Feasibility, Dosimetric Quality, and Early Clinical Outcomes of Total Body Irradiation Using Volumetric Modulated Arc Therapy (VMAT-TBI): An Initial Experience and Technical Report

Objective/Aim: This article demonstrates how an entirely novel, multi-isocenter Volumetric Modulated Arc Therapy-based TBI (VMAT-TBI) method was implemented at an exclusive military cancer center, including its technical specifications, dosimetric practicality, and early therapeutic results.

Methods: A report on technical issues and a retrospective cohort analysis were conducted on patients who were treated from January 2023 to November 2025. In this study, they explore specialised immobilisation, extended-field CT models, target and OAR delineation, and multi-isocenter VMAT planning with overlapped arcs. Dosimetry corroborated the OAR doses and the uniformity of the target area. It investigated the effects of the procedure (CTCAE v5.0), the time it utilised to take effect, and the number of participants who endured it for 100 days.

Results: VMAT-TBI was used to achieve excellent dosimetry. D2% had an average value of 108.4%, and D98% had an average value of 96.1% of the specified amount, which shows that the targets were very similar. The average dose of radiation to the lungs through OAR was reduced from 9.5 Gy to 7.2 Gy with the advent of the AP/PA method, showing considerable amounts of saving. All of the patients had significant neutrophil engraftment (median 14 days). There were predominantly low-grade acute consequences and no Grade 3+ radioactive pneumonitis. 92% were still surviving after 100 days.

Conclusion: Compared to standard TBI, VMAT-TBI is medically possible, better in terms of dose, and safe for patients. This ensures dosage uniformity and OAR protection operate better, which could decrease the proportion of individuals who experience TBI. The technology in this study can be used by centers that use this sophisticated method of instructional material.