Detection of pelvic lymph node metastases in gynecologic malignancy: a comparison of CT, MR imaging, and positron emission tomography

A MRI radiomics-based model for prediction of pelvic lymph node metastasis in cervical cancer

BACKGROUND

Cervical cancer (CC) is a common malignancy of the female reproductive tract, and preoperative prediction of lymph node metastasis (LNM) is essential. This study aims to design and validate a magnetic resonance imaging (MRI) radiomics-based predictive model capable of detecting LNM in patients diagnosed with CC.

METHODS

This retrospective analysis incorporated 86 and 38 CC patients into the training and testing groups, respectively. Radiomics features were extracted from MRI T2WI, T2WI-SPAIR, and axial apparent diffusion coefficient (ADC) sequences. Selected features identified in the training group were then used to construct a radiomics scoring model, with relevant LNM-related risk factors having been identified through univariate and multivariate logistic regression analyses. The resultant predictive model was then validated in the testing cohort.

RESULTS

In total, 16 features were selected for the construction of a radiomics scoring model. LNM-related risk factors included worse differentiation (P < 0.001), more advanced International Federation of Gynecology and Obstetrics (FIGO) stages (P = 0.03), and a higher radiomics score from the combined MRI sequences (P = 0.01). The equation for the predictive model was as follows: -0.0493-2.1410 × differentiation level + 7.7203 × radiomics score of combined sequences + 1.6752 × FIGO stage. The respective area under the curve (AUC) values for the T2WI radiomics score, T2WI-SPAIR radiomics score, ADC radiomics score, combined sequence radiomics score, and predictive model were 0.656, 0.664, 0.658, 0.835, and 0.923 in the training cohort, while these corresponding AUC values were 0.643, 0.525, 0.513, 0.826, and 0.82 in the testing cohort.

CONCLUSIONS

This MRI radiomics-based model exhibited favorable accuracy when used to predict LNM in patients with CC. Relative to the use of any individual MRI sequence-based radiomics score, this predictive model yielded superior diagnostic accuracy.

Value of MRI and diffusion-weighted imaging in diagnosing normal-sized pelvic lymph nodes metastases in patients with cervical cancer

OBJECTIVES

To investigate the value of conventional MRI and diffusion-weighted imaging (DWI) in diagnosing normal-sized pelvic lymph nodes metastases in patients with cervical cancer.

METHODS

102 patients with cervical cancer who underwent MRI and DWI scan were included. 137 lymph nodes were analyzed, including 44 metastatic lymph nodes (MLNs) and 93 non-metastatic lymph nodes (non-MLNs). The morphology and apparent diffusion coefficient (ADC) value of lymph nodes were measured including short-axis diameter (DS), long-axis diameter (DL), ratio of short-to-long-axis diameter (DR), fatty hilum, asymmetry, ADCmax, ADCmean and ADCmin. The Mann-Whitney U-test, independent sample t-test and Chi-square test were employed to compare the differences of all criteria between MLNs and non-MLNs. Logistic regression and decision tree were used to develop the combined diagnostic model. ROC analyses were used to evaluate the diagnostic performance.

RESULTS

The DS and DR of MLNs were significantly higher than those of non-MLNs (p < 0.05), the ADCmax, ADCmean and ADCmin of MLNs were significantly lower than those of non-MLNs (p < 0.05). Presence of fatty hilum and asymmetric lymph nodes between MLNs and non-MLNs were significantly different (p＜0.05). Combined measurement of ADCmin, DS and DR had the highest AUC 0.937 with 90.9% sensitivity and 87.1% specificity. The accuracy of decision tree was 88.3%.

CONCLUSION

MRI with DWI had potential in diagnosing normal-sized pelvic lymph nodes metastases in patients with cervical cancer. The combined evaluation of DS, DR and ADCmin of lymph nodes and decision tree of the combined measure showed better diagnostic performances than sole criteria.

ADVANCES IN KNOWLEDGE

The short-axis diameter, ratio of short-to-long-axis diameter and ADCmin of lymph nodes have moderate value in the diagnosis of the metastases of the normal-sized lymph nodes for the patient with cervical cancer as the sole indices. The combined evaluation of DS, DR and ADCmin is much more valuable in the detection of metastatic lymph nodes.

MRI-based peritumoral radiomics analysis for preoperative prediction of lymph node metastasis in early-stage cervical cancer: A multi-center study

PURPOSE

To evaluate intra- and preitumoral radiomics on the contrast-enhanced T1-weighted (CE-T1) and T2-weighted (T2W) MRI for predicting the LNM, and develop a nomogram for potential clinical uses.

METHODS

We enrolled 169 cervical cancer cases who underwent CE-T1 and T2W MR scans from two hospitals between Dec. 2015 and Sep. 2021. Intra- and peritumoral features were extracted separately and selected by the least absolute shrinkage and selection operator (LASSO) regression. Radiomics signatures were built using the selected features from different regions. Clinical parameters were evaluated by statistical analysis. The nomogram was developed combining the multi-regional radiomics signature and the most predictive clinical parameters.

RESULTS

Five radiomics features were finally selected from the peritumoral regions with 1 and 3 mm distances in the CE-T1 and T2W MRI, respectively. The nomogram incorporating multi-regional combined radiomics signature, MR-reported LN status and tumor diameter achieved the highest AUCs in the training (nomogram vs. combined radiomics signature vs. clinical model, 0.891 vs. 0.830 vs. 0.812), internal validation (nomogram vs. combined radiomics signature vs. clinical model, 0.863 vs. 0.853 vs. 0.816) and external validation (nomogram vs. combined radiomics signature vs. clinical model, 0.804 vs. 0.701 vs. 0.787) cohort. DCA suggested good clinical usefulness of our developed models.

CONCLUSION

The current work suggested clinical potential for intra- and peritumoral radiomics with multi-modal MRI for preoperative predicting LNM.

Heart Rate Variability is an Independent Predictor of Lymph Node Metastasis in Patients with Cervical Cancer

Purpose

Heart rate variability (HRV) has been reported as a useful biomarker for prognostic factors in a variety of cancers. The purpose of this study was to explore the predictive value of preoperative HRV for lymph node metastasis (LNM) in patients with cervical cancer (CC).

Patients and Methods

A total of 77 patients with CC were included, including 18 LNM and 59 non-LNM patients. A five-minute resting electrocardiogram (ECG) was collected before surgery for the analysis of HRV time domain, frequency domain and Poincaré plot parameters (ie, SDNN, RMSSD, LF, HF, LF/HF, SD1, SD2 and SD2/SD1). Student’s t-tests and logistic regression were performed to determine the relationship between HRV and LNM.

Results

The LNM group had significantly lower SDNN, LF, and SD2 than the non-LNM group (all p < 0.05; all Cohen’s d > 0.5). Binary logistic regression analysis indicated that SDNN, LF and SD2 were still significantly associated with LNM. Specifically, for each 1 ms decrease in SDNN and SD2 and each 1 logarithmic unit decrease in ln (LF), the odds of LNM increased by 12%, 9%, and 86%, respectively (all p < 0.05).

Conclusion

These findings suggest an association between HRV and CC LNM, and HRV could be a potential noninvasive biomarker for the prediction of LNM in CC patients.

Computed tomography-based radiomic model at node level for the prediction of normal-sized lymph node metastasis in cervical cancer

•

The metastatic status of lymph nodes in cervical cancer patients can be predicted.

•

Computed tomography-based radiomic model can identify the status of the normal-sized lymph node singly.

