Challenging Contrast-Enhanced Mammography-Guided Biopsies: Practical Approach Using Real-Time Multimodality Imaging and a Proposed Procedural Algorithm.

Contrast-enhanced mammography (CEM) is an emerging functional breast imaging technique that entails the acquisition of dual-energy digital mammographic images after IV administration of iodine-based contrast material. CEM-guided biopsy technology was introduced in 2019 and approved by the U.S. FDA in 2020. This technology's availability enables direct sampling of suspicious enhancement seen only on or predominantly on recombined CEM images and addresses a major obstacle to the clinical implementation of CEM technology. The literature describing clinical indications and procedural techniques of CEM-guided biopsy is scarce. This article describes our initial experience in performing challenging CEM-guided biopsies and proposes a step-by-step procedural algorithm designed to proactively address anticipated technical difficulties and thereby increase the likelihood of achieving successful targeting.

Contrast-Enhanced Mammography-Guided Breast Biopsy: Single-Center Experience.

This prospective single-center study enrolled 50 women with 51 contrast-enhanced mammography (CEM)-enhancing lesions that lacked a sonographic or mammographic correlate. Trial participants underwent CEM-guided biopsy. Biopsy was technically successful for 46 lesions and was not performed for five nonvisualized lesions (all nonmass enhancement), yielding a cancellation rate of 9.8%. Mean biopsy time was 16.6 minutes. All biopsies revealed concordant pathology (25 benign, 10 high-risk, 11 malignant). No non-visualized or benign lesion yielded malignancy at follow-up.

Current Status of Contrast Enhanced Mammography: A Comprehensive Review.

OBJECTIVES: The purpose of this article is to provide a detailed and updated review of the physics, techniques, indications, limitations, reporting, implementation and management of contrast enhanced mammography. BACKGROUND: Contrast enhanced mammography (CEM), is an emerging iodine-based modified dual energy mammography technique. In addition to having the same advantages as standard full-field digital mammography (FFDM), CEM provides information regarding tumor enhancement, relying on tumor angiogenesis, similar to dynamic contrast enhanced magnetic resonance imaging (DCE-MRI). This article reviews current literature on CEM and highlights considerations that are critical to the successful use of this modality. CONCLUSION: Multiple studies point to the advantage of using CEM in the diagnostic setting of breast imaging, which approaches that of DCE-MRI.

The Effect of Registration on Voxel-Wise Tofts Model Parameters and Uncertainties from DCE-MRI of Early-Stage Breast Cancer Patients Using 3DSlicer.

We quantitatively investigate the influence of image registration, using open-source software (3DSlicer), on kinetic analysis (Tofts model) of dynamic contrast enhanced MRI of early-stage breast cancer patients. We also show that registration computation time can be reduced by reducing the percent sampling (PS) of voxels used for estimation of the cost function. DCE-MRI breast images were acquired on a 3T-PET/MRI system in 13 patients with early-stage breast cancer who were scanned in a prone radiotherapy position. Images were registered using a BSpline transformation with a 2 cm isotropic grid at 100, 20, 5, 1, and 0.5PS (BRAINSFit in 3DSlicer). Signal enhancement curves were analyzed voxel-by-voxel using the Tofts kinetic model. Comparing unregistered with registered groups, we found a significant change in the 90th percentile of the voxel-wise distribution of Ktrans. We also found a significant reduction in the following: (1) in the standard error (uncertainty) of the parameter value estimation, (2) the number of voxel fits providing unphysical values for the extracellular-extravascular volume fraction (ve > 1), and (3) goodness of fit. We found no significant differences in the median of parameter value distributions (Ktrans, ve) between unregistered and registered images. Differences between parameters and uncertainties obtained using 100PS versus 20PS were small and statistically insignificant. As such, computation time can be reduced by a factor of 2, on average, by using 20PS while not affecting the kinetic fit. The methods outlined here are important for studies including a large number of post-contrast images or number of patient images.

A Single-Institute Experience With Radioactive Seed Localization of Breast Lesions-A Retrospective Study.

