Development and validation of an 18F-FDG PET/CT-based radiomics nomogram for predicting the prognosis of patients with esophageal squamous cell carcinoma.

RATIONALE AND OBJECTIVES: The aim of this study was to develop and validate a nomogram, integrating clinical factors and radiomics features, capable of predicting overall survival (OS) in patients diagnosed with esophageal squamous cell carcinoma (ESCC). METHODS: In this study, we retrospectively analyzed the case data of 130 patients with ESCC who underwent 18F-FDG PET/CT before treatment. Radiomics features associated with OS were screened by univariate Cox regression (p < 0.05). Further selection was performed by applying the least absolute shrinkage and selection operator Cox regression to generate the weighted Radiomics-score (Rad-score). Independent clinical risk factors were obtained by multivariate Cox regression, and a nomogram was constructed by combining Rad-score and independent risk factors. The predictive performance of the model for OS was assessed using the time-dependent receiver operating characteristic curve, concordance index (C-index), calibration curve, and decision curve analysis. RESULTS: Five radiomics features associated with prognosis were finally screened, and a Rad-score was established. Multivariate Cox regression analysis revealed that surgery and clinical M stage were identified as independent risk factors for OS in ESCC. The combined clinical-radiomics nomogram exhibited C-index values of 0.768 (95% CI: 0.699-0.837) and 0.809 (95% CI: 0.695-0.923) in the training and validation cohorts, respectively. Ultimately, calibration curves and decision curves for the 1-, 2-, and 3-year OS demonstrated the satisfactory prognostic prediction and clinical utility of the nomogram. CONCLUSION: The developed nomogram, leveraging 18F-FDG PET/CT radiomics and clinically independent risk factors, demonstrates a reliable prognostic prediction for patients with ESCC, potentially serving as a valuable tool for guiding and optimizing clinical treatment decisions in the future.

The added prognostic values of baseline PET dissemination parameter in patients with angioimmunoblastic T-cell lymphoma.

To explore the prognostic values of baseline 2-deoxy-2-[18F] fluoro-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) dissemination parameter in angioimmunoblastic T-cell lymphoma (AITL) and its added values to total metabolic tumour volume (TMTV). Eighty-one AITL patients with at least two FDG-avid lesions in baseline PET/CT were retrospectively included. PET parameters including TMTV and the distance between the two lesions that are the furthest apart (Dmax) were obtained. Univariate Cox analysis showed that both Dmax and TMTV were risk factors for progression-free survival (PFS) and overall survival (OS). Multivariate Cox analysis models of different combinations showed that high Dmax (> 65.7 cm) could independently predict both PFS and OS, while high TMTV (>456.6 cm3) was only significant for OS. A concise PET model based on TMTV and Dmax can effectively risk-stratify patients. PFS and OS rates were significantly lower in patients with high Dmax and high TMTV than in patients with low Dmax and low TMTV (3-year PFS rate: 15.0% vs. 48.7%, p = 0.001; 3-year OS rate: 27.6% vs. 79.0%, p < 0.001). Dmax can directly reflect the disease dissemination characteristic and has a significant prognostic value for FDG-avid AITL patients. It has the potential to be introduced into new risk stratification models for tailored treatment.

The combined role of PET/CT metabolic parameters and inflammatory markers in detecting extensive disease in small cell lung cancer.

The combined role of inflammatory markers [including neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), monocyte/lymphocyte ratio (MLR), and systemic immune-inflammation index (SII)] and PET/CT metabolic parameters [including maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), and TLG (total lesion glycolysis)] at baseline in evaluating the binary stage [extensive-stage disease (ED) and limited-stage disease (LD)] of small cell lung cancer (SCLC) is unclear. In this study, we verified that high metabolic parameters and inflammatory markers were related to the binary stage of SCLC patients, respectively (p < 0.05). High inflammatory markers were also associated with high MTV and TLG in patients with SCLC (p < 0.005). Moreover, the incidences of co-high metabolic parameters and inflammatory markers were higher in ED-SCLC (p < 0.05) than those in LD-SCLC. Univariate logistic regression analysis demonstrated that Co-high MTV/NLR, Co-high MTV/MLR, Co-high MTV/SII, Co-high TLG/NLR, Co-high TLG/MLR, and Co-high TLG/SII were significantly related to the binary stage of SCLC patients (p = 0.00). However, only Co-high MTV/MLR was identified as an independent predictor for ED-SCLC (odds ratio: 8.67, 95% confidence interval CI: 3.51-21.42, p = 0.000). Our results suggest that co-high metabolic parameters and inflammatory markers could be of help for predicting ED-SCLC at baseline. Together, these preliminary findings may provide new ideas for more accurate staging of SCLC.

