Imaging Case 32:
Breast cancer - Invasive Ductal Carcinoma with DCIS components
Positive margins in breast cancer surgery can lead to significant consequences, including additional healthcare costs for society and increased health risks for patients. These risks may include the need for surgical re-intervention, supplementary adjuvant, and a higher likelihood of relapse.
Pathology remains the gold standard for evaluating the success of a resection by confirming clear negative margins. This process involves sectioning the specimen into slices and examining them microscopically. However, pathology assessments require multiple time-intensive steps, often delaying definitive results for at least 3–5 working days. For this reason, real-time margin assessment during surgery is essential to allow immediate corrective actions when necessary. Current intraoperative techniques, such as ultrasound (US) and frozen section analysis, offer benefits but also have limitations [1].
Furthermore, sampling the specimen for histopathological assessment may compromise accuracy, as only 0.5% of the total specimen undergoes microscopic examination [2].
In this case, we illustrate how specimen PET-CT imaging enables real-time visualization of the resected tissue during surgery, supporting surgeons in making well-informed decisions [3,4]. Additionally, this imaging technique may have the potential to assist pathologists by directing their attention to specific areas of the specimen that require closer examination.
This case is part of the multi-center prospective BrIMA study (NCT04999917).
Patient history
A 70-year-old woman was diagnosed with Invasive Ductal Carcinoma, NST in her left breast. The tumor size on preoperative imaging was approximately 20 mm. Biopsy showed a grade 2 tumor, with receptor status PR/ER/HER2 + and a Ki-67 index of 5%. Preoperative staging was cT2N0M0. The patient was scheduled for breast-conserving surgery, with sentinel lymph node resection.
Figure 1: Transverse, coronal, and sagittal slices of the specimen PET-CT images of the tumor specimen, together with a 3D view. Specimen orientation is as indicated. The PET tracer scale bar is depicted on the left-hand side. These images reveal a clear region with increased 18F-FDG uptake, for which the uptake is close – but not reaching – the medial-superior border of the specimen.
Specimen PET-CT imaging
The patient received an intramural injection of 99mTc for sentinel node localization, and was intravenously injected with 0.8 MBq/kg of 18F-FDG at the Nuclear Medicine Department. The patient was then transferred to the operating theatre and breast-conserving surgery was performed.
Immediately after resection of the tumor, a high-resolution specimen PET-CT image was acquired in the operating theatre. The images of the tumor specimen clearly visualize the tumor as a bright coloured region. At the superior-medial side of the specimen, 18F-FDG uptake is seen close - but not reaching the specimen border.
The surgeon consulted the CT images as well, for which a dense region is reaching the border of the specimen, see Fig. 2. Although interpretation of the specimen PET-CT suggested that the tumor was completely resected, the surgeon decided, based on the combination of her clinical suspicion with the specimen PET-CT images, to obtain a cavity shave in the superior-medial side of the resection cavity.
Figure 2: Transverse, coronal, and sagittal slices of the specimen CT images of the tumor specimen, together with a 3D view. Specimen orientation is as indicated.
Figure 3: The (a) CT and (b) specimen PET-CT images of the sentinel lymph nodes. The PET tracer scale bar is depicted on the right-hand side. The CT images visualize a circular dense structures allowing confirmation that a lymph node was resected. The specimen PET-CT images of the lymph nodes showed no significant 18F-FDG uptake.
Subsequently, sentinel lymph node dissection was performed, using a gamma probe and technetium. The resected lymph node was placed in specimen containers and imaged using the XEOS AURA 10 specimen PET-CT imager, 90 min after radiotracer injection. The CT images visualize a circular dense structure allowing confirmation that a lymph node was resected, see Fig 3a. Figure 3b shows specimen PET-CT images of the lymph nodes. No significant 18F-FDG uptake is visualized in any of the lymph nodes.
Histopathological evaluation
After PET-CT imaging, the surgical specimen was sent to the pathology department for routine histopathological evaluation, which was available after several days. The histopathological results are listed in Table 1.
A negative, yet close surgical margin of 1.5 mm was found at the superior-medial side. Importantly, a DCIS component was seen inside the invasive component. Even though margins were negative, the cavity shave contained components of DCIS. For the sentinel lymph node, no metastatic deposit was found in final pathology.
Table 1: Tumor and lymph node characteristics assessed by histopathological evaluation.
Discussion and conclusion
In this interesting case, the surgeon opted to perform an additional cavity shave based on specimen PET-CT imaging, which revealed 18F-FDG uptake near the superior-medial border of the specimen. While histopathological evaluation later confirmed clear resection margins in this area, a DCIS component was detected in the cavity shave.
This outcome highlights the value of integrating the surgeon’s clinical expertise with specimen PET-CT imaging in guiding intraoperative decisions. By prompting an additional shave, the surgeon - supported by the PET-CT images- helped to prevent that tumor tissue was left behind in the breast. Furthermore, this case demonstrates how specimen PET-CT imaging can enhance histopathological evaluation by identifying areas that may require closer examination, possibly also improving the accuracy of histopathological margin assessment.
References
[1] St John et al. (2017). Diagnostic Accuracy of Intraoperative Techniques for Margin Assessment in Breast Cancer Surgery: A Meta-analysis. Ann Surg.
[2] Hall N.C et al. (2008). Bringing advanced medical imaging into the operative arena could revolutionize the surgical care of cancer patients. Expert Rev Med Devices. https://doi.org/10.1586/17434440.5.6.663. ;
[3] Göker M. et al. (2020). 18F-FDG micro-PET/CT for intra-operative margin assessment during breast-conserving surgery. Acta Chirurgica Belgica. https://doi.org/10.1080/00015458.2020.1774163 ;
[4] Lambert B. et al. (2025) Feasibility study on the implementation of a mobile high-resolution PET/CT scanner for surgical specimens: exploring clinical applications and practical considerations. Eur J Nucl Med Mol Imaging. https://doi.org/10.1007/s00259-025-07143-z ;