الفهرس 
Anatomical backgroundOnly 14 pages are availabe for public view
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Abstract
Cancer breast is the most common cancer in women. Early and accurate detection of recurrent breast cancer is critical to the treatment and ultimately survival of patients.
Imaging with positron emission tomography (PET) for tumor staging and therapy control has been introduced. Rather than anatomic information, it provides physiologic information on glucose uptake and metabolism.
In dual-modality PET/CT, the fused images help visu¬alize both function and anatomic information at the same location of the body and thereby improve the diagnostic accuracy of FDG PET.
PET/CT has advantages over other imaging methods; it can differentiate benign from malignant lesions, staging and restaging tumors, detect functional changes before there is any change in clinical or radiological size of a mass, better in identifying cancer that has spread, making up treatment plane and monitoring tumor response.
Typically, malignant tumors have an SUV of greater than 2.5-3.0, whereas normal tissues SUVs ranging from 0.5to 2.5. An SUV of 1 means uniform distribution. An SUV greater than 2.5 has been associated with cancer; however, it is best to use SUV as a guide to interpretation rather than an absolute value.
PET/CT is superior to PET or CT alone in the diagnosis and treatment of various primary or metastatic cancers.
FDG-PET-CT accurately determines the extent of disease in locally advanced breast cancer, more sensitive in the detection of distant metastases and seems to be highly useful for monitoring response to therapeutic interventions.
F-18 FDG PET has a sensitivity of 90% and a spec-ificity of 80% for the detection of loco regional or dis¬tant recurrent breast cancer, and is particularly useful in distinguishing postsurgical scarring and fibrosis from recurrent disease. The optimal timing of the PET study varies by the treatment modality; with chemotherapy alone, scheduling an FDG PET scan at least four weeks post treatment may help reduce false positives. When radiotherapy or sur¬gery is involved, FDG PET at two to three months may be more appropriate.
PET/CT appears to be an effective surveillance tool, as it is able to cover the whole body in a single procedure and shows good performance. PET/CT is more accurate in the definition of rTNM stage than PET alone or CT alone.
The major limitation of PET or PET/CT for breast imaging is its poor detection rate for small breast carcinomas and non-invasive breast cancers.