ESTRO 2024 - Abstract Book

S2640

Clinical - Urology

ESTRO 2024

María Cerrolaza Pascual 1 , Agustina Mendez 1 , Cristina Garcia 1 , Victoria Navarro 1 , Alberto Lanuza 1 , Claudia Colom 1 , Ana Galan 1 , Javier Diez 2 , Leticia de la Cueva 3 , María Calderon 3 , Irene Escartin 4 , Susana Solanas 4 , Martin Tejedor 1 1 University Hospital Miguel Servet, Radiation Oncology, ZARAGOZA, Spain. 2 University Hospital Miguel Servet, Physics, ZARAGOZA, Spain. 3 University Hospital Miguel Servet, Nuclear Medicine, ZARAGOZA, Spain. 4 University Hospital Miguel Servet, Radiology, ZARAGOZA, Spain

Purpose/Objective:

after radical prostatectomy (RP), PSA levels should be undetectable. We consider biochemical recurrence when serum PSA is 0.2 ng/dl or higher, with a second confirmation of the same value. Standard imaging with bone scan and MRI has a low detection rate in men with PSA below 2 ng/mL. The EAU-EANM-ESTRO guidelines on prostate cancer recommend with weak evidence in patients with biochemical recurrence after RP offer PSMA PET/CT for men with persistent PSA > 0.2 ng/mL if the results will influence subsequent therapeutic decisions. it has been shown to identify residual cancer in men with post-RP PSA ranges less than 2 ng/mL. In case PSMA PET/CT is not available and the PSA level is > 1 ng/mL, fluciclovine or choline PET/CT can be performed. Our objective has been to evaluate the location of macroscopic recurrences observed in our centre in imaging tests prior to the planning of radiotherapy on the prostatic bed.

Material/Methods:

We evaluated the imaging tests performed after biochemical recurrence following prostatectomy in patients who were candidates for radiotherapy on the prostatic bed in our centre. We retrospectively analysed the clinical and pathological characteristics as well as the type of imaging, location of recurrence and oncological follow-up after radiotherapy. Analyses were performed between the variables, with p < 0.05 being considered statistically significant.

Results:

170 patients out of 198 (85.85%) underwent imaging prior to radiotherapy treatment. Conventional imaging tests (TC and MRI) were performed in 92 patients (54.12%): 88 patients underwent MRI and 4 patients underwent CT. Molecular imaging tests were performed in 78 patients (45.88%): choline PET/CT in 52 patients (30.59%) and PSMA PET/CT in 26 patients (15.29%). Of all patients with imaging tests, macroscopic recurrence was visualised in 98 patients (57.65%) with no significant differences between conventional and molecular imaging tests. The location of the recurrences was: local in 59 patients (60.20%), locoregional in 31 patients (31.63%), distant in the form of bone involvement in 3 patients (3.06%) and locoregional and distant in 5 patients (5.10%). Statistically significant differences were found between the type of imaging test performed (conventional or molecular) and the location: local, or locoregional and distant (p < 0.001), finding locoregional or distant recurrences with molecular imaging tests. Differences were found between baseline PSA and location of recurrence: lower in local recurrence and higher in locoregional/distant recurrence (p=0.04), as well as PSA achieved after RP (p=0.001), with no difference found in PSA achieved after RP.