A comparison of planned dose in TBI VMAT treatment to measurement using portal dosimetry®, IBA Matrix®, and TLD-100®

Bone Marrow Transplant (BMT) is a therapeutic modality used in the treatment of numerous diseases. Since the work of E. Donnal Thomas and his group in March 1969, radiotherapy has been used as a preconditioning treatment in the form of Total Body Irradiation (TBI). This type of treatment aims to irradiate the patient's body as a whole to eradicate residual diseases and/or induce immunosuppression, facilitating the transplantation of infused cells and reducing the likelihood of rejection. The traditional methodology applied to TBI uses widely open radiation fields to irradiate the patient in regions distant from the isocenter, often distances greater than 2 meters. With the introduction of modulated treatment techniques, several authors have shown the feasibility of using Volumetric Modulated Arc Therapy (VMAT) for TBI applications. The application of VMAT technique in TBI treatments, as demonstrated by various authors [4-8], offers significant advantages, including the possibility of using smaller rooms, eliminating compensators or shields, and the ability to reduce dose to organs at risk. These advantages can not only reduce the costs associated with implementing the technique but also improve the patient's quality of life. However, there are still open questions about this new treatment methodology. One particular point is the correlation between the delivered dose and the dose measured by patient-specific quality control systems. Most studies in the literature use a single type of device, usually a planar detector, to verify the delivery of the planned dose. Therefore, the aim of this work is to plan the dose delivery to an anthropomorphic phantoms from CIRS, Adult Female model, and compare the dose planned to those ones evaluated using two planar measurement systems and thermoluminescent (TL) dosimetry applying TLD 100 (LiF;Mg,Ti). (author)