Quantification of lesion size, depth, and uptake using a dual‐head molecular breast imaging system

Hruska, Carrie B.; O’Connor, Michael K.

doi:10.1118/1.2885371

Cited by 38 publications

(42 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For 99m Tc-sestamibi-based imaging, although a method of quantification with dual-head systems has been described (56), intensity of uptake is not routinely quantified with current software. Subcutaneous fat is used as the reference standard, with backgroundparenchyma uptake and lesion uptake described qualitatively as photopenic (less than subcutaneous fat), mild, moderate, or marked.…”

Section: Standardized Interpretive Criteria and Quantificationmentioning

confidence: 99%

Nuclear Breast Imaging: Clinical Results and Future Directions

Berg

2016

J Nucl Med

View full text Add to dashboard Cite

Interest in nuclear breast imaging is increasing because of technical improvements in dedicated devices that allow the use of relatively low doses of radiotracers with high sensitivity for even small breast cancers. For women with newly diagnosed cancer, primary chemotherapy is often recommended, and improved methods of assessing treatment response are of interest. With widespread breast density notification, functional rather than anatomic methods of screening are of increasing interest as well. For a cancer imaging technology to be adopted, several criteria must be met that will be discussed: evidence of clinical benefit with minimal harm, standardized interpretive criteria, direct biopsy guidance, and acceptable cost-effectiveness. Twor adiotracers have been used widely to depict breast cancer: the g-emitting 99m Tc-sestamibi ( 99m Tc-methoxyisobutylisonitrile), 140 keV, half-life of 6 h, originally developed as a myocardial perfusion agent; and the positron-emitting glucose analog 18 F-FDG, 511 keV, half-life of 2 h. Standard lead shielding as is used in a mammography suite is sufficient when using 99m Tc-sestamibi. Using 18 F-FDG requires much more extensive shielding and may not be feasible because of workspaces above or below the planned unit. State licensing requirements for nuclear medicine must be considered; typically, a hot lab with oversight by a trained nuclear medicine technologist and a physicist is required (1).Both 99m Tc-sestamibi and 18 F-FDG were initially studied for breast cancer using whole-body scanners. Low sensitivity to invasive cancers smaller than 1 cm was observed with whole-body g-camera imaging in a prospective multicenter series at 48.2%, compared with 74.2% for larger tumors (2); detection of small cancers, particularly small invasive cancers, is a major goal of breast imaging. Similar results were observed with whole-body PET, with sensitivity to invasive tumors 2 cm or smaller of only 30 of 44 (68%) compared with 57 of 62 (92%) for larger cancers (3).Dedicated breast g-camera imaging can be performed with singledetector scintillating-crystal systems such as breast-specific g-imaging (BSGI) (Dilon Technologies) with a 20 · 15 cm field of view, 3.3-mm pixel size; or using dual-head cadmium-zinc-telluride detector systems, often referred to as molecular breast imaging (MBI) (GE Healthcare, with a 24 · 16 cm field of view and 2.5-mm pixel size; or Gamma Medica, Inc., with a 20 · 16 cm field of view and 1.6 mm pixel size). Both approaches use positioning similar to that of mammography, with the breast gently stabilized between a compression paddle and the detector (BSGI) or between 2 detectors (MBI). It is important to include mammographic technologists in the positioning of the patients, at least for a minimum number of cases (e.g., 25), to ensure full inclusion of posterior tissues for both a craniocaudal and a mediolateral oblique (MLO) acquisition. Particularly with the dualhead systems, it can be difficult to prevent skin folds or to ensure that the nipple is in profile becau...

show abstract

Section: Standardized Interpretive Criteria and Quantificationmentioning

confidence: 99%

Nuclear Breast Imaging: Clinical Results and Future Directions

Berg

2016

J Nucl Med

View full text Add to dashboard Cite

show abstract

“…Previous work on the quantification of Tc99m-sestamibi uptake in MBI-detected lesions has shown that lesion depth can be estimated to within 1 mm using the ratio of counts in the conjugate views of the breast acquired from the opposed detectors. 18 However, the use of a dual-head system with the breast compressed between the two detectors substantially limits a radiologist's access to the breast for the biopsy procedure. In this work, we propose a design where one of the detectors is replaced with a compression paddle, thus reducing the MBI-guided biopsy system to a single-detector system (Fig.…”

