Prognostic value of preoperative dynamic contrast-enhanced MRI perfusion parameters for high-grade glioma patients

Introduction

The prognostic value of the dynamic contrast-enhanced (DCE) MRI perfusion and its histogram analysis-derived metrics is not well established for high-grade glioma (HGG) patients. The aim of this prospective study was to investigate DCE perfusion transfer coefficient (K^trans), vascular plasma volume fraction (v_p), extracellular volume fraction (v_e), reverse transfer constant (k_ep), and initial area under gadolinium concentration time curve (IAUGC) as predictors of progression-free (PFS) and overall survival (OS) in HGG patients.

Methods

Sixty-nine patients with suspected anaplastic astrocytoma or glioblastoma underwent preoperative DCE-MRI scans. DCE perfusion whole tumor region histogram parameters, clinical details, and PFS and OS data were obtained. Univariate, multivariate, and Kaplan–Meier survival analyses were conducted. Receiver operating characteristic (ROC) curve analysis was employed to identify perfusion parameters with the best differentiation performance.

Results

On univariate analysis, v_e and skewness of v_p had significant negative impacts, while k_ep had significant positive impact on OS (P < 0.05). v_e was also a negative predictor of PFS (P < 0.05). Patients with lower v_e and IAUGC had longer median PFS and OS on Kaplan–Meier analysis (P < 0.05). K^trans and v_e could also differentiate grade III from IV gliomas (area under the curve 0.819 and 0.791, respectively).

Conclusions

High v_e is a consistent predictor of worse PFS and OS in HGG glioma patients. v_p skewness and k_ep are also predictive for OS. K^trans and v_e demonstrated the best diagnostic performance for differentiating grade III from IV gliomas.

     

The complementary roles of dynamic contrast-enhanced MRI and 18F-fluorodeoxyglucose PET/CT for imaging of carotid atherosclerosis

Purpose

Inflammation and neovascularization in vulnerable atherosclerotic plaques are key features for severe clinical events. Dynamic contrast-enhanced (DCE) MRI and FDG PET are two noninvasive imaging techniques capable of quantifying plaque neovascularization and inflammatory infiltrate, respectively. However, their mutual role in defining plaque vulnerability and their possible overlap has not been thoroughly investigated. We studied the relationship between DCE-MRI and ¹⁸F-FDG PET data from the carotid arteries of 40 subjects with coronary heart disease (CHD) or CHD risk equivalent, as a substudy of the dal-PLAQUE trial (NCT00655473).

Methods

The dal-PLAQUE trial was a multicenter study that evaluated dalcetrapib, a cholesteryl ester transfer protein modulator. Subjects underwent anatomical MRI, DCE-MRI and ¹⁸F-FDG PET. Only baseline imaging and biomarker data (before randomization) from dal-PLAQUE were used as part of this substudy. Our primary goal was to evaluate the relationship between DCE-MRI and ¹⁸F-FDG PET data. As secondary endpoints, we evaluated the relationship between (a) PET data and whole-vessel anatomical MRI data, and (b) DCE-MRI and matching anatomical MRI data. All correlations were estimated using a mixed linear model.

Results

We found a significant inverse relationship between several perfusion indices by DCE-MRI and ¹⁸F-FDG uptake by PET. Regarding our secondary endpoints, there was a significant relationship between plaque burden measured by anatomical MRI with several perfusion indices by DCE-MRI and ¹⁸F-FDG uptake by PET. No relationship was found between plaque composition by anatomical MRI and DCE-MRI or ¹⁸F-FDG PET metrics.

Conclusion

In this study we observed a significant, weak inverse relationship between inflammation measured as ¹⁸F-FDG uptake by PET and plaque perfusion by DCE-MRI. Our findings suggest that there may be a complex relationship between plaque inflammation and microvascularization during the different stages of plaque development. ¹⁸F-FDG PET and DCE-MRI may have complementary roles in future clinical practice in identifying subjects at high risk of cardiovascular events.     

