Transperineal TRUS-guided prostate brachytherapy using loose seeds versus RAPIDStrand: A dosimetric analys

Purpose An analysis of the effect of stranded 125I and loose (predominantly 103Pd) sources on dosimetric outcomes of brachytherapy of the prostate. Methods and materials Between September 1998 and December 2003, 473 patients were treated with brachytherapy for biopsy-proven carcinoma of the prostate. Of these, 337 (71%) procedures were performed using free seeds placed with a Mick applicator. Beginning in April 2002, a program of stranded 125I sources (RAPIDStrand) was implemented; 136 (29%) patients were treated via this approach. Dosimetric variables were collected, as were events of urinary retention. Results Mean V100 values for the stranded 125I approach were greater than those for free seeds (p<0.0005), whether 125I or 103Pd (p<0.005). Use of the strand was the most significant determinant of V100 of all variables examined. The stranded 125I approach was also associated with higher mean D90 values and lower V150-urethral doses. Conclusions Use of stranded 125I was associated with superior dosimetric outcomes in this group of patients.