ESTRO 2024 - Abstract Book

S407

Brachytherapy - Urology

ESTRO 2024

Results:

We calculated the following biological doses for brachytherapy from mean values in Fig.1(all patients) and 5*5=25 Gy SBRT (100 % isodose) as follows, according to the linearquadratic equations:

EQD2 prostate D90LDR+SBRT=101,8 Gy (a/b=1,5), EQD2 rectum D1LDR+SBRT=101,9 Gy (a/b=3,5) and EQD 2 urethra D1LDR+SBRT=129,2 Gy (a/b=3,5)

In the whole time, only one patient with high-risk disease showed distant oncological progression within 4 months after treatment, resulting in biochemical control rates of 100% for low risk disease, 100 % for intermediate risk disease and 98 % for high risk disease. Local control was 100% in the total cohort. Mean PSA after 12 months is 0,93 ng/ml (0,1 - 1,82 ng/ml). For 85 patients, functional data at baseline, 6 months and 12 months after treatment were available. Functional results from EPIC 26 questionnaires are displayed in Fig. 2. All patients (100%) reported grade I or II urinary toxicities within the first months after treatment, but no higher-grade toxicity was observed, and no patient required urinary catheterization. Similarly, rectal toxicity was low with grade 1 toxicity reported in 43 patients (50,5 %).

Reported sexual activity was already low at baseline. There was a serious impact of ADT on sexual activity after 6 and 12 months. Functional impairments were found reduced at 12 months vs. 6 months.

Fig.2 Epic 26 results