Accuracy and precision of contrast enhanced mammography versus MRI for predicting breast cancer size: how "good" are they really?

OBJECTIVE: To evaluate and compare the accuracy and precision of contrast-enhanced mammography (CEM) vs MRI to predict the size of biopsy-proven invasive breast cancer. METHODS: Prospective study, 59 women with invasive breast cancer on needle biopsy underwent CEM and breast MRI. Two breast radiologists read each patient's study, with access limited to one modality. CEM lesion size was measured using low-energy and recombined images and on MRI, the first post-contrast series. Extent of abnormality per quadrant was measured for multifocal lesions. Reference standards were size of largest invasive malignant lesion, invasive (PathInvasive) and whole (PathTotal). Pre-defined clinical concordance ±10 mm. RESULTS: Mean patient age 56 years, 42 (71%) asymptomatic. Lesions were invasive ductal carcinoma 40 (68%) with ductal carcinoma in situ (31/40) in 78%, multifocal in 12 (20%). Median lesion size was 17 mm (invasive) and 27 mm (total), range (5-125 mm). Lin's concordance correlation coefficients for PathTotal 0.75 (95% CI 0.6, 0.84) and 0.71 (95% CI 0.56, 0.82) for MRI and contrast-enhanced spectral mammography (CESM) respectively. Mean difference for total size, 3% underestimated and 4% overestimated, and for invasive 41% and 50% overestimate on MRI and CESM respectively. LOAs for PathTotal varied from 60% under to a 2.4 or almost threefold over estimation. MRI was concordant with PathTotal in 36 (64%) cases compared with 32 (57%) for CESM. Both modalities concordant in 26 (46%) cases respectively. CONCLUSION: Neither CEM nor MRI have sufficient accuracy to direct changes in planned treatment without needle biopsy confirmation. ADVANCES IN KNOWLEDGE: Despite small mean differences in lesion size estimates using CEM or MRI, the 95% limits of agreement do not meet clinically acceptable levels.

Vacuum-assisted excision biopsy for definitive diagnosis of breast lesions of uncertain malignant potential (B3 lesions) on core biopsy - A single centre Western Australian experience.

INTRODUCTION: In Australia, the usual approach to breast lesions where core biopsy returns an uncertain result ("B3" breast lesion) is to perform surgical diagnostic open biopsy (DOB). This is associated with patient time off work, costs of hospital admission, risks of general anaesthesia and surgical complications. The majority of B3 lesions return benign results following surgery. Vacuum assisted excision biopsy (VAEB) is a less invasive, lower cost alternative, and is standard of care for selected B3 lesions in the United Kingdom. Similar use of VAEB in Australia, could save many women unnecessary surgery. The aim of this study was to document our experience during the introduction of VAEB as an alternative to DOB for diagnosis of selected B3 lesions. METHODS: The multidisciplinary team developed an agreed VAEB pathway for selected B3 lesions. Technically accessible papillary lesions, mucocele-like lesions and radial scars without atypia measuring ≤ 15mm were selected. RESULTS: Over a 7 month period, 18 women with 20 B3 lesions were offered VAEB. 16 women (18 lesions) chose VAEB over DOB. Papillomas were the commonest lesion type. All lesions were successfully sampled: 17/18 were benign. One lesion (6%) was upgraded to malignancy (ductal carcinoma in situ on VAEB, invasive ductal carcinoma at surgery). No major complications occurred. Patient satisfaction was high: 15/16 respondents would again choose VAEB over surgery. CONCLUSION: VAEB is a patient-preferred, safe, well-tolerated, lower-cost alternative to DOB for definitive diagnosis of selected B3 breast lesions.

Pre-operative localization of impalpable breast lesions using iodine 125 seeds: Placement accuracy and multidisciplinary challenges.

INTRODUCTION: The number of impalpable breast lesions requiring pre-operative lesion localization (PLL) continues to increase. The use of Radio-guided Occult Lesion Localization with Iodine 125 Seeds (ROLLIS) offers multiple benefits for the multidisciplinary team (MDT), but is not without challenges. AIMS: The aims of this audit were to review our multidisciplinary team's experience following introduction of ROLLIS as standard of care for PLL, identify challenges and evaluate seed placement accuracy (SPA). RESULTS/OUTCOMES: Over a nineteen month period, 327 seeds were inserted: 96% of single seed localizations were within 10 mm, 91% within 5 mm and 42% within or in contact with the lesion (or marker clip surrogate) on post-insertion two view mammography. Each component of the MDT reported on benefits of the ROLLIS program and challenges faced. Examples included: an undetectable seed in the operating room, a seed damaged in pathology during specimen processing, suboptimal seed position requiring hook-wire localization (HWL) and delayed seed removal in a patient who initially refused to return for surgery. CONCLUSION: ROLLIS results in high seed placement accuracy. Despite clear advantages, use of ROLLIS presents some multidisciplinary challenges. Robust patient information, training of new staff and adherence to strict policies and protocols are required to ensure safe delivery of a ROLLIS program.