Meta-analysis of Influencing Factors of 18F-Fluorodeoxyglucose Uptake of Brown Adipose Tissue in PET/CT Imaging.

Objective To explore the influencing factors of 18F-Fluorodeoxyglucose(18F-FDG) uptake of brown adipose tissue(BAT) in PET/CT imaging by performing meta-analysis.Methods Relevant articles published between 1980 and 2016 were searched in PubMed,EMBASE,Web of Science,CBM,WanFang Data,CNKI,and VIP.The factors of gender,season and age were extracted according to the inclusive criteria.Meta-analysis was performed to analyze the factors.Results The merger OR value and 95% CI of 18F-FDG uptake of BAT with gender,age,season were 2.67 (2.30-3.11),2.17 (1.38-3.39),and 15.35 (4.72-49.95) respectively.The 18F-FDG uptake rate of BAT was 2.16 times in females as that in males,8.67 times in the minors as that in the adults,and 1.94 times in winter as that in summer.Conclusion Gender,season,and age are risk factors for 18F-FDG uptake of BAT.

Fusion Oncogenes in Patients With Locally Advanced or Distant Metastatic Differentiated Thyroid Cancer.

CONTEXT: Fusion oncogenes are involved in the underlying pathology of advanced differentiated thyroid cancer (DTC), and even the cause of radioactive iodine (RAI)-refractoriness. OBJECTIVE: We aimed to investigation between fusion oncogenes and clinicopathological characteristics involving a large-scale cohort of patients with advanced DTC. METHODS: We collected 278 tumor samples from patients with locally advanced (N1b or T4) or distant metastatic DTC. Targeted next-generation sequencing with a 26-gene ThyroLead panel was performed on these samples. RESULTS: Fusion oncogenes accounted for 29.86% of the samples (72 rearrangement during transfection (RET) fusions, 7 neurotrophic tropomyosin receptor kinase (NTRK) fusions, 4 anaplastic lymphoma kinase (ALK) fusions) and occurred more frequently in pediatric patients than in their adult counterparts (P = .003, OR 2.411, 95% CI 1.329-4.311) in our cohort. DTCs with fusion oncogenes appeared to have a more advanced American Joint Committee on Cancer (AJCC)_N and AJCC_M stage (P = .0002, OR 15.47, 95% CI 2.54-160.9, and P = .016, OR 2.35, 95% CI 1.18-4.81) than those without. DTCs with fusion oncogenes were associated with pediatric radioactive iodine (RAI) refractoriness compared with those without fusion oncogenes (P = .017, OR 4.85, 95% CI 1.29-15.19). However, in adult DTCs, those with fusion oncogenes were less likely to be associated with RAI refractoriness than those without (P = .029, OR 0.50, 95% CI 0.27-0.95), owing to a high occurrence of the TERT mutation, which was the most prominent genetic risk factor for RAI refractoriness in multivariate logistic regression analysis (P < .001, OR 7.36, 95% CI 3.14-17.27). CONCLUSION: Fusion oncogenes were more prevalent in pediatric DTCs than in their adult counterparts and were associated with pediatric RAI refractoriness, while in adult DTCs, TERT mutation was the dominant genetic contributor to RAI refractoriness rather than fusion oncogenes.

Hypermetabolic Broad Ligament Leiomyoma in Postmenopausal Women Mimicking Ovarian Tumors on 18 F-FDG PET/CT.

ABSTRACT: Extrauterine leiomyomas are rare and often occur in broad ligament or fallopian tube. Diagnosis of broad ligament leiomyoma is challenging for its solid nature and special location. Leiomyomas typically exhibit mild FDG uptake, especially in postmenopausal woman. We here reported a 57-year-old postmenopausal woman with intense FDG-avid broad ligament leiomyoma on 18 F-FDG PET/CT, which might be misdiagnosed as ovarian tumor.

Mesenteric Castleman Disease Misdiagnosed as Lymph Node Metastasis of Rectal Cancer on 18 F-FDG PET/CT.

