Comparative Diagnostic Utility of Low-Dose Breast-Specific Gamma Imaging to Current Clinical Standard.

To retrospectively compare low-dose (7-10 mCi) to high-dose (15-30 mCi) breast-specific gamma imaging (BSGI) in the detection of breast cancer. A retrospective review of 223 consecutive women who underwent BSGI exam between February 2011 and August 2013 with subsequent pathologic analysis was performed. Women were divided into low-dose and high-dose groups. The results of BSGI and pathology were compared, and the sensitivity, positive predictive value (PPV), and negative predictive value (NPV) were determined. A subgroup analysis was performed to evaluate specificity using benign follow-up imaging to establish true-negative results. There were 223 women who met inclusion criteria with 109 patients with 153 lesions in the low-dose group and 114 patients with 145 lesions in the high-dose group. Pathologic correlation demonstrates sensitivities of 97.6% (95% CI = 90.9-99.6%) and 94.6% (95% CI = 84.2-98.6%; p = 0.093), PPVs of 62.1% (95% CI = 53.2-70.3%) and 50.5% (95% CI = 40.6-60.3%, p = 0.089), and NPVs of 90.5% (95% CI = 68.2-98.3%) and 92.5% (95% CI = 78.5-98.0%, p = 0.781) in the low-dose and high-dose groups, respectively. Subgroup analysis included 72 patients with 98 lesions in the low-dose group and 116 patients with 132 lesions in the high-dose group, with a specificity of 53.7% (95% CI = 39.7-67.1%) and 66.3% (95% CI = 56.2-75.2%%, p = 0.143), respectively. Low-dose BSGI demonstrated high sensitivity and NPV in the detection of breast cancer comparable to the current standard dose BSGI, with moderate specificity and PPV in a limited subgroup analysis, which was associated with a substantial number of false-positives.

Assessing improvement in detection of breast cancer with three-dimensional automated breast US in women with dense breast tissue: the SomoInsight Study.

PURPOSE: To determine improvement in breast cancer detection by using supplemental three-dimensional (3D) automated breast (AB) ultrasonography (US) with screening mammography versus screening mammography alone in asymptomatic women with dense breasts. MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained for this HIPAA-compliant study. The SomoInsight Study was an observational, multicenter study conducted between 2009 and 2011. A total of 15 318 women (mean age, 53.3 years ± 10 [standard deviation]; range, 25-94 years) presenting for screening mammography alone with heterogeneously (50%-75%) or extremely (>75%) dense breasts were included, regardless of further risk characterization, and were followed up for 1 year. Participants underwent screening mammography alone followed by an AB US examination; results were interpreted sequentially. McNemar test was used to assess differences in cancer detection. RESULTS: Breast cancer was diagnosed at screening in 112 women: 82 with screening mammography and an additional 30 with AB US. Addition of AB US to screening mammography yielded an additional 1.9 detected cancers per 1000 women screened (95% confidence interval [CI]: 1.2, 2.7; P < .001). Of cancers detected with screening mammography, 62.2% (51 of 82) were invasive versus 93.3% (28 of 30) of additional cancers detected with AB US (P = .001). Of the 82 cancers detected with either screening mammography alone or the combined read, 17 were detected with screening mammography alone. Of these, 64.7% (11 of 17) were ductal carcinoma in situ versus 6.7% (two of 30) of cancers detected with AB US alone. Sensitivity for the combined read increased by 26.7% (95% CI: 18.3%, 35.1%); the increase in the recall rate per 1000 women screened was 284.9 (95% CI: 278.0, 292.2; P < .001). CONCLUSION: Addition of AB US to screening mammography in a generalizable cohort of women with dense breasts increased the cancer detection yield of clinically important cancers, but it also increased the number of false-positive results.

Screening breast ultrasound: past, present, and future.

OBJECTIVE. This article discusses breast ultrasound for the detection of breast cancer in the screening environment, as well as strategies for integrating screening breast ultrasound, including automated breast ultrasound. CONCLUSION. Breast density is an increasingly pertinent issue in breast cancer diagnosis. Breast density results in a decrease in the sensitivity of mammography for cancer detection, with a significant increase in the risk of breast cancer. Ultrasound detects additional cancers.

Breast-specific gamma imaging for the detection of breast cancer in dense versus nondense breasts.

