A pilot study evaluating shaved cavity margins with micro-computed tomography: a novel method for predicting lumpectomy margin status intraoperatively

Usefulness of microfocus computed tomography in life science research: preliminary study using murine micro-hepatic tumor models

PURPOSE

Microfocus computed tomography (micro-CT) has not been widely used at high radiation intensity (industrial micro-CT) in life science fields. In this preliminary study, we investigated its potential value in the detection of micro-hepatic tumors in a mouse model.

METHODS

The liver with micro-hepatic tumors was surgically resected en-bloc from mice, and examined with industrial micro-CT and lower intensity micro-CT (small animal micro-CT). The number of hepatic tumors was manually counted on serial images. Then, the accuracy of each technique was determined by preparing matching liver sections and comparing the number of tumors identified in a conventional pathological examination.

RESULTS

The number of hepatic tumors evaluated with industrial micro-CT showed high concordance with the results of the pathological examinations (intraclass correlation coefficient [ICC]: 0.984; 95% confidence interval [CI] 0.959-0.994). On the other hand, the number of hepatic tumors evaluated with the small animal micro-CT showed low concordance with the number identified in the pathological examinations (ICC: 0.533; 95% CI 0.181-0.815).

CONCLUSION

Industrial micro-CT improved the detection of small structures in resected specimens, and might be a promising solution for life science research.

Micro-computed tomography enables rapid surgical margin assessment during breast conserving surgery (BCS): correlation of whole BCS micro-CT readings to final histopathology

Background

Roughly 23% of breast conserving surgery (BCS) patients undergo a second re-excision procedure due to pathologically positive surgical margins. We investigated the feasibility and potential value of micro-Computed Tomography (micro-CT) as a surgical margin guidance tool during BCS.

Methods

A cohort of 32 BCS specimens was prospectively imaged with a pre-clinical micro-CT system upon arrival in the surgical pathology laboratory. Reconstructed micro-CT scans were evaluated retrospectively by an experienced breast radiologist, who provided binary determinations whether lesions extended to the specimen margin. These readings were then compared to the final pathological diagnosis and to 2D specimen radiography readings.

Results

Of the 32 specimens imaged, 28 had malignant and four had benign pathological diagnoses. Overall five (four malignant, one benign) of the 32 specimens had lesion tissue extending to the margin. For all 32 specimens, micro-CT reconstructions were calculated (< 4 min. acquisition + reconstruction time) and each specimen was volumetrically analyzed by a radiologist. Of the 28 malignant specimen readings, 18 matched the final pathological diagnosis [64%, 95 CI (47%–81%)], with a negative predictive value of 89% [95 CI (74%–96%)]. Micro-CT readings revealed changes in the tumor location and margin status as compared to single-projection radiography readings.

Conclusions

Micro-CT scanning of BCS specimens enabled margin status assessment over the entirety of the surgical surface in a clinically relevant time frame, provided additional spatial information over single-projection radiography, and may be a potentially useful BCS guidance tool.

Electronic supplementary material

The online version of this article (10.1007/s10549-018-4951-3) contains supplementary material, which is available to authorized users.

Early clinical applications for imaging at microscopic detail: microfocus computed tomography (micro-CT)

Microfocus CT (micro-CT) has traditionally been used in industry and preclinical studies, although it may find new applicability in the routine clinical setting. It can provide high-resolution three-dimensional digital imaging data sets to the same level of detail as microscopic examination without the need for tissue dissection. Micro-CT is already enabling non-invasive detailed internal assessment of various tissue specimens, particularly in breast imaging and early gestational fetal autopsy, not previously possible from more conventional modalities such as MRI or CT. In this review, we discuss the technical aspects behind micro-CT image acquisition, how early work with small animal studies have informed our knowledge of human disease and the imaging performed so far on human tissue specimens. We conclude with potential future clinical applications of this novel and emerging technique.

Cavity Shaving plus Lumpectomy versus Lumpectomy Alone for Patients with Breast Cancer Undergoing Breast-Conserving Surgery: A Systematic Review and Meta-Analysis

The margin status is a well-established prognostic predictor for patients undergoing breast-conserving surgery (BCS). Recent data suggested that cavity shaving in addition to lumpectomy might be a promising approach for improving the clinical outcomes. We aimed to compare the efficacy and safety between cavity shaving plus lumpectomy and lumpectomy alone with a systematic review and meta-analysis. We searched the PubMed, Embase, and Cochrane CENTRAL databases for studies comparing cavity shaving with lumpectomy before June 10, 2016. Both comparative studies and self-control studies were included. A random-effects model was used to estimate the odds ratios (ORs) for positive margin rate, reoperation rate, recurrence rate, and weighted mean difference (WMD) for excised tissue volume. Twenty-six studies were included in the meta-analysis. The cavity shaving group had a significantly lower positive margin rate than the BCS-alone group (16.4% vs. 31.9%; OR = 0.41, 95% CI 0.32-0.53, P < 0.05). Cavity shaving was associated with a significantly decreased rate of reoperation (OR = 0.42, 95% CI 0.30-0.59, P < 0.05). The overall locoregional rate was low for cavity shaving and BCS-alone (3% vs. 4%). Cavity shaving had no significant effect on the risk of locoregional recurrence (OR = 0.86, 95% CI 0.32-2.35; P = 0.78). The excised tissue volume did not differ substantially between cavity shaving and BCS alone (WMD = -23.88, 95% CI -55.20 to 7.44, P = 0.14). For patients undergoing BCS, additional cavity shaving was an effective method to decrease the positive margin rate and avoid reoperation. The addition of cavity shaving did not appear to have excessive excised tissue volume compared with partial mastectomy alone.