ABSTRACT: Two years ago, a 64-year-old man underwent an 18 F-FDG PET/CT for staging rectal cancer. Besides the hypermetabolic rectal lesion, the image revealed a mesenteric lymph node with intense activity and multiple lung nodules with slight FDG uptake, which were highly suspected of metastases. After surgery and multiple cycles of chemotherapy, the follow-up 18 F-FDG PET/CT showed remission of all lesions except for the enlarged mesenteric lymph node with higher metabolic activity. Serum CEA remained normal during the follow-up. Postoperative pathology of the mesenteric lymph node confirmed Castleman disease.

Is response evaluation criteria in solid tumors (RECIST) effective in patient selection for radical resection after neoadjuvant immunotherapy with advanced NSCLC?

BACKGROUND: Neoadjuvant immunotherapy combined with chemotherapy has been used to treat locally advanced non-small cell lung cancer (NSCLC). Several systems have been developed for response evaluation. The aim of this study was to evaluate the predictive value of response evaluation criteria in solid tumors (RECIST) and propose modified RECIST (mRECIST). METHODS: Eligible patients received chemotherapy combined with personalized neoadjuvant immunotherapy. Radical resection was subsequently performed for potentially resectable tumors evaluated by RECIST. The resected specimens were evaluated to determine the response to neoadjuvant therapy. RESULTS: A total of 59 patients received radical resection following neoadjuvant immunotherapy combined with chemotherapy. According to RECIST, four patients had complete remission, 41 had partial remission, and 14 had progressive disease. Postoperative pathological examination showed 31 patients achieved complete pathological remission, and 13 achieved major pathological remission. The final pathological results were uncorrelated with RECIST assessment (p = 0.086). The ycN stage and pN stage were irrelevant (p < 0.001). When the cutoff of sum of diameters (SoD) is 17%, the Youden's index reached its highest value. A correlation was found between mRECIST and final pathological results. Patients with squamous cell lung cancer showed higher proportions in objective response (OR) (p < 0.001) and complete pathological remission (CPR) (p = 0.001). A shorter time to surgery (TTS) was correlated with a better OR (p = 0.014) and CPR (p = 0.010). The decrease in SoD was correlated with better OR (p = 0.008) and CPR (p = 0.002). CONCLUSIONS: mRECIST was effective for patient selection for radical resection after neoadjuvant immunotherapy with advanced NSCLC. Two modifications were suggested for RECIST: (1) the cutoff value was adjusted to 17% for partial remission. (2) Changes in lymph nodes on computed tomography were eliminated. A shorter TTS, a larger decrease in SoD and squamous cell lung cancer (vs. adenocarcinoma) were correlated with better pathological responses.

Neoadjuvant immunotherapy followed by surgery with curative intent in 35 patients with advanced NSCLC: the retrospective experiences of a multidisciplinary team.

Background: In recent years, neoadjuvant immunotherapy combined with chemotherapy has been used to treat locally advanced non-small cell lung cancer (NSCLC); however, no data are available to guide the selection of patients suitable for radical resection. In this paper, we report a clinical mode based on a multidisciplinary team (MDT). Methods: We retrospectively analyzed the clinical data of patients with advanced NSCLC who were treated in our center between 26 December, 2019 and 1 October, 2021. These cases received an MDT assessment first. Eligible patients then received chemotherapy combined with personalized neoadjuvant immunotherapy. Adverse events were recorded. Chest computed tomography (CT) was performed every other cycle for tumor assessment. Radical resection was subsequently performed for potentially resectable tumors. Intraoperative conditions and surgical complications were recorded. The resected specimens were evaluated to determine the response to neoadjuvant therapy. Results: The MDT team selected a total of 35 patients (squamous cell carcinoma: n=26, adenocarcinoma: n=8, adenosquamous carcinoma: n=1) for radical resection following neoadjuvant immunotherapy combined with chemotherapy. According to the Response Evaluation Criteria in Solid Tumors (RECIST) findings, 1 patient had complete remission, 27 had partial remission, 6 had progressive disease, and 1 had stable disease. All participants underwent radical resection, including video-assisted thoracoscopic surgery [VATS; 32 (91.4%)], sleeve resection [7 (20.0%)], and multilobar resection [7 (20.0%)]. A total of 17 patients (48.6%) achieved complete pathological remission, and 10 (28.6%) achieved major pathological remission. After surgery, the pathological grade was reduced in 33 patients (94.2%); the RECIST findings were unrelated to postoperative pathological remission (P=0.15). Conclusions: The MDT mode helps to select suitable patients for radical resection and results in satisfactory pathological remission.