Quantitative in vivo imaging of tissue factor expression in glioma using dynamic contrast-enhanced MRI derived parameters

ObjectiveTissue Factor (TF) has been well established in angiogenesis, invasion, metastasis, and prognosis in glioma. A noninvasive assessment of TF expression status in glioma is therefore of obvious clinical relevance. Dynamic contrast-enhanced (DCE) MRI parameters have been used to evaluate microvascular characteristics and predict molecular expression status in tumors. Our aim is to investigate whether quantitative DCE-MRI parameters could assess TF expression in glioma.Materials and methodsThirty-two patients with histopathologically diagnosed supratentorial glioma who underwent DCE-MRI were retrospectively recruited. Extended Tofts linear model was used for DCE-MRI post-processing. Hot-spot, whole tumor cross-sectional approaches, and histogram were used for analysis of model based parameters. Four serial paraffin sections of each case were stained with TF, CD105, CD34 and α-Sooth Muscle Actin, respectively for evaluating the association of TF and microvascular properties. Pearson correlation was performed between percentage of TF expression area and DCE-MRI parameters, multiple microvascular indexes.ResultsVolume transfer constant (K^trans) hot-spot value best correlated with TF (r = 0.886, p < 0.001), followed by 90th percentile K^trans value (r = 0.801, p < 0.001). Moreover, histogram analysis of K^trans value demonstrated that weak TF expression was associated with less heterogeneous and positively skewed distribution. Finally, pathology analysis revealed TF was associated with glioma grade and significantly correlated with these two dynamic angiogenic indexes which could be used to explain the strong correlation between K^trans and TF expression.ConclusionOur results indicate that K^trans may serve as a potential clinical imaging biomarker to predict TF expression status preoperatively in gliomas.     

Prognostic value of O-(2-18F-fluoroethyl)-L-tyrosine PET and MRI in low-grade glioma.

In glioma of World Health Organization (WHO) grade II (low-grade glioma), the natural course of a particular patient is not predictable and the treatment strategy is controversial. We determined prognostic factors in adult patients with untreated, nonenhancing, supratentorial low-grade glioma with special regard to PET using the amino acid O-(2-(18)F-fluoroethyl)-L-tyrosine ((18)F-FET) and MRI. METHODS: In a prospective study, baseline (18)F-FET PET and MRI analyses were performed on 33 consecutive patients with histologically confirmed low-grade glioma. None of the patients had radiation or chemotherapy. Clinical, histologic, therapeutic (initial cytoreduction vs. biopsy), (18)F-FET uptake, and MRI morphologic parameters were analyzed for their prognostic significance. Statistical endpoints were clinical or radiologic tumor progression, malignant transformation to glioma of WHO grade III or IV (high-grade glioma), and death. RESULTS: Baseline (18)F-FET uptake and a diffuse versus circumscribed tumor pattern on MRI were highly significant predictors of prognosis (P < 0.01). By the combination of these prognostically significant variables, 3 major prognostic subgroups of low-grade glioma patients could be identified. The first of these subgroups was patients with circumscribed low-grade glioma on MRI without (18)F-FET uptake (n = 11 patients, progression in 18%, no malignant transformation and no death). The second subgroup was patients with circumscribed low-grade glioma with (18)F-FET uptake (n = 13 patients, progression in 46%, malignant transformation to a high-grade glioma in 15%, and death in 8%). The third subgroup was patients with diffuse low-grade glioma with (18)F-FET uptake (n = 9 patients, progression in 100%, malignant transformation to a high-grade glioma in 78%, and death in 56%). CONCLUSION: We conclude that baseline amino acid uptake on (18)F-FET PET and a diffuse versus circumscribed tumor pattern on MRI are strong predictors for the outcome of patients with low-grade glioma.     

Comparative diagnostic accuracy of contrast-enhanced MRI and 18F-FDOPA PET-CT in recurrent glioma

Objectives

To compare the diagnostic accuracy of contrast enhanced magnetic resonance imaging (Ce-MRI) and ¹⁸F-fluorodopa (¹⁸F-FDOPA) positron emission tomography (PET)-computed tomography (CT) for detecting recurrent glioma.

Methods

In this prospective study, 35 patients (age, 36.62?±?0.86 years; 80 % male) with histopathologically proven glioma with clinical suspicion of recurrence were evaluated using Ce-MRI and ¹⁸F-FDOPA PET-CT. ¹⁸F-FDOPA PET-CT images were evaluated qualitatively and semi-quantitatively. Combination of clinical follow-up (minimum 1 year), repeat imaging and/or biopsy (when available) was taken as the reference standard.