OBJECTIVES: To assess the benefits associated with radioactive seed localization (RSL) in comparison to conventional wire localization (WL) for nonpalpable breast lesions. METHODS: Radioactive seed localization was initiated at our institution in July 2013. Retrospective review of all WL performed between June 2012 and July 2013 (2013) and all RSL performed during June 2015 and July 2016 (2016). Patients who received neoadjuvant therapy or did not undergo their planned surgeries and WL performed in 2016 were excluded. The following data were collected: final pathology, resection margins for malignant lesions, time to surgery, seed migration, and number of localized lumpectomies performed by each surgeon. RESULTS: A total of 292 WL procedures (288 women) in 2013 and 194 RSL procedures (186 women) in 2016 were eligible for the study. All WLs were inserted the day of surgery. Mean time from RSL insertion to surgery was 4.0 ± 2.8 days (range: 1-17 days). There was no difference in specimen size for malignant lesions (6.8 ± 2.8 cm for WL and 6.9 ± 2.9 cm for RSL; P = .5). Specimen radiographs were obtained in 233 (80%) of 292 WL compared to 194 (100%) of 194 RSL (P < .001). For malignant lesions, positive margins were present in 34 (17.2%) of 198 with WL compared to 15 (10.3%) of 146 with RSL (P < .001). Close margins (≤1 mm) were present in 31 (15.6%) of 198 with WL compared to 1 (0.6%) of 146 with RSL (P < .001). The seed fell out of the specimen during surgery in 6 (3.1%) of 194. No seed loss was recorded. The surgeons (n = 4) who transitioned to RSL increased the number of surgeries per month from a mean of 4.4 ± 2.6 in 2013 to 6.9 ± 3.5 in 2016, equivalent to a 41% increase (P = .003). CONCLUSIONS: The use of RSL, as compared to conventional WL, resulted in a reduction in the number of pathologically involved surgical margins and was associated with an increased number of surgeries. Furthermore, RSL can be performed up to 14 days prior to surgery, which may improve scheduling flexibility in the radiology department.

COVID-19: Safe Guidelines for Breast Imaging During the Pandemic.

During the COVID-19 pandemic, breast imaging must be performed using safe practices. Balancing the need to avoid delays in the diagnosis of breast cancer while avoiding infection requires careful attention to personal protective equipment and physical distancing and vigilance to maintain these practices. The Canadian Society of Breast Imaging/Canadian Association of Radiologists guideline for breast imaging during COVID-19 is provided based on priority according to risk of breast cancer and impact of delaying treatment. A review of the best practices is presented that allow breast imaging during COVID-19 to maximize protection of patients, technologists, residents, fellows, and radiologists and minimize spread of the infection. The collateral damage of delaying diagnosis of breast cancer due to COVID-19 should be avoided when possible.

New Palpable Breast Lump With Recent Negative Mammogram: Is Repeat Mammography Necessary?

OBJECTIVE: The purpose of this article is to determine the utility of repeat mammography, compared with targeted ultrasound and previous mammogram, in the assessment of an interval palpable breast lump found within 1 year after a negative mammogram study. MATERIALS AND METHODS: Women who were examined for a new palpable lump with mammography and targeted ultrasound between January 2005 and December 2012, who also had a negative mammogram within the previous 6-12 months, were included. The following data were collected: age, mammographic findings, change from previous mammogram, ultrasound findings, BI-RADS category, and biopsy results. RESULTS: A total of 618 palpable lumps in 612 women (mean [± SD] age, 55.9 ± 11.2 years) were included in this study. In 314 of 618 cases (50.8%), a sonographic finding or mammographic change, or both was detected in the region of the palpable lump. Ultrasound detected a finding in 311 cases (50.3%), whereas repeat mammography detected a change in only 80 (12.9%) cases (p < 0.001). Of the 314 cases with imaging findings, 234 findings (74.5%) were detected by ultrasound alone. Repeat mammography identified a more prominent focal asymmetry in the palpable region in three cases with no sonographic correlate; none had malignancy. Eighty lesions were biopsied, and 48 (60.0%) of them were positive for malignancy. The repeat mammogram findings were unchanged for 10 of these lesions. CONCLUSION: Interval palpable breast lumps should be evaluated with targeted ultrasound. Mammography does not appear to add value beyond sonography performed by trained ultrasound technologists and should not be routinely performed.

Enhanced full-inversion-based ultrasound elastography for evaluating tumor response to neoadjuvant chemotherapy in patients with locally advanced breast cancer.

