Prediction of pathological margin status using preoperative contrast-enhanced MRI in patients with early breast cancer who underwent skin-sparing mastectomy.

Skin-sparing mastectomy (SSM) with immediate reconstruction is standard surgical treatment for early breast cancer with widespread ductal carcinoma in situ (DCIS). The local recurrence rate after SSM is up to 7.0%. We investigated prediction of the pathological margin using contrast-enhanced MRI, and evaluated the cut-off point to obtain the safety margin. We performed SSM with immediate reconstruction in 216 early breast cancer patients with widespread DCIS and/or invasive cancer from January 2014 to December 2015. Forty cases were retrospectively reviewed after excluding those with >15 mm between skin and tumor, determined by preoperative contrast-enhanced MRI, or involving reconstructive surgery for local recurrence, immeasurable lesion by preoperative contrast-enhanced MRI, or neoadjuvant chemotherapy. We defined a positive pathological margin as <1 mm from the cancer nest. We reviewed the distance between skin and tumor by MRI and pathological examination. To identify the cut-off for predicting a positive pathological margin, we performed sensitivity analysis using an ROC curve. The margin-positive rate by pathological examination was 27.5% (n = 11/40), with a moderate correlation of MRI margin and pathological margin (r = 0.44). The best cut-off point for margin positivity was 5 mm of MRI margin, with sensitivity and specificity of 54% and 86%, respectively (P = 0.009). This is the first prediction of pathological margin by preoperative contrast-enhanced MRI in early breast cancer patients with SSM. Care is required for SSM if the MRI margin is less than 5 mm due to pathological margin positivity.

Utility of high-definition FDG-PET image reconstruction for lung cancer staging.

BACKGROUND: High-definition (HD) positron emission tomography (PET) image reconstruction is a new image reconstruction method based on the point spread function system, which improves the spatial resolution of the images. PURPOSE: To compare the utility of HD reconstruction of PET images for staging lung cancer with that of conventional 2D ordered subset expectation maximization + Fourier rebinning (2D) reconstruction. MATERIAL AND METHODS: Thirty-five lung cancer patients (24 men, 11 women; median age, 66 years) who underwent surgery after 18F-2-deoxy-fluoro-D-glucose (FDG)-PET-CT were studied. Their PET data were reconstructed with 2D and HD PET reconstruction algorithms. Two radiologists individually TNM staged both sets of images. They also evaluated the quality of the images and the diagnostic confidence that the images afforded them using 5-point scales. RESULTS: T, N, and M stages were correctly diagnosed on both the 2D and HD reconstructed images in 23 (66%), 25 (71%), and 30 (86%) of 35 cases, respectively. Overall TNM stage was correctly diagnosed on both types of reconstructed images in 23 cases (66%), underestimated in three (9%), and overestimated in nine (26%). No significant difference in T, N, or M stage or overall TNM stage was observed between the two reconstruction methods. However, the HD reconstructed images afforded a significantly higher level of diagnostic confidence during TNM staging than the 2D reconstructed images and were also of higher quality than the 2D reconstructed images. CONCLUSION: Although HD reconstruction of FDG-PET images did not improve the diagnostic accuracy of lung cancer staging compared with 2D reconstruction, the quality of the HD reconstructed images and the diagnostic confidence level they afforded the radiologists were higher than those of the conventional 2D reconstructed images.