S1274
Clinical - Urology
ESTRO 2026
Conclusion: According to our preliminary results, local prostate irradiation seems to potentially improve clinical outcomes in castration-resistant prostate cancer patients receiving systemic therapy. These preliminary findings should be validated in prospective studies due to their potential therapeutic relevance Keywords: radiotherapy, CRPC Assessment of acute and late toxicity in post- prostatectomy MR-guided radiotherapy patients Spencer Martin 1 , Hilary L Byrne 1,2 , Hao-Wen Sim 3 , David Crawford 1 , Charles Tran 1 , Farshad Kasrei 1 , Jeremy de Leon 1 1 Radiation Oncology, GenesisCare, NSW, Australia. 2 Faculty of Medicine and Health, The University of Sydney, Sydney, Australia. 3 The Kinghorn Cancer Centre, St Vincent's Hospital, Sydney, Australia Digital Poster 3756 Purpose/Objective: Emerging evidence supports the feasibility and clinical utility of magnetic resonance-guided adaptive radiotherapy (MRgART) in the post-prostatectomy radiotherapy (PPRT) setting. Wegener et al. reported on 15 patients with MRgART. Toxicity was low, with Grade 1–2 genitourinary (GU) toxicity in 4/15 patients, no Grade ≥ 2 gastrointestinal (GI) events1. Hassan et al. conducted a study of 7 patients. Treatment was well tolerated, with one reported Grade 1 GU and Grade 2 GI toxicity2.This study reports the toxicities and preliminary clinical outcomes for post-prostatectomy MRgART on the 1.5T Elekta Unity system at one center. Material/Methods: Patients who had previously undergone radical prostatectomy with biochemically recurrent +/- PSMA- PET avid recurrent disease underwent salvage MRgRT treating prostate bed +/- pelvic lymph nodes with or without ADT in an HREC-approved study. All patients were treated using an Adapt-To-Shape workflow. PSA levels, GI and GU toxicity including erectile function was recorded at baseline, 3-, 6-, and 12-months post- treatment as well as most recent clinical review as per Common Terminology Criteria for Adverse Effects (CTCAE) v.5. Results: 51 post-radical prostatectomy patients of median age 69 years underwent daily adaptive MRgART. Prescriptions included 52.5Gy in 20 fractions, 66Gy in 33 fractions, or 70Gy in 35 fractions, with simultaneous infield boost (SIB) to gross disease (4.0- 12.5Gy) in 24 patients. Median follow-up time was 19.5 months (12-49 months). Toxicities are reported in Table 1. At 3 months, 47% of patients experienced GU
Digital Poster 3704
Local prostate irradiation may improve clinical outcomes in castration-resistant prostate cancer patients: a multicentric analysis David Alberto Santos Hernandez 1,2 , Donatella Russo 3 , Maurizio Valeriani 4 , Salvatore La Mattina 2 , Fabio Trippa 5 , Beatrice Detti 6 , Elisa Ciurlia 3 , Gianluca Ingrosso 7,8 , Sara De Matteis 3 , Maria Cristina Barba 3 , Andrea Lancia 2 1 Radiation Oncology, Centro Nacional de Radioterapia, San Salvador, El Salvador. 2 Radiation Oncology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy. 3 Radiotherapy Unit, Vito Fazzi Hospital, Lecce, Italy. 4 Radiation Oncology, Sant'Andrea Hospital, Rome, Italy. 5 Radiotherapy, Santa Maria Hospital, Terni, Italy. 6 Radiotherapy, Presidio Villa Fiorita, Azienda USL Centro Toscana, Prato, Italy. 7 Radiation Oncology, Perugia General Hospital, Perugia, Italy. 8 Radiation Oncology, University of Perugia, Perugia, Italy Purpose/Objective: We present clinical outcomes from metastatic (mCRPC) and non-metastatic castration-resistant prostate cancer (nmCRPC) patients who received local prostate radiotherapy in addition to systemic therapy. Material/Methods: twenty-seven patients diagnosed with CRPC from seven Italian hospitals between January 2018 and October 2024 were included in the analysis; sixteen of them had a diagnosis of nmCRPC while eleven were mCRPC. Clinical and treatment characteristics were collected for all patients. Descriptive survival and progression analyses were performed using Kaplan- Meier method. Prostate-specific antigen progression (TTP-PSA) and overall survival (OS) were calculated from the initiation of systemic therapy to the time of CRPC diagnosis. Results: Mean age was 70 years (60 – 85 years) and mean follow-up was 46 months. All patients had previously received androgen deprivation therapy (ADT): four had been treated with androgen receptor pathway inhibitors (ARPI), and six had received docetaxel. At the time of CRPC diagnosis, systemic therapy consisted of ADT in 20 patients, ADT + ARPI in six patients and only one patient was treated with ARPI alone. The median time from CRPC diagnosis to radiotherapy was nine months. Seven patients received Stereotactic Radiation Therapy (SBRT) as treatment modality, while four patients did also receive pelvic irradiation. In nmCRPC, median time to prostate-specific antigen progression (TTP-PSA) was 30 months (38 months for those who received ADT only) and overall survival (OS) was 58.5 months. in the mCRPC group, TTP-PSA was 27 months and OS 56.6 months.
Made with FlippingBook - Share PDF online