Brown adipose tissue can be activated or inhibited within an hour before 18F-FDG injection: a preliminary study with microPET.

Brown adipose tissue (BAT) is emerging as a potential target for treating human obesity. It has been indicated that BAT is rich in innervations of sympathetic nerve control. Using (18)F-FDG microPET imaging, this study aims at evaluating how factors related to sympathetic activation/inhibition changed BAT metabolism of mice. BAT (18)F-FDG uptake were semiquantitatively evaluated in different groups of mice under temperature (cold or warm stimulus) or pharmacological interventions (norepinephrine, epinephrine, isoprenaline, or propranolol) and were compared with the corresponding controls. It was found that BAT activation can be stimulated by cold exposure (P = 1.96 × 10(-4)), norepinephrine (P = .002), or both (P = 2.19 × 10(-6)) within an hour before (18)F-FDG injection and can also be alleviated by warming up (P = .001) or propranolol lavage (P = .027). This preliminary study indicated that BAT function could be evaluated by (18)F-FDG PET imaging through short-term interventions, which paved the way for further investigation of the relationship between human obesity and BAT dysfunction.

Diagnostic and prognostic value of FDG PET-CT in patients with suspected recurrent thymic epithelial tumors.

This study aimed to evaluate the diagnostic and prognostic value of FDG PET/CT in patients with suspected recurrent thymic epithelial tumors (TETs). We retrospectively reviewed 83 patients with histopathologically proven TETs (50 thymomas; 33 thymic carcinomas) who underwent FDG PET/CT after surgery. The sensitivity and specificity of FDG PET/CT in detecting recurrence were calculated. The progression-free survival rate (PFS) was calculated by the Kaplan-Meier method. FDG PET/CT results were positive in 50 patients and negative in 33. Recurrent TETs were confirmed in 40 of 50 patients with positive PET/CT findings. The sensitivity and specificity of FDG PET/CT were 100% and 76.7%, respectively. Disease progression occurred in 28 patients during the follow-up. FDG PET/CT showed added prognostic value over the Masaoka stage and histopathology. Among patients with the same Masaoka stage, negative PET/CT was significantly associated with better PFS (P < 0.001). Similarly, among patients with the same histopathology, negative PET/CT was also associated with a significantly longer PFS (P < 0.001). FDG PET/CT demonstrated a good diagnostic performance in patients with recurrent TETs and had an important prognostic value in assessing the risk of disease progression.

Prognostic Value of FDG PET/CT in Patients With Neuroendocrine Carcinoma of the Uterine Cervix.

PURPOSE: We evaluated the prognostic value of metabolic parameters measured on pretreatment FDG PET/CT in patients with cervical neuroendocrine carcinomas (NECs). METHODS: A total of 22 patients with cervical NECs who underwent pretreatment FDG PET/CT were retrospectively reviewed. The SUVmax, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary lesion were measured. The associations between prognostic factors and progression-free survival (PFS) and overall survival (OS) were investigated using the Kaplan-Meier method, log-rank test, and univariate and multivariate Cox proportional hazards model. RESULTS: Of the 22 patients, 12 developed disease progression, and 5 died during the follow-up period. Univariate analyses revealed that MTV, TLG, and the International Federation of Gynecology and Obstetrics stage were significantly associated with PFS (all P < 0.05), whereas SUVmax did not show a significant correlation with PFS. Kaplan-Meier survival curves revealed that patients with MTV >31.9 cm3 (log-rank, P < 0.001), TLG >154.3 (log-rank, P < 0.001), and higher International Federation of Gynecology and Obstetrics stage (log-rank, P = 0.026) had significantly shorter PFS. In the multivariate analyses, MTV (P = 0.017; hazard ratio [HR], 7.298; 95% confidence interval [CI], 1.427-37.316) and TLG (P = 0.003; HR, 15.175; 95% CI, 2.470-93.244) were independent prognostic factors, whereas for OS, the univariate analysis revealed that only TLG >154.3 showed statistical significance (P = 0.043; HR, 9.821; 95% CI, 1.080-89.290). CONCLUSIONS: Metabolic tumor volume and TLG on FDG PET/CT were the significant prognostic factors of PFS in patients with cervical NECs. Patients with high MTV and TLG had worse clinical outcomes. In addition, TLG may also be a predictor of OS.

