Riassunto analitico
INTRODUCTION
The probability of local control of prostate cancer increases with
increasing dose delivered. Dose escalation with conventional fractionation
requires an extension of the total treatment duration. Hypofractionation
allows for shorter treatment duration. The objective of the study was to
determine whether hypofractionation can improve the efficacy of
radiotherapy in the treatment of prostate cancer in low- or
intermediate-risk prostate cancer patients.
METHODS
In this randomized phase 3 trial, 166 patients from 5 centers in Emilia
Romagna, Italy were enrolled. They were balanced split into the
conventional arm (treated with 3D-CRT or IMRT) and the experimental arm
(treated with IMRT - IGRT). The two endpoints considered were: the
biochemical relapse-free survival (bRFS) at 2 years and the incidence rate
of late rectal (GI) and genitourinary (GU) toxicity obtained with the two
modalities. Early data on acute and late toxicity are reported in this
paper.
Rectal and genitourinary toxicity is reported according to CTCAE v.4
criteria. Differences between groups in categorical variables were analyzed
by χ2 Test. Patients at intermediate risk received 78 Gy (control arm) and
57.3 Gy (experimental arm); those at low risk 74 Gy (control arm) and 54.3
(experimental arm).
RESULTS
The most common acute was noninfectious cystitis (64% of patients).
Proctitis and diarrhea appeared in 13%, urinary retention in 10%, urinary
incontinence in 9%, hemorrhoids in 8%, anal pain in 6%, and fecal
incontinence in 1%.
The most frequent late toxicity was noninfectious cystitis, which appeared
in 38% of patients. Urinary incontinence in 18%, hemorrhoids in 11%,
urinary retention in 9%, fecal incontinence in 7%, diarrhea in 5% and anal
pain in 2%.
We analyzed the evolution of proctitis and noninfective cystitis over time,
and we can see an important reduction or, at least, attenuation of late
toxicity over time.
DISCUSSION
GU and GI toxicities were analyzed separately by grouping grade ≥ 2 adverse
events related to the respective systems so as to compare them with some of
the major randomized trials comparing hypofractionation with standard
fractionation. No statistically significant differences emerged between the
two arms. Our results showed that the standard regimen and the
hypofractionated scheme are equally well tolerated and therefore equivalent
in terms of short- and long-term toxicity.
|
