Accuracy of MRI for diagnosing pelvic and para­aortic lymph node metastasis in cervical cancer.

The current study aimed to evaluate the accuracy of diffusion­weighted imaging and morphological aspects at 3 Tesla (T) and 1.5T MRI for diagnosing metastatic lymph nodes (LN) in cervical cancer. A retrospective study was conducted at the Barretos Cancer Hospital. A total of 45 patients with cervical cancer who underwent MRI examination and pelvic and/or para­aortic lymphadenectomy as part of surgical procedure were included. Data regarding LN images included size (short­axis diameters), morphology (usual, rounded or amorphous), appearance (homogeneous or heterogeneous), limits (regular, irregular or imprecise), presence or absence of necrosis, diffusion (normal or greater restriction than expected for normal tissue) and aspect (suspected, undetermined or normal). These findings were compared with histopathological results. According to histology results, among the 45 patients, 14 (31.1%) LNs were tested positive for metastasis and 31 (68.9%) LNs were tested negative. A total of 41 metastatic positive LNs were detected from a total of 976 resected nodes. Twelve patients from the 45 (26.7%) had LN classified as metastatic by histology and suspected by MRI, 26 (57.8%) as negative in both evaluations, 2 (4.4%) as positive by histology and negative by MRI and five (11.1%) as negative by histology and positive by MRI. Based on these results, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were 85.7, 83.9, 70.6, 92.9 and 84.4%, respectively. The Cohen's κ test exposed a general outcome of 0.657 (P<0.05), demonstrating that the two variables (histology and MRI) have substantial concordance. The κ test results between histological and MRI data for paraaortic and pelvic LNs were found to be 1 and 0.657, respectively. Finally, short axis >10 mm, T2 hypointensity, rounded morphology and greater restriction than expected for normal tissues are the four most common MRI findings associated with metastatic LN. The concordance between MRI and histology was substantial, indicating that this method using MRI for diagnosing suspected LN metastasis is reliable. The results of the current study revealed that the most important aspects to be evaluated in MRI include: Short axis >10 mm, T2 hypointensity, rounded morphology and greater restriction than expected for normal tissues. If these four characteristics are present in MRI, histological evaluation is likely to reveal positive lymph node metastasis.

Predicting the necessity of adding catheters to intracavitary brachytherapy for women undergoing definitive chemoradiation for locally advanced cervical cancer.

PURPOSE: To identify if baseline patient or magnetic resonance imaging (MRI) features can predict which women are at risk for inadequate tumor coverage with only intracavitary tandem and ovoid (T + O) brachytherapy and to correlate tumor coverage with clinical outcomes. METHODS AND MATERIALS: We performed a retrospective study of 50 women with cervical cancer treated with chemoradiation at a single institution between January 2014 and December 2015. All patients had a 3T-MRI performed at baseline (MRI1) and at the completion of external beam radiation therapy (MRI2). Gross tumor volume initial (GTV-Tinit) was measured on MRI1 and high-risk clinical tissue volume (CTVHR) on MRI2. CTVHR extending beyond point A was classified as too large for adequate coverage with T + O and requiring interstitial needles. Multivariate analysis was performed to determine predictive factors of inadequate coverage. Kaplan-Meier and Cox Regression were performed to correlate inadequate coverage with outcomes. RESULTS: Mean patient age was 49.2 ± 13.2 years, and 84% had Federation of Gynecology and Obstetrics IIB/IIIB disease. Forty-two percent of women were estimated to have inadequate tumor coverage with T + O brachytherapy. The GTV-Tinit volume and dimensions (superior-inferior, left-right, anterior-posterior) on MRI1 were all important predictive factors of inadequate coverage on multivariate analysis. Receiver operating characteristics curves identified optimal thresholds of superior-inferior ≥ 4.5 cm (area under the curve [AUC] = 0.718), left-right ≥ 4.5 cm (AUC = 0.745), anterior-posterior ≥ 5.0 cm (AUC = 0.767), and GTV-Tinit ≥ 85 cm3 (AUC = 0.842). Patients with inadequate coverage had worse clinical outcomes. CONCLUSIONS: Baseline MRI tumor size may predict inadequate CTVHR coverage at the time of brachytherapy (i.e., the need for interstitial needles). This may help identify a subset of women requiring early referral to adequately resourced centers to improve clinical outcomes.

Incremental value of MRI for preoperative penile cancer staging.