Prognostic value of baseline total metabolic tumour volume of 18F-FDG PET/CT imaging in patients with angioimmunoblastic T-cell lymphoma.

PURPOSE: The aim of this study was to explore the prognostic value of baseline metabolic parameters of 18F-FDG PET/CT imaging in patients with angioimmunoblastic T-cell lymphoma (AITL). MATERIALS AND METHODS: Fifty-six AITL patients (average age 64.0 ± 1.3 years) diagnosed pathologically from August 2009 to August 2019 were enrolled in this retrospective study. The total metabolic tumour volume (TMTV), total lesion glycolysis (TLG), maximum standardized uptake value (SUVmax), and correlated clinical characteristics were collected and analysed. TMTV was computed with the 41% SUVmax threshold method. The chi-square test or Fisher's exact probability method was used to compare clinical characteristics. Kaplan-Meier curves were used to describe progression-free survival (PFS) and overall survival (OS). The log-rank test was used to analyse the difference within groups. The statistically significant factors in the univariate regression analysis were incorporated into the Cox risk proportional regression model for multivariate survival analysis. RESULTS: The TMTV cut-off value was 514.6 cm3 from the ROC curve analysis. Forty (71.4%) patients progressed and 31 (55.4%) patients died within a median follow-up time of 19.1 (interquartile range 7.8-34.6) months. The 1-year and 3-year PFS rates were 42.9% and 30.1%, and the 3-year and 5-year OS rates were 45.9% and 34.4%, respectively. Univariate survival analysis showed that high TMTV and TLG may be the factors contributing to poor PFS and OS. Multivariate analysis showed that TMTV and prognostic index for T-cell lymphoma (PIT) were independent parameters for PFS and OS in AITL patients. TMTV, combined with PIT, may have better risk stratification performance than TMTV alone. CONCLUSIONS: Baseline TMTV and PIT were independent prognostic predictors in AITL patients. The combination of TMTV and PIT can facilitate prognostic stratification and contribute to personalized therapy.

ZR-75-1 breast cancer models to study the utility of 18F-FES by PET imaging.

BACKGROUND: Breast cancer is a hormone-dependent tumor, and 70-80% of breast cancer patients are estrogen receptor (ER) positive. ZR-75-1 cell lines are more consistent with human breast cancer, which is mostly ER positive and PR positive. To better study the biological characteristics of 18F-fluoroestradiol (18F-FES) in breast cancer patients, ZR-75-1 breast cancer models were selected to provide a basis for further clinical application. METHODS: 18F-FES uptake in vivo was evaluated in ZR-75-1 tumor-bearing mice, using MCF-7 tumor-bearing mice as a positive control. Competitive inhibition experiment was also performed, using ER down-regulator fulvestrant. Biodistribution of 18F-FES was observed in ZR-75-1 breast tumor-bearing mice scanning by 18F-FES-PET/CT in vivo and γ counter ex vivo. The expression of ER was also determined by immunohistochemistry. An abnormal toxicity test was performed in ICR male mice whose behavior and vital signs were observed within 48 hours of 18F-FES injection. OLINDA/EXM 2.0 software was used to calculate the absorbed doses of adult female body phantoms. RESULTS: There was no significant difference in FES uptake between ZR-75-1 and MCF-7 tumor-bearing mice. Intervention with fulvestrant decreased the uptake of 18F-FES. Biodistribution studies demonstrated that the uptake of 18F-FES was high in the liver and kidneys but low in the brain. Other than excretory organs, the uptake of 18F-FES in ER-positive breast tumors was significantly higher than in ER-negative tissues. The estimated human effective dose was 0.016 mSv/MBq for the adult female body model. CONCLUSIONS: The 18F-FES tracer could have suitable properties for imaging ER-positive breast tumors. It may provide an important evidence for individualized treatment of patients with breast cancer.

