Performing sentinel lymph node biopsy without a hand-held gamma probe - overcoming hurdles through team work: an analysis of our learning curve over five years.

Background: Sentinel lymph node biopsy is the standard of care in the management of node negative axilla in breast cancer and in node negative melanomas and penile cancers. The wide spread adoption of this procedure is however, hampered by the availability of the hand-held gamma probe.

Aim: To demonstrate the safety and feasibility of sentinel node biopsy using methylene blue and SPECT CT lymphoscintigraphy.

Patients and methods: A retrospective review of the case records of all patients of breast cancer, penile cancer and melanomas who underwent surgery at our Institute between December 2019 and November 2024 was analysed. Demographic data, operative data, pathological reports and follow up data were analysed.

Results: Out of a total of 628 patients operated for the above cancers, 70 patients underwent a sentinel lymph node biopsy along with surgery for the primary. Localization was possible in all the patients (100%). The time taken to localize the node decreased from 33 min to 16 min over the course of the learning curve (percentage change of -50%). The median number of nodes isolated increased by 200% and the seroma in the nodal basin decreased by 26%. Recurrences in the nodal basin were commonest in penile cancer (16.6%), while those in the axilla (6.5%) could be salvaged surgically.

Conclusion: Sentinel node biopsy can be safely performed even without a hand-held gamma probe, provided strict inclusion criteria, a double dye technique and a dedicated follow up regimen are adhered to.