PURPOSE: To evaluate the incremental value of magnetic resonance imaging (MRI), compared to clinical examination, for penile cancer (PC) local staging. MATERIALS AND METHODS: Twenty-five consecutive patients with histologically proven PC were evaluated prospectively. MRI staging was performed on 1.5 and 3.0T scanners using high-resolution T2 -weighted and postcontrast T1 -weighted images. Two blinded observers interpreted MR images. Clinical local staging was performed by experienced urologists. The pathology report was used as the standard of reference. RESULTS: The interobserver agreement for MRI staging, using a kappa test for T-staging was moderate, 0.52 (95% confidence interval [CI] = 0.24-0.78), P = 0.001, although a high correlation for N-staging, 0.72 (95% CI = 0.42-1.00), P = 0.001, was detected. Clinical staging was correct in 52.0% (13/25) of patients. After pathological staging, five (20.0%) lesions were upstaged and seven (28.0%) lesions were downstaged compared to clinical examination. MRI accurately defined T-staging in 18/25 lesions (72.0%). After pathologic staging, five (20.0%) were upstaged and two downstaged (8.0%), compared to MRI. Fifteen patients were submitted to inguinal and pelvic lymphadenectomy and considered for comparison of accuracy of nodal staging by physical examination and MRI. Clinical staging accurately staged 7/15 patients (46.7%). After histopathologic analysis, six cases had nodal staging upgraded and two cases were downgraded. MRI correctly staged 13/15 (86.7%). Using a chi-square for comparison, differences in proportion of corrected staging between clinical examination and MRI were not significant for T-staging (P = 0.14), but were significant for nodal staging (P = 0.02). CONCLUSION: According to our results, MRI improves local staging of PC patients, particularly for those with limited physical examination. LEVEL OF EVIDENCE: 1 J. Magn. Reson. Imaging 2017;45:118-124.

Pre-treatment MRI minimum apparent diffusion coefficient value is a potential prognostic imaging biomarker in cervical cancer patients treated with definitive chemoradiation.

BACKGROUND: Diffusion Weighted (DW) Magnetic Resonance Imaging (MRI) has been studed in several cancers including cervical cancer. This study was designed to investigate the association of DW-MRI parameters with baseline clinical features and clinical outcomes (local regional control (LRC), disease free survival (DFS) and disease specific survival (DSS)) in cervical cancer patients treated with definitive chemoradiation. METHODS: This was a retrospective study approved by an institutional review board that included 66 women with cervical cancer treated with definitive chemoradiation who underwent pre-treatment MRI at our institution between 2012 and 2013. A region of interest (ROI) was manually drawn by one of three radiologists with experience in pelvic imaging on a single axial CT slice encompassing the widest diameter of the cervical tumor while excluding areas of necrosis. The following apparent diffusion coefficient (ADC) values (×10(-3) mm(2)/s) were extracted for each ROI: Minimum - ADCmin, Maximum - ADCmax, Mean - ADCmean, and Standard Deviation of the ADC - ADCdev. Receiver operating characteristic (ROC) curves were built to choose the most accurate cut off value for each ADC value. Correlation between imaging metrics and baseline clinical features were evaluated using the Mann Whitney test. Confirmatory multi-variate Cox modeling was used to test associations with LRC (adjusted by gross tumor volume - GTV), DFS and DSS (both adjusted by FIGO stage). Kaplan Meyer curves were built for DFS and DSS. A p-value < 0.05 was considered significant. Women median age was 52 years (range 23-90). 67 % had FIGO stage I-II disease while 33 % had FIGO stage III-IV disease. Eighty-two percent had squamous cell cancer. Eighty-eight percent received concurrent cisplatin chemotherapy with radiation. Median EQD2 of external beam and brachytherapy was 82.2 Gy (range 74-84). RESULTS: Women with disease staged III-IV (FIGO) had significantly higher mean ADCmax values compared with those with stage I-II (1.806 (0.4) vs 1.485 (0.4), p = 0.01). Patients with imaging defined positive nodes also had significantly higher mean (±SD) ADCmax values compared with lymph node negative patients (1.995 (0.3) vs 1.551 (0.5), p = 0.03). With a median follow-up of 32 months (range 5-43) 11 patients (17 %) have developed recurrent disease and 8 (12 %) have died because of cervical cancer. ROC curves based on DSS showed optimal cutoffs for ADCmin (0.488 × 10(-3)), ADCmean (0.827 × 10(-3)), ADCmax (1.838 × 10(-3)) and ADCdev (0.148 × 10(-3)). ADCmin higher than the cutoff was significantly associated with worse DFS (HR = 3.632-95 % CI: 1.094-12.054; p = 0.035) and DSS (HR = 4.401-95 % CI: 1.048-18.483; p = 0.043). CONCLUSION: Pre-treatment ADCmax measured in the primary tumor may be associated with FIGO stage and lymph node status. Pre-treatment ADCmin may be a prognostic factor associated with disease-free survival and disease-specific survival in cervical cancer patients treated with definitive chemoradiation. Prospective validation of these findings is currently ongoing.