الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Breast cancer is the most frequently diagnosed cancer in women. It remains the
second most frequent cause of cancer death after lung cancer in women worldwide.
PET-CT provides the needed information about both the metabolic activity as
well the anatomical location of the neoplasm combining the advantages of both CT and
PET.
This study evaluated 30 female patients with breast cancer, age range between
33 and 73 years with mean age 53.5 years by PET/CT to assess the breast cancer and
search for metastasis and recurrence.
In our study PET/CT identified the primary tumor in 10 out of 30 patients
Our study showed that 25 cases were pathologically proven invasive ductal
carcinoma, 3 cases invasive lobular carcinoma, 1case mucinous and 1 case anaplastic.
In our study the contralateral breast affection occurred in 2 cases (2.8%)
- The fused PET/CT images were analyzed and 11 patients were positive for
metabolically active FDG avid axillary nodal lesions (n=11) (36.7 %), cervical
lymph node affection (n=6)(20%), mediastinal lymphadenopathy (n=12) (40%) and
abdominal lymph nodes affection (n=8) (26.7%).
- Bone metastases occurred in 12 cases (40%)
- Hepatic metastases occurred in 5 cases (16.7%)
- Pulmonary metastases occurred in 11 cases (36.7%)
- Other visceral metastasis occurred in 9 cases (30%).
The study showed that the breast malignancy was unilateral in 28 patients
(95.8%) and bilateral in 2 patients (4.2%).
In our study, PET/CT detected operative bed tumor recurrence in 5/30 cases
(16.7 %); being isolated operative bed recurrence after surgery in (1/20) case & mixed
locoregional and distant metastases in (4/20) cases
In follow up of the cases, progression occurred in 14 cases (46.7 %), stationary
course in 10 cases (33.3 %) and regressive course in 6 cases (20.0 %).
In our study, the sensitivity of CT alone in detection of the breast lesions in both
breasts was 81.2%, and PET in combined PET-CT raised this percentage to reach
100%.
The sensitivity of CT alone in detection of lymph node metastasis was calculated to
be 95% and PET in combined PET-CT raise this percentage to reach 100%.
The sensitivity of CT alone in detection of bone lesion deposits was calculated
to be 75% and PET in combined PET-CT raise this percentage to reach 91,6%.
The sensitivity of CT alone in detection of pulmonary nodule metastasis was
72.2% and PET in combined PET-CT raise this percentage to reach 100%.
The sensitivity of CT alone in detection of hepatic deposits was 40% and PET in
combined PET-CT raise this percentage to reach 80%.Summary
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The sensitivity of CT alone in detection of other visceral metastasis was 55.5%
and PET in combined PET-CT raise this percentage to reach 88.8%.
FDG-PET-CT is generally more sensitive in the detection of distant metastases
than conventional imaging, and is therefore a more accurate method of determining
recurrence of the disease.
FDG-PET-CT is highly useful for monitoring response to therapeutic
interventions. This technique can identify response to therapy earlier than any other
imaging method currently available which greatly improves patient management by
allowing termination of ineffective and toxic therapies.
Role of PET-CT in preoperative cases:
1- For detection:
o PET CT has limited role in detecting primary breast cancer, because of its inability
to demonstrate small (subcentimetric) and low-grade lesions.
2- For staging:
o Evaluation of the primary tumor (T staging) e.g assessment of underlying muscle,
skin and chest wall infiltration
o Detection of nodal metastasis (N staging)
- PET CT can’t be used in axillary staging as the modality cannot demonstrate the
number of lymph nodes involved; the number is an important prognostic factor,
and the nodal FDG uptake is not specific for malignancy.
o Detection of distant metastasis (M staging)
- The most important advantage of PET/CT compared with other imaging
modalities is the capability of detecting unsuspected distant metastases during a
single whole-body examination.
- FDG PET/CT is likely to be more useful as a screening test for distant
metastases in patients with an advanced stage of breast cancer.
Role of PET-CT in postoperative cases:
- PET-CT is a good modality to detect operative bed tumoral recurrence and
useful to determine whether this recurrence is isolated or not.
- PET/CT can detect distant metastases not visible on conventional imaging.
- Fused PET/CT was highly efficient in the evaluation of skeletal metastases with
superior performance in detection of early bone marrow infiltration not apparent
on CT.
- PET/CT has no or minimal value in the evaluation of small subcentimetric
pulmonary nodules because of their lower FDG uptake, but it is considered a
useful tool in the evaluation of large pulmonary nodules (> 1.0 cm).
- FDG PET can detect hepatic metastases > 1cm in diameter, but it has a limited
capability for detection of subcentimetric hepatic metastases.
- PET/CT is poorly sensitivity to detect brain metastases due to high brain
physiological FDG uptake.Summary
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Role of PET-CT in follow up cases.
- FDG-PET is useful in therapy response assessment by demonstrating decline in the
tumor glucose metabolism with successful chemotherapy.
- PET-CT provides quantitative evaluation of the therapy-induced changes in tumor
metabolism that is helpful in making decisions about continuation, modification or
cessation of therapy.
Advantages of PET-CT over other modalities:
- PET is more specific than MRI for characterizing and detecting breast lesions > 1
cm.
- Better than bone scan in detecting lytic osseous metastases. PET is complementary
to a bone scan, but it cannot replace a bone scan. PET detects some metastases that
bone scan does not and vice versa.
- Superior than CT alone in detecting early marrow based and healed osseous
deposits.
Disadvantages of PET-CT:
- PET-CT is not sensitive for detecting breast lesions that are < 1 cm and low grade
lesions.
- Cannot replace axillary biopsy as it cannot demonstrate the number of lymph nodes
which is an important prognostic factor, and the nodal uptake is not specific for
malignancy.
- It is not currently used as a screening modality due to its cost.
- Finally, we recommend combined FDG-PET-CT as the investigation of choice for
breast cancer patients, as it has superior results over equivocal findings of the
conventional imaging, greatest role in detection of distant metastasis, tumor
recurrence and newly developed lesions and for its greatest impact on detection of
the disease progression.