Clinical evaluation of Contrast Enhanced Breast CT to improve Staging and treatment follow up in women with breast cancer

Breast CT is a novel modality that has not been largely evaluated in a clinical
setting. Only recently FDA and CE marked BCT machines have been released, and
the number of installed bases internationally is below 10 (although rapidly
rising).
Internationally only a few studies on contrast enhanced breast CT have been
performed in small numbers of patients, albeit with excellent results.
Nevertheless, substantial evidence for this novel modality is still absent. In
particular, the correlation of enhancement and histological grade of DCIS,
correlation of CEBCT findings with histopathology, and prediction and
assessment of primary systemic treatment are open fields for which more
substantial evaluation is clearly needed.

a. Staging of women with breast cancer, particularly those with extensive
carcinoma in situ (DCIS):
1) The concordance of tumor extent between CEBCT and large section
histopathology
2) The non-inferiority of CEBCT to contrast enhanced breast MRI for tumor
staging
3) The frequency of detection of contralateral cancers with CEBCT in women with
breast cancer

b. Evaluation of women treated with primary systemic therapy.
1) Is CEBCT useful for the post-systemic, pre-surgical determination of
residual disease in order to minimize the extent of resection?
2) Are the morphological and enhancement characteristics of cancers on CEBCT
complementary to existing subtyping for predicting response to primary systemic
therapy?
3) Can CEBCT predict response to primary systemic therapy early in treatment?

All participants will undergo a bilateral CEBCT scan using a dedicated breast
CT scanner (Koning, USA). This scanner creates full 3D volumes of the breast
using conebeam reconstruction. The scanner is designed as an exam table, on
which the patient is in prone position during image acquisition. Centrally in
the table a horizontal CT gantry is positioned. A mammographic x-ray tube and
an x-ray flat panel detector are mounted on the CT gantry and circle the breast
during acquisition in 10 seconds. For CEBCT two acquisitions need to be
obtained (1 before and 1 after contrast), and we will perform the CEBCT of both
breasts.
Prior to the examination an iv-canula will be inserted for contrast
administration during the procedure. Like in (contrast enhanced) mammography
the breasts are imaged one at a time. The breast to be imaged is suspended
through the central table opening into the imaging space. In the clinical
protocol we will first image the non-affected breast prior to contrast
administration. Subsequently, the patient is repositioned and the affected
breast will be imaged. Thereafter an iodinated contrast agent is administered
(0.1 mmol/kg) using a power injector. Considering sufficient of time after
contrast administration the affected breast will be scanned again. Finally, the
non-affected breast is repositioned in the gantry, and a post-contrast
acquisition of this breast is obtained as well.

CT imaging is associated with risks related to the use of radiation and
contrast administration. The risks of this study are reduced as much as
possible. In breast CT only the breast is exposed to radiation, sparing the
rest of the chest to any significant amount of radiation. Although, these
patients already get numerous mammographic views during standard clinical care.
There is most probably no effect due to the level of additional radiation
involved in breast CT imaging, considering the course of treatment of the study
population (mastectomy or post-surgery radiation therapy).

The introduction of an imaging technology that will improve staging and
treatment follow up of breast cancer detection, will have impact on survival
rate and quality of life of breast cancer patients. By optimizing the image
quality of this modality we will ensure that this impact on women*s healthcare
is maximized. The research will not be directly beneficial to the subjects
since the research breast CT results will not influence the subject*s
treatment, if any.