@article { author = {Abdulbaqi, Abdulrahman and Abdullah, Siham and Alabedi, Haydar and alazawy, nabaa and Al-Musawi, Mustafa and Heydar, Ahmed}, title = {The Effect of Total Fields' Area and Dose Distribution in Step and Shoot IMRT on Gamma Passing Rate Using OCTAVIUS 4D-1500 Detector Phantom}, journal = {Iranian Journal of Medical Physics}, volume = {18}, number = {4}, pages = {226-231}, year = {2021}, publisher = {Mashhad University of Medical Sciences}, issn = {2345-3672}, eissn = {2345-3672}, doi = {10.22038/ijmp.2020.44712.1690}, abstract = {Introduction: Quality assurance is necessary for every IMRT plan.‎Octavius 4D-1500 detector phantom is ‎one of the new phantoms for ‎determining the treatment plan quality‎.‎ This study aimed to examine the IMRT plans using the ‎Octavius 4D-1500‎‏ ‏‎to determine if ‎it is a reliable, ‎dependable, and durable.  Material and Methods: IMRT QA conducted for 30 cases: HN and pelvis. The Monaco TPS used for treatment planning. The treatment plans ‎were then applied ‎to the Octavius 4D-1500 phantom (virtually and actually), ‎‎the γ-index was calculated in VeriSoft program to evaluate the IMRT plans. Results: Significant differences were observed between the ‎‎‎measured and calculated dose distributions for HN and pelvic plans, while the treatment ‎sites did not affect the GP rate. The results of the global Gp ‎ were higher than the local GP, ‎regardless of the study criteria. The ‎HN plans ‎showed a more significant difference ‎than the pelvic plans. The HN plans, ‎a ‎strong significant correlation was found between the total ‎fields’area and %GP in both global ‎‎and local analyses, while in the pelvic plans, there was only a significant association with the ‎local %GP. Conclusion: The measured dose distributions significantly different from calculated distributions. The relationship between the ‎‎fields’ ‏‎ area ‎and ‎‎‎%GP was inverse. In the HN plans, a ‎significant correlation found between the total ‎‎fields’ ‎area ‎and %GP in both global and ‎local, while only local %GP in the pelvic plans was significant correlation. Overall, the Octavius 4D-1500 detector phantom ‎might be applicable for ‎assessing the QA of IMRT plans.}, keywords = {Gamma Passing Rate,Dose Distribution,Intensity Modulated Radiotherapy,Quality Assurance}, url = {https://ijmp.mums.ac.ir/article_15518.html}, eprint = {https://ijmp.mums.ac.ir/article_15518_dbe64aa0f3fa08564ee1cc297eda4086.pdf} }