of multiples diagnostic tests. Conclusions: The FDG-PET/CT technique allowed to identify 45,2 percent of the primary tumors in this study, which demonstrates that it is very useful tool for the diagnosis of metastases of unknown origin. It is considered that F-FDG-PET/CT studies should be included earlier in the diagnostic algorithms in Cuba, which will allow to indicate subsequent complementary tests(AU)

Distinguishing between Thymic Epithelial Tumors and Benign Cysts via Computed Tomography

OBJECTIVE: To investigate whether computed tomography (CT) and fluorine-18-labeled fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) may be applied to distinguish thymic epithelial tumors (TETs) from benign cysts in the anterior mediastinum. MATERIALS AND METHODS: We included 262 consecutive patients with pathologically proven TETs and benign cysts 5 cm or smaller who underwent preoperative CT scans. In addition to conventional morphological and ancillary CT findings, the relationship between the lesion and the adjacent mediastinal pleura was evaluated qualitatively and quantitatively. Mean lesion attenuation was measured on CT images. The maximum standardized uptake value (SUVmax) was obtained with FDG-PET scans in 40 patients. CT predictors for TETs were identified with multivariate logistic regression analysis. For validation, we assessed the diagnostic accuracy and inter-observer agreement between four radiologists in a size-matched set of 24 cysts and 24 TETs using a receiver operating characteristic curve before and after being informed of the study findings. RESULTS: The multivariate analysis showed that post-contrast attenuation of 60 Hounsfield unit or higher (odds ratio [OR], 12.734; 95% confidence interval [CI], 2.506–64.705; p = 0.002) and the presence of protrusion from the mediastinal pleura (OR, 9.855; 95% CI, 1.749–55.535; p = 0.009) were the strongest CT predictors for TETs. SUVmax was significantly higher in TETs than in cysts (5.3 ± 2.4 vs. 1.1 ± 0.3; p < 0.001). After being informed of the study findings, the readers' area under the curve improved from 0.872–0.955 to 0.949–0.999 (p = 0.066–0.149). Inter-observer kappa values for protrusion were 0.630–0.941. CONCLUSION: Post-contrast CT attenuation, protrusion from the mediastinal pleura, and SUVmax were useful imaging features for distinguishing TETs from cysts in the anterior mediastinum.

Significance of Metabolic Tumor Volume and Total Lesion Glycolysis Measured Using ¹⁸F-FDG PET/CT in Locally Advanced and Metastatic Gallbladder Carcinoma

PURPOSE: This study aimed to determine the prognostic value of new quantitative parameters of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT), including metabolic tumor volume (MTV), in patients with locally advanced and metastatic gallbladder cancer (GBC). MATERIALS AND METHODS: In total, 83 patients initially diagnosed with locally advanced and metastatic GBC and who underwent 18F-FDG PET/CT at the time of initial diagnosis were retrospectively reviewed. The metabolic volume-based PET parameters of primary tumors and metastatic lesions were measured, including maximum and average standardized uptake values (SUV), MTV, and total lesion glycolysis. An overall survival (OS) analysis was performed using the Kaplan-Meier method with PET and clinical parameters. A Cox proportional hazards regression analysis was performed to determine independent prognostic factors. RESULTS: In univariate analysis, pathologic differentiation (p<0.001), performance status (PS; p=0.003), C-reactive protein (CRP) level (p=0.009), and PET-related SUVmt max (the highest SUV among the metastatic lesions) (p=0.040) and MTVtotal (the sum of the MTVs of both the primary and metastatic lesions) (p=0.031), were significant for OS. In multivariate analysis, MTVtotal (hazard ratio: 2.07; 95% confidence interval: 1.23–3.48; p=0.006) remained significant for the prediction of OS, as did differentiation (p=0.001), PS (p=0.001), and CRP (p=0.039). CONCLUSION: In locally advanced and metastatic GBC, volume-based PET/CT parameters of the total tumor burden of malignancy, such as MTVtotal, were found to be useful for the identification of patients with poor prognosis.

