Evaluation of the usefulness of breast CT imaging in delineating tumor extent and guiding surgical management: a prospective multi-institutional study

Breast cancer assessment under neoadjuvant systemic therapy using thoracic photon-counting detector computed tomography in prone position: a pilot study

BACKGROUND

Accurate assessment of treatment response to neoadjuvant systemic therapy (NAST) in breast cancer is important prior to surgery. We aimed at evaluating the feasibility of thoracic photon-counting detector computed tomography (PCCT) in assessing treatment response in breast cancers following NAST.

METHODS

We retrospectively included patients with newly diagnosed breast cancer who received contrast-enhanced thoracic PCCT in prone position before and after NAST. Three experienced radiologists measured tumor size, tumor area, iodine uptake within tumors, number of suspicious breast lesions and of suspicious axillary lymph nodes before and after NAST. We compared the initial tumor size to contrast-enhanced magnetic resonance imaging (MRI), the residual tumor size after NAST to histopathology.

RESULTS

Eighteen PCCT exams in nine patients aged 58 ± 14 years (mean ± standard deviation) were analyzed. After NAST, PCCT correctly identified a reduction in tumor burden in 9 of 9 cases and a complete response in 2 of 2 cases, with a significant reduction in tumor size, area, T-stage, number of suspicious breast lesions and of suspicious lymph nodes (p < 0.001 for all) as well as reduction in cutaneous infiltration (p = 0.010). Mean and maximum iodine uptake showed a nonsignificant reduction in cases with residual tumor after NAST (p = 0.092 and 0.363).

CONCLUSION

These preliminary findings suggest that thoracic PCCT can accurately detect local changes in breast cancer after NAST.

RELEVANCE STATEMENT

Thoracic PCCT offers promising potential for accurately assessing breast cancer response to NAST.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00028997.

KEY POINTS

Prone thoracic contrast-enhanced photon-counting detector computed tomography (PCCT) can accurately detect reductions in tumor size, area, and T-stage. Prone PCCT can identify a decrease in the number of suspicious axillary lymph nodes. This technique shows promising results in identifying breast cancer response to neoadjuvant systemic therapy (NAST).

Dedicated Breast CT: Getting Ready for Prime Time

Dedicated breast CT is an imaging modality that provides true 3D imaging of the breast with many advantages over current conventional breast imaging modalities. The addition of intravascular contrast increases the sensitivity of breast CT substantially. As such, there are immediate potential applications in the clinical workflow. These include using breast CT to replace much of the traditional diagnostic workup when faced with indeterminate breast lesions. Contrast-enhanced breast CT may be appropriate as a supplemental screening tool for women at high risk of breast cancer, similar to breast MRI. In addition, emerging studies are demonstrating the utility of breast CT in neoadjuvant chemotherapy tumor response monitoring as well as planning for surgical treatment options. While short exam times and fully 3D imaging in a noncompressed position are advantages of this modality, limited coverage of chest wall/axilla due to prone positioning and use of ionizing radiation are drawbacks. To date, several studies have reported on the performance characteristics of this promising modality.

Diagnostic Accuracy of Contrast-Enhanced Thoracic Photon-Counting Computed Tomography for Opportunistic Locoregional Staging of Breast Cancer Compared With Digital Mammography: A Prospective Trial

OBJECTIVE

Accurate locoregional staging is crucial for effective breast cancer treatment. Photon-counting computed tomography (PC-CT) is an emerging technology with high spatial resolution and the ability to depict uptake of contrast agents in tissues, making it a promising tool for breast cancer imaging. The aim of this study was to establish the feasibility of locoregional staging of breast cancer through contrast-enhanced thoracic PC-CT, assess its diagnostic performance, and compare it with that of digital mammography (DM).

