683 Background: Various post-lumpectomy radiotherapy (PLRT) regimens currently are used that differ in: total radiation doses, fractionation schedules, volumes of breast treated, techniques of administration, and duration of treatment. These have not been directly compared or systematically reviewed. Methods: We searched PubMed for publications on PLRT through 2003. We categorized PLRT regimens into eight distinct types according to volume of breast treated (whole or partial). Whole-breast (WBRT) variants were distinguished by duration (six, five, four, or two weeks) and also by total dose and fractionation schedule, while partial-breast (PBRT) variants were distinguished by technique (multiplane vs. balloon brachytherapy vs. conformal external beam therapy), with intensity-modulated radiation therapy (IMRT) as a “dual-use” variant for either WBRT or PBRT. We compared all techniques with respect to five criteria: cost, convenience, cosmesis, complications, and control, using available literature according to its strength of evidence. Where literature was lacking, we supplied next-best institutional information. We assigned a composite cost score to each regimen to reflect technical factors and overall treatment time. We then ranked the regimens according to the five evaluation criteria. Results: The available evidence suggested the following regimens rank highest for each evaluation criterion: for cost, 4-week WBRT; for convenience, 2-week WBRT; for cosmesis and complications, 4, 5, and 6-week WBRT: for control, 6-week WBRT. For all PBRT regimens, inadequate follow-up was available to judge complications and control. Conclusions: Since control is the paramount criterion in PLRT, further follow-up and direct randomized comparisons are necessary for evidence-based decision-making. At this time, control data are most mature for 5-week and 6-week WBRT; these should be recommended to most patients. No significant financial relationships to disclose.