바로가기  >

Abstract
Background: Several studies have reported patient-related risk factors for late rectal bleeding following conventionally fractionated radiotherapy for prostate cancer. We investigated patient-related risk factors for late rectal bleeding after hypofractionated radiotherapy.

Methods: A total of 231 patients with local or locally advanced prostate cancer treated with hypofractionated radiotherapy (70 or 67.2 Gy in 28 fractions) were evaluated retrospectively. All patients received intensity-modulated radiotherapy with daily image guidance. The relationships between late rectal bleeding and risk factors like diabetes, hypertension, cirrhosis, and anticoagulant use were analyzed.

Results: During a median follow-up of 23 months, the crude rates of grade ≥ 1, grade ≥ 2, and grade ≥ 3 late rectal bleeding were 23.8%, 16.9%, and 9.5%, respectively. Cirrhosis and anticoagulant use predicted an increased risk of grade ≥ 3 rectal bleeding in multivariable analyses (hazard ratio [HR] 14.37, 95% confidence interval [CI] 3.09-66.87, P = 0.001, and HR 2.93, 95% CI 1.14-7.55, P = 0.026, respectively). The non-anticoagulant group had a significantly superior 5-year freedom from grade ≥ 3 bleeding compared to the anticoagulant group in a propensity-weighted log-rank analysis (88.0% vs. 76.7%, P = 0.041). A receiver operating characteristic curve analysis revealed that rectal bleeding was minimized in the anticoagulant group if the equivalent dose at fractionation of 2 Gy (EQD2) V77 Gy of the rectum was < 4.5% or if the EQD2 V8.2 Gy was < 71.0%.

Conclusions: Patients taking anticoagulants or those with cirrhosis had a significantly higher risk of severe late rectal bleeding than other patients after hypofractionated radiotherapy for prostate cancer in the present study. The bleeding risk could be lowered by minimizing hotspots in patients taking anticoagulants.

Affiliations

Tae Gyu Kim  1 , Byungdo Park  2 , Yun Gyu Song  3 , Hyoun Wook Lee  4 , Tae Hee Oh  5 , Dong-Soo Ryu  5 , Seung Chan Jeong  5 , Daehyeon Cho  6 , Jieun Oh  6 , Kwang Min Kim  6 , Jung Won Lee  6 , Hyoun Soo Lee  6 , Sung Min Kong  6 , Jun Young Kim  6 , Haeyoung Kim  7
1 Department of Radiation Oncology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, 630-522, South Korea. tg1.kim@samsung.com.
2 Department of Radiation Oncology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, 630-522, South Korea.
3 Department of Radiology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, 630-522, South Korea.
4 Department of Pathology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, 630-522, South Korea.
5 Department of Urology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, 630-522, South Korea.
6 Department of Internal Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, 630-522, South Korea.
7 Departments of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, South Korea.