Wei Yang, M.D.
Associate Professor, Diagnostic Radiology
The University of
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Dr. Yang: Welcome back. Good afternoon ladies and gentlemen. This is the follow through with the question and answer session for the breast imaging segment of the educational series. Thank you for your interest and the few questions that we have received regarding the prior presentation on breast imaging.
I'd like to start with the first question which reads as follows: “Would you suggest MR for surveillance of all patients for recurrence of breast cancer? If not, which patients are candidates?” That's an interesting and a slightly tough question to answer in a generic manner. At M. D. Anderson, basically all patients who've had a history of past breast cancer come for annual surveillance with mammography. We do not do MR surveillance for all patients as standard of care. Any abnormalities that are detected on mammography or equivocal findings are first evaluated with breast ultrasound. In the event that both conventional mammography and ultrasound are unable to resolve an area of abnormality or an area of clinical concern, MR surveillance is the next step of imaging. I would like to qualify the statement with the caveat that women who are of extremely high risk - i.e. patients with the BRCA (BRCA mutation), or patients who are young and developed breast cancer at a young age, as well as patients with multiple first degree relatives who have had breast cancer and are themselves breast cancer survivors, are candidates for annual surveillance with breast MR, simply because this has been shown to be the most effective technique for picking up occult breast cancer.
To take the question slightly further, recurrence can either occur at the site of surgery or in a different area of the breast or in the contra-lateral breast. And I would like to draw your attention to a recent publication in the New England Journal of Medicine with first or lead author Lehman, where MR surveillance of the contra-lateral breast in women who have a known primary risk cancer was shown to be an effective method. I hope that answers the question sufficiently and has given you an opportunity to do further reading on that topic.
The second question which I would like to address is as follows: “What is the advantage of combining PET and CT?” I think that's a very valid question and I will address it in the following way. It turned out that PET imaging was the first nuclear medicine imaging of choice using this technique. And essentially the PET systems were handicapped by the fact that the resolution of the system would be down to a level of 6 to 7 millimeters max, and that is inadequate for detection of small intra-breast lesions by which we usually expect that sub-centimeter lesions down to even millimeter sizes (3 to 5 millimeter lesions) must be detectable with any breast imaging modality that is sufficiently of high standard and can be recommended for dedicated breast imaging. Going along that thought pathway, PET on its own would have insufficient resolution to allow for adequate interrogation of the entire breast, as lesions under 1 centimeter in size will not be well demonstrated and will not be detected. PET/CT has an additional advantage over PET in the sense that the resolution of the system is down to 4 millimeters. The expectation therefore will be that smaller lesions in the breast (under 1 centimeter in size) will have a higher capability of being detected. This leads to the next follow-through topic where recently a high resolution dedicated PET system for the breast has been developed and is currently on the market, and this is known as positron emission mammography by the Naviscan vendors. And this system is known for high resolution imaging of the breast which combines a nuclear medicine technique and positron emission technique with a mammographic technique. Essentially, this is a portable system that only images the breast with 2 detectors that are used to compress the breast in a fashion that is similar to mammography: two images are acquired of each breast both in the CC and the MLO projection. And the final image is a series of 12 images or slabs of the breast that will give you a functional image as well as an anatomical image that parallels the mammogram image. This is a new system that has been on the market for a short time. Multiple centers are evaluating the efficacy of this new system both in the detection of occult cancer (i.e. in the screening context), in the diagnostic setup (i.e. patients who present with a problem), and also its role in the staging of breast cancer. We are eagerly awaiting the results of this system, and are also evaluating this in a small study: evaluating its efficacy on its role for monitoring patients who are on neoadjuvant therapy.
The third question reads as follows: “Is it reasonable to screen young
women with adverse family histories with MR in addition to mammography?”
I think this is a very important question and multiple publications over the
last half a decade to 10 years have shown unquestionably that MRI or magnetic
resonance imaging is the modality of choice for screening high risk women. And
by high risk I mean: women who have a strong family history of breast cancer in
first degree relatives, women with genetic mutation carriers. Essentially any
of these women who have a suspicious family history or risk factors should
visit a high risk program or a high risk clinic where the counselors and the
clinicians will be able to assess their lifetime risk profile. And currently
both the
The fourth question is a little lengthier and it goes as follows: “A young woman of 34 years is a married mother with a 4 year old child. She had a mammogram that was read as BI-RADS ACR Category 3 and ultrasound is not available. The question is that the woman's mother had breast cancer at the age of 59 and was the single family member with a history of breast cancer. Please discuss management options”. So this is a good case history to discuss. We are faced with a young woman who's 34 years old with a young child, and having a semi-abnormal mammogram. The BI-RADS ACR Category 3 report by definition implies that there is a 98 percent chance that the lesion is going to be benign and a 2 percent chance that there is a possibility of a suspicious or malignant lesion. For that reason, these patients are followed up at 6 month short-term intervals with the hope that any abnormality that was missed will be detected at the 6 month period without deleterious effects on the outcome of the patient.
There is an interesting point here that ultrasound is not shown. The first question I would have for this individual that submitted the question is we need to know the mammographic finding. Is it a mass or is it calcifications? Calcifications do not require further work-up with ultrasound. The 6 month short term follow up mammogram will allow for evaluation of any interval changes. If the mammogram showed findings such as a mass or architectural distortion, we would be very interested to know what the ultrasound findings were and that would help determine if the BI-RADS 3 Category report is appropriate or if further work up with other forms of imaging or intervention is appropriate.
The history of the mother having breast cancer at age 59 and a single family member affected with breast cancer is significant and will likely have an impact on the patient's risk factor. As we have said, lifetime risks can be calculated and can range from anywhere between zero all the way to 25 and higher. And it's difficult to estimate the risk of the patient based on one aspect of the patient's family history. Proper consultation with a high risk clinic or high risk program will allow the patient to fully appreciate her total risk and as to whether further imaging methods or surveillance methods, for example with MRI, will be appropriate in this context. It's a complicated question and there are many other issues which we would appreciate information on, that will help tweak the management of this patient to the optimal level.
I believe that, that brings us to the end of the question and answer session. I would like to thank you for your interest and your participation in this educational series and for joining us in the breast imaging segment. Thank you very much for your attention.
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