PURPOSE: An enhanced ultrasound elastography technique is proposed for early assessment of locally advanced breast cancer (LABC) response to neoadjuvant chemotherapy (NAC). METHODS: The proposed elastography technique inputs ultrasound radiofrequency data obtained through tissue quasi-static stimulation and adapts a strain refinement algorithm formulated based on fundamental principles of continuum mechanics, coupled with an iterative inverse finite element method to reconstruct the breast Young's modulus (E) images. The technique was explored for therapy response assessment using data acquired from 25 LABC patients before and at weeks 1, 2, and 4 after the NAC initiation (100 scans). The E ratio of tumor to the surrounding tissue was calculated at different scans and compared to the baseline for each patient. Patients' response to NAC was determined many months later using standard clinical and histopathological criteria. RESULTS: Reconstructed E ratio changes obtained as early as one week after the NAC onset demonstrate very good separation between the two cohorts of responders and non-responders to NAC. Statistically significant differences were observed in the E ratio changes between the two patient cohorts at weeks 1 to 4 after treatment (p-value < 0.001; statistical power greater than 97%). A significant difference in axial strain ratio changes was observed only at week 4 (p-value = 0.01; statistical power = 76%). No significant difference was observed in tumor size changes at weeks 1, 2 or 4. CONCLUSION: The proposed elastography technique demonstrates a high potential for chemotherapy response monitoring in LABC patients and superior performance compared to strain imaging.

Contrast-Enhanced Mammography in the Diagnosis of Breast Angiosarcoma.

A 60-year-old female presented for further assessment of a new right breast lump (November 2020). She had a history of a stage I (T1bN0M0) right breast invasive mammary carcinoma, grade 2 (score 7/9) with receptors ER/PR-negative, HER2/neu-positive, diagnosed four years prior to her current presentation. At that time, she was treated with a right breast lumpectomy and local radiation. Breast assessment with contrast-enhanced mammography showed new skin thickening with associated enhancement within the palpable region. Histology of subsequent ultrasound-guided biopsy found radiation-induced breast angiosarcoma. Breast angiosarcoma is a rare entity that represents less than 1% of all breast cancers. To our knowledge, this is the first case describing the imaging findings of breast angiosarcoma on contrast-enhanced mammography.

Management of the Axilla in Early-Stage Breast Cancer: Ontario Health (Cancer Care Ontario) and ASCO Guideline.

PURPOSE: To provide recommendations on the best strategies for the management and on the best timing and treatment (surgical and radiotherapeutic) of the axilla for patients with early-stage breast cancer. METHODS: Ontario Health (Cancer Care Ontario) and ASCO convened a Working Group and Expert Panel to develop evidence-based recommendations informed by a systematic review of the literature. RESULTS: This guideline endorsed two recommendations of the ASCO 2017 guideline for the use of sentinel lymph node biopsy in patients with early-stage breast cancer and expanded on that guideline with recommendations for radiotherapy interventions, timing of staging after neoadjuvant chemotherapy (NAC), and mapping modalities. Overall, the ASCO 2017 guideline, seven high-quality systematic reviews, 54 unique studies, and 65 corollary trials formed the evidentiary basis of this guideline. RECOMMENDATIONS: Recommendations are issued for each of the objectives of this guideline: (1) To determine which patients with early-stage breast cancer require axillary staging, (2) to determine whether any further axillary treatment is indicated for women with early-stage breast cancer who did not receive NAC and are sentinel lymph node-negative at diagnosis, (3) to determine which axillary strategy is indicated for women with early-stage breast cancer who did not receive NAC and are pathologically sentinel lymph node-positive at diagnosis (after a clinically node-negative presentation), (4) to determine what axillary treatment is indicated and what the best timing of axillary treatment for women with early-stage breast cancer is when NAC is used, and (5) to determine which are the best methods for identifying sentinel nodes.Additional information is available at www.asco.org/breast-cancer-guidelines.

Intrafraction motion monitoring to determine PTV margins in early stage breast cancer patients receiving neoadjuvant partial breast SABR.