MATERIALS AND METHODS

Patients with newly diagnosed breast cancer, DM, and indication of thoracic CT staging were prospectively enrolled in this clinical cohort study over a period of 6 months. Participants underwent contrast-enhanced thoracic PC-CT and breast magnetic resonance imaging in prone position. After blinding to patient data, 2 radiologists independently rated PC-CT and DM regarding the following 6 characteristics: (1) diameter of the largest mass lesion, (2) infiltration of cutis/pectoral muscle/thoracic wall, (3) number of mass lesions, (4) presence/absence of adjacent ductal carcinoma in situ (DCIS), (5) tumor conspicuity, and (6) diagnostic confidence. Reference standard was generated from consensus reading of magnetic resonance imaging combined with all histopathological/clinical data by an independent adjudication committee applying TNM eighth edition.

RESULTS

Among 32 enrolled female subjects (mean ± SD age, 59 ± 13.0 years), diagnostic accuracy for T-classification was higher for PC-CT compared with DM (0.94 vs 0.50, P < 0.01). Moreover, the correlation of the number of detected tumor masses with the reference standard was stronger for PC-CT than for DM (0.72 vs 0.50, P < 0.01). We observed that PC-CT significantly ( P < 0.04) outperformed DM regarding not only sensitivity (0.83 and 0.25, respectively) but also specificity (0.99 and 0.80, respectively) for adjacent DCIS. The κ values for interreader reliability were higher for PC-CT compared with DM (mean 0.88 vs 0.54, respectively; P = 0.01).

CONCLUSIONS

Photon-counting computed tomography outperformed DM in T-classification and provided higher diagnostic accuracy for the detection of adjacent DCIS. Therefore, opportunistic locoregional staging of breast cancer in contrast-enhanced thoracic PC-CT is feasible and could overcome limitations of DM with the potential to improve patient management.

ACR Appropriateness Criteria® Imaging of Invasive Breast Cancer

As the proportion of women diagnosed with invasive breast cancer increases, the role of imaging for staging and surveillance purposes should be determined based on evidence-based guidelines. It is important to understand the indications for extent of disease evaluation and staging, as unnecessary imaging can delay care and even result in adverse outcomes. In asymptomatic patients that received treatment for curative intent, there is no role for imaging to screen for distant recurrence. Routine surveillance with an annual 2-D mammogram and/or tomosynthesis is recommended to detect an in-breast recurrence or a new primary breast cancer in women with a history of breast cancer, and MRI is increasingly used as an additional screening tool in this population, especially in women with dense breasts. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Diagnostic value of preoperative examination for evaluating margin status in breast cancer

BACKGROUND

A positive resection margin is a major risk factor for local breast cancer recurrence after breast-conserving surgery (BCS). Preoperative imaging examinations are frequently employed to assess the surgical margin.

AIM

To investigate the role and value of preoperative imaging examinations [magnetic resonance imaging (MRI), molybdenum target, and ultrasound] in evaluating margins for BCS.

METHODS

A retrospective study was conducted on 323 breast cancer patients who met the criteria for BCS and consented to the procedure from January 2014 to July 2021. The study gathered preoperative imaging data (MRI, ultrasound, and molybdenum target examination) and intraoperative and postoperative pathological information. Based on their BCS outcomes, patients were categorized into positive and negative margin groups. Subsequently, the patients were randomly split into a training set (226 patients, approximately 70%) and a validation set (97 patients, approximately 30%). The imaging and pathological information was analyzed and summarized using R software. Non-conditional logistic regression and LASSO regression were conducted in the validation set to identify factors that might influence the failure of BCS. A column chart was generated and applied to the validation set to examine the relationship between pathological margin range and prognosis. This study aims to identify the risk factors associated with failure in BCS.