Section: Iib Design Considerations For Mbi-guided Biopsymentioning

confidence: 99%

“…These technologies include those that detect 18 F-fluorodeoxyglucose (FDG) positron emissions such as positron emission mammography (PEM) and others that utilize single-photon emitting radiotracers (typically Tc-99m sestamibi) such as breast-specific gamma imaging (BSGI) and molecular breast imaging (MBI). [1][2][3] All of these dedicated technologies use small detectors with minimal dead space at the detector edge, permitting the breast to be placed in direct contact with the detector head, thereby allowing high spatial resolution imaging of small breast tumors.…”

Section: Introductionmentioning

confidence: 99%

Collimator design for a dedicated molecular breast imaging‐guided biopsy system: Proof‐of‐concept

et al. 2012

Self Cite

View full text Add to dashboard Cite

Purpose: Molecular breast imaging (MBI) is a dedicated nuclear medicine breast imaging modality that employs dual-head cadmium zinc telluride (CZT) gamma cameras to functionally detect breast cancer. MBI has been shown to detect breast cancers otherwise occult on mammography and ultrasound. Currently, a MBI-guided biopsy system does not exist to biopsy such lesions. Our objective was to consider the utility of a novel conical slant-hole (CSH) collimator for rapid (<1 min) and accurate monitoring of lesion position to serve as part of a MBI-guided biopsy system. Methods: An initial CSH collimator design was derived from the dimensions of a parallel-hole collimator optimized for MBI performed with dual-head CZT gamma cameras. The parameters of the CSH collimator included the collimator height, cone slant angle, thickness of septa and cones of the collimator, and the annular areas exposed at the base of the cones. These parameters were varied within the geometric constraints of the MBI system to create several potential CSH collimator designs. The CSH collimator designs were evaluated using Monte Carlo simulations. The model included a breast compressed to a thickness of 6 cm with a 1-cm diameter lesion located 3 cm from the collimator face. The number of particles simulated was chosen to represent the count density of a low-dose, screening MBI study acquired with the parallel-hole collimator for 10 min after a ∼150 MBq (4 mCi) injection of Tc-99m sestamibi. The same number of particles was used for the CSH collimator simulations. In the resulting simulated images, the count sensitivity, spatial resolution, and accuracy of the lesion depth determined from the lesion profile width were evaluated. Results: The CSH collimator design with default parameters derived from the optimal parallel-hole collimator provided 1-min images with error in the lesion depth estimation of 1.1 ± 0.7 mm and over 21 times the lesion count sensitivity relative to 1-min images acquired with the current parallel-hole collimator. Sensitivity was increased via more vertical cone slant angles, larger annular areas, thinner cone walls, shorter cone heights, and thinner radiating septa. Full width at half maximum trended in the opposite direction as sensitivity for all parameters. There was less error in the depth estimates for less vertical slant angles, smaller annular areas, thinner cone walls, cone heights near 1 cm, and generally thinner radiating septa. Conclusions: A Monte Carlo model was used to demonstrate the feasibility of a CSH collimator design for rapid biopsy application in molecular breast imaging. Specifically, lesion depth of a 1-cm diameter lesion positioned in the center of a typical breast can be estimated with error of less than 2 mm using circumferential count profiles of images acquired in 1 min.

