Hypofractionated Radiation Therapy in Prostate Cancer

• Tolerance to treatment [ Time Frame: up to 5 years ]
  Tolerance to treatment (urinary, rectal, sexual): Acute (up to 90 days) and late (up to 5 years) toxicity follow-up according to NCI CTCAE version 3.0
  
  

• 1. Quality of life [ Time Frame: 9 days (Treatment arm A) or 28 days (Treatment arm B), 12 weeks, 6, 12, 18 months and yearly thereafter, up to 5 years ]
  Quality of life (EORTC QLQ-C30, Prostate cancer module EORTC QLQ-PR25)
  
  
• 2. Local failure [ Time Frame: 9 days (Treatment arm A) or 28 days (Treatment arm B), 12 weeks, 6, 12, 18 months and yearly thereafter, up to 5 years ]
  Assessed by digital rectal examination (DRE). MRI or PET-CT with choline or acetate may be a confirmatory option. Biopsy confirmation is required for those patients with exclusive local failures and candidates for local salvage.
  
  
• 3. Biochemical disease-free survival bDFS [ Time Frame: 9 days (Treatment arm A) or 28 days (Treatment arm B), 12 weeks, 6, 12, 18 months and yearly thereafter, up to 5 years ]
  Phoenix definition (PSA nadir + 2 ng/ml)
  
  
• 4. Metastases-free survival [ Time Frame: 9 days (Treatment arm A) or 28 days (Treatment arm B), 12 weeks, 6, 12, 18 months and yearly thereafter, up to 5 years ]
  Outcomes 3 or 4 - investigations PET-CT choline
  
  
• 5. Disease-specific survival [ Time Frame: 9 days (Treatment arm A) or 28 days (Treatment arm B), 12 weeks, 6, 12, 18 months and yearly thereafter, up to 5 years ]
  Alive/dead status, date and cause of death and prostate cancer disease status (outcomes 3/4 and 5).
  
  

This protocol presents a randomised phase II study aiming to investigate the tolerance and disease control of extreme hypofractionated RT for prostate cancer by delivering 5 x 7.25 Gy = 36.25 Gy over two alternative time schedules: either over 9 days (study A), or over 28 days once-a-week, the same week-day (study B).

The total dose and fractionation schedules have been chosen based on the assumption of their isoeffectivity regarding potential late rectal effects to be expected with a maximum equivalent dose of 74 Gy in 2 Gy fractions and assuming an alpha/beta = 3 Gy for the rectum.

In both arms, the prescribed dose per fraction to the urethra and the surrounding transitional zone will be dropped from 7.25 Gy to 6.5 Gy with a simultaneous integrated boost (SIB) technique. A dose of 5 x 6.5 Gy is equivalent to 31 x 2 Gy assuming an alpha/beta = 3 Gy for the urethra and equivalent to 37 x 2 Gy assuming an alpha/beta = 1.5 Gy for microscopic tumour foci in the transitional zone surrounding the urethra. The two treatment regimens chosen will each be the object of a separate phase I-II study covered by the same protocol and performed in parallel by the participating centres. Randomised assignment to either of the two studies will be introduced to avoid selection bias in treatment assignment within each centre.

OBJECTIVES:

Primary

• To determine the risk of urinary, rectal and sexual acute and late toxicities rates in patients receiving two different time schedules of extreme hypofractionated radiation therapy

  • Secondary

• To determine the Quality of life (EORTC QLQ-C30, Prostate cancer module EORTC QLQ-PR25) in patients receiving two different time schedules of extreme hypofractionated radiation therapy
• To determine the rate of local failure
• To determine in the two study arms the biochemical disease-free survival bDFS rate
• To determine in the two study arms the metastases-free survival rate
• To determine in the two study arms the disease-specific survival rate

OUTLINE:

This is a multicenter study.

Patients undergo extreme hypofractionated radiation therapy for prostate cancer by delivering 5 x 7.25 Gy = 36.25 Gy over two alternative time schedules:

Experimental Arm A: Over 9 days. Experimental Arm B: Over 28 days once-a-week, the same week-day. All patients will be followed up for at least 18 months to contribute to the analysis of the main endpoints of the study. With reference to the secondary endpoints, follow-up will be extended to 10 years.

Stopping rule: In order to avoid exposure of patients to a treatment that may be unsafe, acute GI and GU toxicity will be continuously monitored with the purpose of assisting in the decision of possibly interrupt recruitment in case of an alarming frequency.To this purpose, the procedure of Ivanova et al., 2005 will be applied.