Can contrast enhanced spectral mammography (CESM) play a clinically useful role in the pre-operative assessment of women with Ductal Carcinoma in Situ (DCIS), the ‘CESM D’ study

Women with a biopsy-confirmed diagnosis of ductal carcinoma in situ (DCIS) will be identified in the Breast Clinic at Perth Royal Hospital. Women who give written, informed consent and who meet the eligibility criteria for the study will be given an appointment for Contrast Enhanced Spectral Mammography (CESM). For the CESM study, an intravenous cannula will be inserted by a trained staff member and an injection of non-ionic iodinated contrast (1.5mg/kg delivering 350mg/ml up to a maximum of 125ml) will be given using a power injector at a rate of 3ml/s. Two minutes later, standard mammographic views (CC and MLO of both breasts) will be performed using dual-energy exposures. Additional views may be obtained if necessary. The CESM study will be independently read by two radiologists on standardised case report forms according to modified Breast Imaging Reporting and Data System (BI-RADS) MR descriptors. If the CESM does not show any significant additional findings that would change the recommended treatment plan, no further investigations will be needed prior to the routine surgical appointment. Further assessment will be performed if there are additional findings based on the CESM which could change recommended management if confirmed to be malignant and may include targeted ultrasound (US), additional mammographic views and breast MRI. If there are additional findings that cannot be downgraded to a NBCC 2 or below (i.e. benign) on further work-up and if determination of the underlying pathology will change treatment, core needle biopsy or preoperative image guided localisation for open biopsy will be performed after multidisciplinary discussion. In instances where biopsy is not possible or biopsy result is benign or inconclusive, follow-up breast imaging at six to twelve months post treatment using the most appropriate modality will be the default recommendation. If all further imaging is negative (US, mammogram and CEMRI), surgical planning will proceed as per findings on standard of care imaging with routine annual follow-up mammography. Wherever possible all additional imaging prompted by the CESM study will be performed within the usual time frame between diagnosis and the surgical planning appointment for patients seen in the public system (2 weeks). Surgeons will be asked to complete a questionnaire documenting if / how the findings on CESM influenced the surgical plan recommended to the participant. As per standard of care for patients who have had breast conserving surgery, all participants will have a routine cancer follow-up mammogram 12 months following their treatment.