Treatment of prostate cancer utilizing iodine 125 (125I) interstitial seed implants has become an accepted and widely used modality. Numerous variations in 125I seed implant loading distribution techniques have developed as a result of the preferences of individual institutions implementing the modality. No particular universal standard is currently used for 1251 seed implants. A major concern with 125I seed implants is coverage of the prostate with the desired dose and the minimization of dose to the urethra. A variation of seed distribution per individual anatomy is desirable. Historically, brachytherapy relied on dosimetry systems, such as the Paris, Quimby, and Manchester systems to achieve the desired dose distribution. Use of various peripherally loaded 125I seed implant distributions to accommodate anatomic variations within the same institution prompted the interest of how the results compare to the Manchester system.