Factors influencing the time of sentinel node visualization in breast cancer patients using intradermal injection of the radiotracer.

Background: The objective of our study was to determine the important factors that have influence on the time of sentinel node visualization using intradermal injection of (99m)Tc-antimony sulfide colloid.

Methods: Two hundred fifty consecutive patients with the diagnosis of early-stage breast cancer were evaluated. Anterior and lateral views were acquired in various intervals after intradermal injection of the tracer until 180 minutes or visualization of the sentinel node. The effect of several variables on the time of sentinel node visualization was evaluated by univariate and multivariate analyses.

Results: The time of sentinel node visualization was significantly correlated with age, body mass index (BMI), and interval between biopsy and sentinel node mapping. Standardized beta values for these variables were .1, .3, -.55 respectively.

Conclusions: Older age and higher BMI can result in slow sentinel node visualization. Longer interval between biopsy and sentinel node mapping can be associated with rapid sentinel node detection.