Implementation of total body irradiation using VMAT

Total body irradiation (TBI) is a well-established component of several conditioning regimens required before bone marrow or hematopoietic stem cell transplantation. In this work, we validate the imparted dose in the TBI technique using VMAT in Médica Sur. We used an anthropomorphic phantom ATOM 702-D, CIRS (Norfolk, Virginia), add the upper extremities using a homemade material and scanned it using a CT scanner GE 580RT (General Electric Company). The TBI-VMAT plan was calculated and optimized using Eclipse™ Treatment Planning System V.11.031 (Varian Medical Systems, Palo Alto, CA). We used and adapted the VMAT plan configuration proposed by Springer et al. [1]. The planned doses were compared with the delivered dose in the phantom using Gafchromic EBT3 film (Ashland ISP, Wayne, NJ), placed inside the phantom in planes corresponding to head, lungs, liver, and pelvic region, and irradiated with one single fraction (2 Gy). According to TPS dose-volume histograms, 97.8% of the PTV received 95% of the planned dose (12 Gy in 6 fractions). The mean dose in the plan to the phantom's lungs was 10.03 Gy. These values were consistent with what was measured using EBT3 films and the reported in reference [1], so TBI’s clinical implementation using VMAT is feasible in Médica Sur.