First clinical experience of total body irradiation using volumetric modulated arc therapy technique in Japan.

In recent years, advances in radiotherapy technology have led to the use of high-precision radiotherapy such as volumetric modulated arc therapy (VMAT). Total body irradiation using VMAT technique (VMAT-TBI) was performed for the first time in our hospital. A 56-year-old male patient diagnosed with B-cell acute lymphoblastic leukemia was performed TBI as pretreatment for haploidentical-related peripheral blood stem-cell transplantation. The prescribed dose was 4 Gy for planning target volume in two fractions. The treatment plan was divided into two plans: upper body and lower body with three and two isocenters, respectively. The overall treatment time with VMAT-TBI was approximately 55 min, and it was not significantly longer than that of moving couch techniques. VMAT-TBI is a less burdensome and more accurate treatment for patients, and it may be a useful treatment for TBI.