Contrast-enhanced computed tomography for diagnosing the intraductal component and small invasive foci of breast cancer

Comprehensive analyses with radiological and biological markers of breast cancer on contrast-enhanced chest CT: a single center experience using dual-layer spectral detector CT

OBJECTIVES

To evaluate the predictive value of virtual monoenergetic images (VMIs) by assessing tumor conspicuity on dual-layer spectral detector CT (SDCT) and correlate tumor conspicuity on VMI with prognostic biomarkers in patients with breast cancer.

METHODS

Sixty-four patients underwent arterial phase and 90-s delayed phase dual-layer SDCT. A retrospective tumor conspicuity analysis of 14 benign tumors and 65 breast cancers was performed using conventional images (CIs) and VMI at 40 keV (VMI40) on arterial and delayed phase scans (CI_ART, VMI40_ART, CI_DE, VMI40_DE). Mean Hounsfield units (HU) of tumors were measured on VMI40_ART and VMI40_DE. A receiver operating characteristic (ROC) curve analysis was performed to compare diagnostic accuracy between image sets. Estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki67 levels were evaluated using histopathology. Correlations between VMI analyses and histological characteristics of cancers were analyzed.

RESULTS

Cancers on VMI40 had a significantly higher conspicuity score and mean HU than benign tumors (p < 0.001). VMI40_DE showed the highest conspicuity for cancers (mean, 3.79) and the greatest area under the ROC curve (0.817; 95% confidence interval 0.745-0.889). VMI40_DE yielded significantly higher mean HU for cancers than VMI40_ART (p < 0.001). The conspicuity score and mean HU on VMI40_ART were significantly higher in cancers with ER negativity, PR negativity, and Ki67 positivity (p < 0.05).

CONCLUSIONS

VMI40_DE may be useful in the diagnosis of breast cancers due to higher tumor conspicuity and better enhancement than VMI40_ART. VMI40_ART may be beneficial for the prediction of poor breast cancer prognoses.

KEY POINTS

• VMI40 improved conspicuity of breast cancer than CI. • VMI40_DEyielded higher diagnostic performance of breast cancer than VMI40_ART. • VMI40_ARThas an additional benefit in terms of prognosis prediction in patients with breast cancers.

Multi-detector row CT-guided marking technique for breast-conserving therapy of early breast cancer: margin positivity and local control rates

BACKGROUND

In breast-conserving surgery (BCS), image-guided marking of the tumor border is important for preventing local recurrence and achieving a good cosmetic outcome. The purpose of this study was to evaluate the usefulness of multi-detector row computed tomography (MDCT)-guided marking technique before BCS in patients in whom ultrasound (US)-guided marking was not feasible.

METHODS

Between 2004 and 2010, 94 lesions underwent contrast-enhanced MDCT-guided marking. Margin positivity and local control rates were compared with those of 149 lesions undergoing US-guided marking during the same period.

RESULTS

In 21 lesions undergoing CT marking (22 %) and 20 lesions undergoing US marking (13 %), a negative resection margin could not be achieved, and hence the marking was judged as unsuccessful. Eighty-four lesions of the CT marking group and 119 of the US marking group received postoperative radiotherapy with 50 Gy in 25 fractions with or without an additional 10-Gy boost to the tumor bed. The remaining 10 and 30 patients, respectively, did not receive radiotherapy. The median follow-up period was 54 and 51 months for patients with CT marking and those with US marking, respectively. At 4 postoperative years, the local control rate was 96.5 % for patients with CT marking and 97.3 % for those with US marking (P = 0.89).

CONCLUSIONS

The MDCT marking technique appears to be a valuable tool for determining the surgical margin for BCS in patients in whom ultrasound marking cannot be performed. Combining this technique with appropriate postoperative radiation therapy is expected to yield reasonably high local control rates.

Usefulness of lesion image mapping with multidetector-row helical computed tomography using a dedicated skin marker in breast-conserving surgery

To investigate the usefulness of computed tomography (CT) with skin-marker placement in determining the excision area and decreasing the positive or close margin rates in breast-conserving surgery (BCS). Multidetector-row helical computed tomography (MDCT) mapping images were reconstructed in subjects (n = 117) diagnosed with primary breast cancer who had undergone MDCT using CT skin markers. Serial 5-mm-thick slices prepared from the surgical specimen were used for pathological analyses. A "positive margin" was defined as the presence of malignant cells at the surgical margin, and a "close margin" as a tumor within 5 mm of the surgical margin. The rates of positive and close margins were calculated. We identified the lesions in 111 of 117 cases (94.9%) on MDCT. Of these, 93 underwent BCS under the guidance of MDCT mapping and the remaining 18 underwent mastectomy. Among the 93 cases, 6 (6.5%) had positive or close margins and were diagnosed with ductal carcinoma in situ of low nuclear grade. MDCT mapping with a CT skin marker is feasible for simulating surgical positioning and determining the excision area. MDCT mapping could decrease the positive and close margin rates in BCS.

