Preoperative tumor size at MRI predicts deep myometrial invasion, lymph node metastases, and patient outcome in endometrial carcinomas.

OBJECTIVE: The aim of this study was to explore the relation between preoperative tumor size based on magnetic resonance imaging (MRI) and the surgical pathologic staging parameters (deep myometrial invasion, cervical stroma invasion, and metastatic lymph nodes) and to assess the prognostic impact of tumor size in endometrial carcinomas. Interobserver variability for the different tumor size measurements was also assessed. METHODS/MATERIALS: Preoperative pelvic MRI of 212 patients with histologically confirmed endometrial carcinomas was read independently by 3 radiologists. Maximum tumor diameters were measured in 3 orthogonal planes (anteroposterior, transverse, and craniocaudal planes [CC]), and tumor volumes were estimated. Tumor size was analyzed in relation to surgical staging results and patient survival. The multivariate analyses were adjusted for preoperative risk status based on endometrial biopsy. Intraclass correlation coefficients and receiver operating characteristics curves for the different tumor measurements were also calculated. RESULTS: Anteroposterior tumor diameter independently predicted deep myometrial invasion (P < 0.001), whereas CC tumor diameter tended to independently predict lymph node metastases (P = 0.06). Based on receiver operating characteristic curves, the following tumor size cutoff values were identified: anteroposterior diameter greater than 2 cm predicted deep myometrial invasion (unadjusted odds ratio [OR], 12.4; P < 0.001; adjusted OR, 6.7; P < 0.001) and CC diameter greater than 4 cm predicted lymph node metastases (unadjusted OR, 6.2; P < 0.001; adjusted OR, 4.9; P = 0.009). Large tumor size was associated with reduced progression/recurrence-free survival (P ≤ 0.005 for all size parameters), and CC diameter had an independent impact on survival (adjusted hazards ratio, 1.04; P = 0.009). The interobserver variability for the different size measurements was very low (intraclass correlation coefficient, 0.78-0.85). CONCLUSIONS: Anteroposterior tumor diameter greater than 2 cm predicts deep myometrial invasion, and CC tumor diameter greater than 4 cm predicts lymph node metastases. Tumor size is a strong prognostic factor in endometrial carcinomas. Preoperative tumor measurements based on MRI may potentially improve preoperative risk stratification models and thus enable better tailored surgical treatment in endometrial cancer.

Dynamic contrast-enhanced MRI in endometrial carcinoma identifies patients at increased risk of recurrence.

OBJECTIVES: To study the feasibility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for assessment of tumour microvasculature in endometrial carcinoma patients, and to explore correlations with histological subtype, clinical course and microstructural characteristics based on apparent diffusion coefficient (ADC) values. METHODS: Diffusion-weighted imaging (DWI) and three-dimensional DCE-MRI (1.5 T) with high temporal resolution (2.49 s) were acquired preoperatively in 55 patients. Quantitative modelling allowed the calculation of four independent parameters describing microvasculature: blood flow (Fb), extraction fraction (E), capillary transit time (Tc) and transfer constant from the extravascular extracellular space [EES] to blood (Kep); and four derived parameters: blood volume (Vb), volume of EES (Ve), capillary permeability surface area product (PS) and transfer from blood to EES (Ktrans). RESULTS: Endometrial carcinoma tissue exhibited reduced Fb, E, Vb, Ve, PS and Ktrans compared with normal myometrium. Non-endometrioid carcinomas (n = 12) had lower Fb, and E than endometrioid carcinomas (n = 43; P < 0.05). Tumour Ve positively correlated with tumour ADC value (r = 0.29, P = 0.03). Reduced survival was observed in patients with low tumour Fb and high tumour Tc (P < 0.05). CONCLUSIONS: We demonstrate the feasibility of DCE-MRI in reflecting histological subtype and clinical course in primary endometrial carcinomas. DCE-MRI may potentially provide future biomarkers for preoperative risk stratification in endometrial carcinomas. KEY POINTS: • Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) offers new information about endometrial carcinoma. • Pelvic DCE-MRI with subsequent quantitative modelling seems feasible in endometrial carcinoma patients. • Low tumour perfusion is a feature of a more aggressive tumour subtype. • DCE-MRI provides potential biomarkers for preoperative risk stratification in endometrial carcinoma patients.

