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Updated: May 11, 2026
Radiation Planning Assistant - A Streamlined, Fully Automated Radiotherapy Treatment Planning System
Published on: April 11, 2018
Impact of machines on plan quality: volumetric modulated arc therapy and intensity modulated radiation therapy
S Clemente1, M Cozzolino, C Oliviero
1Department of Radiation Oncology, IRCCS CROB, Via Padre Pio n.1, 85028, Rionero in Vulture, PZ, Italy, clemente_stefania@libero.it.
Purpose:
To evaluate the impact of different machines on plan quality using both intensity modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) techniques.
Materials And Methods:
Eight patients with squamous cell carcinoma of the oropharynx were selected at random. Plans were computed for IMRT and VMAT Smart Arc, using Pinnacle TPS for an Elekta (IMRT-E, VMAT-E) and Varian linac (IMRT-V, VMAT-V). A three-dose level prescription was used to deliver 70, 63 and 58.1 Gy to regions of macroscopic, microscopic high- and low-risk disease, respectively. All doses were given in 35 fractions. Comparisons were performed on dose-volume histogram data, monitor units (MU), and delivery time.
Results:
VMAT-E plans resulted slightly MU efficient (-24 % p < 0.05) compared to VMAT-V while IMRT-V shortened delivery time (-19 % p < 0.05) compared to IMRT-E. All the delivery techniques resulted in equivalent target coverage in terms of D(98) % and D(2) %. For VMAT technique, a significant improvement of 7 % in homogeneity index (HI) for PTV58.1 was observed for Varian machine. A slight improvement in OARs sparing was observed with Elekta machine both for IMRT and VMAT techniques.
Conclusion:
Similar plan quality was observed for Elekta and Varian linacs, significant differences were observed in delivery efficiency, as MU number and delivery times, in favor of Elekta and Varian, respectively.
