Dynamic sentinel lymph node biopsy and its role in invasive staging of cN0 penile cancer. A 10-year experience of one institution
Abstract
Aim: Invasive staging of the inguinal lymph nodes is indicated in penile cancer in intermediate- and high-risk tumours (T1 G2 and higher). Dynamic sentinel lymph node biopsy (DSLNB) or modified inguinal lymph node dissection (mILND) or minimally invasive modified video-endoscopic inguinal lymph node dissection (mVEILND) are used.
Minimally invasive VEILND can also be performed robotically. The aim of this study is to evaluate the results of DSLNB at a single institution over a period of more than 10 years.
Material and methods: A total of 112 patients with penile cancer (mean age 64.2 years, 24-90 years) were hospitalized between 12/2010 and 6/2021. A total of 62 patients underwent invasive lymph node staging.
In 50 of them, we chose the DSLNB method for at least one groin, targeting 92 cN0 inguinal regions. In the case of a non-labeled lymph node, mILND or mVEILND was performed.
For high-risk tumors (>=cT2 or G3) or suspected metastases by imaging (18F-FDG PET/CT/MRI), we chose mVEILND as the primary treatment. We evaluated the applicability and sensitivity of DSLNB.
Results: Sixty-eight groins out of 92 (73.9%) were well scintigraphically labeled. In 2 cases (2.9%; 2/68), cancer metastasis was correctly identified and the procedure was extended to include radical lymphadenectomy.
In 2 cases (2.9%; 2/68), DSLNB was false negative with subsequent development of metastatic involvement of the groin after previous negative DSLNB. In our cohort, DSLNB has a sensitivity of 50% (2/4).
In 24 groins, no labeling occurred (26.1%). Of these, 16 groins were then managed with mILND, in one case the nodes were not captured and metastasis developed further down the line.
The other 3 groins were managed by mVEILND without metastasis finding. Five groins were elected for follow up, and in 1 case, progression of unrecognized nodal metastasis occurred.
Conclusion: In more than a quarter of cases, there was no scintigraphic labeling of the sentinel node, so DSLNB could not be applied. However, even with good labeling and proper performance of DSLNB, 2 of the 4 nodal metastases present were not detected and subsequent progression of metastatic involvement of the groin occurred.
The sensitivity of DSLNB is 50% in our series. Therefore, in invasive staging for penile cancer, we always consider mILND and especially minimally invasive mVEILND.