MDCT of the breast

OBJECTIVE

The purpose of this study was to evaluate retrospectively the accuracy of low-dose MDCT in the differentiation of breast lesions suspected on mammography and sonography.

MATERIALS AND METHODS

MDCT was performed on 61 patients with mammographic or sonographic findings suggestive of breast cancer who could not undergo MR mammography. For each lesion, morphologic features, attenuation, and time-attenuation curve pattern were evaluated. The 1-minute cut point of attenuation was analyzed on the images. CT findings were compared with histopathologic results, which were the reference standard.

RESULTS

Forty-seven of 61 patients underwent surgery, and the pathologic findings revealed 27 malignant and 20 benign lesions. With CT 25 of 27 malignant lesions and all 20 benign lesions were diagnosed correctly. CT had a sensitivity of 92.6%, specificity of 100%, positive predictive value of 100%, negative predictive value of 90.9%, and accuracy of 95.74%. The cutoff attenuation value, which had the best validity for differentiating malignant and benign lesions, was calculated to be 90 H on the 1-minute images.

CONCLUSION

Our results confirm and strengthen the importance of all imaging parameters and not one in particular. Dynamic MDCT can be used in the evaluation of selected patients with suspected breast tumors.

Breast CT

Breast cancer is a serious disease that accounts for approximately 40,000 deaths per year in the United States. Unfortunately, there is no known cause of breast cancer, and therefore the best way to prevent mortality is early detection. In the past 15 years, breast cancer mortality has been reduced significantly, which is in part due to screening with film-screen mammography. Nonetheless, conventional mammography lacks sensitivity, especially for certain subgroups of women such as those with dense breast tissue, those under 50 years old, and pre- or perimenopausal women. In addition, mammography has a very poor positive predictive value for biopsy, with 70%-90% of biopsies performed turning out negative. By improving visualization of breast tissue, X-ray computerized tomography (CT) of the breast can potentially provide improvements in diagnostic accuracy over conventional mammography. Owing to recent technological developments in digital detector technology, flat-panel CT imagers dedicated to imaging of the breast are now feasible. A number of academic groups are currently researching dedicated breast CT and prototype systems are currently being evaluated in the clinical setting.

Clinical Significance of Multidetector-Row Computed Tomography in Breast Surgery

Several reports support the association of higher ipsilateral breast tumor recurrence rates with positive or intermediate margins compared with negative pathologic margins. Precise evaluation of tumor extension and adequate surgical margin are important factors affecting tumor recurrence after breast-conserving surgery (BCS). Many studies have reported the utility of magnetic resonance imaging (MRI) for diagnosing the tumor extension of breast cancer, but few have evaluated the utility of multidetector-row computed tomography (MDCT). The results of this study show the clinical significance of MDCT for detecting cancer extension and demonstrate the clinical role of MDCT in BCS. Subjects comprised 136 patients grouped into two categories based on whether or not tumor extension was evaluated with MDCT preoperatively. The positive surgical margin rate and breast conservation rate were analyzed in each group and the clinical role of MDCT in BCS was evaluated. Moreover, evaluation of intraductal extension was done both with MDCT and histologically, and computed tomography (CT)-pathologic correlations were examined retrospectively. Finally, the margin-positive cases were analyzed in relation to their clinical characteristics. Sensitivity, specificity, positive predictive value, and negative predictive value for detection of the intraductal component were 71.8%, 85.7%, 82.1%, and 76.9%, respectively. The positive surgical margin rate and conservation rate are 7.46% and 81.9%, respectively, for those who were diagnosed with MDCT preoperatively; their corresponding rates without MDCT were 16.67% and 67.9%. Most margin-positive patients have remarkable lymphatic space invasion. Positive surgical margins were often recognized toward the nipple. For diagnosing the intraductal extension, MDCT shows sufficient diagnosability. Moreover, MDCT can provide appropriate information for the determination of adequate surgical margins and contribute to increases in breast conservation rates.