•

The model may help doctors to make staging and clinical decision, and realize individualized treatment.

Purpose

Radiomic models have been demonstrated to have acceptable discrimination capability for detecting lymph node metastasis (LNM). We aimed to develop a computed tomography–based radiomic model and validate its usefulness in the prediction of normal-sized LNM at node level in cervical cancer.

Methods

A total of 273 LNs of 219 patients from 10 centers were evaluated in this study. We randomly divided the LNs from the 2 centers with the largest number of LNs into the training and internal validation cohorts, and the rest as the external validation cohort. Radiomic features were extracted from the arterial and venous phase images. We trained an artificial neural network (ANN) to develop two single-phase models. A radiomic model reflecting the features of two-phase images was also built for directly predicting LNM in cervical cancer. Moreover, four state-of-the-art methods were used for comparison. The performance of all models was assessed using the area under the receiver operating characteristic curve (AUC).

Results

Among the models we built, the models combining the features of two phases surpassed the single-phase models, and the models generated by ANN had better performance than the others. We found that the radiomic model achieved the highest AUCs of 0.912 and 0.859 in the training and internal validation cohorts, respectively. In the external validation cohort, the AUC of the radiomic model was 0.800.

Conclusion

We constructed a radiomic model that exhibited great ability in the prediction of LNM. The application of the model could optimize clinical staging and decision-making.

Multiple U-Net-Based Automatic Segmentations and Radiomics Feature Stability on Ultrasound Images for Patients With Ovarian Cancer

Few studies have reported the reproducibility and stability of ultrasound (US) images based radiomics features obtained from automatic segmentation in oncology. The purpose of this study is to study the accuracy of automatic segmentation algorithms based on multiple U-net models and their effects on radiomics features from US images for patients with ovarian cancer. A total of 469 US images from 127 patients were collected and randomly divided into three groups: training sets (353 images), validation sets (23 images), and test sets (93 images) for automatic segmentation models building. Manual segmentation of target volumes was delineated as ground truth. Automatic segmentations were conducted with U-net, U-net++, U-net with Resnet as the backbone (U-net with Resnet), and CE-Net. A python 3.7.0 and package Pyradiomics 2.2.0 were used to extract radiomic features from the segmented target volumes. The accuracy of automatic segmentations was evaluated by Jaccard similarity coefficient (JSC), dice similarity coefficient (DSC), and average surface distance (ASD). The reliability of radiomics features were evaluated by Pearson correlation and intraclass correlation coefficients (ICC). CE-Net and U-net with Resnet outperformed U-net and U-net++ in accuracy performance by achieving a DSC, JSC, and ASD of 0.87, 0.79, 8.54, and 0.86, 0.78, 10.00, respectively. A total of 97 features were extracted from the delineated target volumes. The average Pearson correlation was 0.86 (95% CI, 0.83–0.89), 0.87 (95% CI, 0.84–0.90), 0.88 (95% CI, 0.86–0.91), and 0.90 (95% CI, 0.88–0.92) for U-net++, U-net, U-net with Resnet, and CE-Net, respectively. The average ICC was 0.84 (95% CI, 0.81–0.87), 0.85 (95% CI, 0.82–0.88), 0.88 (95% CI, 0.85–0.90), and 0.89 (95% CI, 0.86–0.91) for U-net++, U-net, U-net with Resnet, and CE-Net, respectively. CE-Net based segmentation achieved the best radiomics reliability. In conclusion, U-net based automatic segmentation was accurate enough to delineate the target volumes on US images for patients with ovarian cancer. Radiomics features extracted from automatic segmented targets showed good reproducibility and for reliability further radiomics investigations.

Detection of living cervical cancer cells by transient terahertz spectroscopy

The photonic energy of terahertz wave is in the same order of magnitude as the rotational and vibrational energy levels of organic and biological macromolecules, so it has unique advantages in detecting cells and biological macromolecules. However, in the life environment, the dynamic time scale of cell-environment interaction and structural conformation change of biological macromolecules are within picosecond to millisecond, and water has strong absorption to terahertz wave, which has become the bottleneck problem for the detection of cells and biological macromolecules by terahertz technology. In this article, we developed a set of terahertz single measurement system based on the tilt wave front of grating pulse technique. The system was employed for the terahertz detection of trace living cervical cancer cells. We achieved transient detection of the terahertz pulse time-domain waveform of the living HeLa cells. The characteristic absorption peaks were identified by Lambert-Beer law, respectively, at 0.49, 0.71, 1.04, 1.07, 1.26 and 1.37 THz. The absorbance is proportional to the cell concentration.

Usefulness of sentinel lymph node mapping using indocyanine green and fluorescent imaging in the diagnosis of lymph node metastasis in endometrial cancer

The lymph node status is the most important prognostic factor for endometrial cancer. This study aimed to assess whether sentinel lymph node mapping (SLNM) is applicable in endometrial cancer. A retrospective review of patients with endometrial cancer who were diagnosed and treated in Asan Medical Centre from September 2015 to December 2017 was conducted. One hundred patients underwent robotic (da Vinci®) or laparoscopic surgical treatment, including SLNM with indocyanine green (ICG) fluorescence detection using the Firefly® and NIR/ICG systems. At least one lymph node area was observed in 100% of SLNM cases. Sentinel node detection and frozen biopsy were performed in all cases, and all patients with metastasis were found on SLNM. The sensitivity and negative predictive value were both 100% in the patient-by-patient and station-by-station analyses. SLNM appears to be a feasible method to reduce the morbidity and increase the detection rate in early-stage endometrial carcinoma.What is already known on this subject? There are studies that it is safe to diagnose the possibility of lymph node metastasis through sentinel lymph node mapping in endometrial cancer.What do the results of this study add? In this study, it is shown that the accuracy of sentinel lymph node mapping is 100% accurate.What are the implications of these findings for clinical practise and/or further research? Therefore, total lymphadenectomy will not be necessary for the future.

Assessment of pelvic lymph node metastasis in FIGO IB and IIA cervical cancer using quantitative dynamic contrast-enhanced MRI parameters

PURPOSE

We prospectively determined whether the quantitative parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) are useful for predicting pelvic lymph node (LN) status in cervical cancer through node-by-node pathologic validation of images.

METHODS

Overall, 182 LNs harvested from 200 consecutive patients with 2018 FIGO stage IB-IIA cervical cancer (82 metastatic and 100 nonmetastatic) were used for node-by-node assessment. Each LN was quantitatively assessed using Ktrans, Ve, and Kep values. The short-axis diameter, ratio of the long-axis to short-axis diameter, and long-axis diameter were also assessed. Data on metastatic LNs were divided into four groups according to the FIGO staging system. Receiver operating characteristic (ROC) curve analysis was performed to evaluate statistically significant parameters derived from DCE-MRI for the differentiation of metastatic LNs from nonmetastatic LNs.

RESULTS

The mean short-axis diameter of metastatic LNs was significantly larger than that of nonmetastatic LNs (all P < 0.05) despite several overlaps. In comparison with nonmetastatic LNs, metastatic LNs showed a significantly lower Ktrans (all P < 0.05); however, Kep and Ve were not significantly different (all P > 0.05). For IB3 and IIA2 cervical cancer, Ktrans had moderate diagnostic ability for differentiating metastatic LNs from nonmetastatic LNs (for IB3: area under the curve [AUC] 0.740, 95% CI 0.657-0.838, 61.7% sensitivity, 80.2% specificity, P = 0.007; for IIA2: AUC 0.786, 95% CI 0.650-0.846, 60.2% sensitivity, 81.8% specificity, P = 0.008).

