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Hello all and welcome to Noon Conferences hosted by MRI online. In response

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to changes happening around the world right now and the shutting down of

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in person events, we've decided to provide free Noon Conferences to all

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radiologists worldwide. Today, we're joined for a lecture from Dr. Lisa

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Mullen on screening breast MRI. Dr. Mullen joined Johns Hopkins Radiology

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in 2002 and has been based at Johns Hopkins Imaging at Greenspring. She

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has expertise in screening and diagnostic mammography, breast ultrasound,

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breast MRI, and breast interventional procedures, as well as general ultrasound

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and bone densitometry. Dr. Mullen is interested in clinical breast imaging

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and resident and fellow education. She has been the Breast Imaging Fellowship

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Director since 2013. A quick reminder, there will be a Q&A session at

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the end of the lecture, so please use the Q&A feature to ask

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your questions, and we'll get to as many as we can before time

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is up. That being said, thank you all so much for joining us

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today. Dr. Mullen, I'll let you take things from here. All right. Hopefully

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everyone can see my screen. I'm gonna go ahead and get started 'cause

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we have a lot to cover. So today I'm gonna be talking about

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screening breast MRI, and we'll just go ahead and jump in.

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So our objectives for today are to review the benefits of MRI for

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breast cancer detection. Basically, why do we do MRI for this indication?

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And then describe how we do it, the indications, our protocol at Hopkins,

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and basic interpretation. And then discuss some of the newer issues around

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screening breast MRI, including expanding indications and some newer trends.

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So the goal of breast cancer screening is the early detection of small,

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node negative breast cancers. We also want to reduce interval cancers and

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reduce the morbidity and mortality from breast cancer.

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We know that tumor size is related to mortality, and the mammography randomized

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control trials over a series of several decades showed a decreased mortality

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from breast cancer. Of course, all of those trials were done before full

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field digital mammography and digital breast tomosynthesis or DBT. We may

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perform even better now with newer modalities in mammography. But mammography

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is still gonna be limited by overlapping breast tissue, and

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the denser the tissue gets, the worse the performance of mammography. So

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why should we think about using breast MRI? Well,

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it's not limited by breast tissue density. There's no ionizing radiation.

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It's a vascular or functional based screening rather than purely anatomic,

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so that's an advantage. And it's been discovered in multiple trials that

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it's the most sensitive test for breast cancer detection and therefore,

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hopefully for breast cancer screening. It detects small, node negative invasive

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cancers, which is what we're trying to find. There's a low interval cancer

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rate, so that's good too. And it preferentially detects higher grade lesions.

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So there's an implied decrease in morbidity and mortality by using breast

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MRI. This table depicts the multiple trials that were

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published in the early 2000s related to a comparison of breast MRI

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versus mammography and ultrasound. And lots of different

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publications from basically all over the world, US and

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different countries. Germany has been a big proponent of breast MRI for

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a long time, so some of the trials are coming from Germany.

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But what I want to draw your attention to is the line that says, "Sensitivity

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of MRI." And if you read across that line, in every one of

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these trials, we've got 93%, 100%, 94%, 86%. The worst we get is

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77% in a couple of those early trials. But in all of these

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trials, the sensitivity of MRI was demonstrated to be far superior to mammography

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and ultrasound. So that's interesting. And based on all of those studies,

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in 2017, the American Cancer Society published new guidelines recommending

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supplemental screening breast MRI for high risk women. And at that point

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kind of everything opened up and really took off for screening breast MRI.

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In 2010, the ACR guidelines also recommended MRI for high risk women,

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and those references are at the bottom of your screen.

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So that raises the question, well then, Who is considered to be high

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risk? So these are the risk factors that were published in that original

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Debbie Zaslow publication from 2007. It includes patients with lifetime

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risk of 20%25% or greater. So that's based on risk assessment models and

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family history mostly, BRCA gene mutation carriers and untested first degree

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relatives. Patients with chest radiation before age 30 and that was usually

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for Hodgkin's lymphoma. And patients with known genetic syndromes like Li

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Fraumeni and Cowden. And their first degree relatives. So all of those people

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were felt to be at high risk for breast cancer.

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This is an interesting study by Janice Sung and colleagues

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published in 2016 showing tumor histology based on how the tumor was detected.

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And on the x axis of this bar graph, you can see that

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we go from low grade DCIS to intermediate grade DCIS, high grade DCIS, and

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then into the invasive cancers, low, intermediate, and high grade. So we're

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going from the lowest grade cancer that we could possibly detect up to

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high grade invasive ductal carcinoma. And the blue bars represent cancers

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detected on MRI. The green bars represent cancers detected on mammography.

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And you can see that as we get from the lower grade to

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the higher grade cancers, we're detecting a greater and greater percentage

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of those cancers on MRI. And actually mammography is doing a little bit

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less well, so, good at detecting DCIS, which is often presenting as calcifications,

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very visible on mammography, but maybe less good at some of these higher

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grade lesions. So MRI is preferentially depicting high grade lesions.

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And also in that study, MRI was shown to have a higher cancer

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detection rate. It's often shown to be in the teens, someplace between 10

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and 20 per thousand, but in this study it was 14.9.

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And mammography plus ultrasound was in the range of 7 9 per thousand. And

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MRI detects...