Results

Based on the reference standard, 26 patients were positive and nine were negative for recurrence. The sensitivity, specificity and accuracy of Ce-MRI were 92.3 %, 44.4 % and 80 % respectively, whereas those of ¹⁸F-FDOPA PET-CT were 100 %, 88.89 % and 97.1 % respectively. Results of Ce-MRI and ¹⁸F-FDOPA PET-CT were concordant in 74.3 % (29/35) and discordant in 17.1 % of patients (6/35). On McNemar analysis the difference was not statistically significant overall (P?=?0.687), for high-grade tumour (P?=?0.5) or low-grade tumours (P?=?1.0). However, ¹⁸F-FDOPA PET-CT was more specific than Ce-MRI overall (P?=?0.0002), for high-grade tumour (P?=?0.006) and low-grade tumours (P?=?0.004).

Conclusion

F-FDOPA PET-CT shows a high but comparable diagnostic accuracy to Ce-MRI for the detection of recurrent glioma. However, it is more specific than Ce-MRI.

Key Points

? Recurrent glioma in the postoperative site remains a diagnostic dilemma. ? ¹⁸ F-FDOPA PET-CT shows high diagnostic accuracy for detecting recurrent glioma. ? Diagnostic accuracies for ¹⁸ F-FDOPA PET-CT and contrast enhanced MRI are comparable. ? However, ¹⁸ F-FDOPA PET-CT is more specific than Ce-MRI for recurrent glioma.     

Diffusion-weighted MRI, 11C-choline PET and 18F-fluorodeoxyglucose PET for predicting the Gleason score in prostate carcinoma

Objectives

To evaluate the accuracy of transrectal ultrasound-guided (TRUS) biopsy, diffusion-weighted (DW) magnetic resonance imaging (MRI), ¹¹C-choline (CHOL) positron emission tomography (PET), and ¹⁸F-fluorodeoxyglucose (FDG) PET in predicting the prostatectomy Gleason risk (GR).

Methods

The study included 21 patients who underwent TRUS biopsy and multi-technique imaging before radical prostatectomy. Values from five different tests (TRUS biopsy, DW MRI, CHOL PET, FDG PET, and combined DW MRI/CHOL PET) were correlated with the prostatectomy GR using Spearman’s ρ. Tests that were found to have significant correlations were used to classify patients into GR groups.

Results

The following tests had significant correlations with prostatectomy GR: TRUS biopsy (ρ?=?0.617, P?=?0.003), DW MRI (ρ?=?–0.601, P?=?0.004), and combined DW MRI/CHOL PET (ρ?=?–0.623, P?=?0.003). CHOL PET alone and FDG PET only had weak correlations. The correct GR classification rates were 67 % with TRUS biopsy, 67 % with DW MRI, and 76 % with combined DW MRI/CHOL PET.

Conclusions

DW MRI and combined DW MRI/CHOL PET have significant correlations and high rates of correct classification of the prostatectomy GR, the strength and accuracy of which are comparable with TRUS biopsy.

Key Points

? Accurate determination of the Gleason score is essential for prostate cancer management. ? DW MRI ± CHOL PET correlated significantly with prostatectomy Gleason score. ? These correlations are similar to that between TRUS biopsy and prostatectomy.     

18F-氟代脱氧葡萄糖PET在鼻咽癌中的临床应用价值

18F—FDG PET作为一种功能显像技术,通过一次性全身显像,可以检出常规影像学检查阴性的隐匿病灶,对于鼻咽癌颈部淋巴结转移、远处转移有较高的临床价值,对于疗效监测、早期检测残存或肿瘤复发方面也优于传统的影像学方法。但PET对局部组织结构分辨能力远不如 CT和MRI,PET—CT则通过解剖和功能图像的融合技术克服了这一缺陷。     

18F-氟脱氧葡萄糖PET在淋巴瘤中的应用价值

淋巴瘤的发病率逐年升高,18^F-氟脱氧葡萄糖（18^F—FDG）PET作为一种全身性功能代谢显像手段在淋巴瘤的诊断、分期、治疗方案的选择、疗效的评价及残留肿块性质的判断方面具有重要价值,较常规影像学检查提供更多有价值的信息而得到临床的广泛认可,但仍有一定的假阳性及假阴性。     