Interim response in diffuse large B cell lymphoma on CT: what is the optimal size reduction (ΔSPD) for predicting outcome?

OBJECTIVES: To investigate whether there was an optimal interim size reduction (iΔSPD) cutoff value that could discriminate diffuse large B cell lymphoma (DLBCL) patients with poor prognosis. METHODS: This retrospective study enrolled 265 newly diagnosed DLBCL patients with baseline and interim (after 3 cycles) contrast-enhanced computed tomographic scan (CECT) available. Two radiologists evaluated CECT images and selected target lesions according to the Lugano Response Criteria. Lymph nodes greater than 15 mm in longest diameter (LDi) and extra-nodal lesions with LDi greater than 10 mm could be chosen as target lesions and used to calculate iΔSPD. A software tool, X-Tile, was used to calculate the optimal iΔSPD cutoff value to differentiate patients with good vs. poor prognosis. Receiver operating characteristic curve analysis, Cox regression analysis, and Kaplan-Meier analyses were further used to validate the optimal cutoff value. RESULTS: The optimal cutoff value of iΔSPD calculated by X-tile was 80%. Compared with 50% and 100%, 80% cutoff value had the intermediate sensitivity and specificity (57.75% and 86.69% for overall survival (OS), 48.98% and 92.22% for progression-free survival (PFS), respectively), but the maximal Youden index (0.4744 for OS, 0.4120 for PFS, respectively) and areas under the curve (0.737 [0.680, 0.789] for OS). Cox regression analysis also revealed that iΔSPD < 80% could independently predict an inferior OS and PFS (both p < 0.001) while neither iΔSPD < 50% nor iΔSPD = 100% could. CONCLUSIONS: iΔSPD with the cutoff value 80% is an independent predictor of PFS and OS for patients with DLBCL. Results suggest that treatment should be modified for patients with iΔSPD < 80%. KEY POINTS: • The aim of interim response assessment is to identify patients whose disease has not responded to or has progressed on induction therapy. • A cutoff value of 80% in size reduction (ΔSPD) is an independent predictor of PFS and OS for DLBCL patients and is better than 50%. • In DLBCL patients with interim ΔSPD < 80%, a change to a more efficient therapy should be considered.

Development of a generalized model for kidney depth estimation in the Chinese population: A multi-center study.

PURPOSE: To establish an accurate and reliable equation for kidney depth estimation in adult patients from different Chinese geographical regions. METHOD: This multicenter study enrolled Eastern Asian Chinese patients with abdominal PET/CT scans at 26 imaging centers from six macro-regions across China in 3 years. Age, gender, height, weight, primary disease and its extent on PET scans of the participants were collected as potential predictive factors. Kidney depth on CT, defined as the average of the vertical distances from the posterior skin to the farthest anterior and closest posterior surfaces of each kidney, was measured as the standard reference. The new kidney depth model was constructed using a multiple regression model, and its performance was compared to those of three established models by computing the absolute value of estimation errors in comparison with CT-measured kidney depth. RESULTS: A total of 2502 patients were enrolled and classified into training (n=1653) and testing (n = 849) subsets. In the training subset, two kidney depth models were constructed: Left (cm): 0.013×age+0.117×gender-0.044×height+0.087×weight+7.951, Right (cm): 0.005×age+0.013×gender-0.035×height+0.082×weight+7.266 (weight: kg, height: cm, gender = 0 if female, 1 if male). In the testing subset, one-way analysis of variance showed that the estimation errors of the new models did not significantly differ among the 6 regions. Bland-Altman analysis determined that new equations had lower estimated biases (left: 0.039 cm, right: 0.018 cm) compared with other existing models. CONCLUSION: The new equations were highly accurate for kidney depth estimation in adults from all over China, with lower estimation errors compared to other established models.

