Advances in oncologic imaging: update on 5 common cancers.

Imaging has become a pivotal component throughout a patient's encounter with cancer, from initial disease detection and characterization through treatment response assessment and posttreatment follow-up. Recent progress in imaging technology has presented new opportunities for improving clinical care. This article provides updates on the latest approaches to imaging of 5 common cancers: breast, lung, prostate, and colorectal cancers, and lymphoma.

Breast Cancers Detected at Screening MR Imaging and Mammography in Patients at High Risk: Method of Detection Reflects Tumor Histopathologic Results.

Purpose To compare the clinical, imaging, and histopathologic features of breast cancers detected at screening magnetic resonance (MR) imaging, screening mammography, and those detected between screening examinations (interval cancers) in women at high risk. Materials and Methods This retrospective institutional review board-approved, HIPAA-compliant review of 7519 women at high risk for breast cancer who underwent screening with MR imaging and mammography between January 2005 and December 2010 was performed to determine the number of screening-detected and interval cancers diagnosed. The need for informed consent was waived. Medical records were reviewed for age, risk factors (family or personal history of breast cancer, BRCA mutation status, history of high-risk lesion or mantle radiation), tumor histopathologic results, and time between diagnosis of interval cancer and most recent screening examination. The χ(2) test and logistic regression methods were used to compare the features of screening MR imaging, screening mammography, and interval cancers. The Wilcoxon signed-rank test was used to calculate P values. Results A total of 18 064 screening MR imaging examinations and 26 866 screening mammographic examinations were performed. Two hundred twenty-two cancers were diagnosed in 219 women, 167 (75%) at MR imaging, 43 (19%) at mammography, and 12 (5%) interval cancers. Median age at diagnosis was 52 years. No risk factors were associated with screening MR imaging, screening mammography, or interval cancer (P > .06). Cancers found at screening MR imaging were more likely to be invasive cancer (118 of 167 [71%]; P < .0001). Of the 43 cancers found at screening mammography, 38 (88%) manifested as calcifications and 28 (65%) were ductal carcinoma in situ. Interval cancers were associated with nodal involvement (P = .005) and the triple-negative subtype (P = .03). Conclusion In women at high risk for breast cancer who underwent screening with mammography and MR imaging, invasive cancers were more likely to be detected at MR imaging, whereas most cancers detected at screening mammography were ductal carcinoma in situ. Interval cancers were found infrequently and were more likely to be node positive and of the triple-negative subtype. (©) RSNA, 2016.

Incidence of Internal Mammary Lymph Nodes with Silicone Breast Implants at MR Imaging after Oncoplastic Surgery.

PURPOSE: To assess the incidence of benign and malignant internal mammary lymph nodes (IMLNs) at magnetic resonance (MR) imaging among women with a history of treated breast cancer and silicone implant reconstruction. MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant retrospective study and waived informed consent. Women were identified who (a) had breast cancer, (b) underwent silicone implant oncoplastic surgery, and (c) underwent postoperative implant-protocol MR imaging with or without positron emission tomography (PET)/computed tomography (CT) between 2000 and 2013. The largest IMLNs were measured. A benign IMLN was pathologically proven or defined as showing 1 year of imaging stability and/or no clinical evidence of disease. Malignant IMLNs were pathologically proven. Incidence of IMLN and positive predictive value (PPV) were calculated on a per-patient level by using proportions and exact 95% confidence intervals (CIs). The Wilcoxon rank sum test was used to assess the difference in axis size. RESULTS: In total, 923 women with breast cancer and silicone implants were included (median age, 46 years; range, 22-89 years). The median time between reconstructive surgery and first MR imaging examination was 49 months (range, 5-513 months). Of the 923 women, 347 (37.6%) had IMLNs at MR imaging. Median short- and long-axis measurements were 0.40 cm (range, 0.20-1.70 cm) and 0.70 cm (range, 0.30-1.90 cm), respectively. Two hundred seven of 923 patients (22.4%) had adequate follow-up; only one of the 207 IMLNs was malignant, with a PPV of 0.005 (95% CI: 0.000, 0.027). Fifty-eight of 923 patients (6.3%) had undergone PET/CT; of these, 39 (67.2%) had IMLN at MR imaging. Twelve of the 58 patients (20.7%) with adequate follow-up had fluorine 18 fluorodeoxyglucose-avid IMLN, with a median standardized uptake value of 2.30 (range, 1.20-6.10). Only one of the 12 of the fluorodeoxyglucose-avid IMLNs was malignant, with a PPV of 0.083 (95% CI: 0.002, 0.385). CONCLUSION: IMLNs identified at implant-protocol breast MR imaging after oncoplastic surgery for breast cancer are overwhelmingly more likely to be benign than malignant. Imaging follow-up instead of immediate metastatic work-up may be warranted.

