Materials and Methods: The database consisted of consecutive diagnostic breast US scans collected with informed consent with a protocol approved by the institutional review board and compliant with the HIPAA. Images from 508 patients with a total of 1046 distinct abnormalities were used. One hundred one patients had breast cancer. Results both for patients in whom the lesion abnormality was proved with either biopsy or aspiration (n = 183) and for all patients irrespective of biopsy status (n = 508) are presented. The ability of the CAD workstation to help differentiate malignancies from benign lesions was evaluated with a leave-one-out-by-case analysis. The clinical specificity of the radiologists for this dataset was determined according to the biopsy rate and outcome.
Results: In the task of differentiating cancer from all other lesions sent to biopsy, the CAD workstation obtained an area under the receiver operating characteristic curve (AUC) value of 0.88, with 100% sensitivity at 26% specificity (157 cancers and 362 lesions total). The radiologists' specificity at 100% sensitivity for this set was zero. When analyzing all lesions irrespective of biopsy status, which is more representative of actual clinical practice, the CAD scheme obtained an AUC of 0.90 and 100% sensitivity at 30% specificity (157 cancers and 1046 lesions total). The radiologists' specificity at 100% sensitivity for this set was 77%.
Conclusion: Current levels of computer performance warrant a clinical evaluation of the potential of US CAD to aid radiologists in lesion work-up recommendations.
© RSNA, 2008
]]>Materials and Methods: This study was approved by the institutional review board, and the methods comply with HIPAA regulations. A retrospective search of the institutional mammographic results database was done to identify bilateral screening mammographic examinations obtained from January 1, 1999, through July 15, 2005. The search included the term TRAM; the recall and cancer detetion rates were then detected. Subsequently, a decision analytic model was constructed to evaluate a hypothetical cohort of women with TRAM flap reconstructions.
Results: Of 554 mammograms (265 TRAM flap reconstructions), 546 (98.6%) had negative results (Breast Imaging Reporting and Data System category 1 or 2). Eight (1.4%) had positive test results (Breast Imaging Reporting and Data System category 0, 3, 4, or 5). All suspicious lesions underwent biopsy and had benign pathologic results. No interval breast cancers were identified. The detection rate for nonpalpable recurrent breast cancer was 0% (exact 95% confidence interval: 0.0%, 1.4%). According to decision analysis, screening would help detect an estimated 12 additional recurrent cancers per 1000 women screened, providing an additional 1.6 days of life expectancy for the screened cohort. Under base-case conditions, screening of TRAM flap reconstructions is less effective than screening asymptomatic women in their 40s. Sensitivity analysis revealed that a benefit equivalent to that of screening asymptomatic women in their 40s was achievable under conditions related to estimates of screening effectiveness and cancer detection rate.
Conclusion: Routine screening mammography of TRAM flap reconstructions has a very low detection rate for nonpalpable recurrent breast cancer. Decision analysis indicates that screening such women is less effective than screening asymptomatic women in their 40s for primary breast cancer.
© RSNA, 2008
]]>Materials and Methods: Informed consent was waived by the institutional review board for this retrospective review of 1352 cases. In 1061 cases, patients underwent surgical excision of lesions visible at US subsequent to US-guided 14-gauge CNB. Follow-up of another 291 benign lesions at US-guided 14-gauge CNB histologic examination showed stability during clinical and imaging follow-up for at least 2 years. US and histologic findings were reviewed and compared for agreement. A false-negative finding was defined as pathologically proved cancer for which biopsy results were benign. The false-negative rate was defined as the proportion of all breast cancers with a diagnosis of benign disease at US-guided 14-gauge CNB. The underestimation rate was defined as an upgrade of a high-risk lesion at US-guided 14-gauge CNB to malignancy at surgery.
Results: US 14-gauge CNB yielded 671 (63.2%) malignant, 86 (8.1%) high-risk, and 304 (28.7%) benign lesions. Each of the 291 benign lesions without surgery remained stable during follow-up. The agreement of US-guided 14-gauge CNB results, surgical excision findings, and follow-up results was 95.8% ( = 0.93). False-negative findings were encountered in 11 (0.8%) of 1352 cases, and the false-negative rate was 1.6% (11 of 671 malignancies). All false-negative findings were prospectively identified owing to discordance between imaging results and US-guided 14-gauge CNB histologic findings. The underestimation rate was 31.4%.