CONCLUSION

Ktrans appears to be a useful parameter for detecting metastatic LNs, especially for IB3 and IIA2 cervical cancer.

Application of apparent diffusion coefficient values derived from diffusion-weighted imaging for assessing different sized metastatic lymph nodes in cervical cancers

BACKGROUND

Lymph nodes metastasis is an important factor affecting survival rate and recurrence in cervical cancer patients. Currently, diagnosis of metastatic lymph nodes is mainly based on morphological changes on imaging. However, it is difficult to differentiate normal-sized metastatic lymph nodes with short axis of 5-10mm.

PURPOSE

To assess the diagnostic value of apparent diffusion coefficient (ADC) for discriminating different-sized metastatic lymph nodes in patients with cervical cancers.

MATERIAL AND METHODS

Pathologically confirmed cervical cancer patients were documented from January 2013 to July 2018 in our hospital. A total of 133 patients who underwent conventional MRI and diffusion-weighted imaging with complete pathology were finally enrolled. A total of 157 lymph nodes were harvested and analyzed. All lymph nodes were divided into three groups according to pathology and their short axis (S) measured on axial T2-weighted imaging: normal-sized (5 mm<S<10 mm) benign lymph nodes (Group 1); normal-sized (5 mm<S<10 mm) metastatic lymph nodes (Group 2); enlarged (S≥10 mm) metastatic lymph nodes (Group 3). Mean ADC (ADC_mean), minimum ADC (ADC_min), and maximum ADC (ADC_max) values of lymph nodes were analyzed and compared among the three groups.

RESULTS

ADC_mean of Groups 1 and 2 were significantly larger than those of Group 3 (P<0.001, P=0.005, respectively). ADC_min of Group 1 were significantly larger than those of Groups 2 and 3 (P<0.001, P<0.001, respectively). ADC_max was not statistically different among the three groups. ADC_mean had the relatively highest area under the curve (AUC) of 0.644 for assessing enlarged metastatic lymph nodes, with a sensitivity of 64.4% and specificity of 67.9%. ADC_min had the highest AUC of 0.758 for assessing normal-sized metastatic lymph nodes, with a sensitivity of 84.7% and specificity of 60.7%.

CONCLUSION

Diffusion-weighted imaging can be used to differentiate enlarged metastatic lymph nodes from benign lymph nodes, and ADC_min can be further used to identify micro-metastasis in normal-sized lymph nodes.

Pattern and risk factors of local recurrence after nephroureterectomy for upper tract urothelial carcinoma

Purpose

This study aims to identify predictive local recurrence risk factors and site-specific local recurrence pattern of upper tract urothelial carcinoma (UTUC) with different primary tumor locations.

Methods

Three hundred and eighty-nine UTUC patients with radical nephroureterectomy were included in this study. Univariate and multivariate Cox proportional hazards regressions were performed to measure the risk of local recurrence. We also mapped the position of local recurrence sites stratified by primary tumor locations.

Results

A total of 73 patients (18.7%) developed local recurrence within a median follow-up of 41 months (range, 3-80 months). For patients with local recurrence, the median interval of local recurrence was 9 months. Ureter tumor, multifocality, T stage, G grade, lymph node metastasis (LNM), lymph node dissection (LND), and lymph vascular invasion (LVI) were all significantly associated with increased local recurrence by univariable analyses (P < 0.05). Only multifocality, T3–4, G3, and LNM remained independent predictors of increased local recurrence by multivariable analyses. Adjuvant radiotherapy could reduce the local recurrence (HR = 0.177; 95% CI 0.064-0.493, P = 0.001). Patients with local recurrence had poorer cancer-specific survival (4-year cancer-specific survival rate 36 ± 7.5% vs 88.4 ± 2.2%, P = 0.000). We evaluated local recurrence pattern stratified by tumor locations. Para-aortic lymph node region was the most common recurrence area for all the patients. Left-sided UTUC had more than 70% recurrent lymph nodes in the left para-aortic region (LPA). For right-sided UTUC patients, recurrent para-aortic lymph nodes distributed in the LPA (33.3%), aortocaval (AC) (41.5%), and right paracaval (RPC) (25.2%) regions. Recurrence in the internal and external iliac regions was only found in the distal ureter group (P < 0.05). Renal pelvic fossa recurrence was only found in renal pelvic tumor (22.2%, P = 0.007). The ureter tumor bed recurrence rate was higher for ureter patients (P = 0.001).

Conclusions

Multifocality, T3–4, G3, and LNM are predictors of higher local recurrence rate of UTUC. Adjuvant radiotherapy can reduce local recurrence rate. Local recurrence patterns are different according to primary tumor locations.

Noninvasive prediction of lymph node status for patients with early-stage cervical cancer based on radiomics features from ultrasound images

OBJECTIVE

To investigate the feasibility of a noninvasive detection of lymph node metastasis (LNM) for early-stage cervical cancer (ECC) patients with radiomics methods based on the textural features from ultrasound images.

METHODS

One hundred seventy-two ECC patients between January 2014 and September 2018 with pathologically confirmed lymph node status (LNS) and preoperative ultrasound images were retrospectively reviewed. Regions of interest (ROIs) were delineated by a senior radiologist in the ultrasound images. LIFEx was applied to extract textural features for radiomics study. Least absolute shrinkage and selection operator (LASSO) regression was applied for dimension reduction and for selection of key features. A multivariable logistic regression analysis was adopted to build the radiomics signature. The Mann-Whitney U test was applied to investigate the correlation between radiomics and LNS for both training and validation cohorts. Receiver operating characteristic (ROC) curves were applied to evaluate the accuracy of the radiomics prediction models.

RESULTS

A total of 152 radiomics features were extracted from ultrasound images, in which 6 features were significantly associated with LNS (p < 0.05). The radiomics signatures demonstrated a good discrimination between patients with LNM and non-LNM groups. The best radiomics performance model achieved an area under the curve (AUC) of 0.79 (95% confidence interval (CI), 0.71-0.88) in the training cohort and 0.77 (95% CI, 0.65-0.88) in the validation cohort.

CONCLUSIONS

The feasibility of radiomics features from ultrasound images for the prediction of LNM in ECC was investigated. This noninvasive prediction method may be used to facilitate preoperative identification of LNS in patients with ECC.

KEY POINTS

• Few studied had investigated the feasibility of radiomics based on ultrasound images for cervical cancer, even though it is the most common practice for gynecological cancer diagnosis and treatment. • The radiomics signatures based on ultrasound images demonstrated a good discrimination between patients with and without lymph node metastasis with an area under the curve (AUC) of 0.79 and 0.77 in the training and validation cohorts, respectively. • The radiomics model based on preoperative ultrasound images has the potential ability to predict lymph node status noninvasively in patients with early-state cervical cancer, so as to reduce the impact of invasive examination and to optimize the treatment choices.

The efficacy of pretreatment and after treatment 18F-FDG PET/CT metabolic parameters in patients with locally advanced squamous cell cervical cancer

OBJECTIVES

Cervical cancer is one of the main causes of cancer death worldwide. Fluorine-18-fluorodeoxyglucose (F-FDG) PET/computed tomography (PET/CT) has been playing an increasingly important role in staging and monitoring treatment response in the disease. In the current study, we investigated metabolic F-FDG PET/CT parameters among patients with locally advanced squamous cell cervical cancer treated with concurrent chemoradiotherapy for predicting disease-free survival (DFS).

