Use of Tomosynthesis in Intraoperative Digital Specimen Radiography - Is a Reduction of Breast Re-excision Rates Possible?

Intraoperative digital breast tomosynthesis using a dedicated device is more accurate than standard intraoperative mammography for identifying positive margins

AIM

To compare a standard intra-operative mammography (IM) device with digital breast tomosynthesis using a dedicated device (Mozart system) in the evaluation of surgical margins at first excision.

MATERIALS AND METHODS

The study received institutional review board approval and written informed consent was obtained from participants. From January 2018 to December 2018, a prospective analysis of the images of IM device and intra-operative digital breast tomosynthesis with a dedicated device (Mozart system) in n=89 breast cancer patients (average patients age: 58 years, age range: 35-76 years) was undertaken. Images were evaluated by two expert breast radiologists independently of each other and blinded to each other's interpretation, who indicated the positive cases requiring surgical re-excision intra-operatively.

RESULTS

Mean cancer size was 12.5±4.5 mm. Radiological signs of the lesions were microcalcifications (n=71), nodules (n=10), and architectural distortions (n=8). A total of 20/89 (17%) patients underwent intra-operative re-excision for positive margins. Intra-operative digital breast tomosynthesis with a dedicated device and IM showed discrepancies in 15/89 cases (17%). Mozart system results informed the necessity to perform a re-excision (n=15). Overall, receiver operating characteristic (ROC) curve analysis showed and area under the ROC curve (AUC) of 0.82 for the Mozart system versus 0.65 for IM. ROC analysis of radiological findings with microcalcifications showed an AUC of 0.92 for the Mozart system versus 0.74 for IM, whereas AUC in cases with no microcalcifications were 0.87 and 0.75, respectively.

CONCLUSION

Intra-operative digital breast tomosynthesis with a dedicated device provides more information (better accuracy) than IM and facilitated a reduction in re-excision rates.

Digital breast tomosynthesis versus full-field digital mammography-Which modality provides more accurate prediction of margin status in specimen radiography?

OBJECTIVES

To evaluate the reliability of tumor margin assessment in specimen radiography (SR) using digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM) in comparison to postoperative histopathology margin status as the gold standard.

METHODS

After ethics committee approval, 102 consecutive patients who underwent breast conservative surgery for nonpalpable proven breast cancer were prospectively included. All patients underwent ultrasound/mammography-guided wire localization of their lesions. After excision, each specimen was marked for orientation and imaged using FFDM and DBT. Two blinded radiologists (R1, R2) independently analyzed images acquired with both modalities. Readers identified in which direction the lesion was closest to the specimen margin and to measure the margin width. Their findings were compared with the final histopathological analysis. True positive margin status was defined as a margin measuring <1mm for invasive cancer and 5mm for ductal carcinoma in situ (DCIS) at imaging and pathology.

RESULTS

For FFDM, correct margin direction was identified in 45 cases (44%) by R1 and in 37 cases (36%) by R2. For DBT, 69 cases (68%) were correctly identified by R1 and 70 cases (69%) by R2. Overall accuracy was 40% for FFDM and 69% for DBT; the difference was statistically significant (p<0.0001). Sensitivity in terms of correct assessment of margin status was significantly better for DBT than FFDM (77% versus 62%).

CONCLUSION

SR using DBT is significantly superior to FFDM regarding identification of the closest margin and sensitivity in assessment of margin status.

Predictors of re-excision in wire-guided wide local excision for early breast cancer: a Western Australian multi-centre experience

BACKGROUND

A significant proportion of breast cancers present as impalpable lesions requiring radiological guidance prior to surgical excision, commonly by hook-wire placement. Complete lesion excision is an essential part of treatment, and re-excision may be needed to ensure this and minimize local recurrence. We explore a 1-year audit of re-excision of hook-wire-guided excisions in two large public breast units in Western Australia and define factors associated with the requirement for re-excision.

METHODS

A retrospective review of wire-localized wide local excisions for early breast cancer in 2009 at two tertiary breast centres in Western Australia.