RESULTS

The multivariate non-conditional logistic regression analysis demonstrated that various factors raise the risk of positive margins following BCS. These factors comprise non-mass enhancement (NME) on dynamic contrast-enhanced MRI, multiple focal vascular signs around the lesion on MRI, tumor size exceeding 2 cm, type III time-signal intensity curve, indistinct margins on molybdenum target examination, unclear margins on ultrasound examination, and estrogen receptor (ER) positivity in immunohistochemistry. LASSO regression was additionally employed in this study to identify four predictive factors for the model: ER, molybdenum target tumor type (MT Xmd Shape), maximum intensity projection imaging feature, and lesion type on MRI. The model constructed with these predictive factors exhibited strong consistency with the real-world scenario in both the training set and validation set. Particularly, the outcomes of the column chart model accurately predicted the likelihood of positive margins in BCS.

CONCLUSION

The proposed column chart model effectively predicts the success of BCS for breast cancer. The model utilizes preoperative ultrasound, molybdenum target, MRI, and core needle biopsy pathology evaluation results, all of which align with the real-world scenario. Hence, our model can offer dependable guidance for clinical decision-making concerning BCS.

Diagnostic value of preoperative examination for evaluating margin status in breast cancer

BACKGROUND

A positive resection margin is a major risk factor for local breast cancer recurrence after breast-conserving surgery (BCS). Preoperative imaging examinations are frequently employed to assess the surgical margin.

AIM

To investigate the role and value of preoperative imaging examinations [magnetic resonance imaging (MRI), molybdenum target, and ultrasound] in evaluating margins for BCS.

METHODS

A retrospective study was conducted on 323 breast cancer patients who met the criteria for BCS and consented to the procedure from January 2014 to July 2021. The study gathered preoperative imaging data (MRI, ultrasound, and molybdenum target examination) and intraoperative and postoperative pathological information. Based on their BCS outcomes, patients were categorized into positive and negative margin groups. Subsequently, the patients were randomly split into a training set (226 patients, approximately 70%) and a validation set (97 patients, approximately 30%). The imaging and pathological information was analyzed and summarized using R software. Non-conditional logistic regression and LASSO regression were conducted in the validation set to identify factors that might influence the failure of BCS. A column chart was generated and applied to the validation set to examine the relationship between pathological margin range and prognosis. This study aims to identify the risk factors associated with failure in BCS.

RESULTS

The multivariate non-conditional logistic regression analysis demonstrated that various factors raise the risk of positive margins following BCS. These factors comprise non-mass enhancement (NME) on dynamic contrast-enhanced MRI, multiple focal vascular signs around the lesion on MRI, tumor size exceeding 2 cm, type III time-signal intensity curve, indistinct margins on molybdenum target examination, unclear margins on ultrasound examination, and estrogen receptor (ER) positivity in immunohistochemistry. LASSO regression was additionally employed in this study to identify four predictive factors for the model: ER, molybdenum target tumor type (MT Xmd Shape), maximum intensity projection imaging feature, and lesion type on MRI. The model constructed with these predictive factors exhibited strong consistency with the real-world scenario in both the training set and validation set. Particularly, the outcomes of the column chart model accurately predicted the likelihood of positive margins in BCS.

CONCLUSION

The proposed column chart model effectively predicts the success of BCS for breast cancer. The model utilizes preoperative ultrasound, molybdenum target, MRI, and core needle biopsy pathology evaluation results, all of which align with the real-world scenario. Hence, our model can offer dependable guidance for clinical decision-making concerning BCS.

A comparison study between gross tumor volumes defined by preoperative magnetic resonance imaging, postoperative specimens, and tumor bed for radiotherapy after breast-conserving surgery

BACKGROUND

The identification and contouring of target volume is important for breast-conserving therapy. The aim of the study was to compare preoperative magnetic resonance imaging (MRI), postoperative pathology, excised specimens' (ES) size, and tumor bed (TB) delineation as methods for determining the gross tumor volume (GTV) for radiotherapy after breast-conserving surgery (BCS).

