Imaging Case 30:
Breast cancer - Ductal Carcinoma In Situ
Over the past 30 years, breast-conserving surgery (BCS) with radiation therapy has become the standard treatment for early-stage breast cancer, offering survival rates comparable to mastectomy while preserving the natural breast shape and achieving superior cosmetic outcomes. By minimizing the volume of resected tissue, BCS reduces contour deformities, asymmetry, and scarring, leading to improved patient satisfaction and quality of life.
Because BCS does not remove all breast tissue, there is a higher risk of a residual positive margins, which can increase the likelihood of local recurrence and often necessitate reoperation. For this reason, accurate intraoperative margin assessment is crucial in breast cancer surgery. However, the commonly used methods, such as frozen sections and radiography, have limitations in accuracy, efficiency, or practicality, highlighting the need for improved imaging techniques [1]. Recent studies indicate that high-resolution specimen PET-CT imaging with FDG-based radiotracers enables precise visualization of resected breast tumor specimens, offering the surgeon a fast and efficient way to evaluate resection completeness [2,3].
In this case, we illustrate how specimen PET-CT imaging may help the surgeon in this assessment and hence how the information provided by this novel technique can help minimize the removed tissue volume, preserving more healthy breast tissue, and optimizing both oncologic safety and cosmetic outcomes.
This case is part of the multi-center prospective BrIMA study (NCT04999917).
Patient history
A 75-year-old woman was diagnosed with Ductal Carcinoma In Situ (DCIS) in the right breast. The tumor size on preoperative imaging was 16 mm. Biopsy confirmed DCIS with receptor status ER and PR positivity. Preoperative staging was cTisN0M0.
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.
Specimen PET-CT imaging
The patient was intravenously injected with 0.8 MBq/kg of 18F-FDG on the morning of the surgery at the Nuclear Medicine Department. The patient was then transferred to the operating theatre and breast-conserving surgery was performed.
Tumor resection was guided by a harpoon, ensuring correct removal. Immediately after resection, a high-resolution specimen PET-CT image was acquired in the operating theatre. Fig. 1 presents the imaging results, displaying three orthogonal views alongside a 3D reconstruction of the specimen. The images clearly show increased 18F-FDG uptake within the resected tumor specimen, with this uptake located at a certain distance from the tissue border. This suggests that no metabolically active regions, such as cancer cells, are present at the margins.
Following intraoperative PET-CT imaging, the specimen was sent to the radiology department for margin assessment using specimen radiography. This required a courier to physically go to the Radiology department and waiting for communication of the result by the radiologist, interrupting the surgical workflow. According to this standard procedure, all margins deemed negative, allowing the surgical site to be closed.
Table 1: Tumor characteristics assessed by histopathological evaluation. Tumor characteristics
Histopathological evaluation
After margin assessment using specimen radiography, 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. In short, a negative surgical margin was found for all specimen borders.
Discussion and conclusion
This case highlights the power of bringing specimen PET-CT imaging into the operating room. The surgeon decided intraoperatively not to perform an additional cavity shave as imaging indicated 18F-FDG uptake was at a clear distance from the border of the specimen. Final histopathology confirmed complete resection. Therefore, availability of this information at the point of surgery could possibly help the surgeon enhance both surgical and cosmetic outcomes.
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] 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 ;
[3] 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 ;