PATIENTS AND METHODS

Forty-four patients with biopsy-proven locally advanced squamous cell cervical cancer were included in the study. Pretreatment and after treatment F-FDG PET/CT metabolic parameters [metabolic tumor volume, tumor lesion glycolysis, maximum standard uptake value (SUVmax)] for the primary tumor area and/or pelvic/para-aortic lymph nodes and also accompanying distant metastases were analyzed. Treatment response was divided into four groups according to a post-treatment F-FDG PET/CT scan.

RESULTS

For all patients, the 3-year DFS was 79%. Pretreatment primary tumor SUVmax and tumor lesion glycolysis, pelvic lymph node SUVmax, and pretreatment para-aortic lymph node SUVmax were significant prognostic factors for DFS with different cut-off values. In contrast, for metabolic tumor volume-T1, there was no statistical significance for DFS.

CONCLUSION

F-FDG PET/CT cut-off values may help clinicians with their treatment planning and follow-up in locally advanced squamous cell cervical cancer patients.

Radiomic signature as a predictive factor for lymph node metastasis in early-stage cervical cancer

BACKGROUND

Lymph node metastasis (LNM) is the principal risk factor for poor outcomes in early-stage cervical cancer. Radiomics may offer a noninvasive way for predicting the stage of LNM.

PURPOSE

To evaluate a radiomic signature of LN involvement based on sagittal T₁ contrast-enhanced (CE) and T₂ MRI sequences.

STUDY TYPE

Retrospective.

POPULATION

In all, 143 patients were randomly divided into two primary and validation cohorts with 100 patients in the primary cohort and 43 patients in the validation cohort.

FIELD STRENGTH/SEQUENCE

T₁ CE and T₂ MRI sequences at 3T.

ASSESSMENT

The gold standard of LN status was based on histologic results. A radiologist with 10 years of experience used the ITK-SNAP software for 3D manual segmentation. A senior radiologist with 15 years of experience validated all segmentations. The area under the receiver operating characteristics curve (ROC AUC), classification accuracy, sensitivity, and specificity were used between LNM and non-LNM groups.

STATISTICAL TESTS

A total of 970 radiomic features and seven clinical characteristics were extracted. Minimum redundancy / maximum relevance and support vector machine algorithms were applied to select features and construct a radiomic signature. The Mann-Whitney U-test and the chi-square test were used to test the performance of clinical characteristics and potential prognostic outcomes. The results were used to assess the quantitative discrimination performance of the SVM-based radiomic signature.

RESULTS

The radiomic signatures allowed good discrimination between LNM and non-LNM groups. The ROC AUC was 0.753 (95% confidence interval [CI], 0.656-0.850) in the primary cohort and 0.754 (95% CI, 0584-0.924) in the validation cohort.

DATA CONCLUSIONS

A multiple-sequence MRI radiomic signature can be used as a noninvasive biomarker for preoperative assessment of LN status and potentially influence the therapeutic decision-making in early-stage cervical cancer patients.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:304-310.

Prognostic significance of lymph node ratio in node-positive cervical cancer patients

To determine whether the pelvic lymph node ratio (LNR) has significant prognostic value for survival and disease recurrence in node-positive, early stage cervical cancer patients.The medical records of 872 consecutive women who received postoperative adjuvant chemoradiotherapy were reviewed. Of these, 397 women with pathologically proven lymph nodal metastasis were included in this analysis and categorized into 3 groups according to their LNR: low (<0.1, n = 251), intermediate (0.1-0.4, n = 121), and high (>0.4, n = 25). The association between LNR and oncological outcome was evaluated using the Kaplan-Meier method and multivariate analysis.A total of 13,491 LNs were retrieved from 397 women, with a median harvest of 32 nodes per patient. There was a strong positive correlation between the number of metastatic LNs and LNR (r = 0.83, P < .01). With a median follow-up duration of 48 months, the 5-year overall survival (OS) and disease-free survival (DFS) rates were 73% and 67%, respectively. The OS and DFS curves among the pelvic LNR groups significantly differed: the 5-year OS rates of the low, intermediate, and high pelvic LNR groups were 83%, 66%, and 17% (P < .01), and the 5-year DFS rates were 77%, 56%, and 20% (P < .01), respectively.LNR is an important prognostic factor for survival outcomes in patients with uterine cervical cancer who underwent radical hysterectomy followed by adjuvant chemoradiotherapy.

[18F]FDG-PET/CT and MRI for initial pelvic lymph node staging in patients with cervical carcinoma: The potential usefulness of [18F]FDG-PET/MRI

The current study aimed to determine the optimum diagnostic imaging technique out of magnetic resonance imaging (MRI), ¹⁸F-fludeoxyglucose positron emission tomography/computed tomography ([¹⁸F]FDG-PET/CT, otherwise known as PET/CT) and [¹⁸F]FDG-PET/MRI (otherwise known as PET/MRI) for the pelvic lymph node staging (N-staging) of untreated cervical carcinoma (CC). A total of 27 patients were included in the present study. All patients had undergone pre-treatment with PET/CT and MRI ≤45 days prior to undergoing a lymphadenectomy. The results from PET (separated from PET/CT), MRI and the statistically combined results of (virtual) PET/MRI were compared to those from histological analyses (the gold standard). A per-patient-based analysis of the detection of pelvic lymph node metastases indicated that PET/MRI had a sensitivity of 64%. The specificity of PET/CT and MRI were 69 and 62%, respectively. The positive predictive value (PPV) was 69 and 64% for PET/CT and MRI, respectively. The negative predictive value (NPV) was 64 and 62% for PET/CT and MRI, respectively. The sensitivity of the PET-guided PET/MRI and the MRI-guided PET/MRI was 64% for both. The specificity of the PET-guided PET/MRI and the MRI-guided PET/MRI was 77 and 62%, respectively. The PPV was 75% for PET-guided PET/MRI and 64% for MRI-guided PET/MRI, and the NPV was 67 and 62%, respectively. PET/CT and the virtual PET/MRI exhibited the same low sensitivity (64%). PET/MRI exhibited slightly better results than PET/CT regarding specificity (77 vs. 69%, respectively), PPV (75 vs. 69%, respectively) and NPV (67 vs. 64%, respectively). The results of the present study suggested that PET/CT and MRI are not optimal diagnostic modalities, and that PET/MRI does not necessarily lead to better results than PET/CT, in the pelvic N-staging of CC.

Terahertz imaging of metastatic lymph nodes using spectroscopic integration technique

Terahertz (THz) imaging was used to differentiate the metastatic states of frozen lymph nodes (LNs) by using spectroscopic integration technique (SIT). The metastatic states were classified into three groups: healthy LNs, completely metastatic LNs, and partially metastatic LNs, which were obtained from three mice without infection and six mice infected with murine melanoma cells for 30 days and 15 days, respectively. Under histological examination, the healthy LNs and completely metastatic LNs were found to have a homogeneous cellular structure but the partially metastatic LNs had interfaces of the melanoma and healthy tissue. THz signals between the experimental groups were not distinguished at room temperature due to high attenuation by water in the tissues. However, a signal gap between the healthy and completely metastatic LNs was detected at freezing temperature. The signal gap could be enhanced by using SIT that is a signal processing method dichotomizing the signal difference between the healthy cells and melanoma cells with their normalized spectral integration. This technique clearly imaged the interfaces in the partially metastatic LNs, which could not be achieved by existing methods using a peak point or spectral value. The image resolution was high enough to recognize a metastatic area of about 0.7 mm size in the partially metastatic LNs. Therefore, this pilot study demonstrated that THz imaging of the frozen specimen using SIT can be used to diagnose the metastatic state of LNs for clinical application.