18F-FDG PET/CT imaging features of patients with multicentric Castleman disease.

OBJECTIVE: The aim of this study is to investigate the role of 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) in the evaluation of multicentric Castleman disease (MCD). METHODS: Thirty-five patients with pathologically confirmed MCD who underwent 18F-FDG PET/CT were retrospectively included. The FDG uptake and CT findings of lymph nodes, pulmonary involvement, spleen, and bone marrow were assessed and the maximum standardized uptake value (SUVmax) of each lesion was measured. The locations of lymph nodes were also evaluated. RESULTS: 18F-FDG PET/CT showed increased uptake in multiple nodal regions in 34 out of 35 MCD patients. The most frequently involved nodal sites were the cervical, iliac, axillary, and inguinal areas, and the least common was paraaortic and abdominal nodes. The involved lymph nodes were not confluent and presented a relatively symmetric pattern on PET/CT images. The highest SUVmax of lymph nodes per patient ranged from 2 to 19 with a mean value of 5.61 ± 3.12. Pulmonary manifestation including cysts, nodules, and interstitial lung disease were found in 10 patients, eight of whom demonstrated mild to moderate uptake in the lungs. 18F-FDG PET/CT also revealed other findings including hypermetabolic spleen (n = 8) and bone marrow (n = 23), elevated uptake in salivary glands (n = 8). Four patients also underwent follow-up PET/CT scans after therapy, and three of them displayed decreased metabolism. CONCLUSION: 18F-FDG PET/CT is a useful tool in the diagnosis, evaluation, and follow-up of MCD by providing systemic manifestations of lymphadenopathy, pulmonary involvement, and hypermetabolic spleen or bone marrow. Furthermore, the lymphadenopathy in MCD presented a predominantly peripheral distribution, relatively symmetric, moderately hypermetabolic, and not confluent pattern on 18F-FDG PET/CT.

Clinical utility of FDG PET/CT for primary and recurrent papillary renal cell carcinoma.

PURPOSE: Papillary renal cell carcinoma (RCC) is the second most common subtype of RCC, after clear cell RCC. This study aimed to investigate the usefulness of FDG PET/CT in primary and recurrent papillary RCC, and the role of staging FDG PET/CT in predicting survival. METHODS: A total of 66 patients with histopathologically confirmed papillary RCC who underwent either staging or restaging FDG PET/CT scans (30 had staging scans only, 28 had restaging scans only, 8 had both) were retrospectively included in this study. The sensitivity and specificity of restaging FDG PET/CT for detecting recurrence were assessed by histopathology and/or clinical follow-up as standard reference. RESULTS: Staging FDG PET/CT scans were performed in 38 patients, of which 31 (81.5%) showed FDG-positive primary renal lesions. The SUVmax of high-grade (WHO grade 3 and 4) papillary RCCs were significantly higher than that of low-grade (WHO grade 1 and 2) tumors (9.44 ± 6.18 vs 4.83 ± 3.19, P = 0.008). The SUVmax was not significantly different between type 1 and type 2 papillary RCCs (5.71 ± 2.88 vs. 6.99 ± 5.57, P = 0.563). Of the 38 patients, 12 developed disease progression during the follow-up period. Patients with primary tumor SUVmax> 5.85 were associated with significantly shorter progression-free survival (PFS) than those with tumor SUVmax≤5.85 (P = 0.005). Restaging FDG PET/CT scans were performed in 36 patients with suspected recurrent papillary RCCs. FDG PET/CT showed a sensitivity and specificity of 100 and 72.7% for detecting recurrent disease. Comparison of PET/CT scans with CT/MRI imaging was available in 23 patients. FDG PET/CT revealed additional findings in 11 patients, mainly including lymph node and bone metastases. FDG PET/CT findings led to change in management in 5.3% (2/38) of patients in the staging setting and 16.7 (6/36) of patients in the restaging setting. CONCLUSIONS: FDG PET/CT had a sensitivity of 81.5% for detecting primary papillary RCC, and tumor SUVmax derived from staging FDG PET/CT was a predictor of PFS. In the restaging process of papillary RCC, FDG PET/CT was very effective for detecting recurrent disease.