Assessing the extent of breast cancer using multidetector row helical computed tomography

OBJECTIVE

The aim of the study was to evaluate the usefulness of multidetector row helical computed tomography (MD-CT) in assessing the local extent of breast cancer.

METHODS

Seventy-five breast cancer patients were examined using MD-CT with scanning performed in the supine position at 1-mm collimation. The extent of the breast tumors determined using CT was compared with that based on histopathologic mapping with continuous 5-mm slices.

RESULTS

The CT evaluation of the maximum diameter of the extent of breast cancer was much better correlated with the histopathologic diagnosis (correlation coefficient=0.90) than the pre-CT diagnosis (correlation coefficient=0.46). Computed tomography correctly detected mammographically and clinically occult cancer other than the index lesion in 14 of 15 patients. The sensitivity, specificity, and accuracy in the diagnosis of the additional lesions were 93.3%, 98.3%, and 97.3%, respectively. Because the images were obtained in the supine position, they were useful for surgical planning.

CONCLUSION

The extent of breast cancer can be determined accurately using MD-CT.

Low-dose multidetector dynamic CT in the breast

This study investigated the feasibility of using low-dose multidetector dynamic computed tomography (CT) scan for imaging breast. We measured the radiation dose using a phantom at low- and standard-dose CT. To compare the image quality at low- and standard-dose CT, we evaluated normal breasts in 57 cases. In 44 cases with breast cancer, we assessed the staging and time-enhancement curves of breast cancer. In conclusion, the low-dose multidetector dynamic CT scan is feasible for the evaluation of the breast, with reduced radiation dose and with similar image quality when compared with standard-dose CT scan. In breast cancers, low-dose dynamic CT could be used for the staging of breast cancer before surgery.

Usefulness of three-dimensional multidetector-row CT images for preoperative evaluation of tumor extension in primary breast cancer patients

PURPOSE

Usefulness of three dimensional (3D) multidetector-row CT (MDCT) images for preoperative evaluation of tumor extension was studied in primary breast cancer patients.

METHODS

3D-MDCT tumor images of 143 tumors in 143 patients with primary breast cancer were created with the volume rendering method. The transverse tumor size (TS) and vertical tumor size (VS) were then measured in an anterior-posterior view of the 3D-MDCT images. The pathological tumor size was determined according to a map of the tumor spread prepared by pathologists using multi-sliced (3-5 mm intervals) surgical specimens and compared with the tumor size on 3D-MDCT images.

RESULTS

First, the optimal method for creating 3D-MDCT tumor images was determined for the first 40 patients (learning set), resulting in a fairly good correlation of tumor size on 3D-MDCT images with pathological tumor size (r = 0.983 for TS and r = 0.958 for VS). We then carried out a validation study on the next 103 patients (validation set). The 3D-MDCT tumor size's strong correlation with the pathological tumor size demonstrated a high rate of accuracy (r = 0.974 for TS and r = 0.977 for VS). Subset analyses according to histological type showed that correlation coefficients were r = 0.979 for TS and r = 0.981 for VS of invasive ductal carcinomas (n = 88), r = 0.948 for TS and r = 0.970 for VS of ductal carcinomas in situ (n = 10), and r = 0.984 for TS and r = 0.976 for VS of invasive lobular carcinomas (n = 5).

CONCLUSION

3D-MDCT images can assess breast cancer tumor extension highly accurately, and thus seems to be useful for planning the extent of resection in breast conserving surgery.

Multidetector row computed tomography for diagnosing intraductal extension of breast carcinoma

OBJECTIVES

Several reports supported the association of higher ipsilateral breast tumor recurrence rates with positive or intermediate margins compared with negative pathologic margins. Precise evaluation of intraductal component and adequate surgical margin are important factors affecting the tumor recurrence after breast conserving surgery. Numerous studies have reported the utility of magnetic resonance imaging for diagnosing developing intraductal extension of breast cancer, but few have investigated multidetector-row computed tomography (MD-CT). The present study evaluated the clinical utility of MD-CT for detecting intraductal extension of breast carcinoma, and analyzed clinical parameters affecting the detection of intraductal extension under MD-CT.

METHODS

Subjects comprised 44 patients grouped into three categories according to degree of intraductal extension of the main tumor under MD-CT (Intraductal spread grade 1 approximately 3: IDS 1 approximately 3). Tumors were also categorized histopathologically (p-IDS 0 approximately 3), and CT-pathological correlations were examined retrospectively. Clinical parameters were evaluated to determine the affect on detection of intraductal components.

