Hypofractionated intensity-modulated radiotherapy (70 gy at 2.5 Gy per fraction) for localized prostate cancer: long-term outcomes.
OBJECTIVE
To analyze the long-term relapse-free survival and toxicity rates in patients treated with hypofractionated intensity-modulated radiotherapy.


METHODS
The study sample includes the first 100 consecutive localized prostate cancer patients treated to 70.0 Gy at 2.5 Gy per fraction. The median follow-up was 66 months (range, 3 to 75 months). Biochemical failure was the study endpoint, using both the ASTRO definition (A-bRFS) and the alternate "nadir + 2 ng/mL" definition (N-bRFS). RTOG scores were used to assess toxicity.


RESULTS
The 5-year A-bRFS and N-bRFS rates were 85% (95%CI, 78-93%) and 88% (95%CI, 82-95%) for all cases, respectively. For low, intermediate and high-risk disease, the 5-year A-bRFS rates were 97%, 88%, and 70%. The corresponding 5-year N-bRFS rates were 97%, 93%, and 75%, respectively. The acute rectal toxicity scores were 0 in 20, 1 in 61, and 2 in 19 patients. The acute urinary toxicity scores were 0 in 9, 1 in 76, and 2 in 15 patients. The late rectal toxicity scores were 0 in 71, 1 in 19, 2 in 7, and 3 in 3 patients. The actuarial late Grade 3 rectal toxicity rate at 5 years was 3%. A number of the toxicities observed either resolved spontaneously or were corrected. At last follow-up, the rate of combined Grades 2 and 3 late rectal toxicity at 5 years was only 5%. The late urinary toxicity scores were 0 in 75, 1 in 13, 2 in 11, and 3 in 1 patients. The actuarial late Grade 3 urinary toxicity rate at 5 years was 1%.


CONCLUSIONS
With a median follow-up of 66 months, the long-term results after high-dose hypofractionation are excellent. Late toxicity, urinary and rectal, has been limited. High-dose hypofractionation is an alternative dose escalation method in the treatment of localized prostate cancer.
Kupelian
Patrick A
PA
Department of Radiation Oncology, M.D. Anderson Cancer Center Orlando, Orlando, FL 32806, USA. patrick.kupelian@orhs.org
Thakkar
Vipul V
VV
Khuntia
Deepak
D
Reddy
Chandana A
CA
Klein
Eric A
EA
Mahadevan
Arul
A
D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D006471:Gastrointestinal Hemorrhage / Q000209:etiology / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000401:mortality / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000209:etiology / Q000628:therapy; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D012007:Rectum / Q000528:radiation effects*; D016896:Treatment Outcome; D001743:Urinary Bladder / Q000528:radiation effects
D017430:Prostate-Specific Antigen