Helical tomotherapy (HT) is a technique of rotational intensity-modulated radiation therapy allowing dose escalation and normal tissue sparing for various types of cancer. Dosimetric studies of HT in breast cancers showed an improvement in dose homogeneity, conformity and a decrease in high doses of organs at risk compared with standard techniques. On the other hand, HT increases low dose of organs at risk, which in rare cases can increases the risk of secondary cancer. The benefits of HT seem to be greater in complex target volumes in which dose coverage is difficult with standard techniques (funnel chest, tumor in the inner quadrant, obese patients). Indications for breast HT should be personalized and selected according to the expected benefit for every patient.