title: A pilot study evaluating shaved cavity margins with micro-computed tomography: a novel method for predicting lumpectomy margin status intraoperatively.
abstract: Microscopically clear lumpectomy margins are essential in breast conservation, as involved margins increase local recurrence. Currently, 18-50% of lumpectomies have close or positive margins that require re-excision. We assessed the ability of micro-computed tomography (micro-CT) to evaluate lumpectomy shaved cavity margins (SCM) intraoperatively to determine if this technology could rapidly identify margin involvement by tumor and reduce re-excision rates. Twenty-five SCM from six lumpectomies were evaluated with a Skyscan 1173 table top micro-CT scanner (Skyscan, Belgium). Micro-CT results were compared to histopathological results. We scanned three SCM at once with a 7-minute scanning protocol, and studied a total of 25 SCM from six lumpectomies. Images of the SCM were evaluated for radiographic signs of breast cancer including clustered microcalcifications and spiculated masses. SCM were negative by micro-CT in 19/25 (76%) and negative (≥2 mm) by histopathology in 19/25 (76%). Margin status by micro-CT was concordant with histopathology in 23/25 (92%). Micro-CT overestimated margin involvement in 1/25 and underestimated margin involvement in 1/25. Micro-CT had an 83.3% positive predictive value, a 94.7% negative predictive value, 83.3% sensitivity, and 94.7% specificity for evaluation of SCM. Evaluation of SCM by micro-CT is an accurate and promising method of intraoperative margin assessment in breast cancer patients. The scanning time required is short enough to permit real-time feedback to the operating surgeon, allowing immediate directed re-excision.
authors.affiliation: Division of Surgical Oncology, Massachusetts General Hospital, Boston, Massachusetts; Division of Breast Surgery, Hunan Provincial Tumor Hospital, The Affiliated Tumor Hospital of Xiangya Medical School of Central South University, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Tang
authors.forename: Suzanne B
authors.initials: SB
authors.lastname: Coopey
authors.forename: Julliette M
authors.initials: JM
authors.lastname: Buckley
authors.forename: Owen P
authors.initials: OP
authors.lastname: Aftreth
authors.forename: Leopoldo J
authors.initials: LJ
authors.lastname: Fernandez
authors.forename: Elena F
authors.initials: EF
authors.lastname: Brachtel
authors.forename: James S
authors.initials: JS
authors.lastname: Michaelson
authors.forename: Michele A
authors.initials: MA
authors.lastname: Gadd
authors.forename: Michelle C
authors.initials: MC
authors.lastname: Specht
authors.forename: Frederick C
authors.initials: FC
authors.lastname: Koerner
authors.forename: Barbara L
authors.initials: BL
authors.lastname: Smith
mesh_terms: D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental / Q000379:methods*; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D010865:Pilot Projects; D055114:X-Ray Microtomography / Q000379:methods*
keywords: intraoperative; micro-CT; shaved cavity margin