Use of Low-dose Molecular Breast Imaging for the Detection of Small Breast Lesions
Condition: Suspicious Breast Lesion for Which Biopsy is Scheduled
Study type: Observational

Summary: 
      The purpose of this study is to show that improvements in the molecular breast imaging (MBI)
      technology will allow reduction of the administered dose of Tc-99m sestamibi while
      maintaining a sensitivity of 90% for tumor detection.
    

Detailed description: 
      A total of 150 patients will be studied. Each patient will have a suspicious lesion on
      mammogram, ultrasound or breast magnetic resonance imaging (MRI) for which biopsy is
      scheduled. The lesion size on mammogram, ultrasound or breast MRI must be less than 2 cm in
      diameter and must be considered "suspicious" or "highly suspicious" for malignancy. Following
      injection of 8 mCi Tc-99m sestamibi, all patients will undergo craniocaudal (CC) and
      mediolateral oblique (MLO) views of each breast using a molecular breast imaging (MBI) system
      incorporating the latest hardware and software algorithms. Each image will be acquired for 10
      minutes in dynamic mode as 4 x 2.5 minute images. Summation of a given number of frames from
      each acquisition will yield images of an increasing mCi dose. Hence with an 8 mCi injection
      and a dynamic acquisition mode, we can evaluate the sensitivity of MBI as a function of
      administered doses of Tc-99m sestamibi ranging from 2 to 8 mCi. The thickness of the breast
      will be recorded to determine its relevance to lesion detectability.

      Patient Selection

      The goal of this study is to enroll 150 female patients in this study. The rationale for a
      study number of 150 patients is given in Appendix D. Patients referred for a mammogram,
      ultrasound or breast MRI study at Mayo Clinic Rochester will be considered for the study if
      they meet the following criteria:

        -  Have a lesion on mammogram, ultrasound or breast MRI that measured < 2 cm and is
           considered suspicious or highly suggestive of malignancy according to the Breast Imaging
           Reporting and Data System Atlas criteria (BI-RADS 4 or 5). (Note: while 2 cm is larger
           than the desired lesion size that we wish to study, this limit was recommended by our
           radiology colleagues as estimates of lesion size from mammography, ultrasound and MRI
           are not exact)

        -  Are scheduled for biopsy (needle and/or surgical biopsy) of the suspicious lesion

        -  Are > 18 years of age

        -  Had a negative pregnancy test or must be postmenopausal or surgically sterilized

      Eligible patients will be offered enrollment if the time interval between mammogram,
      ultrasound or MRI and scheduled biopsy allows for performance of MBI. Patients with prior
      needle biopsy of the lesion will be excluded from this study, as such biopsies may
      effectively remove all or part of the lesion. Prospective patients will be identified by the
      radiologist based on findings in their mammographic, ultrasound or MRI studies.
    

Observational model: Case-Only
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        A total of 150 patients will be studied. Each patient will have a suspicious lesion on
        mammogram, ultrasound or breast MRI for which biopsy is scheduled. The lesion size on
        mammogram, ultrasound or breast MRI must be less than 2 cm in diameter and must be
        considered "suspicious" or "highly suspicious" for malignancy
      
Keywords: breast; biopsy; suspicious lesion; molecular breast imaging