ESTRO 2024 - Abstract Book

S2530

Clinical - Urology

ESTRO 2024

2440

Digital Poster

Ultrahypofractionated radiotherapy in low and favourable intermediate risk localised prostate cancer

Claudia Colom Pla 1 , Victoria Navarro Aznar 2 , Cristina García Aguilera 1 , María Cerrolaza Pascual 1 , Alberto Lanuza Carnicer 1 , Ana Galán García 1 , Agustina Mendez Villamón 1 1 Miguel Servet Universitary Hospital, Radiation Oncology, Zaragoza, Spain. 2 Clinic Lozano Blesa Universitary Hospital, Radiation Oncology, Zaragoza, Spain

Purpose/Objective:

Stereotactic body radiation therapy (SBRT), an emerging approach in recent years, has positioned itself as a valid option for the treatment of localised prostate cancer. The inherent properties of prostatic adenocarcinoma (low α/β) make it a perfect choice.

Our objective is to analyse overall survival (OS); cancer-specific survival (CSS); disease-free survival (DFS) and acute and chronic toxicity in patients with low and favourable intermediate localised prostate cancer treated with SBRT.

Material/Methods:

We retrospectively analysed 483 patients with localised low and favourable intermediate risk prostate cancer treated with SBRT between February 2014 and September 2023.

All received dietary recommendations and rectal preparation with enema the night before the planning CT scan, which was performed with diuresis control, immobilisation system with wedge under knees and abdominal compressor with 3mm cuts. Intensity modulated radiotherapy was applied using a Linear Electron Accelerator with a photon beam energy of 6MV, administering 35Gy in 7 sessions every other day, over the prostate volume with a uniform margin of 4mm to conform the planning target volume (PTV). Weekly follow-up was carried out during the treatment and once it was finished: at one month, 3 months, to continue with six-month follow-up. Toxicity was analysed according to genitourinary and gastrointestinal RTOG scale and IPSS.

Results:

The median age was 71,6 years. 70,12% had received previous hormone treatment. 42,44% were low risk and 57,56% favourable intermediate risk.

With a median follow-up of 51,66 months, DFS was 95,24% and CSS was 99.79% with an OS of 92,34%.

The IPSS score increased a median of 3 points and normalised after 6 months to baseline values.