Evaluation of the effect of treatment in patients with liver tumors using 18F-fluorodeoxyglucose PET

To evaluate the glucose metabolism in the liver tumor, 18FDG PET (Positron Emission Tomography) was performed in 9 patients with primary and metastatic liver tumors. And usefulness of 18FDG PET in clarifying the effect of treatment on liver tumor was examined. Glucose metabolism of tumor was showed in terms of the coefficient 'C' calculated by Patlak's plot. Each tumor's coefficient 'C' was 0.016-0.054 and it decreased after treatment. Compared with pathological findings, the coefficient 'C' of necrosis part of tumor was 0.004 and fibrous change after irradiation was 0.007. It suggested that coefficient 'C' reflected activity of tumor and it was a useful index to know viability of tumors in the treatment for patients with liver tumors.     

Fusion of PET and MRI for staging of uterine cervical cancer: comparison with contrast-enhanced 18F-FDG PET/CT and pelvic MRI

PurposeTo investigate the fusion of pelvic magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography (PET) for assessment of locoregional extension and nodal staging of cervical cancer.MethodsPET/computed tomography (CT), MRI, and non-fused and fusion of PET and MRI for assessing the extent of the primary tumor and metastasis to nodes were evaluated.ResultsAccuracy for T-status was 83.3% for fused and non-fused PET/MRI and MRI proved significantly more accurate than PET/CT (53.3%) (P= .0077). Sensitivity, specificity, and accuracy for nodal metastasis were 92.3%, 88.2%, and 90.0% for fused PET/MRI and PET/contrast-enhanced CT; 84.6%, 94.1%, and 90.0% for non-fused PET/MRI; and 69.2%, 100%, and 86.7% for MRI.ConclusionFused PET/MRI combines the individual advantages of MRI and PET.     

18^F-FDG PET／CT全身显像对甲状腺偶发瘤的临床意义

目的研究18^F-脱氧葡萄糖（FDG）PET／CT显像对甲状腺偶发瘤的检出率及检出恶性病灶的比例、最大标准摄取值（SUVmax）对鉴别诊断良、恶性病变的价值。方法回顾性分析2007年6月-2008年1月1190例无甲状腺癌病史的PET／CT受检者资料,对PET／CT发现的甲状腺偶发瘤行定性、半定量分析。对数据行Kruskal—Wallis检验或Spearman相关分析。结果18^F-FDG PET／CT全身显像对甲状腺偶发瘤的检出率为2．1％（25／1190）,其中20例取得病理结果,良性病变9例,恶性病变11例（9例乳头状癌、1例滤泡状癌、1例肺癌转移）,恶性比例高达55％（11／20）。良、恶性病变组间SUVmax差异有统计学意义（分别为4．1±1．9和13．3±11．8,Х^2=8．8,P〈0．01）。甲状腺偶发瘤最大径（1．0～4．2cm）与其18^F-FDG摄取（SUVmax为3．0—46．0）之间无相关性（r=0．25,P〉0．01）。结论18^F-FDG PET／CT检查发现甲状腺偶发瘤中甲状腺癌比例很高,其SUVmax对鉴别诊断良、恶性病变有参考价值。     

MRI and 18F-fluorodeoxyglucose positron emission tomography in hemimegalencephaly

We report hemimegalencephaly in a 44-year-old woman with mental retardation, epilepsy and a mild hemiparesis. In addition to typical findings on MRI, 2-deoxy-2[¹⁸F]fluorodeoxyglucose positron-emission tomography (PET) demonstrated glucose hypometabolism of the affected hemisphere. The results of PET have been coregistered with morphological information from the MRI studies by image fusion. Received: 14 December 1999/Accepted: 15 February 2000     

Comparison of 11C-methionine PET and 18F-fluorodeoxyglucose PET in differentiated thyroid cancer

