Consensus Updates Breast Imaging Before Surgery

Pre-operative imaging in breast cancer varies widely across Europe, creating a need for clearer staging pathways before surgery. The new European consensus, published in European Radiology and developed jointly by EUSOBI, ESSO, ESP and ESTRO, sets out practical guidance for breast and axillary imaging, lesion marking, specimen imaging and staging timelines. A panel of 13 experts used a modified Delphi process to vote on statements covering mammography, digital breast tomosynthesis, ultrasound, breast MRI and contrast-enhanced mammography. The resulting toolbox aims to support consistent clinical and technical requirements for breast cancer staging.

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Minimum Imaging Requirements

The toolbox sets minimum technical requirements for imaging before breast cancer surgery. Bilateral mammography, or digital breast tomosynthesis with synthetic mammography, should always be performed before surgery, using craniocaudal and mediolateral oblique views of both breasts. Spot-compression views are not mandatory and repeat mammography after biopsy is required only after marker placement. Digital breast tomosynthesis alone does not replace mammography, but digital breast tomosynthesis with synthetic mammography can serve as an alternative.

Ultrasound of the whole affected breast should also be performed before surgery, even when not used during the diagnostic phase. A high-frequency probe and a dedicated breast radiologist are required. The tumour should be documented in at least two planes and images of the normal breast should also be recorded. Colour Doppler assessment is recommended, while elastography has a weaker level of agreement.

When MRI is performed, the protocol should include T1-weighted imaging before and after contrast, T2-weighted imaging and diffusion-weighted imaging that meets EUSOBI consensus recommendations. Subtraction images should always be created, and maximum intensity projection images are included in the protocol. Contrast-enhanced mammography, when used, requires low-energy and recombined images with bilateral views. It can replace mammography or digital breast tomosynthesis in selected contexts, but not MRI.

MRI Use and Breast Conservation

Breast MRI has a defined but not universal role in pre-operative staging. Not all patients with breast cancer should undergo pre-operative MRI, but several groups may benefit. These include patients with invasive lobular breast cancer, HER2-overexpressing breast cancer or triple-negative breast cancer, and patients with invasive breast cancer not otherwise specified when conventional imaging or palpation raises suspicion of multifocal or multicentric disease. MRI is also indicated when mammography, digital breast tomosynthesis and ultrasound provide unclear or discordant information about lesion extent or an extensive intraductal component.

Patients with a pre-operative diagnosis of high-grade ductal carcinoma in situ on stereotactic biopsy should undergo MRI. Patients receiving neoadjuvant therapy should have MRI before systemic treatment and at the end of treatment. When MRI is contraindicated because of factors such as severe claustrophobia, metallic implants or pregnancy, the imaging method that best depicts lesion extent should be used, with contrast-enhanced mammography considered when feasible. Lactation is not a contraindication to MRI when loco-regional staging or problem-solving is clinically indicated.

Additional findings on ultrasound or MRI require biopsy when they would alter treatment, such as changing the surgical approach or moving from breast conservation to mastectomy. MRI findings beyond mammography require second-look ultrasound by an experienced radiologist. If no ultrasound correlate is found, MRI-guided vacuum-assisted biopsy is required. Institutions should not offer pre-operative MRI unless MRI-guided biopsy can be arranged internally or externally.

Axillary Staging and Lesion Marking

Axillary ultrasound is the method of choice for lymph node assessment and is mandatory in patients with palpable nodes and patients with T1–T2 breast cancer. Fine needle aspiration or core biopsy should be performed on the most suspicious node when present. In patients undergoing neoadjuvant treatment with positive lymph nodes, lymph node marking should take place before treatment and marked nodes should be removed afterwards. Fewer than three lymph nodes should be marked in this setting. There is no clear preference for marker type. CT or PET/CT is recommended when metastatic lymph nodes are confirmed.

Tumour marking supports surgical planning, particularly for breast conservation. Markers should be placed in all non-palpable cancers but are not mandatory in all BI-RADS 4 or 5 lesions or all palpable breast cancers. Any marker type can be used if it can be detected before and during surgery. For relatively spherical lesions, a guide wire should pass through the lesion centre. Irregularly shaped lesions have no clear guide-wire placement recommendation.

Multifocal, multicentric or additional lesions seen on MRI or other imaging should be discussed at a multidisciplinary meeting before biopsy and bracketing. In planned breast conservation with multicentric lesions, each lesion should be marked. The orientation protocol for surgical specimens must be known by radiologists and pathologists, and removal of a localising marker must be documented with a specimen radiograph.

The consensus toolbox brings together technical standards, clinical indications and workflow steps for pre-operative breast cancer imaging. It supports bilateral imaging, whole-breast ultrasound, defined MRI protocols, careful management of additional findings, structured axillary staging and clear lesion localisation before surgery. It also links imaging to specimen assessment and histopathology, with large-section histopathology favoured over small block techniques. Baseline assessment should be completed within 4 weeks of diagnosis, with complete diagnosis and discussion of tailored treatment options within 7 working days.

Source: European Radiology

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