CAN A LOW COST, EASILY AVAILABLE SPECIMEN X-RAY (IOSX) REPLACE SPECIMEN MAMMOGRAPHY (IOSM) FOR INTRAOPERATIVE ASSESSMENT IN PATIENTS UNDERGOING POST NEOADJUVANT SYSTEMIC THERAPY BREAST CONSERVATIVE SURGERY? endosurgeonrinellem@gmail.com

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CAN A LOW COST, EASILY AVAILABLE SPECIMEN X-RAY (IOSX) REPLACE SPECIMEN MAMMOGRAPHY (IOSM) FOR INTRAOPERATIVE ASSESSMENT IN PATIENTS UNDERGOING POST NEOADJUVANT SYSTEMIC THERAPY BREAST CONSERVATIVE SURGERY?

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India

Oral or Poster

Post-neoadjuvant-systemic-treatment(NAST) Breast-conserving-surgery(BCS) in early-breast-cancer(EBC) and locally-advanced-breast cancers(LABC) is aided by pre-NAST marking of tumour with clips. Clips are localized with stereotactic-hookwire, and Intraoperative specimen-mammography(IOSM) performed for intraoperative assessment of BCS specimens. In resource-poor settings, lack of mammography machines and expertise limits IOSM usage. Conventional digital X-ray machines are widely available, low-cost, not requiring specific expertise. This Prospective pilot study compared utility of IOSM and intra-operative specimen-X-ray(IOSX) in clip/hookwire localization and tumour-margin assessment in post-NAST BCS specimen.

Forty patients with tumor-marking clips in-place, undergoing hookwire guided post-NAST BCS(Jan2024-June2025) were prospectively enrolled. BCS specimen were imaged by IOSM and IOSX. IOSX film-focus distance(FDD~70cm) and kilovoltage(40KV;25mAS) matched mammography. Diagnostic information derived- including clip/hookwire, margin, and calcification visibility, were scored by radiologist, senior-surgeon and junior-surgeon as excellent/completely-2, poorly-1, or not visible-0, and compared using appropriate statistical methods. Clip/hookwire proximity to margins(involved/univolved) on both modalities and their impact on intraoperative plan were studied. Gold-standard histology for margin assessment guided subsequent margins management.

Clip/hookwire visibility was similar in both techniques(Median score IOSM vs IOSX[max-min]=6[6-6]vs6[3-6];p=0.317). IOSX limited microcalcification visibility significantly(6[0-6]vs2[0-6];p=0.04). Tumour-margin was accurately assessed on IOSX (6[2-6]vs4[0-6];p=<0.001). Visibility of clips/hookwire proximity to margins was comparable as shown in Figure-1, leading to re-excisions in all suspected cases. Minimal interobserver variability was noted for the three parameters(p>0.05).

IOSX demonstrated sufficient diagnostic capability, comparable to IOSM with no compromise in immediate oncological outcomes. Given its wider availability, low-cost and ease-of-use, IOSX can replace IOSM as feasible and cost-effective alternative in resource-constrained settings, potentially expanding access to intraoperative assessment in BCS.