Figure 1.

The most common total body irradiation configuration used at our institution: a couch unit in which the patient lies on his or her side at a source‐to‐axis distance (SAD) of 380 cm. An 18‐MV beam is used, and the collimator is rotated by 45 degrees and set to $40\times 40\hspace{0.17em}\text{cm}$.