Magnetic Resonance Imaging of Gynecological Malignancies: Role in Personalized Management

Gynecological malignancies are a leading cause of mortality and morbidity in women and pose a significant health problem around the world. Currently used staging systems for management of gynecological malignancies have unresolved issues, the most important being recommendations on the use of imaging. Although not mandatory as per the International Federation of Gynecology and Obstetrics recommendations, preoperative cross-sectional imaging is strongly recommended for adequate and optimal management of patients with gynecological malignancies. Standardized disease-specific magnetic resonance imaging protocols help assess disease spread accurately and avoid pitfalls. Multiparametric imaging holds promise as a roadmap to personalized management in gynecological malignancies. In this review, we will highlight the role of magnetic resonance imaging in cervical, endometrial, and ovarian carcinomas.

Potential Role of PET/MRI for Imaging Metastatic Lymph Nodes in Head and Neck Cancer

OBJECTIVE

This article explores recent developments in PET and MRI, separately or combined, for assessing metastatic lymph nodes in patients with head and neck cancer.

CONCLUSION

The synergistic role of PET and MRI for imaging metastatic lymph nodes has not been fully explored. To facilitate the understanding of the areas that need further investigation, we discuss potential mechanisms and evidence reported so far, as well as future directions and challenges for continued development and clinical research.

Prognostic Value of the Sum of Metabolic Tumor Volume of Primary Tumor and Lymph Nodes Using 18F-FDG PET/CT in Patients With Cervical Cancer

This is an observational study to determine the most relevant parameter of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for predicting recurrence in cervical cancer. Fifty-six patients with International Federation of Gynecology and Obstetrics (FIGO) stage IIB-IVA cervical cancer who underwent pretreatment ¹⁸F-FDG PET/CT were enrolled. PET parameters including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of both primary tumor and pelvic and/or para-aortic lymph nodes were analyzed. SUVmax-S was defined as the sum of the SUVmax of primary tumor and the higher SUVmax of either pelvic or para-aortic lymph nodes. MTV-S was defined as the sum of the MTV of primary tumor and pelvic and para-aortic lymph nodes. TLG-S was calculated in the same way as MTV-S. We evaluated the relationship between these PET parameters and recurrence-free survival (RFS). Univariate analysis revealed that higher FIGO stage (hazard ratio [HR] = 5.61, 95% confidence interval [CI]: 1.68-18.68, P = 0.005), lymph node metastasis (HR = 3.42, 95% CI: 1.08-10.84, P = 0.037), MTV of primary tumor >47.81 cm³ (HR = 6.20, 95% CI: 1.35-28.48, P = 0.019), TLG of primary tumor >215.02 (HR = 11.82, 95% CI: 1.52-91.96, P = 0.018), MTV-S > 59.01 cm³ (HR = 8.24, 95% CI: 1.80-37.77, P = 0.007), and TLG-S > 224.15 (HR =  13.09, 95% CI: 1.68-101.89, P = 0.014) were associated with RFS. In multivariate analysis, FIGO stage (HR = 4.87, 95% CI: 1.38-17.18, P = 0.014) and MTV-S > 59.01 cm³ (HR = 7.37, 95% CI: 1.54-35.16, P = 0.012) were determined to be independent predictive factors for RFS. Our preliminary results reveal that MTV-S is an independent prognostic factor for RFS in patients with cervical cancer treated by definitive chemoradiotherapy.

Pathways of lymphatic spread in gynecologic malignancies

Precise radiologic evaluation of regional adenopathic involvement in pelvic gynecologic tumors is fundamental to clinical practice because of its prognostic and therapeutic significance. Likewise, the identification of metastatic adenopathies at posttreatment imaging is essential for assessing response and detecting recurrence. Similar to urologic neoplasms, gynecologic neoplasms most often spread regionally to the pelvic and retroperitoneal lymph nodes, following the normal drainage pathways of the pelvic organs. Familiarity with routes of dissemination, treatment options, and means of analyzing lymph node characteristics is crucial to determine the extent of disease. Two staging systems can be used in characterizing gynecologic malignancies: the FIGO (International Federation of Gynecology and Obstetrics) system, which is the most commonly and universally used, and the TNM (tumor, node, metastasis) system, which is based on clinical and/or pathologic classification. Anatomic assessment with multidetector computed tomography (CT) and magnetic resonance (MR) imaging is still the most commonly used technique for the detection of lymph node spread, which is mainly based on morphologic criteria, the most important of which is nodal size. However, size has limited diagnostic specificity. Consequently, functional imaging techniques such as diffusion-weighted MR imaging, positron emission tomography combined with CT, lymphoscintigraphy, and sentinel lymph node mapping, which are based on molecular and physiologic activity and allow more precise evaluation, are often incorporated into diagnostic imaging protocols for staging of gynecologic malignancies.

Technical aspects of radiation therapy for anal cancer

Historically treated with surgery, current practice recommends anal carcinoma to be treated with a combination of chemotherapy and radiation. This review will examine the anatomy, modes of disease spread and recurrence, and evaluate the existing evidence for treatment options for these tumors. An in-depth examination of specific radiation therapy (RT) techniques-such as conventional 3D-conformal RT and intensity-modulated RT-will be discussed along with modern dose constraints. RT field arrangement, patient setup, and recommended gross and clinical target volume (CTV) contours will be considered. Areas in need of further investigation, such as the role in treatment for positron emission tomography (PET) will be explored.

Indirect magnetic resonance imaging lymphography identifies lymph node metastasis in rabbit pyriform sinus VX2 carcinoma using ultra-small super-paramagnetic iron oxide

Background

USPIO is a contrast agent for MRI that can generate T2W images with low signal intensities. After subcutaneous or intravenous injection of USPIO, normal lymph node tissues uptake these nano-particles, but tumor cells do not. Thus, tumor metastasis can be detected using this contrast agent.

Objective

The aim of this study was to access the feasibility of USPIO enhanced MRI for the detection of cervical lymph node metastasis in a pyriform sinus carcinoma animal model and to investigate the ability of USPIO to enhance images of cervical lymph node metastases.

Methods and Findings

Twenty New Zealand rabbits were randomly divided into tumor and inflammatory groups, and each group contained 10 rabbits. In the inflammatory group, a 0.5 ml egg yolk emulsion was injected into the sub-mandibular muscle of the rabbits to induce an inflammatory reaction in their cervical lymph nodes. In the tumor group, a VX2 tumor tissue suspension was transplanted into the pyriform sinus sub-mucosa of the rabbits using direct laryngoscope. Four weeks after the tumor or egg yolk injection, MRIs were performed before and after USPIO injection to observe the imaging enhancement features of USPIO. After that, a histo-pathological analysis was performed for all rabbits. We found the metastatic lymph nodes had no signal reduced intensity or irregular signal reduced intensity on T2-weighted image by using USPIO enhancement. In the tumor group,the sensitivity and specificity of plain MRI were 57.6% and 60.7%. The corresponding values of USPIO-enhanced MRl were 96.1% and 85.7%. (P<0.05)

Conclusion

The features and the extent of the lymph node metastases corresponded to those observed on USPIO-enhanced MR images. USPIO-enhanced MRI is useful for the detection and estimation of lymph node metastasis in this cervical carcinoma animal model.

