ESTRO 2024 - Abstract Book

S2579

Clinical - Urology

ESTRO 2024

2857

Digital Poster

RE-IRRADIATION FOR DETECTABLE PROSTATE BED RECURRENCE: A MONOCENTRIC EXPERIENCE

Eugenio Cammareri 1,2 , Giulia Corrao 1 , Mattia Zaffaroni 1 , Maria G Vincini 1 , Dario Zerini 1 , Sabrina Clobiaco 1,2 , Stefano Luzzago 3 , Francesco A Mistretta 3 , Sarah Alessi 4 , Francesco Ceci 5,2 , Giuseppe Petralia 2,4 , Gennaro Musi 3 , Federica Cattani 1 , Ottavio De Cobelli 3 , Giulia Marvaso 1 , Barbara A Jereczek-Fossa 1,2 1 European Institute of Oncology, Radiotherapy, Milan, Italy. 2 University of Milan, Oncology and Hemato-Oncology, Milano, Italy. 3 European Institute of Oncology, Urology, Milan, Italy. 4 European Institute of Oncology, Radiology, Milan, Italy. 5 European Institute of Oncology, Nuclear Medicine and Theranostics, Milan, Italy

Purpose/Objective:

Aim of the present study is to evaluate the safety and effectiveness of re-irradiation for local relapse on patients who underwent prostatectomy followed by radiotherapy (RT), both adjuvant and salvage, as primary treatment for prostate cancer (PCa).

Material/Methods:

Patients from 2008 to 2021 underwent to prostatectomy and then adjuvant or salvage RT (external beam RT (EBRT) or brachytherapy) and with evidence of isolated relapse in prostatic bed at MRI or PET choline re-treated with EBRT were retrospectively considered. GTV was contoured on the basis of the imaging available. Salvage re-EBRT was delivered with image-guided RT (RapidArc®, VERO® and CyberKnife®).

Results:

A total of 38 patients, with a median age at salvage re-EBRT of 69 years, were included in the present analysis. A total of 12 patients received 25 Gy/5 fx, while 15 received 30/5fx and 11 received 35Gy. Median GTV value was 5.4 cc. Median pre-salvage SBRT prostate-specific antigen (PSA) was 1.92 ng/ml. Hormone therapy was received by 11 (28.92%) of patients. Isolated relapse in the prostatic bed was assessed by MRI and PET choline in 34 (89.5%) and 26 patients (68.4%), respectively. At a median follow-up of 40.7 months, a total of 33 patients (86.8%) had biochemical progression with a median time to progression of 12.5 months. Biochemical recurrence-free survival rates at 1- and 2- year were 48.7% and 38.3%, respectively (Figure 1). Clinical progression was observed in 23 (60%) patients. Among them, 6 had both local relapse and distant metastasis, 7 developed only distant metastasis and 10 had only local relapse. Among the 13 patients who developed distant metastasis, four had only lymph nodal lesions, five had only bone lesions, three had both (1 missing). Among the 16 local relapses, 5, 8 and 3 were observed in the 25Gy, in the 30Gy and in the 35Gy groups, respectively. We registered no acute event worse than G1; considering maximum toxicity during the treatment, one G2 late GI event and two G3 and four G4 late GU events (two solved at last FU) were reported.