OBJECTIVE: The purpose of this study was to evaluate the sensitivity of breast-specific gamma imaging (BSGI) for the detection of breast cancer in dense versus nondense breasts. MATERIALS AND METHODS: This was a retrospective study of 341 women with biopsy-proven breast cancer diagnosed from January 2004 to August 2009 who underwent BSGI before surgical excision. Patients with predominantly fatty replaced (BI-RADS density 1) or scattered fibroglandular tissue (BI-RADS density 2) breasts were classified as nondense, and those with heterogeneously dense (BI-RADS density 3) or extremely dense tissue (BIRADS density 4) were classified as dense. BSGI examinations exhibiting focal increased radiotracer uptake in the area of biopsy-proven cancer were classified as positive according to BSGI reports in the medical record. The sensitivity of BSGI was calculated using Microsoft Excel 2003. Between-group differences were evaluated statistically using the Student t test for continuous variables and the chi-square test for categoric variables, with p < 0.05 considered statistically significant. RESULTS: The overall sensitivity of BSGI for breast cancer detection was 95.4%. Positive BSGI examinations were present in 136 of 142 nondense breast cancers and 195 of 205 dense breast cancers, for sensitivities of 95.8% and 95.1%, respectively. There was no significant difference in BSGI breast cancer detection and parenchymal breast density (p = 0.459). CONCLUSION: BSGI has high sensitivities for the detection of breast cancer in women with dense and nondense breasts and is an effective adjunct imaging modality in women with both dense and nondense breasts.

Breast-specific gamma imaging influences surgical management in patients with breast cancer.

Breast-specific gamma imaging (BSGI) is a physiologic breast imaging modality that provides more sensitive detection of breast lesions than mammography or ultrasound, and appears to have greater specificity than breast MRI. The purpose of this study was to evaluate how often BSGI changed surgical management in patients with breast cancer. Charts were reviewed from 218 consecutive eligible patients who had preoperative evaluation with BSGI or MRI before surgery for breast cancer from January 2008 to May 2010. Patients who were initially considered eligible for breast-conserving therapy (BCT) were evaluated to determine how many ultimately had mastectomies. Patients who underwent mastectomy because of personal choice or ineligibility for BCT were excluded. Management was changed to mastectomy in 11.9% of those who had BSGI and 28.9% of those who had MRI. Review of pathology demonstrated that all patients who underwent mastectomies were not candidates for breast conservation. 15.4% of patients who underwent BCT based on BSGI findings required a single re-excision due to positive surgical margins. 14.4% required mastectomy. In the MRI group, 18.8% required a single re-excision, and 6.3% required mastectomy. Evaluation with BSGI changed management to mastectomy in a substantial proportion of patients believed to be eligible for BCT following standard imaging. BSGI is effective in evaluation of extent of disease in patients with breast cancer, and is comparable to MRI in terms of its influence on surgical management.

Full-field digital mammographic interpretation with prior analog versus prior digitized analog mammography: time for interpretation.

OBJECTIVE: The purpose of our study was to quantitatively compare the time for interpretation of screening full-field digital mammography (FFDM) images using prior analog film mammograms for comparison versus digitized prior analog mammograms. MATERIALS AND METHODS: Images from 100 FFDM studies were interpreted by four radiologists. All FFDM images had comparison analog mammograms obtained a minimum of 1 year earlier that were digitized using a 43-µm film digitizer. Initially, the FFDM images were interpreted using the digitized prior mammogram on two, 5-megapixel monitors and PACS. All available PACS tools could be used. Four weeks later, the same 100 screening FFDMs were interpreted using the original analog mammograms on an alternator at 90° to the monitors used to interpret the screening FFDMs. The interpretation times were recorded and compared. The results were compared and evaluated for statistical significance using statistical software, with statistical significance set at p < 0.05. RESULTS: For each radiologist, the mean reading time for FFDM with digitized priors was significantly shorter in length in comparison with the mean reading time calculated for interpreting FFDM using analog film priors. The differences in times recorded between digitized analog versus analog ranged from 11.31 to 74.18 seconds. The reading times for the four readers ranged from 17.32 to 185.94 seconds, with a mean of 58.56 seconds when using analog film prior mammograms. When using digitized analog prior mammograms, the reading times for the four readers ranged from 11.32 to 109.11 seconds with a mean of 39.76 seconds. The average difference in reading time was calculated to be 18.80 seconds, showing that there is a 32% increase in interpretation speed when using a digitized prior analog for comparison studies as opposed to an analog prior. CONCLUSION: There is a statistically significant 32.1% average improvement in interpretation time when FFDM screening mammograms use digitized analog comparison mammograms than if FFDM is interpreted with the original analog film mammograms. This should allow more FFDMs to be interpreted in the same amount of time if digitized prior analog mammograms are used.