Standard 1.5-T MRI of endometrial carcinomas: modest agreement between radiologists.

OBJECTIVES: To evaluate pelvic magnetic resonance imaging (MRI) interobserver agreement for the detection of deep myometrial invasion, cervical stroma invasion and lymph node metastases in endometrial carcinoma patients in relation to surgical staging. METHODS: Fifty-seven patients with histologically confirmed endometrial carcinoma were prospectively included in a study of preoperative 1.5-T MRI. Four radiologists, blinded to patient data, independently reviewed the images for the presence of deep myometrial invasion, cervical stroma invasion and lymph node metastases. Kappa coefficients for interobserver agreement and diagnostic performances for each observer were calculated using final surgical staging results (FIGO 09) as reference standard. RESULTS: Overall agreement among all observers was moderate for cervical stroma invasion (κ = 0.50 [95% CI 0.27-0.73]) and lymph node metastases (κ = 0.56 [0.09-0.80]) and fair for deep myometrial invasion (κ = 0.39 [0.26-0.55]). Sensitivity (specificity) values for the four observers were 72-92% (44-63%) for deep myometrial invasion, 38-63% (82-94%) for cervical stroma invasion and 25-38% (90-100%) for lymph node metastases. CONCLUSIONS: Conventional MRI showed only modest interobserver agreement and diagnostic accuracy for detection of deep myometrial invasion, cervical stroma invasion and lymph node metastases. Improved methods are needed for preoperative imaging in the staging of endometrial carcinomas. KEY POINTS: MRI is an important tool for preoperative endometrial cancer staging. • Staging agreement based on pelvic MRI was modest among different observers. • Preoperative MRI alone was suboptimal in identifying high-risk patients. • Improved imaging and biomarkers may refine preoperative risk stratification in endometrial cancer.

Double reading of radiological examinations in Norway.

BACKGROUND: Double reading of images is a part of the quality assurance activities at many radiological centers. PURPOSE: To investigate the extent of and routines for double reading in Norway and the institutional heads' attitudes toward double reading. MATERIAL AND METHODS: A questionnaire was addressed to the heads of all radiological institutions in Norway. The questionnaire concerned staffing, examinations performed, extent of double reading per imaging modality (except mammography screening), guidelines for double reading, checks of completed radiology reports, frequency of regular quality assurance meetings to discuss missed findings, and the heads' attitudes toward double reading. RESULTS: The response rate was 73% (53/73). The percentage across imaging modalities of examinations being double read was 41% overall: 56% at university hospitals, 37% at local hospitals, and 18% at private centers. Double reading was most common for positron emission tomography (PET)/PET-computed tomography (CT) examinations (100%), and clinical mammography (91%). Almost all examinations read by residents were double read. Only 15% of institutions had written guidelines for double reading, 15% performed random double readings of completed examinations, and 55% organized regular meetings to discuss missed findings. Forty-six percent of the institutional heads wanted an increased use of double reading. CONCLUSION: Double reading is common in Norway, especially in residency training, mammography, and PET/PET-CT. It is less common at private centers. Established routines for double reading are scarce. Many institutional heads want more double reading. The potential of double reading to assure quality in radiology should be better exploited.

Preoperative imaging markers and PDZ-binding kinase tissue expression predict low-risk disease in endometrial hyperplasias and low grade cancers.

PURPOSE: Distinguishing complex atypical hyperplasia (CAH) from grade 1 endometrioid endometrial cancer (EECG1) preoperatively may be valuable in order to prevent surgical overtreatment, particularly in patients wishing preserved fertility or in patients carrying increased risk of perioperative complications. MATERIAL AND METHODS: Preoperative histological diagnosis and radiological findings were compared to final histological diagnosis in patients diagnosed with CAH and EECG1. Imaging characteristics at preoperative magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography/computer tomography (FDG-PET/CT) were compared with tumor DNA oligonucleotide microarray data, immunohistochemistry findings and clinicopathological annotations. RESULTS: MRI assessed tumor volume was higher in EECG1 than in CAH (p=0.004) whereas tumor apparent diffusion coefficient value was lower in EECG1 (p=0.005). EECG1 exhibited increased metabolism with higher maximum and mean standard uptake values (SUV) than CAH (p≤0.002). Unsupervised clustering of EECG1 and CAH revealed differentially expressed genes within the clusters, and identified PDZ-binding kinase (PBK) as a potential marker for selecting endometrial lesions with less aggressive biological behavior. CONCLUSION: Both PBK expression and preoperative imaging yield promising biomarkers that may aid in the differentiation between EECG1 and CAH preoperatively, and these markers should be further explored in larger patient series.