Breast carcinoma in augmented breasts: MRI findings.

OBJECTIVE: The objective of our study was to characterize the MRI features of breast carcinomas detected in augmented breasts. MATERIALS AND METHODS: A review of the MRI database identified 54 patients with biopsy-proven breast carcinoma in augmented breasts. The images were reviewed for the type and location of the implant and for the characteristics of the carcinoma. The cases included 46 (85%) invasive cancers (invasive ductal carcinoma, n = 35; invasive lobular carcinoma, n = 7; and mixed features, n = 4) and eight (15%) ductal carcinomas in situ. RESULTS: The median age of the patients at diagnosis was 49 years (range, 28-72 years). Thirty-eight of the 54 cancers (70%) were palpable. The mean tumor size was 2.8 cm (range, 0.6-9.6 cm). Of the 54 cancers, 34 (63%) presented as masses and 20 (37%) as nonmass enhancement on MRI. There was no detectable difference between implant position and lesion morphology (p = 0.55) or tumor size (p = 1.00). Twenty of 54 (37%) carcinomas abutted the implant, 13 (24%) abutted the pectoralis major muscle, and two (4%) invaded the pectoralis major muscle. Of the tumors abutting the implant, 18 of 20 (90%) spread along the implant capsule for more than 0.5 cm. This pattern of tumor spread was more common in breasts with retroglandular implants (9/16, 56%) than in those with retropectoral implants (9/38, 24%) (p = 0.03). MRI detected the index carcinoma in 16 of 54 (30%) cases, showed a greater extent of disease than was visible on mammography or ultrasound in 21 of 52 (40%) cases, and detected an unsuspected contralateral carcinoma in three of 54 (6%) cases. CONCLUSION: In augmented breasts, breast cancer often contacts either the implant or the pectoralis major muscle. Tumor spread along the implant contour is more often seen with retroglandular implants than with retropectoral implants. MRI should be considered to assess disease extent in women with augmented breasts before surgery.

Detection of Internal Mammary Adenopathy in Patients With Breast Cancer by PET/CT and MRI.

OBJECTIVE: The purpose of this study was to assess the prevalence of internal mammary node (IMN) adenopathy in patients with breast cancer and compare breast MRI and PET/CT for detection of IMN adenopathy. MATERIALS AND METHODS: This retrospective study included 90 women who underwent MRI and PET/CT before neoadjuvant chemotherapy for clinical stage IIA through IIIA disease. MRI and PET/CT examinations were read independently by two readers trained in breast imaging and nuclear medicine. All patients underwent follow-up MRI at the end of chemotherapy, and 10 with hypermetabolic IMNs underwent follow-up PET/CT. Histology was not obtained. Women were considered to have IMN adenopathy when nodes seen on MRI or having standardized uptake value (SUV) greater than mediastinal blood pool decreased in either size or SUV (or both) after treatment. Features including lymphovascular invasion, tumor quadrant(s), and axillary adenopathy were compared between presence and absence of IMN adenopathy using Fisher's exact test. Prevalence was determined on the basis of the percentage of patients with IMN adenopathy by either modality. The McNemar test compared the prevalence of IMN adenopathy on MRI to its prevalence on PET/CT. RESULTS: Prevalence of IMN adenopathy was 16% (14/90) by MRI and 14% (13/90) by PET/CT (p = 0.317). After chemotherapy, IMN adenopathy resolved in 12 of 14 patients (86%). In two patients with poor responses in primary tumors, IMN adenopathy persisted, and both patients developed metastatic disease within 6 months. At 3 years, survival was significantly worse in patients with IMN adenopathy than in those without (85.7% vs 53.3%, respectively; p = 0.009). CONCLUSION: In women with advanced breast cancer receiving neoadjuvant chemo-therapy, prevalence of IMN adenopathy was 16%, equally detected by breast MRI and PET/CT. Identification of IMN adenopathy may affect treatment and provides prognostic information.

Preoperative breast MRI for early-stage breast cancer: effect on surgical and long-term outcomes.