Prediction of primary breast cancer size and T-stage using micro-computed tomography in lumpectomy specimens

Background:

Histopathology is the only accepted method to measure and stage the breast tumor size. However, there is a need to find another method to measure and stage the tumor size when the pathological assessment is not available. Micro-computed tomography. (micro-CT) has the ability to measure tumor in three dimensions in an intact lumpectomy specimen. In this study, we aimed to determine the accuracy of micro-CT to measure and stage the primary tumor size in breast lumpectomy specimens, as compared to the histopathology.

Materials and Methods:

Seventy-two women who underwent lumpectomy surgery at the Massachusetts General Hospital Department of Surgery from June 2011 to September 2011, and from August 2013 to December 2013 participated in this study. The lumpectomy specimens were scanned using micro-CT followed by routine pathological processing. The maximum dimension of the invasive breast tumor was obtained from the micro-CT image and was compared to the corresponding pathology report for each subject.

Results:

The invasive tumor size measurement by micro-CT was underestimated in 24 cases. (33%), overestimated in 37 cases. (51%), and matched it exactly in 11 cases. (15%) compared to the histopathology measurement for all the cases. However, micro-CT T-stage classification differed from histopathology in only 11. (15.2%) with 6 cases. (8.3%) classified as a higher stage by micro-CT, and 5 cases. (6.9%) classified as lower compared to histopathology. In addition, micro-CT demonstrated a statically significant strong agreement (κ =0.6, P < 0.05) with pathological tumor size and staging for invasive ductal carcinoma. (IDC) group. In contrast, there was no agreement. (κ = −2, P = 0.67) between micro-CT and pathology in estimating and staging tumor size for invasive lobular carcinoma. (ILC) group. This could be explained by a small sample size. (7) for ILC group.

Conclusions:

Micro-CT is a promising modality for measuring and staging the IDC.

Intraoperative micro-computed tomography (micro-CT): a novel method for determination of primary tumour dimensions in breast cancer specimens

OBJECTIVES

Micro-CT is a promising modality to determine breast tumour size in three dimensions in intact lumpectomy specimens. We compared the accuracy of tumour size measurements using specimen micro-CT with measurements using multimodality pre-operative imaging.

METHODS

A tabletop micro-CT was used to image breast lumpectomy specimens. The largest tumour dimension on three-dimensional reconstructed micro-CT images of the specimen was compared with the measurements determined by pre-operative mammography, ultrasound and MRI. The largest dimension of pathologic invasive cancer size was used as the gold standard reference to assess the accuracy of imaging assessments.

RESULTS

50 invasive breast cancer specimens in 50 patients had micro-CT imaging. 42 were invasive ductal carcinoma, 6 were invasive lobular carcinoma and 2 were other invasive cancer. Median patient age was 63 years (range 33-82 years). When compared with the largest pathologic tumour dimension, micro-CT measurements had the best correlation coefficient (r = 0.82, p < 0.001) followed by MRI (r = 0.78, p < 0.001), ultrasound (r = 0.61, p < 0.001) and mammography (r = 0.40, p < 0.01). When compared with pre-operative modalities, micro-CT had the best correlation coefficient (r = 0.86, p < 0.001) with MRI, followed by ultrasound (r = 0.60, p < 0.001) and mammography (r = 0.54, p < 0.001). Overall, mammography and ultrasound tended to underestimate the largest tumour dimension, while MRI and micro-CT overestimated the largest tumour dimension more frequently.

CONCLUSION

Micro-CT is a potentially useful tool for accurate assessment of tumour dimensions within a lumpectomy specimen. Future studies need to be carried out to see if this technology could have a role in margin assessment.

ADVANCES IN KNOWLEDGE

Micro-CT is a promising new technique which could potentially be used for rapid assessment of breast cancer dimensions in an intact lumpectomy specimen in order to guide surgical excision.

Micro-computed tomography (Micro-CT): a novel approach for intraoperative breast cancer specimen imaging

Intraoperative radiographic examination of breast specimens is commonly performed to confirm excision of image-detected breast lesions, but it is not reliable for assessing margin status. A more accurate method of intraoperative breast specimen imaging is needed. Micro-CT provides quantitative imaging parameters, image rotation, and virtual "slicing" of intact breast specimens. We explored the use of micro-CT for assessment of a variety of clinical breast specimens. Specimens were evaluated with a table top micro-CT scanner, Skyscan 1173 (Skyscan, Belgium), with a 40-130 kV, 8 W X-ray source. Skyscan software for 3D image analysis (Dataviewer and CTVox) was employed to review 3D graphics of specimens. Scanning for 7 min and another 7 min for image reconstruction provided the desired resolution for breast specimens. Breast lumpectomy specimens, shaved cavity margins, mastectomy specimens, and axillary lymph nodes were imaged by micro-CT. The micro-CT images could be rotated in all directions and cross sections of internal portions of specimens could be visualized from any angle. This provided information about spatial orientation of masses and calcifications relative to margins in intact lumpectomy specimens. Micro-CT is a potentially useful tool for assessment of breast cancer specimens, allowing real-time analysis of tumor location in breast lumpectomy specimens or shaved cavity margins. Micro-CT may also be useful for assessing sentinel lymph nodes and mastectomy specimens.