Prognostic Value of Baseline and Interim Total Metabolic Tumor Volume and Total Lesion Glycolysis Measured on 18F-FDG PET-CT in Patients with Follicular Lymphoma.

PURPOSE: The purpose of this study was to investigate the prognostic significance of total metabolic tumor volume (TMTV) and total lesion glycolysis (TLG) in patients with follicular lymphoma (FL) at baseline and mid-treatment with 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) scans. METHODS: The study analyzed data from 48 patients with FL who were treated in Jiangsu Province Hospital and reviewed their baseline PET-CT scans. TMTV and TLG were computed by using the absolute value of 2.0, 2.5, and 3.0 thresholding method, respectively. RESULTS: Median age was 53 years, 75.0% of patients had stage III to IV disease, 43.8% had a Follicular Lymphoma International Prognostic Index 1 (FLIPI1) score of 3 to 5 and 20.8% had a FLIPI2 score of 3 to 5. Receiver operating characteristic (ROC) curve analysis showed the optimal cut-off values for TMTV3.0 and TLG3.0 were 476.4 (sensitivity, 85.7%; specificity, 78.0%; area under the curve [AUC], 0.760; p=0.003) and 2,676.9 (sensitivity, 71.4%; specificity, 78.0%; AUC, 0.760; p=0.003). On multivariable analysis, TMTV3.0 and TLG3.0 were independent predictors of both progression-free survival (PFS) (hazard ratio [HR], 5.406; 95% confidence interval [CI], 1.326 to 22.040; p=0.019 and HR, 6.502; 95% CI, 1.079 to 39.182; p=0.042) and overall survival (OS) (HR, 4.111; 95% CI, 1.125 to 15.027; p=0.033 and HR, 5.885; 95% CI, 1.014 to 34.148; p=0.049). ROC curve analysis showed the optimal cut-off values for ΔTMTV3.0 and ΔTLG3.0 were 66.3% (sensitivity, 85.7%; specificity, 63.4%; AUC, 0.774; p < 0.001) and 64.5% (sensitivity, 85.7%; specificity, 65.9%; AUC, 0.777; p < 0.001). CONCLUSION: Baseline TMTV and TLG are strong predictors of PFS and OS in FL. Furthermore, interim TMTV (ΔTMTV > 66.3%) and TLG (ΔTLG > 64.5%) reduction are valuable tools for early treatment response assessment in FL patients.

Ectopic insulinomas in the pelvis secondary to rectum neuroendocrine tumour.

We describe a middle-aged woman with recurrent hypoglycaemia, who confirmed with rectum G1 neuroendocrine tumour (NET) 6 years ago. Biochemical assay showed high concentration of serum insulin and C-peptide associated with hypoglycaemia. Because of recurrent hypoglycaemia in June 2015, she underwent a resection of the tail of the pancreas. However, hypoglycaemia attack happened more frequently and severely. 68Ga-DOTA-NOC positron emission tomography/CT revealed five foci in the pelvis with intense uptake. Immediately after excision of the pelvic lesions, insulin and C-peptide decreased to normal levels promptly, and therefore, serum glucose increased significantly. Hypoglycaemia was disappeared, and insulin and C-peptide were normal at 2 years follow-up after surgery. Immunohistochemistry validated the primary rectum NET and pelvic tumours expressed with higher insulin, somatostatin receptor and glucagon-like peptide-1. This is the first reported ectopic pelvic insulinomas secondary to rectum NET, which may originate both from neuroendocrine cells in the rectum and pelvic tissues.

Preclinical Evaluation of Radioiodinated Hoechst 33258 for Early Prediction of Tumor Response to Treatment of Vascular-Disrupting Agents.

