Value of Dynamic Contrast-enhanced and Diffusion-weighted MR Imaging in the Detection of Pathologic Complete Response in Cervical Cancer after Neoadjuvant Therapy: A Retrospective Observational Study.

Purpose To evaluate the association between dynamic contrast material-enhanced (DCE) and diffusion-weighted (DW) magnetic resonance (MR) imaging with pathologic complete response after preoperative combined chemotherapy and radiation therapy for cervical carcinoma and evaluate the risk of local recurrence. Materials and Methods The institutional ethics committee approved the study and waived the requirement to obtain informed consent. The study comprised 52 patients with locally advanced carcinoma, treated first with combined chemotherapy and radiation therapy, who underwent MR imaging before final surgery between June 2011 and July 2015. Three radiologists evaluated conventional, DW, and DCE MR images to identify a complete response. The standard of reference was surgical-pathologic findings. Results An initial increase in signal intensity on DCE MR images that was greater in the cervical lesion than in the myometrium was defined as time-signal intensity curve type B and showed a significant association with incomplete response (P = .0004). DCE MR imaging parameters (ie, maximum slope enhancement, area under the gadolinium concentration-time curve during the first 90 seconds after gadolinium injection [AUGC90], and volume transfer constant [Ktrans]) and a low signal intensity on apparent diffusion coefficient (ADC) maps were significantly associated with an incomplete response (P = .027, P = .041, P = .037, and P = .032, respectively). A mean ADC of 0.0014 m2/sec or less (hazard ratio [HR] = 8.3), low ADC signal intensity (HR = 7.3), high signal intensity at DW imaging (HR = 7.1), and time-signal intensity curve type B (HR = 4.3) were associated with earlier recurrence (P < .05). Excellent agreement between readers was found for time-signal intensity curve analysis (κ > 0.9) and the following parameters: AUGC90, Ktrans, and maximum slope enhancement (intraclass correlation coefficient, >0.9). Conclusion DCE MR imaging parameters, especially the time-signal intensity curve, and DW imaging are associated with complete response and incomplete response and could potentially help oncologists with management decisions. Moreover, DCE and DW MR imaging could help oncologists accentuate the follow-up for patients with a high risk of local recurrence to assess for recurrence. © RSNA, 2017 Online supplemental material is available for this article.

Contribution of FDG PET/CT for the Optimization of the Management of Additional Lesions Detected on Local Staging Breast MRI.

OBJECTIVE: The purpose of this study is to evaluate the added value of FDG PET/CT for the management of additional lesions detected by breast MRI during initial staging of known breast cancer. MATERIALS AND METHODS: We retrospectively queried our database for all consecutive patients with biopsy-confirmed breast cancer who underwent breast MRI and FDG PET/CT before neoadjuvant chemotherapy between November 2011 and November 2012. The final population comprised 80 patients. Initially, two readers retrospectively analyzed the breast MRI data for the presence of lesions in addition to the previously confirmed index neoplasm. Analysis of FDG PET/CT data followed; two different readers evaluated the presence or absence of FDG uptake in both breasts. The reference standard for additional lesions was percutaneous biopsy with subsequent 2-year follow-up for benign results. Statistical analysis was conducted with nonparametric analysis and the Fisher exact test. RESULTS: The readers detected 61 additional breast lesions at MRI in 45 patients (56.2%); 37 of 61 (61%) additional lesions were malignant and 24 of 61 (39%) were benign. Among the 61 additional breast lesions detected by MRI, only 32 were positive at FDG PET/CT, with a positive predictive value of 90.6% and negative predictive value of 72%. The sensitivity, specificity, and accuracy of FDG PET/CT were 78.3%, 87.5%, and 81.9%, respectively. In eight cases, FDG PET/CT missed additional malignant lesions. All missed malignant additional lesions were smaller than 1 cm. In three cases, additional lesions also detected at FDG PET/CT were benign. CONCLUSION: In the case of additional lesions detected at MRI, a negative FDG PET/CT finding could replace a breast biopsy for lesions larger than 1 cm.