Evaluation of positron emission tomographic tracers for imaging of papillomavirus-induced tumors in rabbits

In this study, simultaneous positron emission tomography (PET)/magnetic resonance (MR) imaging was employed to evaluate the feasibility of the PET tracers 2-deoxy-2-18F-fluoro-d-glucose (18F-FDG), 11C-choline, and 18F-fluorothymidine (18F-FLT) to detect papillomavirus-induced tumors in an established rabbit model system. The combined PET/MR allowed the analysis of tracer uptake of the tumors using the morphologic information acquired by MR. New Zealand White rabbits were infected with cottontail rabbit papillomavirus genomes and were imaged for up to 10 months with a simultaneous PET/MR system during the course of infection. The uptake characteristics of the PET tracers 11C-choline and 18F-FLT of tumors and reference tissues were examined relative to the clinical standard, 18F-FDG. Tracer biodistribution of various organs was measured by gamma-counting after the last PET scan and compared to the in vivo PET/MR 18F-FDG uptake. Increased tracer uptake was found 2 months postinfection in primary tumors with 18F-FDG and 11C-choline, whereas 18F-FLT failed to detect the tumors at all measured time points. Our data show that the PET tracer 18F-FDG is superior for imaging papillomavirus-induced tumors in rabbits compared to 11C-choline and 18F-FLT. However, 11C-choline imaging, which has previously been applied to detect various tumor entities in patients, appears to be an alternative to 18F-FDG.

Clinical implication of additional selective lateral lymph node excision in patients with locally advanced rectal cancer who underwent preoperative chemoradiotherapy

PURPOSE

To identify the indication and prognostic significance of lateral lymph node (LLN) excision in locally advanced rectal cancer patients underwent preoperative chemoradiotherapy.

METHODS

Included were 67 consecutive patients with suspicious LLN metastasis who underwent chemoradiotherapy and surgery including selective LLN excision (82 excisions). The excisions were grouped according to the presence of LLN metastasis and compared in terms of the clinicopathological findings and oncological results. The correlation between the largest short-axis diameter of LLN measured by imaging and metastasis rates was explored.

RESULTS

LLN metastases were identified in 32 excisions (40.0 %). The calculated short-axis LLN diameter predicting metastasis was 11.7 mm (before chemoradiotherapy) and 11.4 mm (before surgery). LLN metastasis was observed more frequently in the low rectum (p = 0.031) and associated with higher CEA levels (p = 0.048). The 3-year overall survival rates for patients with and without LLN metastasis were 60.3 % and 90.3 % (p = 0.048), while the 3-year disease-free survival rates were 31.4 % and 70.5 % (p = 0.009). The hazard ratio of LLN metastasis for recurrence was 2.938 (95 % CI = 1.258-6.863).

CONCLUSIONS

LLN metastasis in rectal cancer patients underwent chemoradiotherapy was a distinct poor prognostic factor. Selective LLN excision based on imaging studies may have a role for such patients.

Maximum standardized lymph node uptake value could be an important predictor of recurrence and survival in patients with cervical cancer

OBJECTIVES

To investigate prognostic values of maximum standardized lymph node (LN) uptake (SUVmax), minimum apparent LN diffusion coefficient (ADCmin), and LN short-axis length in women with cervical cancer.

STUDY DESIGN

Retrospective review of diffusion-weighted magnetic resonance imaging (DWI) and positron emission tomography/computed tomography (PET/CT) of LN confined to the pelvis in 80 cervical cancer patients before undergoing radiotherapy (RT) with or without concurrent chemotherapy. Optimal cut-off values for disease-free survival (DFS) and overall survival (OS) were determined by receiver operating characteristic (ROC) curve analysis. We used ROC curve analyses to evaluate whether LN SUVmax, LN ADCmin and LN short-axis length predicted risk of recurrence or survival.

RESULTS

Median DFS and OS for all patients were 18.97 and 22.28 months, respectively. DFS and OS rates of patients with high LN SUVmax was significantly lower than those of patients exhibiting low LN SUVmax (P=0.003 and P=0.019). Patients with low LN ADCmin had poorer DFS and OS than those with high LN ADCmin (P=0.033 and P=0.005). DFS for patients exhibiting longer LN short-axis length was significantly lower than those of patients exhibiting shorter LN short-axis length (P=0.018). Multivariate analyses indicated that high LN SUVmax was an independent predictor for both DFS and OS (P=0.0231 and P=0.0146).

CONCLUSIONS

LN SUVmax could be an important predictor of recurrence and survival in patients with cervical cancer confined to the pelvis.

Mouse model of lymph node metastasis via afferent lymphatic vessels for development of imaging modalities

Animal studies of lymph node metastasis are constrained by limitations in the techniques available for noninvasive monitoring of the progression of lymph node metastasis, as well as difficulties in the establishment of appropriate animal models. To overcome these challenges, this study has developed a mouse model of inter-lymph-node metastasis via afferent lymphatic vessels for use in the development of imaging modalities. We used 14- to 18-week-old MRL/MpJ−/lpr/lpr (MRL/lpr) mice exhibiting remarkable systemic lymphadenopathy, with proper axillary lymph nodes (proper-ALNs) and subiliac lymph nodes (SiLNs) that are 6 to 12 mm in diameter (similar in size to human lymph nodes). When KM-Luc/GFP malignant fibrous histiocytoma-like cells stably expressing the firefly luciferase gene were injected into the SiLN, metastasis could be detected in the proper-ALN within 3 to 9 days, using in vivo bioluminescence imaging. The metastasis route was found to be via the efferent lymphatic vessels of the SiLN, and metastasis incidence depended on the number of cells injected, the injection duration and the SiLN volume. Three-dimensional contrast-enhanced high-frequency ultrasound imaging showed that the blood vessel volume and density in the metastasized proper-ALN significantly increased at 14 days after tumor cell inoculation into the SiLN. The present metastasis model, with lymph nodes similar in size to those of humans, has potential use in the development of ultrasound imaging with high-precision and high-sensitivity as well as other imaging modalities for the detection of blood vessels in lymph nodes during the progression of metastasis.

ADC maps in the prediction of pelvic lymph nodal metastatic regions in endometrial cancer

OBJECTIVES

To evaluate the usefulness of apparent diffusion coefficient (ADC) in discriminating metastatic from non-metastatic pelvic lymph nodal sites in endometrial cancer.

MATERIALS AND METHODS

This retrospective study included 40 patients with endometrial cancer who underwent MRI [T2-weighted, dynamic T1-weighted images and diffusion-weighted images with body background suppression (DWIBS), b-values 0 and 1,000 s/mm(2)], total hysterectomy and pelvic lymphadenectomy. Lymph nodes identifiable on DWIBS were evaluated, classified into six nodal regions, and for each node ADC values, short- and long-axis diameters were measured by two readers. Histopathological findings and follow-up information served as the reference standard.

RESULTS

Average (± standard deviation) mean and minimum ADC region value (0.87 ± 0.15 and 0.74 ± 0.07 × 10(-3) mm(2)/s) of metastatic sites (n = 7) were significantly lower than those of non-metastatic ones (n = 89; 1.07 ± 0.20 and 1.02 ± 0.20; p-value = 0.010 and 0.0004). Mean short-axis and short-to-long axis ratios of metastatic nodes were 7.47 mm and 0.68. Using the minimum ADC region value with threshold 0.807 × 10(-3) mm(2)/s, sensitivity, specificity, positive and negative predictive value and accuracy were 100 %, 98.3 %, 63.6 %, 100 % and 98.3 %, respectively (reader 1).

