ESTRO 2024 - Abstract Book

S2606

Clinical - Urology

ESTRO 2024

Our experience supports the use of SBRT as a salvage reirradiation technique for intraprostatic recurrence after primary EBRT for prostate cancer as a feasible and well-tolerated treatment option with minimal toxicity and encouraging biochemical control.

Keywords: SBRT, prostate, reirradiation

3021

Poster Discussion

Persistent PSA after radical prostatectomy: are there favorable subgroups?

Reinhard Thamm 1 , Sophia Scharl 1 , Luca Gartner 1 , Dirk Böhmer 2 , Alessandra Siegmann 2 , Daniel Zips 2 , Benjamin Mayer 3 , Manuel Krafcsik 1 , Thomas Wiegel 1 1 Ulm University, Department of Radiotherapy and Radiooncology, Ulm, Germany. 2 Charité Berlin, Department of Radiation Oncology and Radiotherapy, Berlin, Germany. 3 Ulm University, Institute for Epidemiology and Medical Biometry, Ulm, Germany

Purpose/Objective:

Patients with radical prostatectomy (RP) for prostate cancer (PCa) should reach undetectable PSA values afterward. In other patients, the post-RP PSA persists with levels above 0.03 – 0.1 ng/ml, which may indicate residual cancer and is associated with a higher risk for biochemical or clinical progression. The European Association of Urology (EAU) supports the possible need for early aggressive multimodality treatment for patients with PSA persistence. However, the lack of randomized clinical trials does not allow firm recommendations. In a total cohort of patients with salvage radiotherapy (SRT), we defined subgroups with undetectable and PSA relapse or persistent PSA dependent on the levels of postoperative PSA nadir and the pre-SRT PSA. Then, we analyzed the subgroups for their risk of biochemical progression, clinical progression, metastases-free survival, and overall survival. The total cohort consists of 698 retrospective patients from two German high-volume radiation oncology clinics (Charité University Hospital, Berlin, University Hospital Ulm, Ulm) who received salvage radiotherapy (3D, IMRT / VMAT) of the prostate bed without pelvic irradiation between 1997 and 2018. None of them had an adjuvant hormone therapy before SRT. Patients with post- RP PSA ≥2 ng/ml (n=5) and pre - SRT PSA ≥2 ng/ml (n=13) were excluded. 362 patients with post-OP PSA Values <0.05 ng/ml underwent SRT for PSA Recurrence, while 318 patients with post- OP PSA Values ≥0.05 ng/ml were identified as patients with persisting PSA. Then, the patient group with PSA Recurrence was divided into a favorable and unfavorable subgroup with pre-SRT PSA levels of different Recurrence thresholds of 0.1 ng/ml, 0.2 ng/ml, and 0.3 ng/ml. Otherwise, the group with persisting PSA was divided into a favorable and unfavorable subgroup based on their post-RP PSA Nadir with the corresponding threshold levels. Post-SRT biochemical recurrence (BCR) was specified as two rising PSA values of 0.2 ng/ml above the post- Material/Methods: