Probiotics for rectal volume variation during radiation therapy for prostate cancer.
OBJECTIVE
To investigate the effect of the probiotic Lactobacillus acidophilus on the percentage volume change of the rectum (PVCR), a crucial factor of prostate movement.


METHODS
Prostate cancer patients managed with tomotherapy as a radical treatment were enrolled in the study to take a probiotic capsule containing 1.0×10(8) colony-forming units of L acidophilus or a placebo capsule twice daily. Radiation therapy was performed at a dose of 78 Gy in 39 fractions. The PVCR, defined as the difference in rectal volume between the planning computed tomographic (CT) and daily megavoltage CT images, was analyzed.


RESULTS
Forty patients were randomized into 2 groups. The L acidophilus group showed significantly lower median rectal volume and median PVCR values than the placebo group. L acidophilus showed a significant reduction effect on the PVCR (P<.001). However, the radiation therapy fraction number did not significantly influence the PVCR.


CONCLUSIONS
L acidophilus was useful in reducing the PVCR, which is the most important determining factor of prostate position, during radiation therapy for prostate cancer.
Department of Radiation Oncology, Pusan National University School of Medicine, Busan, Republic of Korea.
Yongkan
Y
Ki
Wontaek
W
Kim
Jiho
J
Nam
Donghyun
D
Kim
Juhye
J
Lee
Dahl
D
Park
Hosang
H
Jeon
Honggu
H
Ha
Taenam
T
Kim
Dongwon
D
Kim
D000368:Aged; D000369:Aged, 80 and over; D058491:Bacterial Load; D005740:Gases; D006801:Humans; D007779:Lactobacillus acidophilus; D008297:Male; D008875:Middle Aged; D009068:Movement; D009929:Organ Size; D019936:Probiotics / Q000627:therapeutic use*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D011859:Radiography; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D012007:Rectum / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology
D005740:Gases