Factors associated with re-excision in patients with early-stage breast cancer treated with breast conservation therapy.

One of the risks of breast conservation surgery is local recurrence, which predominantly occurs as a result of inadequate surgical margins. The purpose of this study was to identify factors associated with close or positive surgical margins leading to reexcision (RE). The charts of 532 consecutive breast cancer patients treated at our center between September 2001 and June 2007 were reviewed to evaluate patients who opted for breast conservation surgery and needed reexcision. A total of 351 patients were treated with breast conservation, of which 118 (34%) had positive or close surgical margins and went on to RE. On univariate analysis, factors that significantly correlated with RE (P < 0.05) were preoperative diagnosis, final pathology, size of tumor, and presentation with nipple discharge. RE was necessary in 53 per cent of patients with a preoperative diagnosis of ductal carcinoma in situ (DCIS), 57 per cent of patients diagnosed by surgical excision, 86 per cent of patients presenting with nipple discharge, and 87 per cent of patients with DCIS or invasive carcinoma with extensive intraductal component in the final pathology. Additionally, 53 per cent of patients with T3 tumors required RE. Age, race, and grade of tumor had no effect on RE rates. Most (75%) patients were able to ultimately have breast conservation.

Breast-specific gamma imaging in the detection of atypical ductal hyperplasia and lobular neoplasia.

RATIONALE AND OBJECTIVES: Atypical lesions such as atypical ductal hyperplasia (ADH) and lobular neoplasia are nonmalignant lesions that are associated with significant increased risk of developing breast cancer. Atypical lesions have been reported to present with focal increased radiotracer uptake on breast-specific gamma imaging (BSGI) examination, a novel physiologic tool for the detection of breast cancer. To date the sensitivity of BSGI in the detection of atypical lesions has not been reported. The purpose of this study is to determine the sensitivity of BSGI in detecting ADH and lobular neoplasia. MATERIALS AND METHODS: A total of 1316 patients who received a BSGI exam between January 2006 and July 2009 were retrospectively reviewed. All patients who underwent minimally invasive biopsy and subsequent surgical excision where the highest pathology was solely ADH or lobular neoplasia (reported as ALH, lobular carcinoma in situ or lobular neoplasia), according to the pathology database were included (n = 15). The sensitivity was determined as the percentage of positive BSGI exams out of all patients diagnosed with ADH or lobular neoplasia who received a BSGI. RESULTS: Patient ages ranged from 39 to 67 (mean, 52). Eight of 15 patients had ADH, 6/15 lobular neoplasia, and 1/15 ADH and lobular neoplasia in one lesion. Fifteen of the 15 (100%) patients with surgically confirmed ADH or lobular neoplasia had a positive BSGI, with focally increased radiotracer uptake at the site of the verified high-risk lesion. CONCLUSION: BSGI has a high sensitivity for the detection of atypical, high-risk breast lesions. A diagnosis of an atypical lesion is concordant with focal increased radiotracer uptake with BSGI and can identify women at increased risk for breast cancer.

Detection of occult foci of breast cancer using breast-specific gamma imaging in women with one mammographic or clinically suspicious breast lesion.

RATIONALE AND OBJECTIVES: The aim of this study was to determine how often breast-specific gamma imaging (BSGI) identifies occult cancerous lesions in women with one suspicious lesion detected on mammography or physical exam. MATERIALS AND METHODS: A retrospective review was performed of the records of all patients who underwent BSGI between January 1, 2004, and June 4, 2007. Included in the study were 159 women who had one suspicious breast lesion on physical exam and/or mammography and who underwent BSGI to evaluate for occult lesions in the breast. All patients had one or more foci of cancer proven pathologically. BSGI findings were classified as normal or abnormal on the basis of the presence of focal radiotracer uptake. RESULTS: BSGI detected additional suspicious lesions occult to mammography and physical exam in 46 of 159 women (29%). BSGI identified occult cancer in 14 of 40 women (35%) who underwent biopsy or excision because of BSGI findings and in 14 of the 159 (9%) women in this study. In nine women, the occult cancer was present in the same breast as the index lesion (6%), and in five women, the occult cancer was found in the contralateral breast (3%). CONCLUSIONS: BSGI is an effective imaging modality in the identification of mammographically and clinically occult cancer in women with one suspicious breast lesion.