Reoperation rate of ductal carcinoma in situ: impact of tomosynthesis (3D) and spot magnification.

BACKGROUND: Surgical planning depends on precise preoperative assessment of the radiological extent of ductal carcinoma in situ (DCIS). Despite different modalities used, reoperation rates for DCIS due to involved margins are high. PURPOSE: To evaluate the impact of additional imaging views (spot magnification, tomosynthesis) on surgical reoperation rate of DCIS. MATERIAL AND METHODS: The retrospective single institute study includes 157 patients with biopsy-proven pure DCIS seen on mammogram as microcalcifications and treated with breast-conserving surgery. Patients have been divided into three groups according to additional imaging performed: spot magnification, tomosynthesis, and none. All breast images (mammograms, spot magnification, tomosynthesis) were reviewed and the maximum extent of pathological microcalcifications was recorded. Radiological size was compared to final histopathological size. Reoperation rate due to inadequate margins was recorded. RESULTS: Reoperation rates (25%) due to inadequate margins were as follows: spot (18%), tomosynthesis (27%), none (31%); P = 0.488. Spot magnification, tomosynthesis, and digital zoom of full-field digital mammography predicted similarly the final histopathological size. Reoperation group had a significantly greater preoperative radiological median size (26 mm vs. 20 mm; P = 0.014) as well as median size of disease on final histopathological report (29 mm vs. 14 mm; P < 0.001). Discrepancy between radiological and final histopathological size became greater with increasing DCIS extent. CONCLUSION: The main factors for reoperations are DCIS size and discordance between radiological and histopathological sizes. The use of additional imaging views (spot magnification, tomosynthesis) did not reduce reoperation rate.

Vacuum-assisted excision of small breast cancers under ultrasound guidance.

PURPOSE: The purpose of this study was to evaluate if it is possible to completely remove small breast cancer tumours with vacuum-assisted excision (VAE) under ultrasound guidance. METHODS: Women ≥ 50 years old with a biopsy proven invasive cancer ≤ 10 mm were selected between October 2021 and November 2021 based on referrals and enrolled in this prospective study. The patients underwent VAE within six weeks following biopsy to remove the tumour. After the tumour was excised and the biopsy cavities margins were shaved, a radioactive seed was inserted into the biopsy cavity. The VAE excision cavity and surrounding tissue were surgically excised. Preliminary VAE results were evaluated after ten patients. For the study to proceed at least 80 % of the breast cancer tumours had to be completely removed by VAE. RESULTS: The tumours median size in mammography was 8.5 mm (6-9 mm) and in ultrasound 6.5 mm (4-9 mm). The shape of the lesion was round in three (30 %), oval in two (20 %) and irregular in five (50 %) patients. None of the tumours were completely removed in the first VAE specimen, meaning that there was invasive cancer or ductal carcinoma in situ (DCIS) in the "shaved margins" and/or the surgical specimen. In five (50 %) cases, the surgical specimen was free of invasive cancer and DCIS. CONCLUSIONS: None of the small invasive breast cancers were completely excised with VAE under ultrasound guidance, therefore it is not a reliable method to remove small breast cancers.