Disclosed is a brachytherapy seed deployment system, for use in any of a variety of medical procedures such as radiation treatment of the prostate gland. The system includes a number of brachytherapy seed deployment needles, each preloaded with brachytherapy seeds in patterns and activities predetermined for a unique patient. The seeds are contained in transparent tubular sleeves, thereby allowing direct visualization of the brachytherapy seeds and spacers, so that the seed pattern may be inspected at the clinical site. A releasable retainer prevents accidental brachytherapy seed loss. The system additionally includes shipping containers, separately accessible calibration seeds and a display stand for use at the clinical site. Methods are also disclosed.