Hypofractionation vs. conventional fractionation RT in high-risk PCa patients

Thursday, 3 December 2009- Early results of a phase 3 study examining hypofractionation radiotherapy in high-risk prostate cancer patients showed that the hypofractionated schedule is superior than conventional fractionation in terms of freedom from biochemical failure, according to a study presented in Barcelona, Spain, during the 2nd European Multidisciplinary Meeting on Urological Cancers (EMUC).

B. Saracino and colleagues (Rome, Italy/ Madison, USA) compared the efficacy of hypofractionation (62 Gy/20 fractions/5 weeks, 4 fractions per week) vs. conventional fractionation radiotherapy (80 Gy/40 fractions/8 weeks) in patients with high risk prostate cancer.

In their study conducted from January 2003 to December 2007, a total of 168 patients were randomised to receive either hypofractionation (85 patients, arm A) or conventional fractionation (83 patients, arm B) schedules of 3D Conformal Radiotherapy (CRT) to the prostate and seminal vesicles.

All patients received a 9-month course of total androgen blockade (TAB). CRT started 2 months after TAB initiation. Patient assignment to the high risk category was done following the NCCN guidelines. Biochemical failure (BF) was determined according to the nadir+2 Phoenix definition.

The results showed that no differences between the two groups were found with regard to age, GS, T-stage and pretreatment PSA level (iPSA). The median follow-up was 32 (23-43interquartiles) and 35 (24-45 interquartiles) months in the hypofractionation and conventional group respectively.

The 3-year freedom from biochemical failure (FFBF) rates were 87% and 79% in the hypofractionation and conventional fractionation group, respectively (p=0.035, figure 1). The 3-year FFBF in patients at a very high risk (i.e. iPSA>20 ng/ml, GS>8, or T>2c), were 88% and 76% (p=0.014) in the former and latter group, respectively.

The multivariate Cox analysis confirmed fractionation, iPSA and bGS as significant prognostic factors. No patient died. The 3-year rates of freedom from distant metastases were 88% and 82% in the hypofractionation and control arm (p=0.82), respectively.

"Our findings suggest that the hypofractionated schedule used in this trial is superior to conventional fractionation in terms of FFBF," the researchers concluded.

Source: Saracino B., Arcangeli S., et al., "Hypofractionation vs. conventional fractionation radiotherapy in patients with high risk prostate cancer: Early results of a phase III randomized study," P001, Moderated Poster Presentation; 2nd EMUC, Barcelona, Spain,  November 26-29, 2009.

Edited by: Joel Vega

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