Records the date of the sentinel lymph node(s) biopsy procedure. This data item is required for CoC-accredited facilities as of cases diagnosed 01/01/2018 and later. This data item is required for breast and melanoma cases only.

It is a known fact that sentinel lymph node biopsies have been under-reported. Additionally, the timing and results of sentinel lymph node biopsy procedures are used in quality of care measures. This data item can be used to more accurately assess the date of the sentinel lymph node biopsy procedure separate from the date of a subsequent regional node dissection procedure, if performed.