RESULTS

MD-CT detected 44 breast lesions (100%). Sensitivity for detection of intraductal component was 81.2%, specificity was 67.8%, and accuracy was 72.7%. Regarding extent of intraductal components, significant correlations were found between histopathological and MD-CT findings. A strong correlation was found in postmenopausal women between T2 tumor and high histological grade.

CONCLUSIONS

MD-CT findings of intraductal extension from breast carcinoma correlate with histological degree of intraductal extension, and MD-CT may be useful for preoperative assessment of breast-conserving surgery, particularly for postmenopausal women with histological high nuclear grade and T2 tumor.

The use of contrast-enhanced computed tomography before neoadjuvant chemotherapy to identify patients likely to be treated safely with breast-conserving surgery

OBJECTIVE

To select suitable candidates for breast-conserving treatment (BCT) after neoadjuvant chemotherapy (NAC), based on the classification of tumors into localized or diffuse types using contrast-enhanced computed tomography (CE-CT).

SUMMARY BACKGROUND DATA

A relatively high rate of loco-regional failure after BCT has been reported with breast cancer downstaged by NAC. Accurate assessment of the suitability of BCT and the response to NAC, before the initiation of NAC, will allow the optimal selection of an appropriate therapeutic course.

METHODS

We evaluated 110 consecutive patients with operable breast carcinomas measuring 3-cm or more in diameter by CE-CT after NAC treatment with doxorubicin and docetaxel at National Cancer Center Hospital, Tokyo, from May 1998 to November 2001. Lesions were classified as either localized or diffuse types by mammography (MMG), ultrasonography (US), and CE-CT.

RESULTS

Tumors designated as localized type by MMG, US, and CE-CT were reduced to tumors less than 3.0 cm (P < 0.0001) in a concentric circle (P < 0.0001). Localized tumors by CE-CT were treated safely with BCT maintaining a negative margin status (P = 0.01). In contrast, diffuse type tumors shrunk into a mosaic pattern consisting of tumors larger than 3.1 cm. Tumors classified as localized by CE-CT responded better pathologically than diffuse tumors (P = 0.0365). Multivariate analysis demonstrated that morphologic type by CE-CT and histologic type were significant predictors of candidates for safe BCT.

CONCLUSIONS

The classification of tumors into either localized or diffuse types, using CE-CT before NAC administration, accurately predicts which tumors will be suitable candidates for BCT after NAC.

The role of computed tomography in the selection of breast cancer treatment

Contrast-enhanced computed tomography (CE-CT) is one of the most sensitive imaging modalities. CE-CT plays a role in the following: (1) to determine the extent of breast cancer to select the appropriate breast conserving treatment (BCT). The sensitivity and specificity for the detection of extensive intraductal component (EIC) by CE-CT were 82-88% and 75-89%, respectively. The pathological extent of tumors significantly correlated with the extension revealed by CE-CT; (2) to determine the extent of resection following neoadjuvant chemotherapy, which is difficult to assess by other modalities; (3) to diagnose axillary lymph node metastasis. The sensitivity and specificity are 79-90% and 70-89%, respectively; (4) to identify occult breast cancer with axillary metastasis and to diagnose local recurrence after BCT.

Mucocele-like tumor of the breast caused by ductal carcinoma in situ: a case report

A mucocele-like tumor (MLT) of the breast caused by clinging and micropapillary carcinoma in situ is reported. The tumor was a smooth-contoured mass located near the nipple in the lower inner quadrant of the left breast. Ultrasonography showed a cystic tumor and distended ducts. An aspiration specimen contained abundant mucinous material and a small amount of epithelial cell components, but was insufficient for cytological diagnosis. An excisional biopsy specimen disclosed multiple cysts containing mucin with extravasation into the stroma. Additional pathologic diagnosis using consecutive microscopic sections demonstrated ductal carcinoma in situ. Subcutaneous mastectomy was subsequently performed. Histopathologic findings in the resected and biopsy specimens indicated a diagnosis of MLT caused by widely spreading clinging and micropapillary ductal carcinoma in situ. The ductal epithelium of the MLT in an open biopsy specimen must be carefully examined using consecutive microscopic sections to detect occult DCIS.