Prognostic Value of Metabolic Information in Advanced Gastric Cancer Using Preoperative ¹⁸F-FDG PET/CT / 대한핵의학회잡지

PURPOSE: This study evaluated the usefulness of semiquantitative and volumetric PET parameters for predicting prognosis in patients with advanced gastric cancer (AGC).METHODS: We enrolled 213 patients who underwent ¹⁸F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) prior to curative surgery for AGC. Maximum standardized uptake value (SUVmax) and tumor-to-liver uptake ratio (TLR) were measured in all patients. Metabolic tumor volume (MTV) and total lesion glycolysis were measured in volume-measurable patients. For further quantification of FDG uptake, we developed PET prognostic scores by combining SUVmax and MTV (1: low SUVmax/low MTV; 2: high SUVmax/low MTV; 3: high SUVmax/high MTV). Comparison of PET parameters between recurrence and non-recurrence groups was performed. Univariate and multivariate analyses for recurrence-free survival (RFS) and overall survival (OS) were subsequently performed.RESULTS: The recurrence rate was 32.4% (69/213 patients). Mean SUVmax and mean MTV of the recurrence group were significantly higher than those of the non-recurrence group (p = 0.026 and p = 0.025). TLR showed marginal significance (p = 0.051). In multivariate analysis for RFS including all patients, SUVmax (p = 0.022), TLR (p = 0.010), and PET score (p = 0.003) were independent prognostic factors. In post hoc analysis of PET score, significant differences in RFS were observed between PET scores 2 and 3 as well as scores 1 and 3. No significant difference in RFS was observed between scores 1 and 2. Only PET score was statistically significant for OS in univariate analysis. None of the PET parameters were statistically significant for OS in multivariate analysis.CONCLUSION: High SUVmax and high MTV of the primary tumor suggest a high risk of recurrence for AGC patients. Even if SUVmax is similar, the prognosis may vary depending on MTV. Combining PET parameters results in a better prediction for prognosis.

Utility of FDG-PET/CT for the Detection and Characterization of Sternal Wound Infection Following Sternotomy / 대한핵의학회잡지

PURPOSE: FDG-PET/CT has the potential to play an important role in the diagnosis of sternal wound infections (SWI). The purpose of this study was to analyze the diagnostic accuracy of FDG-PET/CT for SWI in patients following sternotomy.METHODS: We performed a single-center, retrospective analysis of patients who had undergone median sternotomy and FDG-PET/CT imaging. The gold standard consisted of positive bacterial culture and/or the presence of purulent material at surgery. Qualitative patterns of sternal FDG uptake, SUV(max), and associated CT findings were determined, and an imaging scoring system was developed. The diagnostic performances were studied in both the recent (≤ 6 months between sternotomy and imaging) and remote surgery phase (> 6 months).RESULTS: A total of 40 subjects were identified with 11 confirmed SWI cases. Consensus interpretation was associated with a sensitivity of 91%and specificity of 97%. Combination of uptake patterns yielded an AUC of 0.96 while use of SUVmax yielded an AUC of 0.82.CONCLUSION: Results suggest that FDG-PET/CT may be useful for the diagnosis of SWI with optimal diagnostic accuracy achieved by identifying specific patterns of uptake. SUV(max) can be helpful in assessing subjects with remote surgery, but its use is limited in the context of recent surgery. Further studies are required to confirm these results.

How Do the More Recent Reconstruction Algorithms Affect the Interpretation Criteria of PET/CT Images? / 대한핵의학회잡지

PURPOSE: Recently, a new Bayesian Penalized Likelihood (BPL) Reconstruction Algorithm was introduced by GE Healthcare, Q.Clear; it promises to provide better PET image resolution compared to the widely used Ordered Subset Expectation Maximization (OSEM). The aimof this study is to compare the performance of these two algorithms on several types of findings, in terms of image quality, lesion detectability, sensitivity, and specificity.METHODS: Between September 6th 2017 and July 31st 2018, 663 whole body 18F-FDG PET/CT scans were performed at the Nuclear Medicine Department of S. Martino Hospital (Belluno, Italy). Based on the availability of clinical/radiological follow-up data, 240 scans were retrospectively reviewed. For each scan, a hypermetabolic finding was selected, reporting both for OSEM and Q.Clear: SUVmax and SUVmean values of the finding, the liver and the background close to the finding; size of the finding; percentage variations of SUVmax and SUVmean. Each finding was subsequently correlated with clinical and radiological follow-up, to define its benign/malignant nature.RESULTS: Overall, Q.Clear improved the SUVvalues in each scan, especially in small findings (< 10mm), high SUVmax values (≥ 10), and medium/low backgrounds. Furthermore, Q.Clear amplifies the signal of hypermetabolic findings without modifying the background signal, which leads to an increase in signal-to-noise ratio, improving overall image quality. Finally, Q.Clear did not affect PET sensitivity or specificity, in terms of number of reported findings and characterization of their nature.CONCLUSIONS: Q.Clear is an iterative algorithm that improves significantly the quality of PET images compared to OSEM, increasing the SUVmax of findings (in particular for small findings) and the signal-to-noise ratio. However, due to the intrinsic characteristics of this algorithm, it will be necessary to adapt and/or modify the current interpretative criteria based of quantitative evaluation, to avoid an overestimation of the disease burden.