show abstract

“…Recently, the development of a dual-head camera for BSGI has allowed the simultaneous acquisition of opposing breast views, providing the quantification of lesion parameters including size, depth to the collimator face and relative tracer uptake [17]. Validation of the methods by Monte Carlo and phantom simulations have shown that using the measured lesion diameter and measurements of counts in the lesion and background breast region, relative radiotracer uptake and tumour to background ratio can be accurately calculated [18].…”

mentioning

confidence: 99%

“…Therefore, the implementation of a lexicon for describing BSGI as proposed by Conners et al [10] is highly advisable for the development of this technique, because it is necessary that the terminology is easy to understand and consistently used by interpreting nuclear medicine physicians. On the other hand, a similar lexicon has recently been published for the standardized reporting of the findings of positron emission mammography (PEM), an emerging molecular imaging technology which produces high-resolution tomographic images of 18 F-FDG uptake in the breasts [13]. With increasing use of BSGI, there is clearly a need for standardized terminology to describe its outcomes, for interpretation and to provide management recommendations, similar to the standardized classification that already exists for other breast imaging modalities.…”

mentioning

confidence: 99%

The importance of standardized interpretation of molecular breast imaging with dedicated gamma cameras

Schillaci

2012

Eur J Nucl Med Mol Imaging

View full text Add to dashboard Cite

Breast cancer (BC) is the most common malignancy and the second leading cause of cancer death in females, accounting in the USA for 29% of the total new cancer cases and 14% of the total cancer deaths in 2012 [1]. Early diagnosis and treatment are of the utmost importance to improve prognosis.For detection and characterization of primary breast lesions, anatomical imaging including mammography, ultrasonography, and MRI are commonly employed. Scintimammography is a molecular nuclear medicine technique for breast imaging which uses single-photon radiopharmaceuticals such as 99m Tc sestamibi and 99m Tc tetrofosmin. It is a functional imaging modality so some of the main drawbacks of mammography are resolved [2]. It was developed almost 20 years ago with standard large field-of-view (FOV) gamma cameras. Certainly, the principal limiting factor in the clinical acceptance of scintimammography has been its low sensitivity for cancers of ≤1 cm in size, mainly because of the lack of suitable equipment specifically designed for breast imaging.Dedicated gamma cameras specifically built for breast imaging are now available. The use of these breast-optimized, small FOV, high-resolution cameras allows both greater flexibility in patient positioning (improving breast imaging by limiting the FOV and reducing image contamination from other organs, i.e. liver and heart) and breast compression, with an important increase in the target-to-background ratio [3]. In fact, the detector can be placed directly against the chest and a mild compression is possible, to reduce breast thickness and improve the camera's sensitivity. Moreover, by design, these specific cameras are also able to provide better intrinsic and extrinsic spatial resolution than standard ones, with an enhancement in contrast resolution for small lesions [4], and to acquire projections similar to those of mammography (craniocaudal, mediolateral oblique and true lateral).Studies comparing standard and breast-specific cameras have provided clinical evidence that the dedicated ones show better accuracy in molecular breast imaging, especially in increasing the sensitivity for subcentimetre lesions [4][5][6]. It is worth noting that a recent retrospective review of one institution's experience with breast-specific gamma imaging (BSGI) has indicated that this test is not only both sensitive (93%) and specific (79%) for the identification of BC, but it is also helpful as an adjunct to standard breast imaging modalities for problem solving in indeterminate cases [7]. Moreover, in this study including 416 cases, BSGI was demonstrated to be useful in evaluating lesions difficult to biopsy and in patients who desired further testing rather than biopsy or short term follow-up of their breast abnormality. These interesting data have been then confirmed in a multicentre clinical patient registry analysis, which aimed to quantify the impact of BSGI on the management of patients with BC in clinical practice, and to identify the subgroups benefiting more from the use of this examinatio...

show abstract

Quantification of lesion size, depth, and uptake using a dual‐head molecular breast imaging system

Cited by 38 publications

References 21 publications

Nuclear Breast Imaging: Clinical Results and Future Directions

Nuclear Breast Imaging: Clinical Results and Future Directions

Collimator design for a dedicated molecular breast imaging‐guided biopsy system: Proof‐of‐concept

The importance of standardized interpretation of molecular breast imaging with dedicated gamma cameras

Contact Info

Product

Resources

About