Session Item

To analyse overall survival (OS); cancer-specific survival (CSS); disease-free survival (DFS) and acute and chronic toxicity in patients with localised prostate cancer treated with extracranial stereotactic radiotherapy (SBRT).

We retrospectively analysed 366 patients with localised prostate cancer treated with SBRT between February 2014 and October 2021.

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 over the prostate volume with a margin of 3mm.

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.

The median age was 72 years. 64.66% had received previous hormone treatment. 38% were low risk, 56% intermediate risk and 6% high risk.

With a median follow-up of 39 months, DFS was 97.81% and CSS was 99.45% with an OS of 90.22%.

The IPSS score increased a median of 2 points and normalised after 6 months to baseline values.

52% experienced acute genitourinary toxicity G1, 4% G2, and 1% G3. Acute G1 gastrointestinal toxicity was experienced in 9% and G2 in 1%. After 6 months, G1 genitourinary toxicity was reported in 3%, G2 in 1%, G1 gastrointestinal toxicity in 1% and G2 in 1%. No toxicities ≥ grade 3 were observed.

SBRT 35Gy is positioned as a safe treatment, with excellent disease control, requiring longer-term follow-up.