To address these drawbacks, the concept of accelerated partial breast irradiation was proposed. It arose out of the realization that the majority of tumor recurrences occur at or near the region of the prior lumpectomy site, suggesting that for well selected patients only the breast tissue surrounding the tumor bed might need radiation treatment. Accelerated partial breast irradiation limits the radiation to a smaller portion of the breast (surrounding the tumor cavity) and has the advantages of reducing radiation-induced toxicity at increased convenience because it is delivered within a much shorter period of time. In reducing the volume of breast treated, a higher dose of radiation can be delivered in each treatment session. Accelerated partial breast irradiation advantages include a reduction of the amount of irradiated skin and therefore the possibility to reduce radiation-induced skin toxicity, and an increased convenience because it can be accelerated.