Dose-Escalated Hypofractionated Intensity-Modulated Radiotherapy in High-Risk Carcinoma of the Prostate : Outcome and Late Toxicity

Abstract EN

Background.

The benefit of dose-escalated hypofractionated radiotherapy using intensity-modulated radiotherapy (IMRT) in prostate cancer is not established.

We report 5-year outcome and long-term toxicity data within a phase II clinical trial.

Materials and Methods.

60 men with predominantly high-risk prostate cancer were treated.

All patients received neoadjuvant hormone therapy, completing up to 6 months in total.

Thirty patients were treated with 57 Gy in 19 fractions and 30 patients with 60 Gy in 20 fractions.

Acute and 2-year toxicities were reported and patients followed longitudinally to assess 5 year outcomes and long-term toxicity.

Toxicity was measured using RTOG criteria and LENT/SOMA questionnaire.

Results.

Median followup was 84 months.

Five-year overall survival (OS) was 83% and biochemical progression-free survival (bPFS) was 50% for 57 Gy.

Five-year OS was 75% and bPFS 58% for 60 Gy.

At 7 years, toxicity by RTOG criteria was acceptable with no grade 3 or above toxicity.

Compared with baseline, there was no significant change in urinary symptoms at 2 or 7 years.

Bowel symptoms were stable between 2 and 7 years.

All patients continued to have significant sexual dysfunction.

Conclusion.

In high-risk prostate cancer, dose-escalated hypofractionated radiotherapy using IMRT results in encouraging outcomes and acceptable late toxicity.