Conclusion: US-guided 14-gauge CNB is an alternative to surgical excision for assessing nonpalpable breast lesions.
© RSNA, 2008
]]>Materials and Methods: This retrospective study was approved by the institutional review board and was HIPAA compliant; informed consent was waived. From 1995 to 2002, gadolinium-enhanced MR imaging data were acquired with a three time point high-resolution method in women undergoing neoadjuvant therapy for invasive breast cancers. Forty-eight women (mean age, 49.1 years; range, 29.7–72.4 years) were divided into recurrence-free or recurrence groups. Volume measurements were tabulated for SER values between set ranges; cutoff criteria were defined to predict disease recurrence after surgery. Wilcoxon rank sum tests and the multivariate Cox proportional hazards regression model were used for evaluation.
Results: Breast tumor volume calculated from the number of voxels with SER values above a threshold corresponding to the upper limit of mean redistribution rate constant in benign tumors (0.88 minutes–1) and the volume of cancerous breast tissue infiltrating into the parenchyma were important predictors of disease recurrence. Seventy-five percent of patients with recurrence and 100% of deceased patients were identified as being at high risk for recurrence. Thirty percent of patients with recurrence and 67% of deceased patients were identified as having high risk before chemotherapy. No patients in the recurrence-free group were misidentified as likely to have recurrence. All three prechemotherapy parameters (total tumor volume, tumor volumes with high and low SER) and the postchemotherapy tumor volume with high SER were significantly different between the two groups. The multivariate Cox proportional hazards regression showed that, of the three prechemotherapy covariates, only the low SER and high SER tumor volumes (P = .017 and .049, respectively) were significant and independent predictors of tumor recurrence. Tumor volume with high SER was the only significant postchemotherapy covariate predictor (P = .038).
Conclusion: High-spatial-resolution SER imaging may improve prediction for patients at high risk for disease recurrence and death.
Supplemental material:
© RSNA, 2008
]]>Materials and Methods: This study was Institutional Review Board approved and Health Insurance Portability and Accountability Act compliant. Informed consent was obtained for participants who were not imaged as part of their clinical protocol but were participating in other Institutional Review Board–approved studies that used BSGI. A retrospective review of 146 women (aged 32–98 years) undergoing BSGI and breast biopsy was performed. Patients underwent BSGI with intravenous injection of 30 mCi (1110 MBq) of technetium 99 (99mTc)-sestamibi and were imaged in craniocaudal and mediolateral oblique projections. Study images were assigned scores, and scores were classified as positive (focal increased radiotracer uptake) or negative (no uptake or scattered heterogeneous physiologic uptake) and compared with biopsy results. The sensitivity, specificity, and positive and negative predictive values were determined.
Results: In 146 patients, 167 lesions underwent biopsy, of which 83 (16 ductal carcinoma in situ [DCIS] and 67 invasive cancers) were malignant. Of 84 nonmalignant lesions, 82 were benign and two showed atypical histologic results (one atypical lobular hyperplasia and one lobular carcinoma in situ). BSGI helped detect cancer in 80 of 83 malignant lesions with a sensitivity of 96.4% (95% confidence interval [CI]: 92%, 99%) and correctly identified 50 of 84 nonmalignant lesions as negative for cancer with a specificity of 59.5% (95% CI: 49%, 70%). The positive predictive value for 80 of 114 malignant lesions with a BSGI examination with findings positive for cancer was 68.8% (95% CI: 60%, 78%) and the negative predictive value for 50 of 53 nonmalignant lesions was 94.3% (95% CI: 88%, 99%). The smallest invasive cancer and DCIS detected were both 1 mm. BSGI helped detect occult cancer not visualized at mammography or ultrasonography in six patients.
Conclusion: BSIG has high sensitivity (96.4%) and moderate specificity (59.5%) helping detect breast cancers.
© RSNA, 2008
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