BACKGROUND: The purpose of this prospective study is to evaluate the possibility of 11C-methionine (Met) PET compared with 18F-fluorodeoxyglucose (FDG) PET for the detection of recurrent or metastatic disease in patients with differentiated thyroid cancer (DTC). MATERIALS AND METHODS: Twenty patients with clinical suspicion of recurrent DTC but negative posttreatment 131I-whole body scans were included in the study. Both 11C-Met PET and 18F-FDG PET were performed within 1 week. PET images were analyzed by two independent and blinded physicians using visual and standardized uptake value analysis. PET results were also correlated with radiologic and/or cytological investigations. RESULTS: Thirteen patients showed concordant findings on both PET scans: six patients showed uptake and in seven no uptake was observed. In six of the seven patients without Met and FDG uptake, additional MRI and ultrasound-guided fine needle aspiration cytology of the lymph nodes revealed inconclusive or negative results. Six patients showed discordant findings on the PET scans: in three patients uptake was only observed on the Met PET, confirmed by MRI in one. In three patients lesions were seen on the FDG PET, confirmed by computed tomography or ultrasound-guided fine needle aspiration cytology. However, those lesions were not compatible with the lesions seen on the Met PET. In general, FDG uptake appeared to be higher than Met uptake, but was not significant (P=0.075). CONCLUSION: This study shows that imaging using radiolabeled amino acids is feasible in DTC. For now, 11C-Met PET has not proven to be superior to 18F-FDG PET in the detection of recurrent disease in DTC. Complementary uptake of Met and FDG has, however, been observed, which has to be further clarified and long-term follow-up is needed to define the true clinical value of the 11C-Met PET, and possible other amino acids tracers.     

Prognostic value of pretreatment volume-based quantitative 18F-FDG PET/CT parameters in patients with malignant pleural mesothelioma

PurposeTo investigate the relationships between pretreatment volume-based quantitative ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) parameters and overall survival (OS) in patients with malignant pleural mesothelioma (MPM).Materials and methodsWe retrospectively reviewed data from 201 MPM patients, of whom 38 underwent surgical resection, and calculated the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), including primary tumors and nodal or distant metastatic lesions, on pretreatment ¹⁸F-FDG PET/CT. Relationships between clinicopathological factors (age, sex, performance status, European Organization for Research and Treatment of Cancer [EORTC] score, histological subtype, TNM stage, and treatment strategy), volume-based quantitative PET/CT parameters, and OS were evaluated using a Cox proportional hazards model and log-rank test.ResultsThe median follow-up was 15 months (range, 1–96 months; median, 17 months). In a univariate analysis of all patients, older age (p < 0.05), high EORTC score (p < 0.001), non-epithelioid histological subtype (p < 0.001), high T stage (p < 0.001), positive N/M status (p < 0.05, p < 0.001), advanced TNM stage (p < 0.001), non-surgical treatment (p < 0.001), and high SUVmax (p < 0.001), MTV (p < 0.001), or TLG (p < 0.001) were associated with significantly shorter OS. A multivariate analysis confirmed non-epithelioid subtype (hazard ratio [HR]: 1.69, 95% confidence interval [CI]: 1.14–2.48; p < 0.05), non-surgical treatment (HR: 0.58, 95% CI: 0.34–0.95; p < 0.05), and high TLG (HR: 1.97, 95% CI: 1.14–3.44; p < 0.05) as independent negative predictors.ConclusionsPretreatment volume-based quantitative ¹⁸F-FDG PET/CT parameters, especially TLG, could serve as potential surrogate markers for MPM prognosis.     

Reliability of semiquantitative F-FDG PET parameters derived from simultaneous brain PET/MRI: A feasibility study

Purpose

Simultaneous brain PET/MRI faces an important issue of validation of accurate MRI based attenuation correction (AC) method for precise quantitation of brain PET data unlike in PET/CT systems where the use of standard, validated CT based AC is routinely available. The aim of this study was to investigate the feasibility of evaluation of semiquantitative ¹⁸F-FDG PET parameters derived from simultaneous brain PET/MRI using ultrashort echo time (UTE) sequences for AC and to assess their agreement with those obtained from PET/CT examination.

