PD19-06 LOCATION AND HISTOLOGY OF RETROPERITONEAL METASTASES IN POST-CHEMOTHERAPY RETROPERITONEAL LYMPH NODE DISSECTION FOR NON-SEMINOMA GERM CELL TUMOUR

Abstract

INTRODUCTION AND OBJECTIVE: Post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) in patients with metastatic non-seminoma germ cell tumour (NSGCT) is a procedure with high complication rate and risk of permanent retrograde ejaculation. The current Swedish and Norwegian Testicular Cancer Group (SWENOTECA) modified unilateral template results in a low complication rate, but a relatively high proportion of patients experiences permanent retrograde ejaculation. The objective was to evaluate the histology of the resected nodes in specific areas and outcome of patients, to identify which patients that safely could benefit from a more restricted unilateral template without resection on the contralateral side of the aorta. METHODS: All NSGCT patients within the SWENOTECA network with post-chemotherapy residual tumour of 10-50mm in the largest axial diameter, treated with PC-RPLND between 2007 and 2014 were evaluated in this prospective population-based study. A modified unilateral PC-RPLND could be selected in patients with residual tumour located in the template of a unilateral PC-RPLND (areas 1-5,7,9 for a right-sided NSGCT and 2,3,6,8,10 for a left-sided NSGCT). Laterality of the testicular NSGCT, location of pathological lymph nodes on the CT scan pre chemotherapy and pre-PC-RPLND, areas dissected and the histology for each area was recorded. Follow-up until end of 2016. RESULTS: There were 113 right and 107 left-sided NSGCT. A black dot represents each patient in each area with a postitive node pre-chemotherapy and pre-PC-RPLND, if the area was dissected and teratoma/cancer at histology was found. A red dot represents each patient with negative nodes pre-PC-RPLND and teratoma/cancer was found. In right-sided and left-sided NSGCT respectively 4/6 and 4/5 patients that had a red dot in a contralateral area of the aorta, had positive nodes on CT in an other contralateral area. During follow-up of median 69 months, 4 patients had an in-field recurrence CONCLUSIONS: If the residual mass is located in the unilateral template of the affected testicle (areas 1,2,4,5,7,9 for a right-sided NSGCT and areas 3,6,8,10 for a left-sided NSGCT) and residual tumour size is 10-50mm, a unilateral template is sufficient to remove all teratoma/vital cancer. If the pre or post chemotherapy CT scan shows a pathological lymph node outside of a unilateral template an extended template is recommendedSource of Funding: none