RESULTS

Of 148 localized lesions, 44 (30%) underwent re-excision. The only significant preoperative finding was the location of tumour in the breast. The intra-operative specimen radiograph provided useful information that influenced re-excision. Smaller (≤5 mm) and larger (>20 mm) tumours on final pathological size were more likely to undergo re-excision as well as a larger difference in actual size to predicted size. The presence of ductal carcinoma in situ (DCIS) increased re-operation, as did multifocality.

CONCLUSION

This study highlights factors that should make the surgeon more cautious for re-excision. Suspicion of DCIS, especially at the periphery of tumours, and a central tumour location increase risk. Lesion localization techniques play an important role in minimizing risk while maintaining cosmesis.

Full Field Digital Mammography (FFDM) versus CMOS Technology, Specimen Radiography System (SRS) and Tomosynthesis (DBT) - Which System Can Optimise Surgical Therapy?

Aim: This prospective clinical study aimed to evaluate whether it would be possible to reduce the rate of re-excisions using CMOS technology, a specimen radiography system (SRS) or digital breast tomosynthesis (DBT) compared to a conventional full field digital mammography (FFDM) system. Material and Method: Between 12/2012 and 2/2013 50 patients were diagnosed with invasive breast cancer (BI-RADS™ 5). After histological verification, all patients underwent breast-conserving therapy with intraoperative imaging using 4 different systems and differing magnifications: 1. Inspiration™ (Siemens, Erlangen, Germany), amorphous selenium, tungsten source, focus 0.1 mm, resolution 85 µm pixel pitch, 8 lp/mm; 2. BioVision™ (Bioptics, Tucson, AZ, USA), CMOS technology, photodiode array, flat panel, tungsten source, focus 0.05, resolution 50 µm pixel pitch, 12 lp/mm; 3. the Trident™ specimen radiography system (SRS) (Hologic, Bedford, MA, USA), amorphous selenium, tungsten source, focus 0.05, resolution 70 µm pixel pitch, 7.1 lp/mm; 4. tomosynthesis (Siemens, Erlangen, Germany), amorphous selenium, tungsten source, focus 0.1 mm, resolution 85 µm pixel pitch, 8 lp/mm, angular range 50 degrees, 25 projections, scan time > 20 s, geometry: uniform scanning, reconstruction: filtered back projection. The 600 radiographs were prospectively shown to 3 radiologists. Results: Of the 50 patients with histologically proven breast cancer (BI-RADS™ 6), 39 patients required no further surgical therapy (re-excision) after breast-conserving surgery. A retrospective analysis (n = 11) showed a significant (p < 0.05) increase of sensitivity with the BioVision™, the Trident™ and tomosynthesis compared to the Inspiration™ at a magnification of 1.0 : 2.0 or 1.0 : 1.0 (tomosynthesis) (2.6, 3.3 or 3.6 %), i.e. re-excision would not have been necessary in 2, 3 or 4 patients, respectively, compared to findings obtained with a standard magnification of 1.0 : 1.0. Conclusion: The sensitivity of the BioVision™, the Trident™ and tomosynthesis was significantly (p < 0.05) higher and the rate of re-excisions was reduced compared to FFDM using a conventional detector at a magnification of 2.0 but without zooming.

Mammographic Density and Prediction of Nodal Status in Breast Cancer Patients

Aim: Nodal status remains one of the most important prognostic factors in breast cancer. The cellular and molecular reasons for the spread of tumor cells to the lymph nodes are not well understood and there are only few predictors in addition to tumor size and multifocality that give an insight into additional mechanisms of lymphatic spread. Aim of our study was therefore to investigate whether breast characteristics such as mammographic density (MD) add to the predictive value of the presence of lymph node metastases in patients with primary breast cancer. Methods: In this retrospective study we analyzed primary, metastasis-free breast cancer patients from one breast center for whom data on MD and staging information were available. A total of 1831 patients were included into this study. MD was assessed as percentage MD (PMD) using a semiautomated method and two readers for every patient. Multiple logistic regression analyses with nodal status as outcome were used to investigate the predictive value of PMD in addition to age, tumor size, Ki-67, estrogen receptor (ER), progesterone receptor (PR), grading, histology, and multi-focality. Results: Multifocality, tumor size, Ki-67 and grading were relevant predictors for nodal status. Adding PMD to a prediction model which included these factors did not significantly improve the prediction of nodal status (p = 0.24, likelihood ratio test). Conclusion: Nodal status could be predicted quite well with the factors multifocality, tumor size, Ki-67 and grading. PMD does not seem to play a role in the lymphatic spread of tumor cells. It could be concluded that the amount of extracellular matrix and stromal cell content of the breast which is reflected by MD does not influence the probability of malignant breast cells spreading from the primary tumor to the lymph nodes.

