open access

Vol 24, No 2 (2019)
Original research articles
Published online: 2019-03-01
Submitted: 2018-09-03
Get Citation

Performance of the eclipse monitor unit objective tool utilizing volumetric modulated arc therapy for rectal cancer

Alejandro Prado, Ángel Gaitán, Mario Leonor, Marta Manzano, Eduardo Cabello, Raúl Díaz, Alejandro Ferrando, Ana Milanés, Gustavo Pozo
DOI: 10.1016/j.rpor.2019.02.004
·
Rep Pract Oncol Radiother 2019;24(2):227-232.

open access

Vol 24, No 2 (2019)
Original research articles
Published online: 2019-03-01
Submitted: 2018-09-03

Abstract

Aim

To assess the performance of the monitor unit (MU) Objective tool in Eclipse treatment planning system (TPS) utilizing volumetric modulated arc therapy (VMAT) for rectal cancer.

Background

Eclipse VMAT planning module includes a tool to control the number of MUs delivered: the MU Objective tool. This tool could be utilized to reduce the total number of MUs in rectal cancer treatments.

Materials and methods

20 rectal cancer patients were retrospectively studied using VMAT and the MU Objective tool. The baseline plan for each patient was selected as the one with no usage of the MU Objective tool. The number of MUs of this plan was set to be the reference number of MUs (MUref). Five plans were re-optimized for each patient only varying the Max MU parameter. The selected values were 30%, 60%, 90%, 120% and 150% of MUref for each patient. Differences with respect to the baseline plan were evaluated regarding MU number and parameters for PTVs coverage evaluation, PTVs homogeneity and OARs doses assessment. A two-tailed, paired-samples t-test was used to quantify these differences.

Results

Average relative differences in MU number obtained was 10% for Max MU values of 30% and 60% of MUref, respectively (p<0.03). PTVs coverage and homogeneity were not compromised and discrepancies obtained with respect to baseline plans were not significant. Furthermore, maximum OARs doses deviations were also not significant.

Conclusions

A 10% reduction in the MU number could be obtained without an alteration of PTV coverage and OARs doses for rectal cancer.

Abstract

Aim

To assess the performance of the monitor unit (MU) Objective tool in Eclipse treatment planning system (TPS) utilizing volumetric modulated arc therapy (VMAT) for rectal cancer.

Background

Eclipse VMAT planning module includes a tool to control the number of MUs delivered: the MU Objective tool. This tool could be utilized to reduce the total number of MUs in rectal cancer treatments.

Materials and methods

20 rectal cancer patients were retrospectively studied using VMAT and the MU Objective tool. The baseline plan for each patient was selected as the one with no usage of the MU Objective tool. The number of MUs of this plan was set to be the reference number of MUs (MUref). Five plans were re-optimized for each patient only varying the Max MU parameter. The selected values were 30%, 60%, 90%, 120% and 150% of MUref for each patient. Differences with respect to the baseline plan were evaluated regarding MU number and parameters for PTVs coverage evaluation, PTVs homogeneity and OARs doses assessment. A two-tailed, paired-samples t-test was used to quantify these differences.

Results

Average relative differences in MU number obtained was 10% for Max MU values of 30% and 60% of MUref, respectively (p<0.03). PTVs coverage and homogeneity were not compromised and discrepancies obtained with respect to baseline plans were not significant. Furthermore, maximum OARs doses deviations were also not significant.

Conclusions

A 10% reduction in the MU number could be obtained without an alteration of PTV coverage and OARs doses for rectal cancer.

Get Citation

Keywords

MU Objective tool; VMAT; Eclipse TPS; Progressive resolution optimizer; Rectal cancer

About this article
Title

Performance of the eclipse monitor unit objective tool utilizing volumetric modulated arc therapy for rectal cancer

Journal

Reports of Practical Oncology and Radiotherapy

Issue

Vol 24, No 2 (2019)

Pages

227-232

Published online

2019-03-01

DOI

10.1016/j.rpor.2019.02.004

Bibliographic record

Rep Pract Oncol Radiother 2019;24(2):227-232.

Keywords

MU Objective tool
VMAT
Eclipse TPS
Progressive resolution optimizer
Rectal cancer

Authors

Alejandro Prado
Ángel Gaitán
Mario Leonor
Marta Manzano
Eduardo Cabello
Raúl Díaz
Alejandro Ferrando
Ana Milanés
Gustavo Pozo

Important: This website uses cookies. More >>

The cookies allow us to identify your computer and find out details about your last visit. They remembering whether you've visited the site before, so that you remain logged in - or to help us work out how many new website visitors we get each month. Most internet browsers accept cookies automatically, but you can change the settings of your browser to erase cookies or prevent automatic acceptance if you prefer.

By "Via Medica sp. z o.o." sp.k., ul. Świętokrzyska 73, 80–180 Gdańsk, Poland
tel.:+48 58 320 94 94, fax:+48 58 320 94 60, e-mail: journals@viamedica.pl