This study aimed to explore the use of 131I-Hoechst 33258 (131I-H33258) for early prediction of tumor response to vascular-disrupting agents (VDAs) with combretastatin-A4 phosphate (CA4P) as a representative. Necrosis avidity of 131I-H33258 was evaluated in mouse models with muscle necrosis and blocking was used to confirm the tracer specificity. Therapy response was evaluated by 131I-H33258 SPECT/CT imaging 24 h after CA4P therapy in W256 tumor-bearing rats. Radiotracer uptake in tumors was validated ex vivo using γ-counting, autoradiography, and histopathological staining. Results showed that 131I-H33258 had predominant necrosis avidity and could specifically bind to necrotic tissue. SPECT/CT imaging demonstrated that an obvious "hot spot" could be observed in the CA4P-treated tumor. Ex vivo γ-counting revealed 131I-H33258 uptake in tumors was increased 2.8-fold in rats treated with CA4P relative to rats treated with vehicle. Autoradiography and corresponding H&E staining suggested that 131I-H33258 was mainly localized in necrotic tumor area and the higher overall uptake in the treated tumors was attributed to the increased necrosis. These results suggest that 131I-H33258 can be used to image induction of cell necrosis 24 h after CA4P therapy, which support further molecular design of probes based on scaffold H33258 for monitoring of tumor response to VDAs treatment.

Evaluation of Necrosis Avidity and Potential for Rapid Imaging of Necrotic Myocardium of Radioiodinated Hypocrellins.

PURPOSE: Rapid noninvasive delineation of necrotic myocardium in ischemic regions is very critical for risk stratification and clinical decision-making but still challenging. This study aimed to evaluate the necrosis avidity of radioiodinated hypocrellins and its potential for rapidly imaging necrotic myocardium. PROCEDURES: The aggregation constants of four natural hypocrellins were analyzed by UV/vis spectroscopy. Then, they were radiolabeled with iodine-131 by iodogen oxidation method. Necrosis avidity of iodine-131-labeled hypocrellins was evaluated in rat models with reperfused liver infarction and muscular necrosis by gamma counting, autoradiography, and histopathology. Their pharmacokinetic properties were examined in normal rats. The potential of iodine-131-labeled hypomycin A ([131I]HD) for early imaging of necrotic myocardium was explored in rat models with reperfused myocardial infarction. Finally, the possible mechanism of necrosis avidity was investigated by in vitro DNA binding and in vivo blocking experiments. RESULTS: The aggregation constants of four hypocrellins were all much smaller than that of hypericin, a most studied necrosis avid agent. The radiochemical purities of the four radiotracers after purification were all greater than 95 %, and more than 90 % of tracers remained intact after incubation in rat serum for 24 h. Among the four tracers, [131I]HD exhibited the highest necrotic to viable tissue uptake ratio and the fastest blood clearance. The necrotic myocardium could be clearly visualized 4 h after injection of [131I]HD by single-photon emission computed tomography/X-ray computed tomography (SPECT/CT). DNA binding studies suggested that HD could bind to DNA through intercalation. Blocking studies demonstrated that uptake of [131I]HD in necrotic muscle could be significantly blocked by excess unlabeled HD and ethidium bromide with 67 and 60 % decline at 6 h after coinjection, respectively. CONCLUSIONS: [131I]HD can be used to rapidly visualize necrotic myocardium. The necrosis avidity mechanism of [131I]HD may be attributed to its binding to the exposed DNA in necrotic tissues.

Brain metabolic correlates of fatigue in Parkinson's disease: a PET study.

PURPOSE: The neural bases of fatigue in Parkinson's disease (PD) remain uncertain. We aimed to assess the brain metabolic correlates of fatigue in patients with PD. PATIENTS AND METHODS: Twenty-seven PD patients without clinically relevant depression (17-item Hamilton Depression Rating Scale (HAMD) score ≥ 14), apathy (Apathy Scale (AS) score ≥ 14) and excessive daytime somnolence (Epworth Sleepiness Scale (ESS) score ≥ 10) were evaluated with Fatigue Severity Scale (FSS). Each patient had an F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) scan. Motor symptoms were measured with the Unified Parkinson's Disease Rating Scale motor part. Levodopa equivalent daily dose for each patient was also calculated. The PET images were analyzed using statistical parametric mapping software. We introduced the age, educational level, HAMD scores, AS scores and ESS scores as covariates. RESULTS: High FSS scores were associated with brain hypermetabolism in areas including the right middle temporal gyrus (Brodmann area (BA) 37) and left middle occipital gyrus (BA 19). Increased FSS scores correlated with hypometabolism in regions such as the right precuneus (BA 23), left inferior frontal gyrus (BA 45) and left superior frontal gyrus (orbital part, BA 11). CONCLUSION: This study demonstrates that brain areas including frontal, temporal and parietal regions indicative of emotion, motivation and cognitive functions are involved in fatigue in PD patients.

