Analytical dosimetric study of intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) for prostate cancer

PURPOSE: The study aimed to compare the dosimetric results and treatment delivery efficiency among four techniques to explore the preferred technique in prostate treatment. MATERIALS AND METHODS: 7 IMRT, 9 IMRT, 1 ARC, and 2 ARC plans were created for 30 prostate cancer patients using the Eclipse™ treatment planning system (Varian Medical Systems). All the plans were designed to deliver 80.0 Gy in 40 fractions to the prostate planning target volume (PTV). Target coverage, organs at risk (OARs), number of monitor units, homogeneity, and conformity were compared across the four techniques to assess the quality of the plans. RESULTS: The study revealed better Planning Target Volume (PTV) dose coverage in the VMAT-2A than in the other plans. At the same time, VMAT-2A plans were found to be significantly lower in terms of Bladder and rectum doses than other techniques. In addition, VMAT has the advantage of considerably reducing the number of monitor units and treatment time. CONCLUSION: For prostate cancer, VMAT may offer a favorable dose gradient profile, conformity, and MU and treatment time compared to IMRT.