Gamma Imaging-Guided Minimally Invasive Breast Biopsy: Initial Clinical Experience.

OBJECTIVE: The purpose of this study was to evaluate our initial experience with gamma imaging-guided vacuum-assisted breast biopsy in women with abnormal findings. MATERIALS AND METHODS: A retrospective review of patients undergoing breast-specific gamma imaging (BSGI), also known as molecular breast imaging (MBI), between April 2011 and October 2015 found 117 nonpalpable mammographically and sonographically occult lesions for which gamma imaging-guided biopsies were recommended. Biopsy was performed with a 9-gauge vacuum-assisted device with subsequent placement of a titanium biopsy site marker. Medical records and pathologic findings were evaluated. RESULTS: Of the 117 biopsies recommended, 104 were successful and 13 were canceled. Of the 104 performed biopsies, 32 (30.8%) had abnormal pathologic findings. Of those 32 biopsies, nine (28.1%) found invasive cancers, six (18.8%) found ductal carcinoma in situ (DCIS), and 17 (53.1%) found high-risk lesions. Of the 17 high-risk lesions, there were three (17.6%) lobular carcinomas in situ, five (29.4%) atypical ductal hyperplasias, two (11.8%) atypical lobular hyperplasias, one (5.9%) flat epithelial atypia, and six (35.3%) papillomas. Two cases of atypical ductal hyperplasia were upgraded to DCIS at surgery. The overall cancer detection rate for gamma imaging-guided biopsy was 16.3%. In this study, gamma imaging-guided biopsy had a positive predictive value of total successful biopsies of 16.3% for cancer and 30.8% for cancer and high-risk lesions. CONCLUSION: Gamma imaging-guided biopsy is a viable approach to sampling BSGI-MBI-detected lesions without sonographic or mammographic correlate. Our results compare favorably to those reported for MRI-guided biopsy.

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.

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.

Invasive lobular carcinoma: detection with mammography, sonography, MRI, and breast-specific gamma imaging.

OBJECTIVE: The objective of our study was to compare the sensitivity of mammography, sonography, MRI, and breast-specific gamma imaging (BSGI) in the detection of invasive lobular carcinoma. MATERIALS AND METHODS: This is a retrospective multicenter study of women with biopsy-proven invasive lobular carcinoma. All patients had undergone mammography and BSGI, and the imaging findings were classified as positive or negative for invasive lobular carcinoma by experienced breast imagers. The results of MRI and sonography, if either was performed, were included. Final surgical pathology results were used as the reference standard and the lesion sensitivities of BSGI, mammography, sonography, and MRI were then statistically compared using CIs. RESULTS: Twenty-six women ranging in age from 46 to 82 years (mean age, 62.8 years) with a total of 28 biopsy-proven invasive lobular carcinomas were included in the study group. Mammograms were negative in six of 28 (21%), yielding a sensitivity of 79%. In the 25 patients who underwent sonography, 17 had focal hypoechoic areas, yielding a sensitivity of 68%. In the 12 patients who underwent MRI, the sensitivity was 83%. BSGI had a sensitivity of 93%. There was no statistically significant difference in the sensitivity of BSGI, MRI, sonography, or mammography, although there was a nonsignificant trend toward improved detection with BSGI. CONCLUSION: BSGI has the highest sensitivity for the detection of invasive lobular carcinoma with a sensitivity of 93%, whereas mammography, sonography, and MRI showed sensitivities of 79%, 68%, and 83%, respectively. BSGI is an effective technique that should be used to evaluate patients with suspected cancer and has a promising role in the diagnosis of invasive lobular carcinoma.

Quantification of radio-tracer uptake in axillary lymph nodes using breast specific gamma imaging (BSGI): benign radio-tracer extravasation versus uptake secondary to breast cancer.

To develop a means of quantifying axillary radio-tracer uptake in patients undergoing breast specific gamma imaging. This may help differentiate uptake secondary to extravasation of the radio-tracer at the injection from increased uptake as a result of breast cancer metastatic to lymph nodes. A retrospective analysis of patients who had undergone breast specific gamma imaging was performed. Scans from 26 patients showing increased axillary uptake of radio-tracer were identified from 939 patients reviewed. Eighteen of these patients had increased axillary uptake ipsilateral to the side of tracer injection in the absence of breast cancer on that side. Of these 18 cases, eight patients had pathologic proven axillary metastatic disease with increased axillary uptake contralateral to the side of tracer injection. The maximum signal intensity for each region of increased radio-tracer uptake was measured using the net maximum uptake per region of interest and the two groups of patients were compared. Statistical significance was determined using a two-tailed p-value and 95% confidence intervals were considered statistically significant. The calculated means of the "net maximum uptake per region of interest" in the subjects with increased radio-tracer uptake secondary to radio-tracer extravasation and metastatic breast cancer were 177.89 and 117.25, respectively. Comparison of the means yielded a two-tailed p-value of 0.0498, which is statistically significant. There is a statistically significant greater intensity of axillary radio-tracer uptake when the uptake occurs secondary to extravasation when compared with metastases to axillary lymph nodes.