Tissue and imaging biomarkers for hypoxia predict poor outcome in endometrial cancer.

Hypoxia is frequent in solid tumors and linked to aggressive phenotypes and therapy resistance. We explored expression patterns of the proposed hypoxia marker HIF-1α in endometrial cancer (EC) and investigate whether preoperative functional imaging parameters are associated with tumor hypoxia. Expression of HIF-1α was explored both in the epithelial and the stromal tumor component. We found that low epithelial HIF-1α and high stromal HIF-1α expression were significantly associated with reduced disease specific survival in EC. Only stromal HIF-1α had independent prognostic value in Cox regression analysis. High stromal HIF-1α protein expression was rare in the premalignant lesions of complex atypical hyperplasia but increased significantly to invasive cancer. High stromal HIF-1α expression was correlated with overexpression of important genes downstream from HIF-1α, i.e. VEGFA and SLC2A1 (GLUT1). Detecting hypoxic tumors with preoperative functional imaging might have therapeutic benefits. We found that high stromal HIF-1α expression associated with high total lesion glycolysis (TLG) at PET/CT. High expression of a gene signature linked to hypoxia also correlated with low tumor blood flow at DCE-MRI and increased metabolism measured by FDG-PET. PI3K pathway inhibitors were identified as potential therapeutic compounds in patients with lesions overexpressing this gene signature. In conclusion, we show that high stromal HIF-1α expression predicts reduced survival in EC and is associated with increased tumor metabolism at FDG-PET/CT. Importantly; we demonstrate a correlation between tissue and imaging biomarkers reflecting hypoxia, and also possible treatment targets for selected patients.

Metabolic Tumor Volume on 18F-FDG PET/CT Improves Preoperative Identification of High-Risk Endometrial Carcinoma Patients.

UNLABELLED: Our objective was to prospectively explore the diagnostic value of (18)F-FDG PET/CT for preoperative staging in endometrial carcinomas and to investigate whether (18)F-FDG PET-specific quantitative tumor parameters reflect clinical and histologic characteristics. METHODS: Preoperative (18)F-FDG PET/CT was prospectively performed on 129 consecutive endometrial carcinoma patients. Two physicians who did not know the clinical findings or staging results independently reviewed the images, assessing primary tumor, cervical stroma involvement and metastatic spread, and determining maximum and mean standardized uptake value (SUVmax and SUVmean, respectively) for tumor, metabolic tumor volume (MTV), and total lesion glycolysis (TLG). All parameters were analyzed in relation to histomorphologic and clinical tumor characteristics. Receiver-operating-characteristic curves for identification of deep myometrial invasion and lymph node metastases were generated, and MTV cutoffs for predicting deep myometrial invasion and lymph node metastases were calculated. RESULTS: The sensitivity, specificity, and accuracy of (18)F-FDG PET/CT for the detection of lymph node metastases were 77%-85%, 91%-96%, and 89%-93%, respectively. SUVmax, SUVmean, MTV, and TLG were significantly related to deep myometrial invasion, presence of lymph node metastases, and high histologic grade (P < 0.015 for all) and independently predicted deep myometrial invasion (P < 0.015) and lymph node metastases (P < 0.025) after adjustment for preoperative histologic risk (based on subtype and grade) in endometrial biopsies. Optimal cutoffs for MTV in predicting deep myometrial invasion (20 mL) and the presence of lymph node metastases (30 mL) yielded odds ratios of 7.8 (P < 0.001) and 16.5 (P = 0.001), respectively. CONCLUSION: (18)F-FDG PET/CT represents a clinically valuable tool for preoperatively evaluating the presence of lymph node metastases in endometrial carcinoma patients. Applying MTV cutoffs for the prediction of deep myometrial invasion and lymph node metastases may increase diagnostic accuracy and aid preoperative identification of high-risk patients, enabling restriction of lymphadenectomy for patients with a low risk of aggressive disease.