Displacement of Surgical Clips in Patients with Human Acellular Dermal Matrix in the Excision Cavity during Whole Breast Irradiation Following Breast-Conserving Surgery

What Should We Know in Postoperative Surveillance Imaging After Oncoplastic Breast-Conserving Surgery with Pellet-Type Acellular Dermal Matrix?

RATIONALE AND OBJECTIVES

The aim of this study was to evaluate the usual postoperative imaging findings among patients who underwent oncoplastic breast-conserving surgery (BCS) with acellular dermal matrix (ADM) and to assess the clinical utility of mammography (MG) and ultrasonography (US) in follow-ups.

MATERIALS AND METHODS

This retrospective review of our prospectively collected database of patients who underwent oncoplastic BCS with ADM was conducted with IRB approval and in HIPPA compliance. A total of 105 patients whose follow-up MG and US studies over 2years after surgery were available were included in this study. Postoperative imaging findings were analyzed based on sequential MG and US follow-ups. The clinical outcomes and pathological data were also reviewed. The diagnostic performance of MG and US for postoperative surveillance was assessed.

RESULTS

On MG, ADM presented as an oval (99/105, 94.3%), circumscribed/obscured (65/105, 61.9%), and high-density (56/105, 53.3%) mass with calcifications (54/105, 51.4%). On US, the ADM-filled cavity presented as an oval (93/105, 88.6%), circumscribed (70/105, 66.7%), heterogenous echoic (65/105, 61.9%) mass with marginal/posterior acoustic shadowing (95/105, 90.5%) on US. During the follow-up period (mean, 46.1months; range, 26-58 months), four tumor recurrences were diagnosed (4/105, 3.8%). One tumor recurrence detected on MG presented as microcalcifications (1/4, 25%), which were differentiated from benign postoperative calcifications due to their suspicious morphology and location. Two additional recurrences (2/4, 50%), which were MG-negative small masses or intraductal lesions, were detected on US. One tumor recurrence was missed on both MG+US and was detected by magnetic resonance imaging performed at clinician's request. The sensitivity and specificity of MG, US, and MG+US for postoperative surveillance were 25%, 50% and 75% and 100%, 98% and 98%, respectively.

CONCLUSION

Recognition and adequate interpretation of the usual findings after oncoplastic BCS with ADM insertion are important in postoperative imaging surveillance. The sole use of MG is not sufficient for the detection of mass-type tumor recurrence due to the density of inserted ADM fillers. Therefore, the combined use of MG+US could serve as a useful postoperative surveillance tool with increased sensitivity in this population.

Imaging surveillance for the detection of ipsilateral local tumor recurrence in patients who underwent oncoplastic breast-conserving surgery with acellular dermal matrix: abbreviated MRI versus conventional mammography and ultrasonography

BACKGROUND

To evaluate the usefulness of surveillance-abbreviated magnetic resonance imaging (AB-MRI) for the detection of ipsilateral local tumor recurrence (LTR) in patients who underwent oncoplastic breast-conserving surgery (BCS) with acellular dermal matrix (ADM) by comparing its diagnostic performance with that of mammography (MG) and ultrasonography (US).

METHODS

The postoperative MG, US, and AB-MRI findings of the ipsilateral breast and pathological results of 324 patients who underwent oncoplastic BCS using ADM were reviewed. The cancer detection rate (CDR), sensitivity, specificity, positive predictive value (PPV) for biopsy, accuracy, and area under the curve (AUC) for each imaging modality were calculated.

RESULTS

A total of 8 ipsilateral LTRs were diagnosed, and most cancers (87.5%) were stage 0 or 1 (median size of invasive cancer, 1.44 cm; range, 0.7-2 cm). The CDRs of MG, US, MG + US, and AB-MRI were 0.009, 0.012, 0.015, and 0.025 per woman, respectively. Three cancers were detectable on only AB-MRI, and the additional CDR of AB-MRI was 0.010. The sensitivity and specificity of MG, US, MG + US, and AB-MRI were 37.5%, 50%, 62.5%, and 100% and 99.7%, 98.4%, 98.1%, and 97.8%, respectively. The PPVs for biopsy were 75%, 44.4%, 45.5%, and 53.3%, respectively. The AUC was significantly higher for AB-MRI (0.989) than for MG alone (0.686, P = 0.0009), US alone (0.742, P = 0.009), and MG + US (0.803, P = 0.04). A total of 66.7% of cancers visible on only AB-MRI were located at the deep posterior portion of the excision cavity, which might have been missed with MG or MG + US due to masking by the ADM filler.

CONCLUSION

AB-MRI can improve the detection of ipsilateral LTR despite postoperative changes caused by ADM fillers compared to conventional MG and US. Patients who undergo BCS with ADM can be candidates for AB-MRI surveillance considering improved cancer detection and high sensitivity.