METHODS

Thirty-three patients with breast cancer who underwent preoperative MRI and radiotherapy after BCS were enrolled. The GTVs determined by MRI, pathology, and the ES were defined as GTVMRI, GTVPAT, and GTVES, respectively. GTVMRI+1 was defined as a 1.0-cm margin around the GTVMRI. The radiation oncologist delineated GTV of the TB (GTVTB) using planning computed tomography according to ≥5 surgical clips placed in the lumpectomy cavity (LC).

RESULTS

The median GTVMRI, GTVMRI+1, GTVPAT, GTVES, and GTVTB were 0.97 cm (range, 0.01-6.88), 12.58 cm (range, 3.90-34.13), 0.97 cm (range, 0.01-6.36), 15.46 cm (range, 1.15-70.69), and 19.24 cm (range, 4.72-54.33), respectively. There were no significant differences between GTVMRI and GTVPAT, GTVMRI+1 and GTVES, GTVES and GTVTB (P = 0.188, 0.070, and 0.264, respectively). GTVMRI is positively related with GTVPAT. However, neither GTVES nor GTVTB correlated with GTVMRI (P = 0.071 and 0.378, respectively). Furthermore, neither GTVES nor GTVTB correlated with GTVMRI+1 (P = 0.068 and 0.375, respectively).

CONCLUSION

When ≥5 surgical clips were placed in the LC for BCS, the volume of TB was consistent with the volume of ES. Neither the volume of TB nor the volume of ES correlated significantly with the volume of tumor defined by preoperative MRI.

Targeted sonography using an image fusion technique for evaluation of incidentally detected breast lesions on chest CT: a pilot study

BACKGROUND

With increasing use of computed tomography (CT), incidentally detected breast lesions are being encountered more frequently. The aim of our study was to verify the utility of targeted sonography using an image fusion technique, real-time virtual sonography (RVS) that coordinates real-time sonography images with previously obtained CT images using a magnetic position tracking system, for evaluation of incidentally detected breast lesions on chest CT.

METHODS

Eleven lesions in 11 women with no history of breast cancer who were referred to our unit for assessment of breast lesions incidentally detected on CT were enrolled in this study. To assess the efficacy of targeted sonography using RVS, we analyzed the frequency of sonographic detection of incidentally detected breast lesions and the difference between sonography- and CT-determined diameters.

RESULTS

Using RVS guidance, all 11 lesions were sonographically detected. Ten (91 %) of 11 lesions underwent sonography-guided biopsy, yielding a success rate of 90 % (9/10). The remaining sonography-guided biopsy failure lesion required surgical biopsy for definitive diagnosis; this was performed after RVS was used to mark CT imaging information onto the breast surface. Four (36 %) lesions subsequently proved to be malignant. The mean diameters provided by RVS were 14.9 ± 6.7 mm for sonography and 16.8 ± 7.5 mm for CT (p = 0.538).

CONCLUSION

Using RVS, a sonographic probe was precisely guided to the lesions. Our results suggest that targeted sonography using RVS is a useful technique for identifying incidentally detected breast lesions on chest CT.

Contrast enhanced computed tomography is indicative for angiogenesis pattern and display prognostic significance in breast cancer

Background

The Prognostic value of microvessel density in cancer remains unclear. Recent studies have suggested that the uneven distribution of microvessels in tumours caused the variation in sample selection which led to different prognostic outcome. The enhancement pattern of Contrast-enhanced computed tomography (CECT) is determined in part by the microvessel distribution in solid tumors. Therefore, survival analysis of tumors grouping by the enhancement pattern and the pattern of microvessel distribution is important.

Methods

Survival analysis grouped by the tumor enhancement pattern and the microvessel distribution was carried out in 255 patients with invasive ductal carcinoma.

Results

There were significant differences in overall survival (OS) and disease-free survival (DFS) among the homogeneous, heterogeneous and peripheral enhancement groups. There were significant differences between OS and DFS groups with uniform and uneven distributions of microvessels.

Conclusions

The distribution of microvessels in a tumor is a potential prognostic indicator in patients with breast cancer, and can be assessed by CECT prior the operation.

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.