The influence of dose distribution on treatment outcome in the SCOPE 1 oesophageal cancer trial
The influence of dose distribution on treatment outcome in the SCOPE 1 oesophageal cancer trial
Purpose: the first aim of this study was to assess plan quality using a conformity index (CI) and analyse its influence on patient outcome. The second aim was to identify whether clinical and technological factors including planning treatment volume (PTV) volume and treatment delivery method could be related to the CI value.
Methods and materials: by extending the original concept of the mean distance to conformity (MDC) index, the OverMDC and UnderMDC of the 95 % isodose line (50Gy prescribed dose) to the PTV was calculated for 97 patients from the UK SCOPE 1 trial (ISCRT47718479). Data preparation was carried out in CERR, with Kaplan-Meier and multivariate analysis undertaken in EUCLID and further tests in Microsoft Excel and IBM’s SPSS.
Results: a statistically significant breakpoint in the overall survival data, independent of cetuximab, was found with OverMDC (4.4 mm, p < 0.05). This was not the case with UnderMDC. There was a statistically significant difference in PTV volume either side of the OverMDC breakpoint (Mann Whitney p < 0.001) and in OverMDC value dependent on the treatment delivery method (mean IMRT = 2.1 mm, mean 3D-CRT = 4.1 mm Mann Whitney p < 0.001). Re-planning the worst performing patients according to OverMDC from 3D-CRT to VMAT resulted in a mean reduction in OverMDC of 2.8 mm (1.6–4.0 mm). OverMDC was not significant in multivariate analysis that included age, sex, staging, tumour type, and position.
Conclusion: although not significant when included in multivariate analysis, we have shown in univariate analysis that a patient’s OverMDC is correlated with overall survival. OverMDC is strongly related to IMRT and to a lesser extent with PTV volume. We recommend that VMAT planning should be used for oesophageal planning when available and that attention should be paid to the conformity of the 95 % to the PTV.
Carrington, Rhys
6819f24e-1dbe-4dd9-88c3-568422190e97
Spezi, Emiliano
2eab7319-0edc-4658-996d-9b00959b9124
Gwynne, Sarah
0cbce6d8-328d-430e-9f5e-a5885deedac8
Dutton, Peter
b984314b-813d-41f5-9040-c713c07ebb33
Hurt, Chris
bf8b37a0-8f08-4b47-b3f3-6fc65f7ab87f
Staffurth, John
db58e06d-eb84-485a-8656-ea5d48ba548e
Crosby, Thomas
82fd6364-ad6d-4e24-bb81-e1868258c4e6
Carrington, Rhys
6819f24e-1dbe-4dd9-88c3-568422190e97
Spezi, Emiliano
2eab7319-0edc-4658-996d-9b00959b9124
Gwynne, Sarah
0cbce6d8-328d-430e-9f5e-a5885deedac8
Dutton, Peter
b984314b-813d-41f5-9040-c713c07ebb33
Hurt, Chris
bf8b37a0-8f08-4b47-b3f3-6fc65f7ab87f
Staffurth, John
db58e06d-eb84-485a-8656-ea5d48ba548e
Crosby, Thomas
82fd6364-ad6d-4e24-bb81-e1868258c4e6
Carrington, Rhys, Spezi, Emiliano and Gwynne, Sarah
,
et al.
(2016)
The influence of dose distribution on treatment outcome in the SCOPE 1 oesophageal cancer trial.
Radiation Oncology, 11, [19].
(doi:10.1186/s13014-016-0594-x).
Abstract
Purpose: the first aim of this study was to assess plan quality using a conformity index (CI) and analyse its influence on patient outcome. The second aim was to identify whether clinical and technological factors including planning treatment volume (PTV) volume and treatment delivery method could be related to the CI value.
Methods and materials: by extending the original concept of the mean distance to conformity (MDC) index, the OverMDC and UnderMDC of the 95 % isodose line (50Gy prescribed dose) to the PTV was calculated for 97 patients from the UK SCOPE 1 trial (ISCRT47718479). Data preparation was carried out in CERR, with Kaplan-Meier and multivariate analysis undertaken in EUCLID and further tests in Microsoft Excel and IBM’s SPSS.
Results: a statistically significant breakpoint in the overall survival data, independent of cetuximab, was found with OverMDC (4.4 mm, p < 0.05). This was not the case with UnderMDC. There was a statistically significant difference in PTV volume either side of the OverMDC breakpoint (Mann Whitney p < 0.001) and in OverMDC value dependent on the treatment delivery method (mean IMRT = 2.1 mm, mean 3D-CRT = 4.1 mm Mann Whitney p < 0.001). Re-planning the worst performing patients according to OverMDC from 3D-CRT to VMAT resulted in a mean reduction in OverMDC of 2.8 mm (1.6–4.0 mm). OverMDC was not significant in multivariate analysis that included age, sex, staging, tumour type, and position.
Conclusion: although not significant when included in multivariate analysis, we have shown in univariate analysis that a patient’s OverMDC is correlated with overall survival. OverMDC is strongly related to IMRT and to a lesser extent with PTV volume. We recommend that VMAT planning should be used for oesophageal planning when available and that attention should be paid to the conformity of the 95 % to the PTV.
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s13014-016-0594-x
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Accepted/In Press date: 27 January 2016
e-pub ahead of print date: 6 February 2016
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Local EPrints ID: 488240
URI: http://eprints.soton.ac.uk/id/eprint/488240
ISSN: 1748-717X
PURE UUID: ecdb1e24-eab7-4269-9f13-5c7c1bcf9e29
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Date deposited: 19 Mar 2024 17:35
Last modified: 23 Mar 2024 03:13
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Author:
Rhys Carrington
Author:
Emiliano Spezi
Author:
Sarah Gwynne
Author:
Peter Dutton
Author:
Chris Hurt
Author:
John Staffurth
Author:
Thomas Crosby
Corporate Author: et al.
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