Chapter 1: Screening, diagnosis & staging of breast cancer and multidisciplinary team working
Other staging examinations
Figure 1.10: An example of MRI in assessment of cancer size. A 29-year-old woman with a small breast tumour on mammography and ultrasound, but cancer encompasses almost the entire breast on MRI.
Abbreviations: MRI, magnetic resonance imaging.
Credit: Dr Mazen Sudah, Department of Radiology, Kuopio University Hospital, Dr Katja Hukkinen, Department of Radiology, Helsinki University Hospital and Dr Päivi Heikkilä, Department of Pathology, Helsinki University Hospital.
MRI may identify BCs not detected by mammography or US. MRI may be associated with reduced re-excision rates in patients with BC, but at the expense of an increased mastectomy rate.
MRI has high sensitivity, but false-positive findings occur in 5%–10% of patients. A biopsy should be considered when a lesion is visible only on MRI.
When assessing response to neoadjuvant chemotherapy, and screening women who are susceptible to BC, MRI is superior to other imaging methods, although US 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 measurement of alkaline phosphatase and calcium levels are recommended before surgery and systemic treatment.
For patients at high and intermediate risk of distant relapses, imaging of the chest, abdomen and bone is recommended prior to administration of systemic treatments.
Figure 1.11: An example of CT in breast cancer staging. A 61-year-old patient with multicentric invasive ductal breast cancer of the right breast and axillary metastases. The CT scan shows several small pulmonary metastases in both lungs.
Abbreviations: CT, computed tomography.
Credit: Dr Mazen Sudah, Department of Radiology, Kuopio University Hospital, Dr Katja Hukkinen, Department of Radiology, Helsinki University Hospital and Dr Päivi Heikkilä, Department of Pathology, Helsinki University Hospital.
If clinical signs or laboratory values suggest the presence of metastases, imaging exams are mandatory.
18F-Fluorodeoxyglucose-positron emission tomography (18F-FDG-PET) or PET combined with computed tomography (PET–CT) are not usually 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.
Figure 1.12: An example of FDG-PET in BC staging. BC metastases in lumbar vertebrae III, IV and V and the sacrum in an FDG-PET scan. The metastases were not visible on CT.
Abbreviations: BC, breast cancer; CT, computed tomography; FDG-PET, fluorodeoxyglucose-positron emission tomography.
Credit: Dr Mazen Sudah, Department of Radiology, Kuopio University Hospital, Dr Katja Hukkinen, Department of Radiology, Helsinki University Hospital and Dr Päivi Heikkilä, Department of Pathology, Helsinki University Hospital.
PET may show response to systemic therapy earlier than CT or MRI. 18F-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 on 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?
