Update of the HIPRO study: Late toxicity and outcome at seven years.

81 Background: Dose-escalated radiotherapy for localised prostate cancer improves disease control but at the expense of increased overall treatment time and late toxicity. Given the low alpha-beta ratio for prostate cancer, treatment with hypofractionation should be biologically advantageous. Intensity-modulated radiotherapy (IMRT) allows dose escalation with hypofractionation, while achieving acceptable levels of toxicity. We report our 7 year late toxicity data in patients treated with two such regimens within the Hypofractionated Dose Escalation utilising Intensity-modulated Radiotherapy in Carcinoma of the Prostate (HIPRO) study. Methods: Sixty men, median age 75 years (50-87), with localised adenocarcinoma of prostate (T1-3NOMO) and either Gleason score ≥7 or PSA 20-50ng/L received 57Gy in 19 fractions (n=30) or 60Gy in 20 fractions (n=30) using 5-field inverse-planned IMRT. All patients received neoadjuvant hormone therapy, continuing for up to 6 months after treatment. Late toxicity was assessed at...