open access

Vol 21, No 5 (2016)
Original research articles
Published online: 2016-09-01
Submitted: 2016-01-08
Get Citation

Influence of the contrast agents on treatment planning dose calculations of prostate and rectal cancers

Sahel Heydarheydari, Negin Farshchian, Abbas Haghparast
DOI: 10.1016/j.rpor.2016.04.004
·
Rep Pract Oncol Radiother 2016;21(5):441-446.

open access

Vol 21, No 5 (2016)
Original research articles
Published online: 2016-09-01
Submitted: 2016-01-08

Abstract

Aim

The aim of the present study is to quantify differences in dose calculations caused by using CA and determine if the resulting differences are clinically significant.

Background

The influence of contrast agents (CA) on radiation dose calculations must be taken into account in treatment planning.

Materials and methods

Eleven patients with pelvic cancers were included in this study and two sets of CTs were taken for each patient (without and with CA) in the same position and coordinates. Both sets of images were transferred to the DosiSoft ISOgray treatment planning system for contouring and calculating the dose distribution and monitor units (MUs) with Collapsed Cone and Superposition algorithms, respectively. All plans were generated on pre-contrast CT and subsequently copied to the post-contrast CT. Radiation dose calculations from the two sets of CTs were compared using a paired sample t-test.

Results

The results showed a statistically insignificant difference between pre- and post-contrast CT treatment plans for target volume and OARs (p[[ce:hsp sp="0.25"/]]>[[ce:hsp sp="0.25"/]]0.05), except bladder organ in the prostate region (p[[ce:hsp sp="0.25"/]]<[[ce:hsp sp="0.25"/]]0.05) but the relative mean dose and MU differences were less than 2% in any patient for 18[[ce:hsp sp="0.25"/]]MV photon beam.

Conclusions

Treatment planning on contrasted images generally showed a lower radiation dose to both target volume and OARs than plans on non-contrasted images. The results of this research showed that the small radiation dose differences between the plans for the CT scans with and without CA seem to be clinically insignificant; therefore, contrast-enhanced CT can be used for both target delineation and treatment planning of prostate and rectal cancers.

Abstract

Aim

The aim of the present study is to quantify differences in dose calculations caused by using CA and determine if the resulting differences are clinically significant.

Background

The influence of contrast agents (CA) on radiation dose calculations must be taken into account in treatment planning.

Materials and methods

Eleven patients with pelvic cancers were included in this study and two sets of CTs were taken for each patient (without and with CA) in the same position and coordinates. Both sets of images were transferred to the DosiSoft ISOgray treatment planning system for contouring and calculating the dose distribution and monitor units (MUs) with Collapsed Cone and Superposition algorithms, respectively. All plans were generated on pre-contrast CT and subsequently copied to the post-contrast CT. Radiation dose calculations from the two sets of CTs were compared using a paired sample t-test.

Results

The results showed a statistically insignificant difference between pre- and post-contrast CT treatment plans for target volume and OARs (p[[ce:hsp sp="0.25"/]]>[[ce:hsp sp="0.25"/]]0.05), except bladder organ in the prostate region (p[[ce:hsp sp="0.25"/]]<[[ce:hsp sp="0.25"/]]0.05) but the relative mean dose and MU differences were less than 2% in any patient for 18[[ce:hsp sp="0.25"/]]MV photon beam.

Conclusions

Treatment planning on contrasted images generally showed a lower radiation dose to both target volume and OARs than plans on non-contrasted images. The results of this research showed that the small radiation dose differences between the plans for the CT scans with and without CA seem to be clinically insignificant; therefore, contrast-enhanced CT can be used for both target delineation and treatment planning of prostate and rectal cancers.

Get Citation

Keywords

Radiotherapy; Treatment planning; CT simulation; Contrast agent; Prostate and rectal cancers

About this article
Title

Influence of the contrast agents on treatment planning dose calculations of prostate and rectal cancers

Journal

Reports of Practical Oncology and Radiotherapy

Issue

Vol 21, No 5 (2016)

Pages

441-446

Published online

2016-09-01

DOI

10.1016/j.rpor.2016.04.004

Bibliographic record

Rep Pract Oncol Radiother 2016;21(5):441-446.

Keywords

Radiotherapy
Treatment planning
CT simulation
Contrast agent
Prostate and rectal cancers

Authors

Sahel Heydarheydari
Negin Farshchian
Abbas Haghparast

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