Dosimetric, radiobiological and secondary cancer risk evaluation in head-and-neck three-dimensional conformal radiation therapy, intensity-modulated radiation therapy, and volumetric modulated arc therapy: A phantom study

Jalil Ur Rehman, Muhammad Isa, Nisar Ahmad, Gulfam Nasar, H M. Noor Ul Huda Khan Asghar, Zaheer Abbas Gilani, James C. L. Chow, Muhammad Afzal, Geoffrey S IbbottJournal of Medical Physics 2018 43(2):129-135This analysis estimated secondary cancer risks after volumetric modulated arc therapy (VMAT) and compared those risks to the risks associated with other modalities of head-and-neck (H&N) radiotherapy. Images of H&N anthropomorphic phantom were acquired with a computed tomography scanner and exported via digital imaging and communications in medicine (DICOM) standards to a treatment planning system. Treatment plans were performed using a VMAT dual-arc technique, a nine-field intensity-modulated radiation therapy (IMRT) technique, and a four-field three-dimensional conformal therapy (3DCRT) technique. The prescription dose was 66.0 Gy for all three techniques, but to accommodate the range of dosimeter responses, we delivered a single dose of 6.60 Gy to the isocenter. The lifetime risk for secondary cancers was estimated according to National Council on Radiation Protection and Measurements (NCRP) Report 116. VMAT delivered the lowest maximum doses to esophagus (23 Gy), and normal brain (40 Gy). In comparison, maximum doses for 3DCRT were 74% and 40%, higher than those for VMAT for the esophagus, and normal brain, respectively. The normal tissue complication probability and equivalent uniform dose for the brain (2.1%, 0.9&...
Source: Journal of Medical Physics - Category: Physics Authors: Source Type: research