Chapter 1 - Diagnosis and Staging of Breast Cancer and Multidisciplinary Team Working
MRI may identify BCs not detected by mammography or ultrasonography. MRI may be associated with reduced re-excision rates in patients with lobular BC, but at the expense of an increased mastectomy rate.
False-positive MRI findings occur in 10%–15% of patients. A biopsy should be considered when a lesion is visible only at MRI.
When assessing response to neoadjuvant chemotherapy, and screening women who are susceptible to BC, MRI is superior to other imaging methods, although ultrasound may be equally useful for response assessment. It is also useful in the detection of occult BC in a patient with overt axillary metastases from an unknown primary.
For the assessment of general health status, full blood count, liver, renal and cardiac function tests, and alkaline phosphatase and calcium levels are recommended.
For patients at high and intermediate risk of distant relapses, before systemic treatments are administered, imaging of chest, abdomen and bone is recommended. This can be done through isotope bone scintigraphy, X-ray or computed tomography (CT) of the chest, or CT or ultrasound of the abdomen. If clinical signs or laboratory values suggest the presence of metastases, imaging exams are mandatory.
Positron emission tomography (PET), usually based on uptake of fluorine-18 labelled glucose (fluorodeoxyglucose, FDG) in tumour or PET combined with CT (PET-CT) are not indicated in the staging of most BCs (clinical Stage I, II or operable Stage IIIA).
The spatial resolution of PET (5–6 mm) does not allow detection of small lesions. PET-CT may show false-positive findings due to inflammation or other non-malignant conditions with increased glucose uptake.
PET may show response to systemic therapy earlier than CT or MRI. FDG-PET may identify regional or distant metastases undetected by other means, such as bone metastases undetected by CT, and may be helpful when the findings of standard imaging are unclear.
Revision Questions
- What are the indications for breast MRI?
- When is staging with imaging indicated to detect distant metastases?
- Which imaging methods can be used for staging?
