660 / 1542
Craniospinal irradiation
Spinal field
• Direct posterior field
prescribed at depth (depends
on MRI)
• Superior: Match the lower
border of the cranial field
(usually at C3-C4 junction)
• Lateral: cover the dural recess
so extend to the transverse
process
• Inferior: 1 cm below the lower
end of the thecal sac