Overview: current status of breast conserving therapy in Japan

Breast conserving operations have become the standard operation for early breast cancer. They were performed in about 40% of all breast cancer patients in Japan in 2000, and the percentage is still increasing. Ductal carcinoma in situ (DCIS) accounts for about 7% of all breast cancers and breast conserving operations for DCIS have been followed by a low in-breast recurrence rate, leading to wider indications for breast conserving operations as screening mammography has come to be used in Japan. In-breast recurrence is correlated to surgical margin status. It is important to evaluate the surgical margin for volume of cancer cell nests as well as for positivity. Neoadjuvant chemotherapy has become popular as an in vivo sensitivity test and as a means of down-staging to increase the possibility of performing a breast conserving operation. There are two patterns of shrinkage when neoadjuvant chemotherapy is effective: cocentric and honeycomb, and the pattern of residual cancer cell nests must be determined before surgery. MRI is an effective method of evaluating residual cancer cell nests. The in-breast recurrence rate after down-staging to perform breast conserving operations is reported to be higher than among candidates for breast conserving operation at the start. Sentinel node biopsy techniques and endoscopic operations are now being assessed in conjunction with breast conserving operations. The current status of breast conserving operations in Japan is reviewed in comparison with their status in Western countries.

3D imaging of intraductal spread of breast cancer and its clinical application for navigation surgery

BACKGROUND

To perform optimal tumor resection of breast cancer, preoperative information concerning intraductal spread of cancer (ISC) is very important.

METHODS

To detect ISC, three-dimensional (3D) imaging methods including helical CT, MRI, and ultrasound were examined in patients with primary breast cancer by comparison with multi-sliced pathological specimens.

RESULTS

The sensitivity of each modality for detecting ISC was 64.7%, 90.2% and 78.6%, and the specificity was 97.1%, 62.9% and 100%, respectively. Subsequently, the potential of each modality for navigation in breast conserving surgery was assessed. Three-dimensional helical CT navigation could reduce the positive rate of the specimen margins, and 3D MRI navigation using a special mapping sheet enabled removal of non-palpable breast cancer without positive margins in 66.7% of patients preliminarily. Real-time 3D ultrasound images correlated with the resected tumor size, with the difference between the two less than 2 cm in 72.7 % of the patients with ISC.

CONCLUSION

Three-dimensional images from each modality were reliable enough for diagnosis of tumor spread, and surgical navigation using these images seemed to have potential clinical application for breast conserving surgery. Prospective studies for navigation surgery with more patients are needed.

Breast-conserving treatment after neoadjuvant chemotherapy in large breast cancer

Several recent trials have demonstrated that neoadjuvant chemotherapy can allow more patients to successfully undergo breast-conserving treatment (BCT), and does not confer a survival disadvantage compared with standard adjuvant chemotherapy. In addition, the pathological response of primary breast tumors to neoadjuvant chemotherapy appears to be a surrogate marker for patient outcome. In our series, during the period from May 1995 to December 2000, 86 patients with tumors between 3.1 and 6.0 cm in diameter received epirubicin-based neoadjuvant chemotherapy. There were 55 (64.0%) responders and ultimately 64 patients (74.4%) were treated with BCT. The margin positive rate was 14.1%(9/64), similar to the rate after BCT for early-stage breast cancers, the largest diameter of which was smaller than 3 cm. At a median follow-up of 30 months, only 3 patients in the BCT group have developed local recurrence; the local recurrence rate appears to be comparable to that after BCT for early stage breast cancers. Long term follow-up is required, however, to establish whether this procedure is a safe alternative to mastectomy for patients with large breast cancers.

Comparison between high-resolution helical CT and pathology in breast examination

PURPOSE

To determine whether high-resolution helical CT can show the architectural features of breast carcinomas of non-limited extent (non-BCLE) and to establish the CT characteristic morphology of non-BCLE.

MATERIAL AND METHODS

We prospectively studied high-resolution helical CT of 136 invasive breast carcinomas before breast-conserving surgery. Non-BCLE were defined as ductal carcinomas in situ and invasive carcinomas beyond 1 cm from the edge of the dominant mass. Non-BCLE were defined as positive if enhanced beyond 1 cm from the edge of the focal enhancement on CT. After surgical resection, specimens were sliced in serial sections at 5-mm intervals, and the gross morphology and histology were correlated with the appearance of the preoperative CT lesion images.

RESULTS

Non-BCLE were present in 47 invasive carcinomas. The sensitivity and specificity of non-BCLE evaluation by high-resolution helical CT were 70% and 89%, respectively. The morphology of non-BCLE on CT agreed with histologic findings. The morphological pattern on CT significantly correlated with intraductal tumor density adjacent to invasive tumor.

CONCLUSION

Comparison of high-resolution helical CT with histologic data suggests that demonstration of a non-BCLE morphology can make the CT breast carcinoma local staging more accurate.