I have read with interest the article by Orr et al1 and agree entirely with their recommendation that surgeons beginning to do sentinel lymph node (SLN) biopsy should perform backup axillary lymph node dissection (ALND) early in their experience. I find their other considerations anything but practical.
Any model is only as good as its assumptions.
Cody HS. The Learning Curve for Sentinel Lymph Node Biopsy in Breast Cancer. Arch Surg. 2000;135(5):605. doi: