V11-06: Dynamic Sentinel Lymph Node Biopsy for Penile Cancer: Accuracy is in the Technique

Jonathan O'Brien*, Jiasian Teh, Kenneth Chen, Brian Kelly, Melbourne, Australia, Justin Chee, East Melbourne, Australia, Nathan Lawrentschuk, Melbourne, Australia

Introduction: Penile squamous cell carcinoma (SCC) is a rare disease where long-term survival depends on lymph node metastases. Minimally invasive surgical techniques have improved morbidity and oncological outcomes for men with intermediate or high-risk primary tumours. EAU and NCCN guidelines recognize dynamic sentinel lymph node biopsy (DSLNB) as a standard for assessing inguinal lymphadenopathy in this patient cohort. DSLNB accuracy has been linked with technique and surgical experience, yet no videos exist which establish an operative standard. This video demonstrates an operative technique for DSLNB and analyses oncological outcomes with 2.5 years of follow up.

Methods: A retrospective analysis was performed on patients undergoing DSLNB for inguinal lymph node staging of histologically proven penile SCC. Data was included from 2 experienced uro-oncologists with subspecialty training in penile cancer working in Victoria, Australia between January 2015 and July 2021.  Variables collected included patient demographics, tumour histology, DSLNB pathology, progression to radical inguinal lymph node dissection (ILND) and recurrence patterns. Data is used to calculate DSLNB sensitivity and incidence groin sparing rate.

Results: DSLNB was performed on 127 groins (64 patients) during the study period. Within the cohort, 44% (n=28) of patients had a pre-operative lymphoscintigraphy with single-photon emission computed tomography (SPECT/CT). A narrated video highlights the surgical technique for DSLNB. Analysis of primary tumour intervention demonstrates that 82.8% (n=53) of men underwent penile sparing surgery. Tumor histology in 88% of patients (n=56) demonstrated pT1-pT2 disease. Overall n=19 groins undergoing DSLNB positive for malignancy and n=108 were negative. 36 groins progressed to ILND during a mean follow up of 29 months. Only 2 groins that previously had a negative DSLNB were positive on ILND, representing a false negative rate of 1.9%. Overall sensitivity was 90.5% and 71.7% of groins undergoing DSLNB proceeded for surveillance instead of prophylactic radical ILND.

Conclusions: DSLNB is a safe and accurate method for assessing inguinal lymphadenopathy in men with intermediate to high risk penile SCC and impalpable groins. This video study establishes an operative standard for DSLNB with oncological outcomes that are consistent with international expectations. Standardized use of DSLNB by an experienced team will reduce morbidity while maintaining oncological safety.

Source of Funding: Self funded