Progression-free survival, PFS, depending on the site of lymph-node metastases in patients after salvage lymph node dissection, sLAD, in lymph node only recurrent prostate cancer.

131 Background: To analyze the influence of anatomic site in patients with lymph node only recurrent disease in 68Ga-PSMA-PET. Methods: We retrospectively analyzed PFS after salvage lymph node dissection in 98 patients. Patients were stratified to Group 1 advanced (retroperitoneal) (=9), Group 2 atypical (pararectal, presacral)(n=5), Group 3 typical (A iliaca externa, interna, Fossa obturator, A iliaca communis) (n=74) and Group 4 multifocal (combination of all groups)(n=10) recurrence. There were no statistically significant differences in the four patient groups in preoperative clinical parameters. Results: The most obvious PSA reduction after sLAD could have been demonstrated in patients with atypically located lymph node metastases (3.6ng/ml to 0.25ng/ml) although this did not reach statistic significance. Patients in the advanced group showed stable PSA values (3,55ng/ml to 3.26ng/ml). Significant results are seen in Group3 (2,52ng/ml to 1,7ng/ml)(p=0.01). Even patients with multifocal disease had a significant decrease in PSA (3.24ng/ml to 1.41ng/ml). 6- and 12 months PFS for Group 1-4 was 41.7% and 13.9%, 60% and 40%, 52.7% and 25.7% and 60% and 40% respectively. Conclusions: SLAD is an individual treatment approach for patients with lymph node only recurrent disease after radical prostatectomy and or radiotherapy. In our preliminary results we could not demonstrate a significant difference in early oncologic results in the four patient groups. Nevertheless, there might be an influence by patient numbers in the different groups so that a validation in a larger cohort is recommended.