ESTRO 2026 Congress Report
Report by the ESTRO Urology Focus Group

In the management of biochemical recurrence following radical prostatectomy, considerable controversy remains regarding the safety of moderate hypofractionation, owing to the limited availability of robust long-term data. During ESTRO 2026, the SHARE phase III randomised trial was presented, evaluating whether hypofractionated salvage radiotherapy (HYPO) could improve outcomes compared with conventional fractionation (CONV) in patients experiencing biochemical recurrence after radical prostatectomy. Between 2019 and 2021, 299 patients were randomised to receive either 65 Gy in 26 fractions (EQD2 = 74.3 Gy) or 66 Gy in 33 fractions, with 295 patients ultimately included in the analysis. Treatment was delivered to the prostate bed using intensity-modulated radiotherapy and daily image guidance, while androgen deprivation therapy and elective pelvic nodal irradiation were administered at the discretion of the treating physicians. The primary endpoint was biochemical progression-free survival (bPFS), with secondary endpoints including distant metastasis-free survival (DMFS), cancer-specific survival (CSS), toxicity, and patient-reported quality of life.

After a median follow-up of 52.6 months, the study demonstrated no significant difference in oncological outcomes between the two treatment arms. Four-year bPFS rates were comparable, reaching 80.1% in the HYPO group and 78.1% in the CONV group (p = 0.88). Similarly, DMFS and CSS rates were nearly identical. These findings indicate that hypofractionation did not provide superior disease control but achieved efficacy comparable to that of conventional treatment schedules. It is important to emphasise that SHARE evaluated not only hypofractionation but also a dose-escalation strategy, with an EQD2 of 74.3 Gy in the experimental arm. The results, therefore, further support the findings of two previous randomised studies demonstrating the lack of oncological benefit from dose escalation in the salvage setting.

To date, only the NRG-GU003 trial has evaluated hypofractionation in a phase III randomised design, and its relatively short follow-up has made the widespread adoption of moderate hypofractionation debatable; the SHARE study is therefore of considerable interest. The 4-year cumulative incidence of grade ≥2 gastrointestinal (GI) toxicity was significantly higher in the HYPO arm (8.0% versus 0.7%, p = 0.003). Interestingly, a subgroup analysis of patients treated with an endorectal balloon was also presented. Among patients who did not receive an endorectal balloon, the rate of grade ≥2 GI toxicity increased to 15.3% and 1.9% in the HYPO and CONV arms, respectively (p = 0.02). Conversely, the use of an endorectal balloon appeared to reduce the cumulative incidence of grade ≥2 GU toxicity in both treatment arms. Importantly, patient-reported quality-of-life outcomes did not differ significantly between groups… with a short follow-up!

Once again, following this study, hypofractionated radiotherapy after radical prostatectomy remains a controversial topic, and additional long-term data are needed before this approach can be considered a standard of care for all!

Dr. Paul Sargos
Amethyst Radiotherapy Group

La Garenne-Colombes, Paris, France.

E-mail: paul.sargos@amethyst.fr

ESTRO Urology Focus Group Core Expert