Breast-specific gamma imaging as an adjunct imaging modality for the diagnosis of breast cancer.

PURPOSE: To retrospectively determine the sensitivity and specificity of breast-specific gamma imaging (BSGI) for the detection of breast cancer by using pathologic results as the reference standard. 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 ((99m)Tc)-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.

Lobular neoplasia at percutaneous breast biopsy: variables associated with carcinoma at surgical excision.

OBJECTIVE: The purpose of our study was to better define the rate and variables associated with cancer underestimation when lobular neoplasia is found at minimally invasive breast biopsy. MATERIALS AND METHODS: The records of 32,420 patients who underwent imaging-guided needle biopsy of the breast for mammographic or sonographic abnormalities from 1988 to 2000 were retrospectively reviewed. The 278 cases in which lobular neoplasia was the highest-risk lesion at biopsy were included. Of the 278 cases, 164 proceeded to surgical excision, allowing calculation of rates of underestimation from minimally invasive biopsy. RESULTS: Of the 32,420 minimally invasive breast biopsies, lobular neoplasia was found in 278 (0.9%). One hundred sixty-four of the 278 (59%) continued to surgical excision, where cancer was pathologically confirmed in 38 (23%). No difference was seen in the underestimation rates for lesions diagnosed as lobular carcinoma in situ (25%, 17 of 67 lesions) versus atypical lobular hyperplasia (22%, 21 of 97 lesions). Statistically significant underestimation of carcinoma was found with biopsy of masses (with or without associated microcalcifications) rather than calcifications only, a higher BI-RADS category (p < 0.0001), use of a core biopsy device rather than a vacuum device (p < 0.01), and obtaining fewer specimens (p < 0.0001). CONCLUSION: Significant sampling error occurs regardless of the type of core biopsy device, number of specimens obtained, histologic-radiographic concordance, mammographic appearance, and complete excision of the lesion as determined by imaging. For this reason, all patients with lobular neoplasia at core or vacuum-assisted biopsy should undergo surgical excision until further differentiating criteria can be determined.

Detection of ductal carcinoma in situ with mammography, breast specific gamma imaging, and magnetic resonance imaging: a comparative study.

RATIONALE AND OBJECTIVES: To evaluate the sensitivity of high-resolution breast-specific gamma imaging (BSGI) for the detection of ductal carcinoma in situ (DCIS) based on histopathology and to compare the sensitivity of BSGI with mammography and magnetic resonance imaging (MRI) for the detection of DCIS. MATERIALS AND METHODS: Twenty women, mean 55 years (range 34-76 years), with 22 biopsy-proven DCIS were retrospectively reviewed. After injection of 25-30 mCi (925-1,110 MBq) technetium 99m-sestamibi, patients had BSGI with a high-resolution, small-field-of-view gamma camera in craniocaudal and mediolateral oblique projections. BSGI studies were prospectively classified according to focal radiotracer uptake using a 1 to 5 scale, as normal 1), with no focal or diffuse uptake; benign 2), with minimal patchy uptake; probably benign 3), with scattered patchy uptake; probably abnormal 4), with mild focal radiotracer uptake; and abnormal 5), with marked focal radiotracer uptake. Imaging findings were compared to findings at biopsy or surgical excision. The sensitivity of BSGI, mammography, and when performed, MRI were determined for the detection of DCIS. Breast MRI was performed on seven patients with eight biopsy-proven foci. The sensitivities were compared using a two-tailed t-test and confidence intervals were determined. RESULTS: Pathologic tumor size of the DCIS ranged from 2 to 21 mm (mean 9.9 mm). Of 22 cases of biopsy-proven DCIS in 20 women, 91% were detected with BSGI, 82% were detected with mammography, and 88% were detected with magnetic resonance imaging. BSGI had the highest sensitivity for the detection of DCIS, although this small sample size did not demonstrate a statistically significant difference. Two cases of DCIS (9%) were diagnosed only after BSGI demonstrated an occult focus of radiotracer uptake in the contralateral breast, previously undetected by mammography. There were two false-negative BSGI studies CONCLUSIONS: BSGI has higher sensitivity for the detection of DCIS than mammography or MRI and can reliably detect small, subcentimeter lesions.

Breast-Specific γ-Imaging for the Detection of Mammographically Occult Breast Cancer in Women at Increased Risk.

