Amy Lynn Conners

JOURNAL CLUB: Molecular Breast Imaging at Reduced Radiation Dose for Supplemental Screening in Mammographically Dense Breasts

OBJECTIVE. The purpose of this study was to assess the diagnostic performance of supplemental screening molecular breast imaging (MBI) in women with mammographically dense breasts after system modifications to permit radiation dose reduction. SUBJECTS AND METHODS. A total of 1651 asymptomatic women with mammographically dense breasts on prior mammography underwent screening mammography and adjunct MBI performed with 300-MBq (99m)Tc-sestamibi and a direct-conversion (cadmium zinc telluride) gamma camera, both interpreted independently. The cancer detection rate, sensitivity, specificity, and positive predictive value of biopsies performed (PPV3) were determined. RESULTS. In 1585 participants with a complete reference standard, 21 were diagnosed with cancer: two detected by mammography only, 14 by MBI only, three by both modalities, and two by neither. Of 14 participants with cancers detected only by MBI, 11 had invasive disease (median size, 0.9 cm; range, 0.5-4.1 cm). Nine of 11 (82%) were node negative, and two had bilateral cancers. With the addition of MBI to mammography, the overall cancer detection rate (per 1000 screened) increased from 3.2 to 12.0 (p < 0.001) (supplemental yield 8.8). The invasive cancer detection rate increased from 1.9 to 8.8 (p < 0.001) (supplemental yield 6.9), a relative increase of 363%, while the change in DCIS detection was not statistically significant (from 1.3 to 3.2, p =0.250). For mammography alone, sensitivity was 24%; specificity, 89%; and PPV3, 25%. For the combination, sensitivity was 91% (p < 0.001); specificity, 83% (p < 0.001); and PPV3, 28% (p = 0.70). The recall rate increased from 11.0% with mammography alone to 17.6% (p < 0.001) for the combination; the biopsy rate increased from 1.3% for mammography alone to 4.2% (p < 0.001). CONCLUSION. When added to screening mammography, MBI performed using a radiopharmaceutical activity acceptable for screening (effective dose 2.4 mSv) yielded a supplemental cancer detection rate of 8.8 per 1000 women with mammographically dense breasts.

Gamma camera breast imaging lexicon

OBJECTIVE The standardized terminology and reporting structure of the BI-RADS for mammography, ultrasound, and MRI findings facilitates patient management. To date, no such terminology has been available for gamma camera breast imaging. We present an illustrated lexicon including description of background uptake, mass and nonmass uptake, lesion intensity, associated findings, and review of common artifacts. CONCLUSION This proposed lexicon should facilitate standardized interpretation, communication of results, and outcomes monitoring of examinations using dedicated devices for gamma camera breast imaging.

Diagnostic workup and costs of a single supplemental molecular breast imaging screen of mammographically dense breasts

OBJECTIVE The purpose of this study was to examine additional diagnostic workup and costs generated by addition of a single molecular breast imaging (MBI) examination to screening mammography for women with dense breasts. SUBJECTS AND METHODS Women with mammographically dense breasts presenting for screening mammography underwent adjunct MBI performed with 300 MBq (99m)Tc-sestamibi and a direct-conversion cadmium-zinc-telluride dual-head gamma camera. All subsequent imaging tests and biopsies were tracked for a minimum of 1 year. The positive predictive value of biopsies performed (PPV3), benign biopsy rate, cost per patient screened, and cost per cancer detected were determined. RESULTS A total of 1651 women enrolled in the study. Among the 1585 participants with complete reference standard, screening mammography alone prompted diagnostic workup of 175 (11.0%) patients and biopsy of 20 (1.3%) and yielded five malignancies (PPV3, 25%). Results of combined screening mammography plus MBI prompted diagnostic workup of 279 patients (17.6%) and biopsy of 67 (4.2%) and yielded 19 malignancies (PPV3, 28.4%). The benign biopsy rates were 0.9% (15 of 1585) for screening mammography alone and 3.0% (48 of 1585) for the combination (p < 0.001). The addition of MBI increased the cost per patient screened from

99mTc-sestamibi using a direct conversion molecular breast imaging system to assess tumor response to neoadjuvant chemotherapy in women with locally advanced breast cancer.

176 for mammography alone to

Background Parenchymal Uptake During Molecular Breast Imaging and Associated Clinical Factors

571 for the combination. However, cost per cancer detected was lower for the combination (

Radial scar/complex sclerosing lesions: a clinicopathologic correlation study from a single institution ☆ ☆☆

47,597) than for mammography alone (

Tumor Sequencing and Patient-Derived Xenografts in the Neoadjuvant Treatment of Breast Cancer

55,851). CONCLUSION The addition of MBI to screening mammography of women with dense breasts increased the overall costs and benign biopsy rate but also increased the cancer detection rate, which resulted in a lower cost per cancer detected than with screening mammography alone.

