PET scans

I have metastatic breast cancer for which I am currently taking Taxol weekly. At 3 months into treatment a PET scan showed that I have one lesion remaining on my right hip. (I started with lesions in lymph nodes under left arm, liver and several bones). It seems the chemo is working well and quickly. My questions are:

1. How much can I trust the results of the PET scan? Does it show lesions that are quite small? In other words, can I be pretty sure that the cancer is almost gone (besides microscopic amounts)?

2. Can organs get in the way of the PET scan detecting cancer in underlying organs? Can breast implants get in the way?

Thank you so much for your help!

[CCF-RN,MSN-rf]

Dear Chellesk:  No test is perfect.  A PET scan is designed to detect areas of hypermetabolic activity - which is common in cancer. Having a negative (or positive) PET scan may increase or decrease the concern about cancer but no scan can guarantee that there are no microscopic cells.  Organs, including breast implants, would not interfere with a PET scan.