OBJECTIVE: The purpose of this study was to evaluate the effect of the use of preoperative breast MRI on surgical and long-term outcomes among women with early-stage breast cancer undergoing breast conservation therapy. MATERIALS AND METHODS: A retrospective review yielded the cases of 174 women with stage 0, I, or II breast cancer who underwent preoperative MRI between 2000 and 2004. A control group of 174 patients who did not undergo preoperative MRI before breast conservation therapy was matched by age, histopathologic finding, stage, and surgeon. Features compared included breast density, presence of mammographically occult disease, margin status, lymph node involvement, lymphovascular invasion, extensive intraductal component, hormone receptor status, and use of adjuvant therapy. Outcomes, including rates of reexcision, ipsilateral recurrence, and disease-free survival, were compared by Kaplan-Meier methods and the log-rank test. RESULTS: Patients referred for preoperative breast MRI were more likely to have extremely dense breasts (28% vs 6%, p < 0.0001) and mammographically occult cancer (24% vs 9%, p = 0.0003). The two groups had identical rates of final negative margins, lymph node involvement, lymphovascular invasion, extensive intraductal component status, positive hormone receptor results, and systemic adjuvant therapy. Fewer patients in the preoperative MRI group needed reexcision (29% vs 45%, p = 0.02). The median follow-up period after treatment was 8 years. There was no significant difference in locoregional recurrence (p = 0.33) or disease-free survival (p = 0.73) rates between the two groups. CONCLUSION: Reexcision rates among patients with early breast cancer undergoing conservation therapy were lower among women who underwent preoperative breast MRI. There was no statistically significant effect of the use of preoperative MRI on rates of locoregional recurrence or disease-free survival.

Bilateral contrast-enhanced dual-energy digital mammography: feasibility and comparison with conventional digital mammography and MR imaging in women with known breast carcinoma.

PURPOSE: To determine feasibility of performing bilateral dual-energy (DE) contrast agent-enhanced (CE) digital mammography and to evaluate its performance compared with conventional digital mammography and breast magnetic resonance (MR) imaging in women with known breast cancer. MATERIALS AND METHODS: This study was approved by the institutional review board and was HIPAA compliant. Written informed consent was obtained. Patient accrual began in March 2010 and ended in August 2011. Mean patient age was 49.6 years (range, 25-74 years). Feasibility was evaluated in 10 women with newly diagnosed breast cancer who were injected with 1.5 mL per kilogram of body weight of iohexol and imaged between 2.5 and 10 minutes after injection. Once feasibility was confirmed, 52 women with newly diagnosed cancer who had undergone breast MR imaging gave consent to undergo DE CE digital mammography. Positive findings were confirmed with pathologic findings. RESULTS: Feasibility was confirmed with no adverse events. Visualization of tumor enhancement was independent of timing after contrast agent injection for up to 10 minutes. MR imaging and DE CE digital mammography both depicted 50 (96%) of 52 index tumors; conventional mammography depicted 42 (81%). Lesions depicted by using DE CE digital mammography ranged from 4 to 67 mm in size (median, 17 mm). DE CE digital mammography depicted 14 (56%) of 25 additional ipsilateral cancers compared with 22 (88%) of 25 for MR imaging. There were two false-positive findings with DE CE digital mammography and 13 false-positive findings with MR imaging. There was one contralateral cancer, which was not evident with either modality. CONCLUSION: Bilateral DE CE digital mammography was feasible and easily accomplished. It was used to detect known primary tumors at a rate comparable to that of MR imaging and higher than that of conventional digital mammography. DE CE digital mammography had a lower sensitivity for detecting additional ipsilateral cancers than did MR imaging, but the specificity was higher. © RSNA, 2012.

MR imaging features of triple-negative breast cancers.

Triple-negative (TN) breast cancers, which are associated with a more aggressive clinical course and poorer prognosis, often present with benign imaging features on mammography and ultrasound. The purpose of this study was to compare the magnetic resonance imaging features of TN breast cancers with estrogen (ER) and progesterone (PR) positive, human epidermal growth factor receptor (HER2) negative cancers. Retrospective review identified 140 patients with TN breast cancer who underwent a preoperative breast MRI between 2003 and 2008. Comparison was made to 181 patients with ER+/PR+/HER2- cancer. Breast MRIs were independently reviewed by two radiologists blinded to the pathology. Discrepancies were resolved by a third radiologist. TN cancers presented with a larger tumor size (p = 0.002), higher histologic grade (<0.001), and were more likely to be unifocal (p = 0.018) compared with ER+/PR+/HER2- tumors. MRI features associated with TN tumors included mass enhancement (p = 0.026), areas of intratumoral high T2 signal intensity (p < 0.001), lobulated shape (p < 0.001), rim enhancement (p < 0.001), and smooth margins (p = 0.005). Among the TN tumors with marked necrosis, 26% showed a large central acellular zone of necrosis.