Ipsilateral Hyperhidrosis: Atypical Symptom of Small Lung Adenocarcinoma Evaluated by ¹⁸F-FDG PET-CT / 대한핵의학회잡지

A 45-year-old male visited our clinic due to right palmar anhidrosis and contralateral hyperhidrosis. Chest computed tomography (CT) showed a solitary pulmonary nodule with mediastinal lymph node enlargement, but a cause for atypical palmar anhidrosis was not identified. Subsequent fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed (PET/CT) revealed a localized pleural metastasis at the right apex with direct invasion of the paravertebral sympathetic chain. The pleural metastasis, which was not seen on chest CT, evoked ipsilateral anhidrosis independent of a mass effect or direct invasion by the primary lung tumor. 18F-FDG PET/CT can be helpful in identifying the cause of atypical symptoms in patient with small sized lung cancer.

Radiomics in Oncological PET/CT: a Methodological Overview / 대한핵의학회잡지

Radiomics is a medical imaging analysis approach based on computer-vision. Metabolic radiomics in particular analyses the spatial distribution patterns of molecular metabolism on PET images. Measuring intratumoral heterogeneity via image is one of the main targets of radiomics research, and it aims to build a image-based model for better patient management. The workflow of radiomics using texture analysis follows these steps: 1) imaging (image acquisition and reconstruction); 2) preprocessing (segmentation & quantization); 3) quantification (texture matrix design & texture feature extraction); and 4) analysis (statistics and/or machine learning). The parameters or conditions at each of these steps are effect on the results. In statistical testing or modeling, problems such as multiple comparisons, dependence on other variables, and high dimensionality of small sample size data should be considered. Standardization of methodology and harmonization of image quality are one of the most important challenges with radiomics methodology. Even though there are current issues in radiomics methodology, it is expected that radiomics will be clinically useful in personalized medicine for oncology.

The value of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) in evaluating the stability of atherosclerotic plaques / 中华内科杂志

Objective@#Positron emission tomography-computed tomography (PET-CT) has been used to quantify inflammatory response in the body. The aim of the present study was to explore the possibility of using this method to evaluate the stability of atherosclerotic plaques and the efficacy of atorvastatin in stabilizing atherosclerotic plaques.@*Methods@#Twenty New Zealand male white rabbits were included and divided into the atorvastatin intervention group and the control group, with 10 rabbits in each group. Rabbits in both groups were fed with a high fat diet for 20 weeks, and treated with thoracoabdominal aortic balloon-pulling to establish atherosclerosis model at the end of the 2nd week. Rabbits in atorvastatin intervention group was given atorvastatin intragastrically once a day. At the 8th week, thoracoabdominal aortic ultrasound was used to detect plaques in all rabbits. Blood was drawn at the 3rd and the 20th week, respectively, to measure blood lipids, high-sensitive C-reactive protein (hs-CRP) and matrix metalloproteinase-9 (MMP-9). At the end of experiment, survival animals were scanned by 18F-FDG PET-CT, and the average and maximum standard uptake values (SUVmean, SUVmax) of aortic segments were measured. Thereafter, the animals were sacrificed and aortic specimens of rabbits were taken and examined by immunohistochemistry. The pathological indexes were measured and compared.@*Results@#At the end of experiment, the total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), hs-CRP [ (4.58±0.51) ng/ml vs.(5.87±0.66) ng/ml, P<0.01], MMP-9[ (43.93±2.16) ng/ml vs. (50.77±2.32) ng/ml, P<0.01], SUVmean (0.59±0.15 vs. 0.68±0.20, P<0.05) , SUVmax (0.68±0.20 vs. 0.81±0.27, P<0.05) , plaque area [ (0.36±0.24) mm2 vs. (0.50±0.34) mm2, P<0.05) ] and density of macrophage[ (4.34±1.54) % vs. (5.65±1.89) %, P<0.01] in the atorvastatin intervention group were significantly lower than those in the control group. In contrast, fiber cap thickness of the plaque[ (4.12±0.66) μm vs. (2.96±0.37) μm, P<0.01] in the atorvastatin intervention group was higher than that of the control group, and the difference was statistically significant. The arterial plaque areas were positively correlated with SUVmean (r=0.27, P<0.05) and SUVmax (r=0.43, P<0.01) . Fiber cap thickness was negatively correlated with SUVmean (r=-0.38, P<0.05) and SUVmax (r=-0.47, P<0.01) . The density of macrophage were positively correlated with SUVmean (r=0.52, P<0.01) and SUVmax (r=0.51, P<0.01) .@*Conclusion@#18F-FDG PET/CT can be used to evaluate the efficacy of atorvastatin by the stability of atherosclerotic plaques.