Positron Emission mammography (PEM) is a very good diagnostic tool for diagnosing breast cancer. It has revolutionized mammography imaging and has the ability to replace normal mammography in future. One very big advantage over normal mammography is that it is not affected by breast density. Few article find it better than MRI in terms of differentiating between benign and malignant lesions, lesion localization, number of lesions especially if they are small and axillary nodal staging. It is very useful in finding out small satellite nodules , thereby ruling out futile breast conserving surgeries. Newer radio tracer can be used for finding out ER/PR status, though they are in research state at present.

However, there are certain cons also; first being the cost, though I feel that it only transient as the dose of radio tracer that is required in PEM, is very less as compared to whole body PET imaging. Second is - localized field of view, so misses on distant metastases which is not the problem in whole body PET. Similarly using whole body PET with newer tracers like F-18 fluoroestradiol, we can see the estrogen receptor status of the metastases as well and used it for monitoring the response of treatment administered.

In my opinion, PEM is useful in doubtful cases i.e. BIRADS III & IV or when there is strong suspicion of breast cancer like family history or ovarian cancer. In cases of proven metastases, whole body PET is useful.

Hope this will help...

If you ask if having PEM is a must to diagnose breast cancer, I would say definitely not. Mammography is the only diagnostic test you need to diagnose breast cancer as it is shown in all screening programs around the world. There are, however, many other diagnostic tests that helps mammography to increase its sensitivity and specificity, being ultrasound the most important one.

I agree with Dr. Gorane, that PEM is not a must for diagnosis of breast cancer and it is very unlikely to become the screening tool for diagnose breast cancer. My previous post also says that it should be reserved for "SPECIAL INDICATIONS ONLY".

The limiting factors for its widespread use being availablity of this facility, high cost and limited supply of radiopharmaceutical. Mammography can be done any time of the day, but PEM require radioisotope injection which is available for limited time only.

We know that basis for any screening test is that it should have high senstivity (like ELISA in HIV) while second test should have high specificty (e.g. Western blot in HIV). Though PEM has high sensitivity and specificity other factors enumerated by me makes it use very limited.

Regarding USG breast, we know that it is very operator dependent and should be used in conjuction with mammography..

Hope this might clear some doubts..

Dear Ms. Jasna Davidovic,

Our hospital uses breast mammography / tomosynthesis for diagnosis of breast cancer in conjunction with USG. PET is indicated in inoperable cases of stage III & IV. At present we do not have PEM, hence we do not use it, instead if clearly indicated, we go ahead with PET.

PEM is "NOT" used for screening of breast cancer for the reasons already stated by me. The institutions having PEM also uses only for specific indications.

Regarding radiation burden.. It is much more hyped that it really is. A few simple measures can significantly reduce the radiation burden. Newer PET scanners with time of flight (TOF) techniques require half the dose of F-18 FDG for injection without any compromise in image quality and interpretation. All books refer to radiation dose given by non-TOF systems which is not correct. Secondly reducing the kV and mA of CT significantly reduces the dose depending on the weight of patient instead of using a blanket standard for everyone.

Regarding CESM.. the more we complicate the screening test, more it will move out of vogue. Screening test should be affordable, as simple as possible, readily available and can be done in primary settings without much support..