Methods

Sixteen patients (age range 18–73 years; mean age 49.43 (19.3) years; 13 men 3 women) underwent simultaneous brain PET/MRI followed immediately by PET/CT. Quantitative analysis of brain PET images obtained from both studies was undertaken using Scenium v.1 brain analysis software package. Twenty ROIs for various brain regions were system generated and 6 semiquantitative parameters including maximum standardized uptake value (SUV max), SUV mean, minimum SUV (SUV min), minimum standard deviation (SD min), maximum SD (SD max) and SD from mean were calculated for both sets of PET data for each patient. Intra-class correlation coefficients (ICCs) were determined to assess agreement between the various semiquantitative parameters for the two PET data sets.

Results

Intra-class co-relation between the two PET data sets for SUV max, SUV mean and SD max was highly significant (p < 0.00) for all the 20 predefined brain regions with ICC > 0.9. SD from mean was also found to be statistically significant for all the predefined brain regions with ICC > 0.8. However, SUV max and SUV mean values obtained from PET/MRI were significantly lower compared to those of PET/CT for all the predefined brain regions.

Conclusion

PET quantitation accuracy using the MRI based UTE sequences for AC in simultaneous brain PET/MRI is reliable in a clinical setting, being similar to that obtained using PET/CT.     

Combined pre-treatment MRI and 18F-FDG PET/CT parameters as prognostic biomarkers in patients with cervical cancer

Objective

To determine the associations of quantitative parameters derived from multiphase contrast-enhanced magnetic resonance imaging (CE-MRI), diffusion-weighted (DW) MRI and 18F-fluorodeoxyglucose (18F-FDG) positron-emission tomography/computed tomography (PET/CT) with clinico-histopathological prognostic factors, disease-free survival (DFS) and overall survival (OS) in patients with cervical cancer.

Methods and materials

Our institutional review board approved this retrospective study of 49 patients (median age, 45 years) with histopathologically proven IB-IVB International Federation of Gynecology and Obstetrics (FIGO) cervical cancer who underwent pre-treatment pelvic MRI and whole-body 18F-FDG PET/CT between February 2009 and May 2012. Maximum diameter (_maxTD), percentage enhancement (PE) and mean apparent diffusion coefficient (ADC_mean) of the primary tumor were measured on MRI. Maximum standardized uptake value (SUV_max), metabolic tumor volume (MTV), total lesion glycolysis (TLG) were measured on 18F-FDG PET/CT. Correlations between imaging metrics and clinico-histopathological parameters including revised 2009 FIGO stage, tumor histology, grade and lymph node (LN) metastasis at diagnosis were evaluated using the Wilcoxon rank sum test. Cox modeling was used to determine associations with DFS and OS.

Results

Median follow-up was 17 months. 41 patients (83.6%) were alive. 8 patients (16.3%) died of disease. Progression/recurrence occurred in 17 patients (34.6%). Significant differences were observed in ADC_mean, SUV_max, MTV and TLG according to FIGO stage (p < 0.001–0.025). There were significant correlations between ADC_mean, MTV, TLG and LN metastasis (p = 0.017–0.032). SUV_max was not associated with LN metastasis. FIGO stage (p = 0.017/0.033), LN metastases (p = 0.001/0.020), ADC_mean (p = 0.007/0.020) and MTV (p = 0.014/0.026) were adverse predictors of both DFS/OS. _maxTD (p = 0.005) and TLG (p = 0.024) were adverse predictors of DFS. PE and SUV_max did not correlate with DFS or OS (p = 0.18–0.72).

Conclusions

Quantitative parameters derived from pre-treatment DW-MRI (ADC_mean) and from 18F-FDG PET/CT (MTV and TLG) were associated with high-risk features and may serve as prognostic biomarkers of survival in patients with cervical cancer.     

18F-氟脱氧葡萄糖PET、超声内镜及CT在食管癌术前分期中的应用

食管癌术前准确分期对治疗方案的选择及预后判断有重要意义。目前，食管癌分期方法主要有^18F-氟脱氧葡萄糖（^18F-FDG）PET、超声内镜及CT。超声内镜对食管癌T分期价值较高，三种方法对食管癌局部淋巴结的分期（N分期）各有优缺点，^18F-FDGPET对远处转移灶（M分期）的发现有明显的优势。综合运用^18F-FDGPET、超声内镜及CT可明显提高食管癌术前分期的准确性。