Cerebral metabolic change in Parkinson's disease patients with anxiety: A FDG-PET study.

OBJECT: To detect the cerebral metabolic bases of Parkinson's disease (PD) patients with anxiety. METHODS: Totally 28 idiopathic PD patients without depression (17-item Hamilton Depression Rating Scale, HAMD score <14) were enrolled in our study. All subjects were classified into PD with anxiety (PD-A) (n=13) and PD without anxiety (PD-NA) (n=15) by cutoff score of 11 according to Hamilton Anxiety Rating Scale (HAMA). Besides, age- and gender- matched healthy controls (HCs) (n=15) were selected. A resting-state F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) scan was applied to estimate cerebral metabolic activity. All statistical analyses were performed using IBM SPSS Statistics V20.0.0 software, while statistical parametric mapping software (SPM) was used to analyze the FDG-PET images. RESULTS: PD-A showed decreased glucose metabolism in the bilateral orbitofrontal cortex (OFC, BA10 and BA11) when compared with PD-NA. Significant decrease of cerebral glucose metabolism in the bilateral OFC, bilateral supplementary motor area (SMA, BA6), bilateral dorsal anterior cingulate cortex (dACC, BA32), right dorsolateral prefrontal cortex (dlPFC, BA9), right ventrolateral prefrontal cortex (vlPFC, BA44), right putamen and left caudatum was detected in PD-A compared with HCs. There was significant reduced glucose metabolism of the bilateral SMA in PD-NA when compared with HCs (uncorrected p<0.005). CONCLUSION: The anxiety of PD was associated with the metabolic reductions of PFC and striatal areas. OFC, part of PFC, could be taken as a characteristic feature for anxiety in PD. This metabolic pattern suggested that deficits of prefrontostriatal pathways might affect anxiety mood in PD.

[Clinical Value of 18F-FDG PET/CT for Patients with B Cell Lymphoma-Associated Hemophagocytic Syndrome].

OBJECTIVE: To investigate the clinical value of 18F-FDG PET/CT for patients with B cell lymphoma-associated hemophagocytic syndrome. METHODS: The clinical characteristics, laboratory parameters and 18F-FDG PET/CT data of 23 newly diagnosed patients sufferred from B cell lymphoma-associated hemophagocytic syndrome were retrospectively analyzed. The correlation between PET and laboratory parameters were determined using Spearman correlation test. The prognostic factors were analyzed by the Kaplan-Meier method. RESULTS: 23 patients were all examined by 18F-FDG PET/CT before chemotherapy, the 18F-FDG uptake of spleen positively correlated with neutrophil count and hemoglobin content (r=0.588, P=0.035;r=0.699, P=0.008), respectively, and the 18F-FDG uptake of bone marrow positively correlated with neutrophil count only (r=0.691, P=0.009). Among all the clinical or laboratorial parameters and 18F-FDG PET/CT, only PET parameter was poor factor affecting prognosis of patients with B cell lymphoma-associated hemophagocytic syndrome. Out of 6 patients received PET/CT scans after 6 cycles of treatment, the 5 patients with negative PET/CT survived, and one patient with positive result died. CONCLUSION: Baseline 18F-FDG PET/CT may provide prognostic information for the management of patients with B cell lymphoma-associated hemophagocytic syndrome, and the data of 18F-FDG PET/CT before chemotherapy may predict the pregnosis of the patients with negative results, and the negative PET/CT results after chemotherapy betokens a better prognosis of patients.

68Ga-PSMA-11 PET/CT for prostate cancer staging and risk stratification in Chinese patients.

