Lymph node biopsy in resource-limited breast cancer systems: a scoping review of non-nuclear mapping, implementation and outcomes

This study aimed to map non-nuclear sentinel lymph node biopsy techniques for breast cancer in resource-limited systems and synthesise implementation requirements and outcomes. Scoping review following Joanna Briggs Institute guidance and PRISMA-ScR. Setting: Services meeting a service-level definition of resource limitation; low- or middle-income country location alone was insufficient. Information sources: PubMed, Europe PMC and backward citation searching. Subjects: Clinical studies, implementation reports, surveys, reviews and guidelines on axillary staging. Outcome measures: Identification, false-negative performance, morbidity, axillary dissection avoided, cost, barriers and training. The merged database exports contained 2,301 records; 1,252 unique records were screened and 36 evidence sources included. Methylene blue (MB) programmes reported 85.7%–100% identification, with a 13% false-negative rate in one meta-analysis. Fluorescein plus MB achieved 82%–100% identification with false-negative rates of 6.3%–8.7%. Indocyanine green series achieved 95.7%–100% identification but required near-infrared equipment. Gentian violet achieved 97.5% identification in a small cohort. Ethiopian programmes achieved 100% identification; one avoided axillary dissection in 80%. North African data showed less lymphoedema after sentinel biopsy than dissection (3.8% versus 23.0%). Constraints were nuclear medicine, pathology, supply, training and follow-up. Non-nuclear sentinel node biopsy appears feasible in resource-limited services when introduced as a governed pathway rather than dye substitution. MB was the lowest-cost/lowest-infrastructure option identified; fluorescein plus MB adds redundancy, while indocyanine green suits services able to support reusable imaging. Evidence is insufficient to establish oncological equivalence. Prospective implementation studies with audited recurrence, morbidity and cost are required.