Trial Information

Evaluation of a Small Field of View Gamma Camera for Scintimammography in Patients With Atypical Ductal Hyperplasia, Atypical Lobular Hyperplasia, and Lobular Carcinoma In Situ

Management of atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), and
lobular carcinoma in situ (LCIS) diagnosed by breast needle core needle biopsy is
controversial. Current practice is to recommend excisional biopsy to rule out malignant
lesions, which have been reported in more than half of cases in some series. No consistent
clinical, pathologic, or radiologic factors have been identified to select patients who do
not require surgical excision. This is due, in part, to overlap in the mammographic
features of benign and malignant lesions. Furthermore, reliance on mammography for
surveillance of these high-risk patients is problematic. This highlights the need for a
complementary imaging modality to improve the radiologic distinction between benign and
malignant tumors and improve post-biopsy surveillance.

We are evaluating a new semiconductor-based gamma camera which we call Molecular Breast
Imaging (MBI) which improves resolution by a factor of 2-3 compared to conventional gamma
cameras, and, unlike mammography, is not affected by breast density. Preliminary clinical
studies (IRB 0-1761-01)) have shown that scintimammography (SM) using Tc-99m sestamibi and
the CZT camera (CZT-SM) has a high sensitivity and specificity for the evaluation of small
(5-10 mm) lesions seen on mammography. We hypothesize that the MBI will reliably distinguish
lesions that require excisional biopsy from lesions that do not. A secondary aim is to
compare the role of MBI with mammography in post-biopsy surveillance.

We aim to enroll 50 Mayo patients who have received a diagnosis of ADH, ALH, or LCIS on core
biopsy, who have not yet undergone excisional biopsy, and who consent to undergo MBI of both
breasts. For images in which there is discordance with mammographic findings, ultrasound
will be used to determine if additional abnormalities warrant excision. Using pathologic
correlation, we will determine: 1) If residual foci of ADH, ALH, and LCIS are visible on MBI
images; and 2) If MBI images can reliably predict contiguous or separate foci of malignant
lesions in either breast.