To eliminate divergence of the brain and spinal portals in craniospinal treatment, what angle should the table be rotated?

In craniospinal treatment, it is important to minimize the divergence of the treatment beams to ensure that the radiation dose is precisely delivered to the intended targets in the brain and spinal cord while limiting the exposure to surrounding healthy tissues. Rotating the treatment table adjusts the angle at which the radiation beams intersect the patient, which helps achieve a more parallel alignment of the beams as they travel from the source to the treatment area.

A rotation of 4.3° is significant because it is a calculated angle that has been found effective in achieving optimal collimation of the beams as they enter the craniospinal target. This angle allows for the proper alignment and ensures that the dose distribution from the radiation does not overly diverge, thus maintaining the integrity of the treatment plan. The chosen angle must carefully balance the need for effective treatment while minimizing potential side effects due to radiation exposure in surrounding areas.

The importance of this angle in treatment planning and execution is underscored by the specific attention it receives in medical protocols aimed at optimizing therapeutic outcomes in craniospinal irradiation.