CONCLUSION

In endometrial cancer, mean and minimum ADC region values of metastatic nodal sites are significantly lower than those found at normal sites.

Differential diagnosis of axillary inflammatory and metastatic lymph nodes in rabbit models by using diffusion-weighted imaging: compared with conventional magnetic resonance imaging

Objective

This experiment aims to determine the diagnostic value of diffusion-weighted imaging (DWI) in the differentiation of axillary inflammatory lymph nodes from metastatic lymph nodes in rabbit models in comparison with conventional magnetic resonance imaging (MRI).

Materials and Methods

Conventional MRI and DWI were performed at 4 weeks after successful inoculation into the forty female New Zealand white rabbits' mammary glands. The size-based and signal-intensity-based criteria and the relative apparent diffusion coefficient (rADC) value were compared between the axillary inflammatory lymph nodes and metastatic lymph nodes, with histopathological findings as the reference standard. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of the aforementioned criteria and rADC value in differentiating the axillary inflammatory lymph nodes from metastatic lymph nodes.

Results

Thirty-two axillary inflammatory lymph nodes and 46 metastatic ones were successfully isolated and taken into pathological analysis. The differences of the aforementioned criteria between the two groups were not statistically significant (p > 0.05). However, the rADC value of the inflammatory lymph nodes (0.9 ± 0.14) was higher than that of metastatic ones (0.7 ± 0.18), with significant difference (p = 0.016). When the rADC value was chosen as 0.80, the area under the ROC curve is greater than all other criteria, and the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for differentiating two groups were 86.2%, 79.3%, 81.2%, 84.2%, and 85.6%, respectively.

Conclusion

Diffusion-weighted imaging is a promising new technique for differentiating axillary inflammatory lymph nodes from metastatic lymph nodes. Compared with routine magnetic resonance sequences, DWI could provide more useful physiological and functional information for diagnosis.

Staging of uterine cervical carcinoma: whole-body diffusion-weighted magnetic resonance imaging

PURPOSE

To evaluate the clinical value of magnetic resonance whole-body diffusion-weighted imaging (WB-DWI) in the staging of uterine cervical carcinoma.

MATERIALS AND METHODS

Twenty-six patients with untreated uterine cervical carcinoma received preoperative conventional MR and WB-DWI scans. WB-DWI scans were also obtained in 30 healthy volunteers. Measurements of apparent diffusion coefficient (ADC) were made on scans of normal uterine cervix and uterine cervical carcinoma, and benign and metastatic lymph nodes. Statistical analysis was applied to the obtained data.

RESULTS

Mean ADC value of uterine cervical carcinoma was significantly lower than the 3 layers of normal uterine cervix (P = 0.00). When an ADC value of 1.28 × 10(-3) mm(2)/s is used as the threshold, its sensitivity is 96%, specificity is 100%, and accuracy is 98%. Mean ADC value of metastatic nodes [(0.96 ± 0.14) × 10(-3) mm(2)/s] was significantly lower than that of benign nodes [(1.39 ± 0.19) × 10(-3) mm(2)/s] (t = 9.93, P = 0.00). When an ADC value of 1.14 × 10(-3) mm(2)/s is used as the threshold, its sensitivity is 83%, specificity is 98%, and accuracy is 94%.

CONCLUSION

WB-DWI scan is capable of distinguishing uterine cervical carcinoma from normal uterine cervix, and is capable of separating metastatic nodes from benign nodes.

PET/CT imaging in gynecologic malignancies: a critical overview of its clinical impact and our retrospective single center analysis

Gynecologic cancers represent a major global healthcare problem since they are associated with a significant mortality and morbidity. Over the last decade, considerable efforts have been spent in the development and optimization of novel diagnostic modalities to achieve an early diagnosis, aid in choosing appropriate treatment, improving long term surveillance, with the ultimate goal of increasing survival of gynecologic cancer patients. A growing body of evidence defines PET/CT as one of the most powerful tools for tumor, nodal and metastasis (TNM) cancer staging both in pre-treatment and in post treatment follow-up settings. At any phase of cancer evaluation, detection of metastasis represents one of the most critical impediments to the cure of tumor; traditional diagnostic imaging modalities, such as computed tomography (CT), are frequently found to inadequately stage the tumor, based on subsequent outcomes. As a consequence, patients may undergo pointless surgery for disease that could be treated with local medical therapies. In the setting of restaging, the ability to describe primary lesion, lymph nodes, possible metastases to peritoneum, bone, liver, lungs and brain renders PET/CT a potential alternative for a series of tests, including bone scanning, MRI or ultrasound, diagnostic CT, lymph node surgical sampling, that need to be used in combination in order to obtain a level of clinical confidence. In this review, we describe, the theoretical advantage and prognostic implications of PET/CT in the management of gynecologic cancer patients.

Diagnosis of lymph node metastasis in uterine cervical cancer: usefulness of computer-aided diagnosis with comprehensive evaluation of MR images and clinical findings

BACKGROUND

Lymph node (LN) status is an important parameter for determining the treatment strategy and for predicting the prognosis for patients with uterine cervical cancer. Computer-aided diagnosis (CAD) can be feasible for differentiating metastatic from non-metastatic lymph nodes in patients with uterine cervical cancer.

PURPOSE

To determine the usefulness of CAD that comprehensively evaluates MR images and clinical findings for detecting LN metastasis in uterine cervical cancer.

MATERIAL AND METHODS

In 680 LNs from 143 patients who underwent radical hysterectomy for uterine cervical cancer, the CAD system using the Bayesian classifier estimated the probability of metastasis based on MR findings and clinical findings. We compared the diagnostic accuracy for detecting metastatic LNs in the CAD and MR findings.

RESULTS

Metastasis was diagnosed in 70 (12%) LNs from 34 (24%) patients. The area under ROC curves of CAD (0.924) was greater than those of the mean ADC (0.854), minimum ADC (0.849), maximum ADC (0.827), short-axis diameter (0.856) and long-axis diameter (0.753) (P < 0.05). The specificity and accuracy of the CAD (86%, 86%) were greater than those of the mean ADC (77%, 77%), maximum ADC (77%, 77%), minimum ADC (68%, 70%), and short-axis diameter (65%, 67%) (P < 0.05).

CONCLUSION

CAD system can improve the diagnostic performance of MR for detecting metastatic LNs in uterine cervical cancer.

Usefulness of semi-automatic volumetry compared to established linear measurements in predicting lymph node metastases in MSCT

BACKGROUND

Volumetry of lymph nodes potentially better reflect asymmetric size alterations independently of lymph node orientation in comparison to metric parameters (e.g. long-axis diameter).

PURPOSE

To distinguish between benign and malignant lymph nodes by comparing 2D and semi-automatic 3D measurements in MSCT.

MATERIAL AND METHODS

FDG-18 PET-CT was performed in 33 patients prior to therapy for malignant melanoma at stage III/IV. One hundred and eighty-six cervico-axillary, abdominal and inguinal lymph nodes were evaluated independently by two radiologists, both manually and with the use of semi-automatic segmentation software. Long axis (LAD), short axis (SAD), maximal 3D diameter, volume and elongation were obtained. PET-CT, PET-CT follow-up and/or histology served as a combined reference standard. Statistics encompassed intra-class correlation coefficients and ROC curves.

