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Figure
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Figure
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History:
62 year old female who is status post breast cancer surgery and
subsequent radiotherapy 2 years ago. Patient was referred to Main
Street Radiology for tumor restaging.
Findings:
Coronal (figure 1) and sagittal (figure 2) whole body images
demonstrate multiple foci of increased activity (black) in the spine,
right axilla, and both inguinal regions, compatible with metastatic
disease. Normal physiological activity is seen in the brain, heart,
and urinary bladder.
Discussion:
Accurate staging of breast cancer
recurrence is critical for therapeutic planning. Traditional
non-invasive imaging include CT and bone scan. Limitations of CT
include the difficulty in distinguishing post-operative and
post-radiation changes from recurrence, and inability to identify and
characterize small lesions. In addition, detection of lesions is
limited to the anatomic region being imaged, as a whole-body CT is not
typically performed. Bone scan, although a sensitive study for
skeletal metastases, results frequently in false positive diagnoses.
Whole-body positron emission tomography
(PET) has been shown to be both more sensitive and specific than CT
for the diagnosis of recurrent breast cancer. It has also been shown
to be more specific than bone scan. Although PET is more sensitive
than bone scan for lytic bone metastases, it is less sensitive for the
less common osteoblasic lesions. Therefore, bone scan should still be
performed as complementary study to the PET scan. (Radiographics.
2002;22:5-17)
In the initial diagnosis of breast
cancer, PET scan should not replace breast biopsy, when warranted by
mammographic, ultrasound, MRI, or clinical findings. In addition, PET
is less sensitive than surgical axillary node staging. PET is reserved
for patients with clinical suspicion of metastatic disease or local
recurrence, where PET has been shown to be superior to CT.
Clinical Case
Studies
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Main
Street Radiology
PET
Clinical
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