Clinical Differences Among Volumetric Modulated Arc Therapy, Intensity Modulated Radiation Therapy, and 3D- Conformal Radiation Therapy in Prostate Cancer: A Brief Review Study

The present study aimed at identifying monitor unit (MU), treatment time variations, volume coverage dissimilarity, and second tumor incidence among Volumetric Modulated Arc Therapy (VMAT), Intensity Modulated Radiation Therapy (IMRT), and 3D-Conformal Radiation Therapy (3D-CRT), and treatment plans for prostate cancer based on literature review. A literature search was conducted on Pubmed/MEDLINE, BioMed Central (BMC)-part of Springer Nature, Google Scholar, and Insight Medical Publishing (iMED-Pub LTD) using the following keywords for filtering: 3D-CRT, IMRT, VMAT, Prostate Cancer, Conformity, and Homogeneity Index. IMRT was consisted of several treatment fields with different directions, hundreds of beamlets with modulated intensity, and an advantage over 3D-CRT, whereas VMAT had the advantage over IMRT due to rotating-beam utilization. VMAT usually required a longer dose optimization time and a rapid treatment, allowing patient comfort, reduced intra- fraction motion, and increased throughput compared to IMRT and 3D-CRT. VMAT has slightly better conformity and homogeneity with lower doses to normal tissue and MUs and treatment times compared to IMRT and 3D-CRT. Lower MUs reduce the risk of secondary malignancies. If target coverage and normal tissue sparing are comparable among different techniques, the risk of secondary malignancy should then be an important factor to choose the treatment modality.