BACKGROUND AND PURPOSE: To quantify intra-fraction tumor motion using imageguidance and implanted fiducial markers to determine if a 5 mm planning-target-volume (PTV) margin is sufficient for early stage breast cancer patients receiving neoadjuvant stereotactic ablative radiotherapy (SABR). MATERIALS AND METHODS: A HydroMark© (Mammotome) fiducial was implanted at the time of biopsy adjacent to the tumor. Sixty-one patients with 62 tumours were treated prone using a 5 mm PTV margin. Motion was quantified using two methods (separate patient groups): 1) difference in 3D fiducial position pre- and post-treatment cone-beam CTs (CBCTs) in 18 patients receiving 21 Gy/1fraction (fx); 2) acquiring 2D triggered-kVimages to quantify 3D intra-fraction motion using a 2D-to-3D estimation method for 44 tumours receiving 21 Gy/1fx (n = 22) or 30 Gy/3fx (n = 22). For 2), motion was quantified by calculating the magnitude of intra-fraction positional deviation from the pretreatment CBCT. PTV margins were derived using van Herkian analysis. RESULTS: The average ± standard deviation magnitude of motion across patients was 1.3 ± 1.15 mm Left/Right (L/R), 1.0 ± 0.9 mm Inferiorly/Superiorly (I/S), and 1.8 ± 1.5 mm Anteriorly/Posteriorly (A/P). 85/105 (81%) treatment fractions had dominant anterior motion. 6/62patients (9.7%) had mean intra-fraction motion during any fraction > 5 mm in any direction, with 4 in the anterior direction. Estimated PTV margins for single and three-fx patients in the L/R, I/S, and A/P directions were 6.0x4.1x5.9 mm and 4.5x2.9x4.3 mm, respectively. CONCLUSION: Our results suggest that a 5 mm PTV margin is sufficient for the I/S and A/P directions if a lateral kV image is acquired immediately before treatment. For the L/R direction, either further immobilization or a larger margin is required.

Lipid-weighted intraoperative photoacoustic tomography of breast tumors: Volumetric comparison to preoperative MRI.

With a lifetime risk of 1 in 8, breast cancer continues to be a major concern for women and their physicians. The optimal treatment of the disease depends on the stage of the cancer at diagnosis, which is typically assessed using medical imaging. However, currently employed imaging systems for breast tumor measurement rarely agree perfectly. Our group developed an Intraoperative Photoacoustic Screening (iPAS) soft tissue scanner featuring high bulk tissue sensitivity, a clinically compatible scan-time of 6 min, imaging depths greater than 2 cm and the capability to visualize whole breast tumors based on their lipid, rather than hemoglobin, profile. Here, we report on the first clinical experience with breast cancer patients by comparing tumor-measurement using iPAS, preoperative dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) and gold-standard pathology. Tumor size was measured volumetrically for iPAS and DCE-MRI, and separately using maximum diameters for pathology, DCE-MRI and iPAS. Comparisons were performed using Pearson's correlation coefficients, and the non-parametric Wilcoxon signed-rank test. Twelve consecutive patients were included in the study, contingent on pathologically documented invasive carcinoma. iPAS volumetric tumor size was positively correlated to DCE-MRI (Pearson's r = 0.78, p = 0.003) and not significantly different (Wilcoxon, p = 0.97). In comparison to pathology, tumor diameters given by iPAS were positively correlated (Pearson's r = 0.87, p = 0.0002) and significantly different (Wilcoxon, p = 0.0015). The results indicated that volumetric-measurement of invasive breast tumors with iPAS is similar to that of DCE-MRI. On the other hand, tumor diameter measurements were less reliable. Beyond enhancing surgical specimen examination, an extension of this technology to diagnostic imaging promises a new perspective on tumor assessment, potentially improving our current understanding and treatment of breast cancer.

DCE-MRI assessment of response to neoadjuvant SABR in early stage breast cancer: Comparisons of single versus three fraction schemes and two different imaging time delays post-SABR.

PURPOSE: To determine the effect of dose fractionation and time delay post-neoadjuvant stereotactic ablative radiotherapy (SABR) on dynamic contrast-enhanced (DCE)-MRI parameters in early stage breast cancer patients. MATERIALS AND METHODS: DCE-MRI was acquired in 17 patients pre- and post-SABR. Five patients were imaged 6-7 days post-21 Gy/1fraction (group 1), six 16-19 days post-21 Gy/1fraction (group 2), and six 16-18 days post-30 Gy/3 fractions every other day (group 3). DCE-MRI scans were performed using half the clinical dose of contrast agent. Changes in the surrounding tissue were quantified using a signal-enhancement threshold metric that characterizes changes in signal-enhancement volume (SEV). Tumour response was quantified using Ktrans and ve (Tofts model) pre- and post-SABR. Significance was assessed using a Wilcoxin signed-rank test. RESULTS: All group 1 and 4/6 group 2 patients' SEV increased post-SABR. All group 3 patients' SEV decreased. The mean Ktrans increased for group 1 by 76% (p = 0.043) while group 2 and 3 decreased 15% (p = 0.028) and 34% (p = 0.028), respectively. For ve, there was no significant change in Group 1 (p = 0.35). Groups 2 showed an increase of 24% (p = 0.043), and Group 3 trended toward an increase (23%, p = 0.08). CONCLUSION: Kinetic parameters measured 2.5 weeks post-SABR in both single fraction and three fraction groups were indicative of response but only the single fraction protocol led to enhancement in the surrounding tissue. Our results also suggest that DCE-MRI one-week post-SABR may be too early for response assessment, at least for single fraction SABR, whereas 2.5 weeks appears sufficiently long to minimize confounding acute effects.

