ESTRO 2025 - Abstract Book

S1945

Clinical - Urology

ESTRO 2025

Results: For the median follow-up of 23 months since starting Darolutamide (3-81) we analyzed 100 nmCRPC with a relevant reduction in PSA. The median PSA after one month of treatment was 3.02ng/mL (0-24), after 3 months was 1.68ng/mL (0-12.4) and the median PSA nadir was 1.176ng/mL (0-12.1). A progression to metastatic castration resistant prostate cancer (mCRPC) appeared in16(16%), 7(41.18%) of which underwent advanced imaging tests (NGIs) for diagnosis of mCRPC. Oligoprogression determined by NGIs was considered in 4(25%) patients treated with SBRT without needing a change to another systemic treatment. The MFS from the start of Darolutamide was 21 months (8-35). First line treatment for mCRPC was Docetaxel in 9(75%), Enzalutamide in 2(16.66%), and Radium-223 in 1(8.33%). At the time of this analysis 87 (87%) patients were alive, with a small percentage 3(3%) deceased due to prostate cancer with an overall survival of 20 months (11-28) since starting Darolutamide. We observed 24(24%) adverse events. Fatigue in 14(58,33%), HTA in 7(29,17%), laboratory abnormalities in 2(8,33%) and neurological impairment in 1(4,17%). The distribution of toxicity was as follows: 15 (62,5%) Grade 1, 7 (27,14%) Grade 2 and 2(8,33%) Grade 3. The vast majority, 90(90%), did not require suspension due to toxicity and only 1(1%) needed change to a new drug. Conclusion: In conclusion, this real-world data analysis suggests that Darolutamide in nmCRPC patients is effective in reducing PSA with a low rate of metastatic progression and promising overall survival providing insights into the safety profile and tolerability of Darolutamide as confirmed in ARAMIS trial. Digital Poster Tumour Response Assessment with PSMA-PET Scan (PSMA Scan) Following Stereotactic Ablative Body Radiotherapy (SABR) for Renal Cell Carcinoma (RCC) Tee Sin Lim 1,2 , Tamara Fogarty 1 , Richard Gauci 3 , Serena Sia 1 , Eugene Leong 1 , Matthew Lim 4 , Dickon Hayne 5,2 1 GenesisCare, Fiona Stanley Hospital, Murdoch, Australia. 2 UWA Medical School, University of Western Australia, Perth, Australia. 3 Department of Nuclear Medicine, Fiona Stanley Hospital, Murdoch, Australia. 4 Curtin Medical School, Curtin University, Bentley, Australia. 5 Department of Urology, Fiona Stanley Hospital, Murdoch, Australia Purpose/Objective: SABR is an effective treatment option for patients with either medically or surgically inoperable, localized RCC 1-2 . Current guidelines recommend six-monthly CT chest and abdomen scans to assess treatment response after SABR. However, CT scans provide only anatomical data and do not assess pathological or metabolic changes in the tumour after treatment. 2 . PSMA is an angiogenic marker for hypervascular tumours like RCC. PSMA PET scans have shown potential in staging and restaging of RCC, based on small retrospective studies .3-4 . The study aimed to investigate the role of PSMA PET in monitoring treatment response in patients undergoing SABR for localised RCC and evaluate efficacy of SABR and its impact on renal function. Material/Methods: This retrospective study included 20 patients, who underwent 21 courses of SABR to the kidney at Genesiscare (GC), Fiona Stanley Hospital (FSH), Perth, Australia, between June 2021 and October 2024. All patients were deemed medically or surgically unsuitable for nephrectomy and SABR was recommended. SABR was delivered in 3-5 fractions, with doses greater than 5 Gy per fraction. Eligible patients had no prior local ablative therapy and had a minimum 6-month follow-up. Keywords: PSA, Darolutamide, CPRC 1464