Patient follow-up after concordant histologically benign imaging-guided biopsy of MRI-detected lesions.

OBJECTIVE: The purpose of this study was to review the reported experience and suggest follow-up after biopsy for MRI-detected lesions. CONCLUSION: Imaging-guided biopsy, using MRI or sonographic guidance, of MRI-detected lesions may result in false-negative results that are not appreciated at the time of the biopsy. A 6-month follow-up MRI is suggested as the most appropriate interval to identify lesions that were missed at biopsy without clinically significant delay in diagnosis of those lesions that are malignant.

Papilloma diagnosed at MRI-guided vacuum-assisted breast biopsy: is surgical excision still warranted?

OBJECTIVE: The objective of our study was to determine the frequency of cancer at surgery in breast lesions yielding papilloma at MRI-guided 9-gauge vacuum-assisted biopsy (VAB) and to determine whether any features are associated with cancer upgrade. MATERIALS AND METHODS: For this study, 1487 MRI-guided vacuum-assisted biopsies performed from January 2004 to March 2011 were reviewed. Lesions yielding papilloma were identified and classified as papilloma with or without atypia. Surgical findings were reviewed to determine the cancer rate. Statistical analysis was performed and 95% CIs were calculated. RESULTS: Papilloma was identified in 75 of the 1487 MRI-guided vacuum-assisted biopsies (5%). These 75 papillomas occurred in 73 women with a median age of 49 years (age range, 27-70 years). Of the 75 papillomas, 25 (33%) had atypia and 50 (67%) did not on core needle biopsy. Subsequent surgery of 67 of the 75 papillomas (89%) yielded ductal carcinoma in situ (DCIS) in four (6%; 95% CI, 2-15%). Surgery yielded DCIS in two of 23 papillomas with atypia (9%; 95% CI, 1-28%) at MRI-guided VAB and in two of 44 papillomas without atypia (5%; 95% CI, 0.4-16%) at MRI-guided VAB; these cancer rates did not differ significantly (p=0.6). Postmenopausal status (p=0.04) and histologic size of less than 0.2 cm (p=0.04) had a significant association with the cancer upgrade rate. CONCLUSION: Papilloma with or without atypia was found in 5% of patients who underwent MRI-guided VAB during the study period. Surgery revealed cancer in 6%. DCIS was found at surgery in 9% of lesions yielding papilloma with atypia versus 5% of lesions yielding papilloma without atypia. For lesions yielding papilloma with or without atypia at MRI-guided VAB, surgical excision is warranted.

Screening breast MR imaging in women with a history of chest irradiation.

PURPOSE: To assess the utility of screening magnetic resonance (MR) imaging in detecting otherwise occult breast cancers in women with a history of radiation therapy to the chest. MATERIALS AND METHODS: This HIPAA-compliant study was approved by the authors' institutional review board. The need for informed consent was waived. Retrospective review of the radiology department database identified 247 screening breast MR imaging examinations performed between January 1999 and December 2008 in 91 women with a history of chest irradiation. Findings and recommendations for each breast MR study and on the most recent mammogram were reviewed. The number of cancers diagnosed, their method of detection, and tumor characteristics were examined. The exact 95% binomial proportion confidence intervals were calculated by using methods described by Clopper and Pearson. RESULTS: Biopsy was recommended for 32 suspicious lesions on 27 (11%) of 247 MR imaging studies in 21 women. Seven cancers were identified in 30 lesions sampled (23%). Biopsy was recommended in five additional patients on the basis of mammographic findings, and malignancy was detected in three. Ten cancers were detected during the study period: four detected with MR imaging alone, three with MR imaging and mammography, and three with mammography alone. The four cancers detected with MR imaging alone were invasive carcinomas. Two of three cancers detected with mammography alone were ductal carcinoma in situ (DCIS), and the third was DCIS with microinvasion. CONCLUSION: MR imaging is a useful adjunct modality to screen high-risk women with a history of chest irradiation, resulting in a 4.4% (95% confidence interval: 1.2%, 10.9%) incremental cancer detection rate; the sensitivity for detecting breast cancers by using a combination of MR imaging and mammography was higher than that for either modality alone.