Freehand versus guided breast biopsy: comparison of accuracy, needle motion, and biopsy time in a tissue model.

OBJECTIVE: Freehand ultrasound-guided breast biopsy may present difficulties in needle visualization within the scanning plane of the ultrasound image. Scanning plane and needle misalignment, an unknown needle insertion site (relative to the ultrasound image), needle trajectory before insertion, and physician experience play roles in the difficulty of these biopsy procedures. The objective of our study was to compare the currently used freehand technique with the use of a needle guidance system that limits needle motion to within the ultrasound scanning plane for breast biopsy. MATERIALS AND METHODS: We developed a needle guidance system for breast biopsy that is composed of an electronically tracked passive mechanical arm and braking mechanism. The system was attached to an ultrasound transducer, and biopsy needles were inserted through the guidance arm. Both experienced and inexperienced radiologists performed ultrasound-guided biopsy on simulated breast lesions with and without the guidance system. Success rates were scored on the basis of the presence of lesions in the core biopsy samples. The biopsy procedures were analyzed using procedure time and total needle tip travel distance before firing. RESULTS: The biopsy success rates were greater using the guidance system (p < 0.05) than using the freehand technique. Experienced radiologists and inexperienced radiologists performed biopsy significantly faster using the needle guidance system (p < 0.001). Additionally, needle tip motion was significantly greater when using the freehand technique (p < 0.001) than using the guidance system. CONCLUSION: Biopsy using the developed needle guidance system is feasible and its use decreases procedure time and decreases needle motion; thus, it has the potential to reduce patient morbidity. Moreover, less operator experience is required for a successful breast biopsy using the needle guidance system than using the freehand technique.

Proximal splenic artery embolization in the management of splenic rupture.

OBJECTIVE: To report the use of proximal splenic artery embolization for management of spontaneous splenic rupture. DESIGN: Case report and literature review. SETTING: A tertiary pediatric critical care unit in a university teaching hospital. INTERVENTIONS: Proximal splenic artery embolization. MEASUREMENTS AND MAIN RESULTS: An 8-yr-old boy presented with abdominal pain radiating to the left shoulder 9 days after completing induction chemotherapy for acute lymphoblastic leukemia. Imaging revealed a splenic rupture with parenchymal and subcapsular hematomas, with no evidence of active extravasations. The patient was admitted to the pediatric critical care unit for close hemodynamic monitoring and frequent measurements of hemoglobin. His lowest recorded hemoglobin and hematocrit were 63 g/L and 0.19 L/L, respectively. Posttransfusion of packed red blood cells, he was taken to interventional radiology for proximal splenic artery embolization under moderate sedation. Several coils were successfully placed in the proximal splenic arterial system resulting in a marked reduction of splenic blood flow without disruption of collaterals. The patient recovered well from proximal splenic artery embolization in the pediatric critical care unit and experienced short lasting abdominal pain and fever for 1 day. He was discharged home 4 days after the procedure and follow-up imaging showed resolving hematomas with preserved splenic blood flow. CONCLUSION: Proximal splenic artery embolization in children may be a safe therapeutic alternative to either conservative or surgical management in spontaneous splenic rupture. Preservation of splenic tissue with a reduced risk of repeated hemorrhage can be obtained with proximal splenic artery embolization.

Lung contusion in children--early computed tomography versus radiography.