We evaluated the clinical utility of 68Ga-PSMA-11 PET/CT for staging and risk stratification of treatment-naïve prostate cancer (PCa) and metastatic castrate-resistant prostate cancer (mCRPC). Twenty-two consecutive patients with treatment-naïve PCa and 18 with mCRPC were enrolled. 68Ga-PSMA-11 PET/CT and magnetic resonance imaging (MRI) were performed for the evaluation of primary prostatic lesions, and bone scans were used for evaluation bone metastasis. Among the 40 patients, 37 (92.5% [22 treatment-naïve PCa, 15 mCRPC]) showed PSMA-avid lesions on 68Ga-PSMA-11 images. Only 3 patients with stable mCRPC after chemotherapy were negative for PSMA. The sensitivity, specificity and accuracy of 68Ga-PSMA-11 imaging were 97.3%, 100.0% and 97.5%, respectively. The maximum standardized uptake (SUVmax) of prostatic lesions was 17.09 ± 11.08 and 13.33 ± 12.31 in treatment-naïve PCa and mCRPC, respectively. 68Ga-PSMA-11 revealed 105 metastatic lymph nodes in 15 patients; the SUVmax was 16.85 ± 9.70 and 7.54 ± 5.20 in treatment-naïve PCa and mCRPC, respectively. 68Ga-PSMA-11 PET/CT also newly detected visceral metastasis in 9 patients (22.5%) and bone metastasis in 29 patients (72.5%). 68Ga-PSMA-11 PET/CT exhibits potential for staging and risk stratification in naïve PCa, as well as improved sensitivity for detection of lymph node and remote metastasis.

Prognostic significance of bone marrow infiltration detected by PET-CT in newly diagnosed diffuse large B cell lymphoma.

The aim of this study was to examine the prognostic value of bone marrow involvement (BMI) assessed by baseline PET-CT (PET(0)-BMI) in treatment-naïve patients with diffuse large B-cell lymphoma (DLBCL). All patients from a single centre diagnosed as DLBCL between 2005 and 2014 had data extracted from staging PET-CT (PET(0)-CT), bone marrow biopsy (BMB), and treatment records. The PET(3)-CT (PET-CT scan after cycle 3 of immunochemotherapy) was performed on all the patients with PET(0)-BMI positivity (PET(0)-BMI(+)). Of 169 patients, 20 (11.8%) had BMI on BMB, whereas 35 (20.7%) were PET(0)-BMI positive. Among PET(0)-BMI(+) patients, patients with maximum of standard uptake value (SUVmax) of bone marrow (SUVmax(BM)) more than 8.6 were significantly associated with high IPI score (3-5) (P=0.002), worse progression-free survival (PFS) and overall survival (OS) (P=0.025 and P=0.002, respectively). In the 68 stage IV cases, 3-year OS was higher in the patients with negative PET(0)-BMI (PET(0)-BMI(-)) than that with PET(0)-BMI(+) (84.2%±6.5% vs. 44.1%±8.6%; P=0.003), while 3-year PFS only shown a trend of statistic significance (P=0.077) between the two groups. Among the 69 patients of inter-risk of IPI (2-3), patients with PET(0)-BMI(+) had significantly inferior PFS and OS than that with PET(0)-BMI(-) (P=0.009 and P<0.001, respectively). The cut-off value of the decreased percentage of SUVmax(BM) between PET(0)-CT and PET(3)-CT (ΔSUVmax(BM)) was 70.0%, which can predict PFS (P=0.003) and OS (P=0.023). These data confirmed that along with the increased sensitivity and accuracy of identifying bone marrow by PET-CT, novel prognostic values of marrow involvement were found in patients with DLBCL.

The Neural Basis of Postural Instability Gait Disorder Subtype of Parkinson's Disease: A PET and fMRI Study.

