Session Item

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 extracranial stereotactic radiotherapy (SBRT).

We retrospectively analysed 466 patients with localised low and favourable intermediate risk prostate cancer treated with SBRT between February 2014 and October 2022.

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 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.

The median age was 72 years. 68% had received previous hormone treatment. 39% were low risk and 61% favourable intermediate risk.
With a median follow-up of 44 months, DFS was 94.64% and CSS was 99.57% with an OS of 89.48%.
The IPSS score increased a median of 2 points and normalised after 6 months to baseline values.
49.14% experienced acute genitourinary toxicity G1, 5.36% G2, and 0.43% G3. Acute G1 gastrointestinal toxicity was experienced in 7.3%, G2 in 0.86% and G3 in 0.21%. After 6 months, G1 genitourinary toxicity was reported in 3.06%, G2 in 0.71%, G1 gastrointestinal toxicity in 0.71% and G2 in 0.47%. There were 5 cases of actinic proctitis and 3 of them required argon laser coagulation.

SBRT is positioned as a safe treatment for localised prostate low and favourable intermediate risk cancer, with excellent disease control and a low toxicity profile.