Cancellation of MR imaging-guided breast biopsy due to lesion nonvisualization: frequency and follow-up.

PURPOSE: To determine the rate of canceled magnetic resonance (MR) imaging-guided breast biopsies due to nonvisualization of the lesion and to assess associated features and outcome data for these cases. MATERIALS AND METHODS: With the approval of the institutional review board, a HIPAA-compliant retrospective review, in which the requirement for informed consent was waived, was performed for 907 patients scheduled for MR imaging-guided breast biopsy from 2004 to 2008. In 70 patients, MR imaging biopsy was canceled due to lesion nonvisualization. Medical records and imaging studies were reviewed to identify patient, parenchymal, lesion features and outcome data. Statistical analysis was performed with the Fisher exact test. The 95% confidence interval (CI) was calculated. RESULTS: Cancellation of MR-guided biopsy due to lesion nonvisualization occurred in 8% (70 of 907) of patients and in 8% (74 of 911) of lesions. Factors associated with a significantly higher cancellation rate included marked and moderate versus mild and minimal background parenchymal enhancement (38 of 316 [12%] vs 32 of 591 [5%], P = .001), extremely and heterogeneously dense versus scattered fibroglandular densities and fatty parenchymal volume (64 of 712 [9%] vs six of 195 [3%], P = .006), and lesions 1 cm or less in size (52 of 520 [10%] vs 22 of 391 [6%], P = .02).The rate of cancellation per year was highest in the first year, with a decrease in subsequent years (14 of 102 [14%] vs 56 of 805 [7%], P = .025). A significantly lower rate was found in women with synchronous breast cancer (nine of 240 [4%] vs 61 of 667 [9%], P = .007), and a significantly higher rate was found in women with a history of cancer (35 of 315 [11%] vs 35 of 592 [6%], P = .01). Among 58 women who had MR imaging follow-up, no cancers were identified. Among three women who underwent mastectomy after cancellation, one had ductal carcinoma in situ in the same quadrant as the MR-depicted lesion. The cancer detection rate among 61 women who underwent either MR imaging or pathologic follow-up was 2% (one of 61) (95% CI: 0.4%, 9%). CONCLUSION: MR imaging-guided breast biopsy was canceled due to lesion nonvisualization in 8% of the patients. Although the cancer detection rate among the lesions for which biopsy was canceled is low (95% CI: 0%, 9%), short-term follow-up MR imaging is prudent.

Screening breast MR imaging in women with a history of lobular carcinoma in situ.

PURPOSE: To assess the utility of screening magnetic resonance (MR) imaging in the detection of otherwise occult breast cancers in women with a history of lobular carcinoma in situ (LCIS). MATERIALS AND METHODS: This HIPAA-compliant study received institutional review board approval. The need for informed consent was waived. Retrospective review of the database yielded 670 screening breast MR studies obtained between January 2003 and September 2008 in 220 women with a history of LCIS. MR and mammographic findings were reviewed. Number of cancers diagnosed, method of detection, and tumor characteristics were examined. The cumulative incidence of developing breast cancer as detected with MR imaging and mammography was calculated. Breast density was examined as a prognostic factor in the cumulative incidence analysis. RESULTS: Biopsy was recommended in 63 lesions seen in 58 (9%) of 670 screening MR studies. Eight additional lesions were identified at short-term follow-up MR imaging for a total of 71 lesions in 59 patients. Twelve cancers (20%) were identified in 60 lesions sampled. Biopsy was recommended in 26 additional lesions identified at mammography; biopsy was performed in 25 of these lesions and revealed malignancy in five (20%). Overall, 17 cancers were detected in 14 patients during the study period. Of these, 12 were detected with MR imaging alone, and five were detected with mammography alone. Of the 12 cancers detected at MR imaging, there were nine invasive cancers and three cases of ductal carcinoma in situ (DCIS). Of the five cancers detected at mammography, two were invasive and three were DCIS. CONCLUSION: MR imaging is a useful adjunct modality with which to screen women with a history of LCIS at high-risk of developing breast cancer, resulting in a 4.5% incremental cancer detection rate. Sensitivity in the detection of breast cancers with a combination of MR imaging and mammography was higher than sensitivity of either modality alone.