UNLABELLED: Breast-specific γ-imaging (BSGI) is a physiologic imaging modality that can detect subcentimeter and mammographically occult breast cancer, with a sensitivity and specificity comparable to MRI. The purpose of this study was to determine the incremental increase in breast cancer detection when BSGI is used as an adjunct to mammography in women at increased risk for breast cancer. METHODS: All patients undergoing BSGI from April 2010 through January 2014 were retrospectively reviewed. Eligible patients were identified as women at increased risk for breast cancer and whose most recent mammogram was benign. Examinations exhibiting focally increased radiotracer uptake were considered positive. Incremental increase in cancer detection was calculated as the percentage of mammographically occult BSGI-detected breast cancer and the number of mammographically occult breast cancers detected per 1,000 women screened. RESULTS: Included in this study were 849 patients in whom 14 BSGI examinations detected mammographically occult breast cancer. Patients ranged in age from 26 to 83 y, with a mean age of 57 y. Eleven of 14 cancers were detected in women with dense breasts. The addition of BSGI to the annual breast screen of asymptomatic women at increased risk for breast cancer yields 16.5 cancers per 1,000 women screened. When high-risk lesions and cancers were combined, BSGI detected 33.0 high-risk lesions and cancers per 1,000 women screened. CONCLUSION: BSGI is a reliable adjunct modality to screening mammography that increases breast cancer detection by 1.7% (14/849) in women at increased risk for breast cancer, comparable to results reported for breast MRI. BSGI is beneficial in breast cancer detection in women at increased risk, particularly in those with dense breasts.

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.

Nonvisualization of a sentinel lymph node on lymphoscintigraphy requiring reinjection of sulfur colloid in a patient with breast cancer.

PURPOSE: The injection techniques and use of lymphoscintigraphy for sentinel lymph node (SLN) biopsy in breast cancer patients vary. Some do not advocate routine use of lymphoscintigraphy. The purpose of this case report is to illustrate when lymphoscintigraphy should be used. METHODS: At our institution, we use periareolar intradermal injections of 0.6 mCi Tc-99m sulfur colloid followed by lymphoscintigraphy with reported identification rates greater than 99%. The only patient in our series who did not have a SLN identified had presented after excisional biopsy of an upper outer quadrant cancer. We report the case of another patient who presented after excision of an upper outer quadrant invasive ductal carcinoma and had no evidence of lymphatic drainage on lymphoscintigraphy after the periareolar injections of radioisotope. RESULTS: Additional injections of 0.4 mCi Tc-99m sulfur colloid were performed lateral to the incision in the upper outer quadrant. On lymphoscintigraphy a SLN was visualized and was subsequently successfully identified intraoperatively. CONCLUSION: This case report supports the value of lymphoscintigraphy for successful identification of a SLN in a patient with prior surgery. We therefore recommend imaging patients who have had prior breast surgery, particularly excisions in the upper outer quadrant.

Breast-specific gamma imaging with 99mTc-Sestamibi and magnetic resonance imaging in the diagnosis of breast cancer--a comparative study.

The purpose of this study was to compare the sensitivity and specificity of breast-specific gamma imaging (BSGI) using a high-resolution breast-specific gamma camera and magnetic resonance imaging (MRI) in patients with indeterminate breast findings. Twenty-three women with an indeterminate breast finding that required BSGI and MRI as deemed necessary by the interpreting radiologist or referring physician were included. MRI was performed on a GE 1.5T scanner and BSGI was performed on a Dilon high-resolution breast-specific gamma camera. All imaging findings were correlated with pathologic diagnosis. Thirty-three indeterminate lesions were evaluated in the study. There were a total of nine pathologically confirmed cancers. There was no statistically significant difference in sensitivity of cancer detection between BSGI and MRI. BSGI demonstrated a greater specificity than MRI, 71% and 25%, respectively. BSGI has equal sensitivity and greater specificity than MRI for the detection of breast cancer.

Evaluation of breast cancer with a computer-aided detection system by mammographic appearance and histopathology.

BACKGROUND: The objective of this study was to evaluate the performance of a computer-aided detection (CAD) system for the detection of breast cancer, based on mammographic appearance and histopathology. METHODS: From 1000 consecutive screening mammograms from women with biopsy-proven breast carcinoma, 273 mammograms were selected randomly for retrospective evaluation by CAD. The sensitivity of the CAD system for breast cancer was assessed from the proportion of masses and microcalcifications detected. The corresponding tumor histopathologies also were evaluated. Normal mammograms (n = 155 patients) were used to determine the false-positive rate of the system. RESULTS: Of the 273 breast carcinomas, 149 appeared mammographically as masses, and 88 appeared as microcalcifications, including 36 carcinomas that presented as mixed lesions. The CAD system marked 125 of 149 masses correctly (84%), marked 86 of 88 microcalcifications correctly (98%), and marked 32 of 36 of mixed lesions correctly (89%.). The system showed a high sensitivity for the detection of ductal carcinoma in situ (95%; 73 of 77 lesions), invasive lobular carcinoma (95%; 18 of 19 lesions), invasive ductal carcinoma (85%; 125 of 147 lesions), and invasive mammary carcinoma (90%; 27 of 30 lesions). The highest CAD system sensitivity was for all invasive carcinomas that presented as microcalcifications (100%). On normal mammograms, there was an average of 1.3 false-positive CAD marks per image. CONCLUSIONS: The CAD system correctly marked a large majority of biopsy-proven breast cancers, with a greater sensitivity for lesions with microcalcifications and without significant impact of performance based on tumor histopathology. CAD was highly effective in detecting invasive lobular carcinoma (sensitivity, 95%) and ductal carcinoma in situ (sensitivity, 95%). CAD represents a useful tool for the detection of breast cancer.