Total Body Irradiation with Step Translation and Dynamic Field Matching

Abstract EN

The purpose of this study is to develop a total body irradiation technique that does not require additional devices or sophisticated processes to overcome the space limitation of a small treatment room.

The technique aims to deliver a uniform dose to the entire body while keeping the lung dose within the tolerance level.

The technique treats the patient lying on the floor anteriorly and posteriorly.

For each AP/PA treatment, two complementary fields with dynamic field edges are matched over an overlapped region defined by the marks on the body surface.

A compensator, a spoiler, and lung shielding blocks were used during the treatment.

Moreover, electron beams were used to further boost the chest wall around the lungs.

The technique was validated in a RANDO phantom using GAFCHROMIC films.

Dose ratios at different body sites along the midline ranged from 0.945 to 1.076.

The dose variation in the AP direction ranged from 96.0% to 104.6%.

The dose distribution in the overlapped region ranged from 98.5% to 102.8%.

Lateral dose profiles at abdomen and head revealed 109.8% and 111.7% high doses, respectively, at the body edges.

The results confirmed that the technique is capable of delivering a uniform dose distribution to the midline of the body in a small treatment room while keeping the lung dose within the tolerance level.