RESULTS

Compared to manual assessment, semi-automatic inter-observer variability was found to be lower, e.g. at 2.4% (95% CI 0.05-4.8) for LAD. The standard of reference revealed metastases in 90 (48%) of 186 lymph nodes. Semi-automatic prediction of lymph node metastases revealed highest areas under the ROC curves for volume (reader 1 0.77, 95%CI 0.64-0.90; reader 2 0.76, 95%CI 0.59-0.86) and SAD (reader 1 0.76, 95%CI 0.64-0.88; reader 2 0.75, 95%CI 0.62-0.89). The findings for LAD (reader 1 0.73, 95%CI 0.60-0.86; reader 2 0.71, 95%CI 0.71, 95%CI 0.57-0.85) and maximal 3D diameter (reader 1 0.70, 95%CI 0.53-0.86; reader 2 0.76, 95%CI 0.50-0.80) were found substantially lower and for elongation (reader 1 0.65, 95%CI 0.50-0.79; reader 2 0.66, 95%CI 0.52-0.81) significantly lower (p < 0.05).

CONCLUSION

Semi-automatic analysis of lymph nodes in malignant melanoma is supported by high segmentation quality and reproducibility. As compared to established SAD, semi-automatic lymph node volumetry does not have an additive role for categorizing lymph nodes as normal or metastatic in malignant melanoma.

Discrimination of metastatic from hyperplastic pelvic lymph nodes in patients with cervical cancer by diffusion-weighted magnetic resonance imaging

PURPOSE

To evaluate the diagnostic value of diffusion-weighted MR imaging for differentiating metastatic and hyperplastic pelvic lymph nodes in patients with cervical carcinoma.

MATERIALS AND METHODS

In this prospective study, 61 untreated patients were scanned with both morphological MR and diffusion-weighted imaging (DWI). Bilateral pelvic lymphadenectomy was then performed in all patients. Of the 1118 total dissected and histopathologically evaluated pelvic lymph nodes, 153 enlarged nodes with short-axis diameter larger than 5 mm were included for further study. The mean ADC values of all enlarged lymph nodes and the relative ADC values between tumors and nodes were also measured and, respectively, compared between the metastatic and hyperplastic node groups.

RESULTS

The mean ADC value of metastatic [(1.046 ± 0.198) × 10⁻³ mm²/s] nodes was significantly lower than that of hyperplastic [(1.289 ± 0.194) × 10⁻³ mm²/s] nodes (P < 0. 001). The relative ADC values between tumor and nodes were significantly lower in malignant [(0.19 ± 0.17) × 10⁻³ mm²/s] than hyperplastic [(0.4 ± 0.21) × 10⁻³ mm²/s] nodes (P < 0. 001). When a mean ADC value of 1.15 × 10⁻³ mm²/s was used as a threshold value for differentiating metastatic from hyperplastic nodes, the best results were obtained with a sensitivity of 83.3%, specificity of 74.7%, and accuracy of 78.4%.

CONCLUSION

DWI is useful in differentiating metastatic and hyperplastic pelvic lymph nodes in patients with cervical carcinoma.

Correlation between tumor size and surveillance of lymph node metastasis for IB and IIA cervical cancer by magnetic resonance images

PURPOSE

To assess the feasibility of preoperative MRI based measurement of tumor size with regard to lymph node (LN) metastasis in early uterine cervical cancer.

MATERIAL AND METHODS

A retrospective review of patients with FIGO stage IB-IIA cervical cancer who underwent lymphadenectomy was performed. Diagnostic accuracy of MRI in detecting LN metastasis and rate of LN recurrence in terms of tumor size (≤4cm versus >4cm) were analyzed. ROC curve analysis was used to determine LN size for differentiating LN metastasis in terms of tumor size. P<0.05 was considered statistically significant.

RESULTS

Of the 200 patients, 45 (22.3%) had LN metastasis. There was no statistical difference between patients-based and region-specific analysis. The patients with tumor size with >4cm revealed higher diagnostic accuracy of MRI in detecting LN metastasis (85.4% versus 50.6%, P=0.023) and rate of LN recurrence (20.0% versus 6.4%, P=0.031) in than those with size with ≤4cm, the differences were statistically significant. Discriminant analysis of LN size for the differentiation of metastasis from non-metastasis resulted in cut-off values (11.8mm; size with >4cm versus 8.3mm; size with ≤4cm) and diagnostic accuracy (84.0% of size with >4cm versus 72.0% of size with ≤4cm).

CONCLUSION

MRI has limited sensitivity, but high specificity in predicting surveillance of LN metastasis in the preoperative early cervical cancer, especially useful tool for patients with tumor size with >4cm.

Role of magnetic resonance imaging and positron emission tomography/computed tomography in preoperative lymph node detection of uterine cervical cancer

OBJECTIVE

The aim of this study was to compare magnetic resonance imaging (MRI) with positron emission tomography/computed tomography (PET/CT) in the preoperative detection of lymph node metastases in patients with uterine cervical cancer.

STUDY DESIGN

This retrospective study reviewed patients with cervical cancer who had undergone both preoperative MRI and PET/CT before radical surgery, including lymphadenectomy between 2004-2008.

RESULTS

Eighty-three patients were identified, of whom 28 (33.7%) had pelvic lymph node metastasis. The sensitivity, specificity, and accuracy for detecting lymph node metastasis were 64.3%, 69.1%, and 67.5% for MRI, and 28.6%, 83.6%, and 65.1% for PET/CT, respectively. The area under the receiver operating characteristics for the MRI and PET/CT were 0.667 and 0.561, respectively (P = .013). MRI showed significantly higher sensitivity for detecting metastatic lymph nodes than PET/CT (P = .006).

CONCLUSION

MRI was more sensitive than PET/CT for detecting metastatic lymph node in patients with cervical cancer.

Magnetic resonance lymphography in gynaecological malignancies

Following the submission of this article to Cancer Imaging, unfortunately the European manufacturer of ferumoxtran-10 (Guerbet) has withdrawn the product pending further phase III studies. This is secondary to the view of the Committee for Medicinal Products for Human Use that the phase III data did not provide adequate statistical demonstration of the product's efficacy.

Magnetic resonance lymphography holds much promise for the non-invasive evaluation of lymph nodes. The technique utilizes ultrasmall superparamagnetic particles of iron oxide and has been shown to be highly sensitive and specific in the diagnosis of malignant lymph nodes. This article reviews the technique and the performance of magnetic resonance lymphography in studies to date; alternative newer methods of nodal assessment such as fluorodeoxyglucose-positron emission tomography/computed tomography and diffusion-weighted magnetic resonance imaging are also discussed, with emphasis on gynaecological malignancies.

Nodal staging

Lymph node metastases are a poor prognostic indicator in many tumours and therefore accurate identification during staging is important prior to commencing treatment. The presence of lymph node metastases can significantly alter patient management and therefore accurate diagnosis of the presence and extent of nodal disease can help optimise patient management. In this review, the radiologic features that aid in the differentiation of malignant and benign lymph nodes are discussed. The keys to successful interpretation on cross-sectional computed tomography (CT) and magnetic resonance imaging of nodal metastases are highlighted. The clinical role of positron emission tomography-CT imaging for nodal staging is discussed and emerging imaging techniques that may further improve nodal staging accuracy are surveyed.

Management of early and locally advanced cervical cancer

Cervical cancer is the second most common malignancy in women and the third most common cause of cancer mortality worldwide. While primary and secondary preventions exist, the lack of widespread adoption leaves the treatment of cervical cancer an important oncologic problem. In this article, the management of early and locally advanced cervical carcinoma is reviewed, including staging, imaging, prognostic factors, and primary and adjuvant therapy and their outcomes.