Indocyanine green fluorescent image-guided inguinal sentinel node biopsy for vulvar cancer: criteria and intraoperative challenges.

We read with great interest the article entitled “Indocyanine green fluorescent image-guided inguinal sentinel lymph node biopsy in vulvar cancer.” by Kwak et al. [1].

We would like to congratulate the authors for their excellent surgical technique. The method was applied in a patient with a 3 cm sized palpable vulval mass, and the final histology revealed a vulval adenoid cystic carcinoma with positive sentinel lymph node (International Federation of Obstetrics and Gynecology stage IIIa). Based on the findings of GROINSS-V study and GOG-173 trial [2,3], inguinofemoral lymphadenectomy could be omitted in the case of a negative sentinel lymph node biopsy. Adenoid cystic carcinoma of the vulva is rarely reported; however, it is described as slowly progressing with late and distant recurrences [4,5].

We would like to ask the authors if frozen sections are used in their center, and what protocol is followed in the case of a positive frozen section. Do they complete an inguinofemoral lymphadenectomy? We would also like to highlight that currently, a new Swedish clinical trial is trying to clarify whether such an approach can be offered in non-squamous cell vulvar cancers, tumors >4 cm in diameter, multifocal tumors, or local recurrences [6].

A recent systematic review revealed that the diagnostic value of indocyanine green fluorescent guided biopsy is equal to that of other techniques, e.g., blue dye or technetium-99 m techniques [7].

Once again, we would like to thank the authors for their contribution.