AIMS: The aim of this study is to further uncover the neural basis of postural instability gait disorder (PIGD) subtype of Parkinson's disease. METHODS: With F-18 fluorodeoxyglucose PET (FDG-PET), brain glucose metabolism of patients with PIGD (n = 15) was compared with healthy controls (n = 17) and tremor-dominant (TD) patients (n = 15), and the correlation between metabolism and PIGD symptoms was also assessed. Within PIGD symptom-correlated hypometabolic areas, the relationship of functional connectivity (FC) with motor and cognitive symptoms was examined by using functional MRI. RESULTS: Compared with controls, patients with PIGD displayed a distributed pattern of brain hypometabolism including striatal, frontal, and parietal areas. Relative to the pattern of TD patients, the pattern of patients with PIGD had additional metabolic decreases in caudate and inferior parietal lobule (IPL, Brodmann area [BA] 40). In PIGD group, the metabolic reductions in IPL (BA 40), middle frontal gyrus (MFG, BA 9) and fusiform gyrus (FG, BA 20) were associated with severe PIGD symptoms. Regions showing such correlation were chosen for further seed-based FC analysis. Decreased FC within the prefrontal-parietal network (between the MFG and IPL) was associated with severe PIGD symptoms. CONCLUSION: The involvement of the caudate, FG, and prefrontal-parietal network may be associated with the prominent gait impairments of PIGD subtype. Our findings expand the pathophysiological knowledge of PIGD subtype and provide valuable information for potential neuromodulation therapies alleviating gait disorders.

Exploring the role of bone marrow increased FDG uptake on PET/CT in patients with lymphoma-associated hemophagocytic lymphohistiocytosis: a reflection of bone marrow involvement or cytokine storm?

The role of 18F-2-fluoro-2-deoxy-D-glucose (FDG) uptake of bone marrow (BM) on positron emission tomography/computed tomography (PET/CT) in patients with lymphoma-associated hemophagocytic lymphohistiocytosis (LA-HLH) remains uncertain. This retrospective study included 34 LA-HLH patients who underwent both PET/CT and comprehensive BM examinations prior to treatment. Comparison between PET/CT and BM examinations for the assessment of bone marrow involvement (BMI) indicated statistical difference (p = 0.039). The specificity of PET/CT in detecting BMI was 11.1% compared to BM examinations. However, a significant correlation was found between PET parameters of BM and laboratory parameters associated with HLH, such as C-reactive protein, ferritin, fibrinogen and soluble CD25. By multivariate analysis, PET parameters of marrow were significantly associated with overall survival. The findings suggest that FDG uptake of marrow might fail to detect lymphomatous BMI, but reflected the level of cytokine storm to a certain extent and might be a prognostic factor in patients with LA-HLH.

[Prognostic Value of Maximum Standard Uptake on Pretreatment ¹8F-FDG PET/CT Scan in Newly Diagnosed Follicular Lymphoma].

OBJECTIVE: To determine the prognostic value of maximum standard uptake (SUV(max)) of pretreatment ¹8F-FDG PET/CT scan in newly diagnosed follicular lymphoma (FL). METHODS: The clinical data and detection results of ¹8F-FDG PET/CT scan of 30 patients with FL before treatment from November 2005 to October 2013 were analyzed retrospectively. The relation of SUV(max) with prognostic factors, therapeutic efficacy and survival time was evaluated in term of pathologic grade, FLIPI2 absence and presence of bulky disease and bone marrow involvement, clinical indicators and outcome of treatment. RESULTS: There was significant differences of SUV(max) among pathological grade 1, grade 2 and grade 3 (P = 0.040), but no significant difference was found among FLIPI 2 low risk group, intermediate risk group and high risk groups (P = 0.431). No difference of SUV(max) was observed in patients with and without bulky disease, or with and without bone marrow involvement (both P > 0.05). SUV(max) was not related with such patient characteristics as stage, ß2-microglobulin level, hemoglobin content, lactate dehydrogenase and Ki-67 (both P > 0.05). And the difference of SUV(max) was no significant for patients with complete remission (CR) and non-CR, or with efficacy and no efficacy (both P > 0.05). With the cutoff values of 10 and 15, the CR rate, overall response rate, 3-year progression-free survival (PFS) rate and 2-year overall survival (OS) rate were not different between the patients with SUV(max) below and above cut-off value (both P > 0.05). CONCLUSION: In our study the prognostic value of SUV(max) on PET/CT is indeterminate, and it can not be used to predict the FL patients prognosis.