OBJECTIVE: To investigate, in children, the correlation between the extent of lung contusion as detected on early radiologic examination (chest radiograph [CXR] and/or thoracic computed tomography [TCT]) and subsequent clinical outcome measures. DESIGN: Retrospective chart review study with blinded assessment of thoracic imaging. SETTING: A university-affiliated, level 1 designated pediatric trauma center. INTERVENTIONS: None. PATIENTS: Patients (1-18 yrs) who, between April 2000 and October 2005, were diagnosed with lung contusion were eligible for study entry. The medical records of those patients who underwent early (within the first 24 hrs of admission) thoracic imaging (CXR and/or TCT) were reviewed. A pulmonary contusion score (PCS) was assigned to each thoracic image according to the extent of contusion injury by two investigators blinded to each others score and the clinical details of the patient. RESULTS: Seventy-four patients were included in the study. Twenty patients had undergone CXR only, whereas 54 had undergone both CXR and TCT. The mean PCS on CXR was 3.9 +/- 3.6 compared with 6.5 +/- 3.49 on TCT (p < .001). In eight patients (15%) who underwent TCT and CXR, the CXR failed to demonstrate a lung contusion. The PCS derived from CXR examination correlated positively with lower Pao2/Fio2 (r = -.36, p = .019), higher ventilation index (r = .35, p = .014), and longer length of ventilation (r = .28, p = .019). No such correlation was seen with TCT-derived PCS. CONCLUSIONS: The severity of lung contusion determined by CXR, but not TCT, correlates with impairment of oxygenation, CO2 exchange, and duration of ventilatory support.

Intraoperative photoacoustic screening of breast cancer: a new perspective on malignancy visualization and surgical guidance.

High re-excision rates in breast-conserving surgery call for a new intraoperative approach to the lumpectomy margin evaluation problem. The unique intraoperative imaging system, presented here, demonstrated the capability of photoacoustic tomography (PAT) to deliver optical sensitivity and specificity, along with over 2-cm imaging depth, in a clinical setting. The system enabled the evaluation of tumor extent, shape, morphology, and position within lumpectomy specimens measuring up to 11 cm in diameter. The investigation included all major breast cancer-related lesions, such as invasive ductal carcinoma (IDC), multifocal IDC, ductal carcinoma in situ and combinations of these variants. Coregistration with established ultrasound (US) technology, as well as comparison to specimen radiography, validated the performance of PAT, which appeared to facilitate better tumor visualization. Contrary to expected PA contrast mechanisms, PAT images of hemoglobin distribution correlated poorly with US-determined tumor location, while hypointense regions in lipid-weighted PAT images were in better agreement with US.

Comparison of wait times across the breast cancer treatment pathway among screened women undergoing organized breast assessment versus usual care.

OBJECTIVE: The benefit of organized breast assessment on wait times to treatment among asymptomatic women is unknown. The Ontario Breast Screening Program (OBSP) offers screening and organized assessment through Breast Assessment Centres (BAC). This study compares wait times across the treatment pathway among screened women diagnosed with breast cancer through BAC and usual care (UC). METHODS: A retrospective design identified two concurrent cohorts of postmenopausal women aged 50-69 within the OBSP diagnosed with screen-detected invasive breast cancer and assessed in BAC (n = 2010) and UC (n = 1844) between 2002 and 2010. Demographic characteristics were obtained from the OBSP. Medical chart abstraction provided prognostic and treatment data. Multinomial logistic regression examined associations of assessment type with wait times from abnormal mammogram to surgery, chemotherapy or radiotherapy. RESULTS: Compared with through UC, postmenopausal women diagnosed through BAC were significantly less likely to have longer wait times (days) from an abnormal mammogram to definitive surgery (> 89 vs. ≤ 47; OR = 0.63; 95% CI = 0.52-0.77), from final surgery to radiotherapy (> 88 vs. ≤ 55; OR = 0.71; 95% CI = 0.54-0.93) and from final chemotherapy to radiotherapy (> 41 vs. ≤ 28; OR = 0.52; 95% CI = 0.36-0.76). Conversely, women assessed through BAC compared with through UC were more likely to experience longer wait times from final surgery to chemotherapy (> 64 vs. ≤ 40; OR = 1.49; 95% CI = 1.04-2.14). CONCLUSION: Shorter wait times to most treatments for postmenopausal women diagnosed in BAC further supports that women with an abnormal mammogram should be managed through organized assessment. Continued evaluation of factors influencing wait times to treatment is essential for quality improvement and patient outcomes.