Direct-Conversion Molecular Breast Imaging of Invasive Breast Cancer: Imaging Features, Extent of Invasive Disease, and Comparison Between Invasive Ductal and Lobular Histology

Purpose The objective of this study was to determine the ability of breast imaging with 99mTc-sestamibi and a direct conversion–molecular breast imaging (MBI) system to predict early response to neoadjuvant chemotherapy (NAC). Methods Patients undergoing NAC for breast cancer were imaged with a direct conversion–MBI system before (baseline), at 3 to 5 weeks after onset, and after completion of NAC. Tumor size and tumor-to-background (T/B) uptake ratio measured from MBI images were compared with extent of residual disease at surgery using the residual cancer burden. Results Nineteen patients completed imaging and proceeded to surgical resection after NAC. Mean reduction in T/B ratio from baseline to 3 to 5 weeks for patients classified as RCB-0 (no residual disease), RCB-1 and RCB-2 combined, and RCB-3 (extensive residual disease) was 56% (SD, 0.20), 28% (SD, 0.20), and 4% (SD, 0.15), respectively. The reduction in the RCB-0 group was significantly greater than in RCB-1/2 (P = 0.036) and RCB-3 (P = 0.001) groups. The area under the receiver operator characteristic curve for determining the presence or absence of residual disease was 0.88. Using a threshold of 50% reduction in T/B ratio at 3 to 5 weeks, MBI predicted presence of residual disease at surgery with a diagnostic accuracy of 89.5% (95% confidence interval [CI], 0.64%–0.99%), sensitivity of 92.3% (95% CI, 0.74%–0.99%), and specificity of 83.3% (95% CI, 0.44%–0.99%). The reduction in tumor size at 3 to 5 weeks was not statistically different between RCB groups. Conclusions Changes in T/B ratio on MBI images performed at 3 to 5 weeks following initiation of NAC were accurate at predicting the presence or absence of residual disease at NAC completion.

Performance characteristics of dedicated molecular breast imaging systems at low doses.

OBJECTIVE. The purposes of this study were to describe the prevalence of background parenchymal uptake categories observed at screening molecular breast imaging (MBI) and to examine the association of background parenchymal uptake with mammographic density and other clinical factors. MATERIALS AND METHODS. Adjunct MBI screening was performed for women with dense breasts on previous mammograms. Two radiologists reviewed images from the MBI examinations and subjectively categorized background parenchymal uptake into four groups: photopenic, minimal-mild, moderate, or marked. Women with breast implants or a personal history of breast cancer were excluded. The association between background parenchymal uptake categories and patient characteristics was examined with Kruskal-Wallis and chi-square tests as appropriate. RESULTS. In 1149 eligible participants, background parenchymal uptake was photopenic in 252 (22%), minimal-mild in 728 (63%), and moderate or marked in 169 (15%). The distribution of categories differed across BI-RADS density categories (p < 0.0001). In 164 participants with extremely dense breasts, background parenchymal uptake was photopenic in 72 (44%), minimal-mild in 55 (34%), and moderate or marked in 37 (22%). The moderate-marked group was younger on average, more likely to be premenopausal or perimenopausal, and more likely to be using postmenopausal hormone therapy than the photopenic or minimal-mild groups (p < 0.0001). CONCLUSION. Among women with similar-appearing mammographic density, background parenchymal uptake ranged from photopenic to marked. Background parenchymal uptake was associated with menopausal status and postmenopausal hormone therapy but not with premenopausal hormonal contraceptives, phase of menstrual cycle, or Gail model 5-year risk of breast cancer. Additional work is necessary to fully characterize the underlying cause of background parenchymal uptake and determine its utility in predicting subsequent risk of breast cancer.

Factors Influencing the Uptake of 99mTc-Sestamibi in Breast Tissue on Molecular Breast Imaging

Radial scars (RSs) or complex sclerosing lesions (CSLs) of the breast are benign radiologic and histologic entities. With the introduction of population-based screening programs, their incidence has increased to 0.03% to 0.09% of all core needle biopsies (CNBs). They can pose diagnostic difficulty because their radiologic and histologic appearances mimic carcinoma. We retrospectively searched for and reviewed all cases of RS/CSL diagnosed on image-guided CNB from January 1, 1994, to August 31, 2013, at a single institution. We also assessed the pathologic reports from excisional biopsies to identify cases upstaged to atypia or neoplasm. After exclusions, 100 CNBs were identified from 97 women, which showed RS/CSL without concomitant atypia. Mean age of the women was 52.9 years. Thirty-five women (38/100 CNBs, 38%) had follow-up excision. The median size of the excised RS/CSLs was 1.2 cm; 69% were larger than 1.0 cm. Almost all excised cases (92%) showed radiologic and pathologic concordance, and 79% were designated as suspicious for malignancy (Breast Imaging Reporting and Data System level 4). The most common findings of 38 follow-up excisional biopsies were residual RS (22 [58%]), atypical lobular hyperplasia (5 [13%]), and no residual lesion (5 [13%]). Eleven excisional biopsies (29%) were upstaged to invasive or in situ carcinoma or to atypical hyperplasia. Follow-up excisional biopsy is warranted for RS/CSLs, specifically those larger than 1.0 cm with worrisome radiographic findings or with radiologic and pathologic discordance. Approximately 29% of cases were upstaged to in situ or invasive carcinomas or other high-risk lesions in our study.