18F-FDG PET/computed tomography scan in patients with suspicion of recurrent neuroendocrine carcinoma of the cervix.

OBJECTIVES: The aim of this study was to investigate the value of [18F]fluoro-2-deoxy-D-glucose (18F-FDG) PET/computed tomography (CT) to detect recurrent cervical neuroendocrine carcinoma and its subsequent impact on patient management. METHODS: A total of 25 patients who had undergone 30 18F-FDG PET/CT studies for suspected recurrent cervical neuroendocrine carcinoma (18 small cells, 2 large cells, 1 atypical carcinoid, and 4 unclassified) were retrospectively analyzed. The findings of the PET/CT images were compared with the histopathologic results in 8 scans and with clinical follow-up in 22 scans. RESULTS: Of the 30 PET/CT studies, 63.3% (19/30) were positive for recurrence while 36.7% (11/30) were negative. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 18F-FDG PET/CT for detecting recurrent disease of cervical neuroendocrine carcinomas were 90.0, 90.0, 94.7, 81.8, and 90.0%, respectively. Metastasis to distant organs was the most common (89.4%), followed by lymph node recurrence (52.6%). Lungs were the most frequent site of distant metastasis (63.1%). 18F-FDG PET/CT findings led to the change of the management in 10 out of 25 patients (40%) by introducing the use of previously unplanned therapeutic procedures. CONCLUSIONS: 18F-FDG PET/CT is an efficient technique for detecting recurrent cervical neuroendocrine carcinoma, and may thus contribute to improving patient management.

68Ga-NOTA-Evans Blue PET/CT findings in lymphangioleiomyomatosis compared with 99mTC-ASC lymphoscintigraphy: a prospective study.

BACKGROUND: Lymphangioleiomyomatosis (LAM) is a rare multisystem disease characterized by cystic lung disease and extrapulmonary manifestations, including lymphatic system disorder. The objective of this study was to investigate the findings of 68Ga-NOTA-Evans Blue (NEB) PET/CT in LAM and compare it with that of 99mTc-ASC lymphoscintigraphy. METHODS: Ten patients diagnosed with LAM according to the American Thoracic Society/Japanese Respiratory Society guidelines for LAM were recruited in this study. PET/CT acquisition was performed at 20 to 40 min after subcutaneous injection of 68Ga-NEB into the first interdigital spaces of both feet (0.3 ml, 37 MBq/foot). All subjects also underwent 99mTc-antimony sulfide colloid (ASC) lymphoscintigraphy within a week for comparison. RESULTS: 68Ga-NEB PET/CT displayed various lymphatic system abnormalities in 10 (100%) of 10 patients. These included pulmonary lymphatic abnormalities in 10 (100%) of 10 patients, enlarged lymph nodes in 5 (50%), lymphangioleiomyomas in 2 (20%), dilation of the lumbar trunk and/or iliac lymph vessels in 5 (50%), thoracic duct dilation in 2 (20%), chylous effusion in 1 (10%). For pulmonary lymphatic abnormalities, the positive rates of 68Ga-NEB PET/CT and 99mTc-ASC lymphoscintigraphy were 100% (10/10) and 10% (1/10), respectively (P < 0.001). As for the 7 patients with extrapulmonary lymphatic manifestations, 68Ga-NEB PET/CT also presented more information than 99mTc-ASC lymphoscintigraphy. CONCLUSION: 68Ga-NEB PET/CT visualized pulmonary lymphatic abnormality and displayed extrapulmonary lymphatic system disorders of LAM, and might play a role in the diagnosis and evaluation of the disease. 68Ga-NEB PET/CT is advantageous over conventional 99mTc-ASC lymphoscintigraphy in LAM by providing more detailed information of lymphatic dysfunction.