Diagnostic usefulness of water-to-fat ratio and choline concentration in malignant and benign breast lesions and normal breast parenchyma: an in vivo (1) H MRS study.

PURPOSE: To compare total choline concentrations ([Cho]) and water-to-fat (W/F) ratios of subtypes of malignant lesions, benign lesions, and normal breast parenchyma and determine their usefulness in breast cancer diagnosis. Reference standard was histology. MATERIALS AND METHODS: In this HIPPA compliant study, proton MRS was performed on 93 patients with suspicious lesions (>1 cm) who underwent MRI-guided interventional procedures, and on 27 prospectively accrued women enrolled for screening MRI. (W/F) and [Cho] values were calculated using MRS data. RESULTS: Among 88 MRS-evaluable histologically-confirmed lesions, 40 invasive ductal carcinoma (IDC); 10 invasive lobular carcinoma (ILC); 4 ductal carcinoma in situ (DCIS); 3 invasive mammary carcinoma (IMC); 31 benign. No significant difference observed in (W/F) between benign lesions and normal breast tissue. The area under curve (AUC) of receiver operating characteristic (ROC) curves for discriminating the malignant group from the benign group were 0.97, 0.72, and 0.99 using [Cho], (W/F) and their combination as biomarkers, respectively. (W/F) performs significantly (P < 0.0001;AUC = 0.96) better than [Cho] (AUC = 0.52) in differentiating IDC and ILC lesions. CONCLUSION: Although [Cho] and (W/F) are good biomarkers for differentiating malignancy, [Cho] is a better marker. Combining both can further improve diagnostic accuracy. IDC and ILC lesions have similar [Cho] levels but are discriminated using (W/F) values.

Background parenchymal enhancement on baseline screening breast MRI: impact on biopsy rate and short-interval follow-up.

OBJECTIVE: Background parenchymal enhancement on breast MRI refers to normal enhancement of the patient's fibroglandular tissue. The aim of this study was to determine the effect of background parenchymal enhancement on short-interval follow-up, biopsy, and cancer detection rate on baseline screening MRI in a high-risk group. MATERIALS AND METHODS: Two hundred fifty baseline high-risk screening MRI examinations were reviewed. For each, the background parenchymal enhancement pattern was recorded (minimal, ≤ 25%; mild, 26-50%; moderate, 51-75%; and marked, > 75%), as were BI-RADS category, biopsy rate, and final pathology result. Results were compared for each enhancement category. RESULTS: Of the 250 MRI examinations, 24.8% showed minimal enhancement; 34%, mild; 24%, moderate; and 17.2%, marked enhancement. Women with minimal enhancement had a significantly higher number of BI-RADS categories 1 and 2 examinations (64.5%) than women with mild (38.8%), moderate (40%), or marked (25.6%) enhancement. The BI-RADS category 3 rate was 43.6% overall and was significantly lower for women with minimal enhancement (27.4% vs 47.1% for women with mild, 45.0% for women with moderate, and 58.1% for women with marked enhancement). At follow-up, 86.2% of the BI-RADS 3 lesions were converted to BI-RADS category 1 or 2 and 13.8% were converted to BI-RADS 4, with a malignancy rate of 0.9% for lesions undergoing short-interval follow-up. There was no significant difference in biopsy rate or cancer detection rate among enhancement categories. CONCLUSION: Mild, moderate, and marked background parenchymal enhancement is associated with a significantly lower rate of BI-RADS categories 1 and 2 assessments and a significantly higher rate of BI-RADS category 3 assessments than minimal enhancement. There was no significant difference in biopsy rate or cancer detection rate among the enhancement categories.

Breast MRI screening of women with a personal history of breast cancer.