Re-excision Rates and Local Recurrence in Breast Cancer Patients Undergoing Breast Conserving Therapy

Background: Controversy continues over the impact of re-excision (RE) on local recurrence (LR) in patients with invasive breast cancer. Patients and Methods: We investigated factors which could effect RE rates in patients undergoing breast-conserving or oncoplastic surgery. Between 2000 and 2003, 489 patients with stage pT1-pT2 or pN0/1 tumors were evaluated. 74 patients fulfilled the inclusion criteria. Patients were categorized into 3 groups: no RE (n = 25), RE during primary surgery (n = 28), and RE performed during secondary or even tertiary procedure (n = 21). All tumor slides were re-evaluated by a pathologist specializing in breast cancer. Results: Mean follow-up was 70 months with an overall LR rate of 4.1 %. Binary logistic regression revealed no tumor-specific risk factors for RE. There was no LR in the group of patients who did not have RE. There was one case of LR in the group of patients who had RE during primary surgery. Two cases of LR were observed in the group of patients who had two or more surgical procedures. Conclusion: New risk factors for increased RE rates were not observed, reflecting the inconsistent data on risk factors for RE. However, breast cancers should be excised in a single procedure and oncoplastic procedures should be considered.

Full Field Digital Mammography (FFDM) versus CMOS Technology versus Tomosynthesis (DBT) - Which System Increases the Quality of Intraoperative Imaging?

Aim: The aim of this prospective clinical study was to assess whether it would be possible to reduce the rate of re-excisions and improve the quality using CMOS technology or digital breast tomosynthesis (DBT) compared to a conventional FFDM system. Material and Methods: An invasive breast cancer (BI-RADS 5) was diagnosed in 200 patients in the period from 5/2011 to 1/2012. After histological verification, a breast-conserving therapy was performed with intraoperative imaging. Three different imaging systems were used: 1) Inspiration™ (Siemens, Erlangen, Germany), amorphous selenium, tungsten source, focus 0.1 mm, resolution 85 µm pixel pitch, 8 l/mm as the standard; 2) BioVision™ (Bioptics, Tucson, USA), flat panel photodiode array, tungsten source, focus 0.05, resolution 50 µm pixel pitch, 12 l/mm; 3) Tomosynthesis (Siemens, Erlangen, Germany), amorphous selenium, tungsten source, focus 0.1 mm, resolution 85 µm pixel pitch, 8 l/mm, range: 50°, 25 projections, scan time > 20 s, geometry: uniform scanning, reconstruction: filtered back projection. The 600 radiograms were prospectively shown to 3 radiologists. Results: Out of a total of 200 patients with histologically confirmed breast cancer (BI-RADS 6) 156 patients required no further operative therapy (re-excision) after breast-conserving therapy. A retrospective analysis (n = 44) showed an increase in sensitivity with tomosynthesis compared to the BioVision™ (CMOS technology) and the Inspiration™ at a magnification of 1.0 : 1.0 of 8 % (p < 0.05), i.e. re-excision would not have been necessary in 16 patients with tomosynthesis. Conclusions: The sensitivity of tomosynthesis for intraoperative radiography is significantly (p < 0.05) higher compared to both CMOS technology and an FFDM system with a conventional detector. Additional studies using higher magnification, e.g. 2.0 : 1.0, but no zooming will be necessary to evaluate the method further.