Prospective phase II trial of hypofractionated intensity-modulated radiotherapy for localized prostate cancer

Abstract

Objective To prospectively evaluate the efficacy and toxicity of hypofractionated intensity-modulated radiotherapy (IMRT) for prostate cancer.Methods Fifty-two consecutive patients with localized prostate cancer were enrolled in this study between Feb.2009 and Mar.2011.All patients received hypofractionated IMRT (2.7 Gy/fx,25 fractions,total 67.5 Gy) to the prostate and seminal vesicles.32 high risk patients also received prophylactic irradiation to the pelvic lymph nodes concurrently (2 Gy/fx,25 fractions).Imaging-guided radiotherapy was employed in 35 patients.Androgen deprivation therapy was adopted in 48 of 52 patients.Results After a median follow-up of 13 months,the mean prostate specific antigen (PSA) was reduced from (40.3 ± 36.6) ng/ml before treatment to (0.5 ± 1.7)ng/ml at the last follow-up.By the time of last follow-up,2 patients (4％) failed.One had PSA failure and the other had both PSA failure and pelvic lymph node relapse.25％ of the patients experienced grade 2 acute gastrointestinal (GI) toxicity and 4％ experienced grade 3 GI toxicity.Acute grade 2 and grade 3genitourinary ( GU ) toxicity occurred in 15％ and 2％,respectively.The incidence of late grade 2 and grade 3 GI toxicity was 17％ and 0％,respectively.Late grade 2 and 3 GU toxicity was 8％ and 2％.The potency was unable to evaluate because most of the patients received androgen deprivation therapy.Conclusions The short-term PSA-free survival after 2.7 Gy/fx,25 fractions' hypofractionated IMRT for localized prostate cancer is favorable,and the acute and late GI and GU toxicity are acceptable.A longer time follow-up is warranted to ascertain the long term efficacy and safety of this regimen. Key words: Prostate neoplasms/ intensity-modulated radiotherapy; Intensity-modulated radiotherapy,hypofractionation; Efficacy and toxicity