OBJECTIVE: The purpose of this article is to determine the cancer detection and biopsy rate among women who have breast MRI screening solely on the basis of a personal history of breast cancer. MATERIALS AND METHODS: This retrospective review of 1,699 breast MRI examinations performed from 1999 to 2001 yielded 144 women with prior breast cancer but no family history who commenced breast MRI screening during that time. Minimal breast cancer was defined as ductal carcinoma in situ (DCIS) or node-negative invasive breast cancer < 1 cm in size. RESULTS: Of 144 women, 44 (31% [95% CI, 15-29%]) underwent biopsies prompted by MRI examination. Biopsies revealed malignancies in 17 women (12% [95% CI, 7-18%]) and benign findings only in 27 women (19% [95% CI, 13-26%]). Of the 17 women in whom cancer was detected, seven also had benign biopsy results. In total, 18 malignancies were found. One woman had two metachronous cancers. MRI screening resulted in a total of 61 biopsies, with a positive predictive value (PPV) of 39% (95% CI, 27-53%). The malignancies found included 17 carcinomas and one myxoid liposarcoma. Of the 17 cancers, 12 (71%) were invasive, five (29%) were DCIS, and 10 (59%) were minimal breast cancers. Of 17 cancers, 10 were detected by MRI only. The 10 cancers detected by MRI only, versus seven cancers later found by other means, were more likely to be DCIS (4/10 [40%] vs 1/7 [14%]; p = 0.25) or minimal breast cancers (7/10 [70%] vs 3/7 [43%]; p = 0.26). CONCLUSION: We found that breast MRI screening of women with only a personal history of breast cancer was clinically valuable finding malignancies in 12%, with a reasonable biopsy rate (PPV, 39%).

Breast MRI after conservation therapy: usual findings in routine follow-up examinations.

OBJECTIVE: The objective of our study was to define the usual alterations in the ipsilateral and contralateral breast on MRI of women who have undergone surgery and radiation for the treatment of primary breast cancer. MATERIALS AND METHODS: Database searches identified 744 breast MR examinations of 248 women with newly diagnosed primary breast cancer who had undergone standard breast conservation therapy (BCT) and who had undergone MRI before radiotherapy and at least twice after BCT; these MR examinations were reviewed retrospectively. In each MR study, both breasts were evaluated for background enhancement and cystic alteration. In the treated breast, edema, skin thickening, seroma, and enhancement at the lumpectomy site were assessed. RESULTS: Background enhancement and cystic alteration decreased bilaterally on MRI after completion of surgery and radiation. Edema, skin thickening, seroma, and enhancement at the lumpectomy site progressively decreased over time. These changes never resolved in some women, with edema present in 25.9% of women at 6 or more years after BCT and seroma present in 3.7%. Lumpectomy site enhancement was seen in 37% of studies obtained in the first 12 months after treatment and persisted in 15% of women at 5 or more years. Rim enhancement was seen in women with seromas, whereas focal enhancement was typically seen in those without seromas. The persistence of lumpectomy site enhancement was seen in 12 of 16 women with fat necrosis, indicated by fat signal in the seroma and was seen in only five of 19 patients without fat seen in the surgery cavity (p = 0.007). CONCLUSION: After a patient has undergone BCT, MRI shows changes in both breasts. Although the changes in our study population were greatest in the treated breast, parenchymal enhancement and cystic alteration decrease bilaterally indicating a systemic influence. Edematous changes, seroma, focal enhancement, and skin thickening were seen only in the treated breast. All posttreatment MRI findings decrease progressively, and all may persist. Lumpectomy site enhancement is most persistent in women with fat necrosis.

MRI follow-up after concordant, histologically benign diagnosis of breast lesions sampled by MRI-guided biopsy.

OBJECTIVE: Follow-up MRI can be useful to confirm a benign diagnosis after MRI-guided breast biopsy. This retrospective study was undertaken to evaluate appropriate timing and imaging interpretation for the initial follow-up MRI when a benign, concordant histology is obtained using MRI-guided breast biopsy. MATERIALS AND METHODS: Retrospective review was performed of 177 lesions visualized only by MRI in 172 women who underwent 9-gauge, vacuum-assisted core biopsy and marker placement with imaging-concordant benign histology. All underwent follow-up MRI within 12 months. Timing of the follow-up study, change in size, results of second biopsy if performed, and distance of localizing marker to the lesion on the follow-up study were recorded. RESULTS: At initial follow-up, 155 lesions were decreased or gone, 14 lesions were stable, and eight were enlarged. Seventeen (9.6%, 17/177) lesions underwent a second biopsy, including six enlarging, 10 stable, and one decreasing. Of these, four were malignant. Enlargement was seen in two carcinomas at 6 and 12 months. Two carcinomas, one stable at 2 months and another stable at 3 and 11 months, were rebiopsied because of suspicion of a missed lesion in the former and worrisome mammographic and sonographic changes in the latter. The distance of the marker from the lesion on follow-up did not correlate with biopsy accuracy. CONCLUSION: Follow-up MRI did not detect missed cancers because of lesion enlargement before 6 months after biopsy; two of four missed cancers were stable. The localizing marker can deploy away from the target despite successful sampling.