Clinical and dosimetric factors associated with acute rectal toxicity in patients treated with 131Cs brachytherapy for prostate cancer

This study identifies R-V50, R-V75, R-D-1cc, and R-D-2cc as factors associated with patient-appreciated acute rectal toxicity. We are performing dosimetric analysis to determine the optimal distance for the posterior needles from the prostate-rectal interface to decrease rectal dose while still maintaining adequate coverage of prostate.