Performance of 68Ga-DOTA-SST PET/CT, octreoscan SPECT/CT and 18F-FDG PET/CT in the detection of culprit tumors causing osteomalacia: a meta-analysis.

OBJECTIVES: The objective of this study was to assess and compare the performance of Ga-DOTA-conjugated-somatostatin-receptor-targeting-peptides (Ga-DOTA-SST) PET/CT, octreoscan-SPECT/CT and F-FDG-PET/CT in the detection of tumor-induced osteomalacia (TIO). METHODS: Relevant studies reporting the performance Ga-DOTA-SST PET/CT, octreoscan-SPECT/CT and F-FDG-PET/CT in TIO were identified by searching PubMed, EMBASE, and Web of Science (last updated June 2019). Two authors independently extracted the numbers of true and false positives, and true and false negatives. The pooled estimates on a per-patient basis were calculated with 95% confidence interval (CI) obtained using a random-effects model. RESULTS: Fourteen studies comprising 346 patients were included in this meta-analysis. The meta-analysis provided the following results on a per-patient analysis. The pooled sensitivities of both Ga-DOTA-SST PET/CT (90%, 95% CI 82-95%) and octreoscan-SPECT/CT (83%, 95% CI 75-89%) were found to be significantly higher (P < 0.005) than that of F-FDG PET/CT (67%, 95% CI 53-80%). There was no statistically significant difference between the sensitivity of Ga-DOTA-SST PET/CT and octreoscan-SPECT/CT (P = 0.161). Owing to the low number of articles with true negative findings, the pooled specificities were not calculated. A total of 287 tumors were identified in 287 patients according to the data the included studies offered. The majority of the tumors were located in the lower extremities (59.6%, 171/287), followed by craniofacial regions (24.0%, 69/287), torso (9.4%%, 27/287), and upper extremities (6.9%, 20/287). CONCLUSION: This meta-analysis demonstrates that somatostatin receptor-based imaging modalities outperformed F-FDG PET/CT in the detection of TIO, with Ga-DOTA-SST PET/CT performing slightly better than octreoscan-SPECT/CT.

FDG PET/CT Findings in a Patient With Ovarian Metastasis of Pheochromocytoma.

Pheochromocytoma metastasizing to the ovary is extremely rare. We report the case of a 59-year-old woman who underwent right adrenal pheochromocytoma resection 14 years ago and remained asymptomatic until recently when she complained of palpitation, perspiration, and hypertension. F-FDG PET/CT revealed a left adnexal mass with increased activity, which was later surgically removed and pathologically confirmed as ovarian metastasis of pheochromocytoma.

Rosai-Dorfman Disease of the Right Atrium Revealed by FDG PET/CT.

Rosai-Dorfman disease, or sinus histiocytosis with massive lymphadenopathy, is an uncommon histiocytic disorder, which is rare and typically occurs in lymph nodes. However, one third of the cases manifest as extranodal disease. The cardiac involvement of this disease is extremely rare. We reported here the FDG PET/CT findings of a pathologically confirmed Rosai-Dorfman disease occurring in the right atrium in a 60-year-old man.

Rosai-Dorfman Disease Presenting as a Pulmonary Artery Mass on FDG PET/CT.

Rosai-Dorfman disease (RDD) is an uncommon histiocytic disorder typically involving the lymph nodes and occasionally manifests as extranodal disease. Extranodal RDD involving pulmonary artery without lymphadenopathy or other extranodal lesions is very rare. We present the case of a 48-year-old woman complaining of shortness of breath on exertion for 6 months. F-FDG PET/CT revealed a pulmonary artery mass with intense FDG avidity. No other abnormal FDG-avid lesion was observed. The pulmonary artery mass was then surgically removed, and the pathological and immunohistochemical results confirmed RDD.