Impact of organ shape variations on margin concepts for cervix cancer ART

Yvette Seppenwoolde; Markus Stock; Martin Buschmann; Dietmar Georg; Kwei-Yuang Bauer-Novotny; Richard Pötter; Petra Georg

doi:10.1016/j.radonc.2016.08.004

Impact of organ shape variations on margin concepts for cervix cancer ART

Yvette Seppenwoolde, Markus Stock, Martin Buschmann, Dietmar Georg, Kwei-Yuang Bauer-Novotny, Richard Pötter, Petra Georg

Research output: Journal article (peer-reviewed) › Journal article

27 Citations (Scopus)

Abstract

BACKGROUND AND PURPOSE: Target and organ movement motivate adaptive radiotherapy for cervix cancer patients. We investigated the dosimetric impact of margin concepts with different levels of complexity on both organ at risk (OAR) sparing and PTV coverage.

MATERIAL AND METHODS: Weekly CT and daily CBCT scans were delineated for 10 patients. The dosimetric impact of organ shape variations were evaluated for four (isotropic) margin concepts: two static PTVs (PTV6mm and PTV15mm), a PTV based on ITV of the planning CT and CBCTs of the first treatment week (PTVART ITV) and an adaptive PTV based on a library approach (PTVART Library).

RESULTS: Using static concepts, OAR doses increased with large margins, while smaller margins compromised target coverage. ART PTVs resulted in comparable target coverage and better sparing of bladder (V40Gy: 15% and 7% less), rectum (V40Gy: 18 and 6cc less) and bowel (V40Gy: 106 and 15cc less) compared to PTV15mm. Target coverage evaluation showed that for elective fields a static 5mm margin sufficed.

CONCLUSION: PTVART Library achieved the best dosimetric results. However when weighing clinical benefit against workload, ITV margins based on repetitive movement evaluation during the first week also provide improvements over static margin concepts.

Original language	English
Pages (from-to)	526-531
Number of pages	6
Journal	Radiotherapy and Oncology
Volume	120
Issue number	3
DOIs	https://doi.org/10.1016/j.radonc.2016.08.004
Publication status	Published - 01 Sept 2016
Externally published	Yes

Keywords

Female
Humans
Movement
Organ Sparing Treatments/methods
Organs at Risk/radiation effects
Radiation Dosage
Radiometry/methods
Radiotherapy Dosage
Radiotherapy Planning, Computer-Assisted/methods
Rectum/radiation effects
Tomography, X-Ray Computed
Urinary Bladder/diagnostic imaging
Uterine Cervical Neoplasms/diagnostic imaging
Uterus/diagnostic imaging
Workload

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10.1016/j.radonc.2016.08.004

Cite this

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title = "Impact of organ shape variations on margin concepts for cervix cancer ART",

abstract = "BACKGROUND AND PURPOSE: Target and organ movement motivate adaptive radiotherapy for cervix cancer patients. We investigated the dosimetric impact of margin concepts with different levels of complexity on both organ at risk (OAR) sparing and PTV coverage.MATERIAL AND METHODS: Weekly CT and daily CBCT scans were delineated for 10 patients. The dosimetric impact of organ shape variations were evaluated for four (isotropic) margin concepts: two static PTVs (PTV6mm and PTV15mm), a PTV based on ITV of the planning CT and CBCTs of the first treatment week (PTVART ITV) and an adaptive PTV based on a library approach (PTVART Library).RESULTS: Using static concepts, OAR doses increased with large margins, while smaller margins compromised target coverage. ART PTVs resulted in comparable target coverage and better sparing of bladder (V40Gy: 15% and 7% less), rectum (V40Gy: 18 and 6cc less) and bowel (V40Gy: 106 and 15cc less) compared to PTV15mm. Target coverage evaluation showed that for elective fields a static 5mm margin sufficed.CONCLUSION: PTVART Library achieved the best dosimetric results. However when weighing clinical benefit against workload, ITV margins based on repetitive movement evaluation during the first week also provide improvements over static margin concepts.",

keywords = "Female, Humans, Movement, Organ Sparing Treatments/methods, Organs at Risk/radiation effects, Radiation Dosage, Radiometry/methods, Radiotherapy Dosage, Radiotherapy Planning, Computer-Assisted/methods, Rectum/radiation effects, Tomography, X-Ray Computed, Urinary Bladder/diagnostic imaging, Uterine Cervical Neoplasms/diagnostic imaging, Uterus/diagnostic imaging, Workload",

author = "Yvette Seppenwoolde and Markus Stock and Martin Buschmann and Dietmar Georg and Kwei-Yuang Bauer-Novotny and Richard P{\"o}tter and Petra Georg",

note = "Publisher Copyright: {\textcopyright} 2016 Elsevier Ireland Ltd",

year = "2016",

month = sep,

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doi = "10.1016/j.radonc.2016.08.004",

language = "English",

volume = "120",

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journal = "Radiotherapy and Oncology",

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publisher = "Elsevier Ireland Ltd",

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T1 - Impact of organ shape variations on margin concepts for cervix cancer ART

AU - Seppenwoolde, Yvette

AU - Stock, Markus

AU - Buschmann, Martin

AU - Georg, Dietmar

AU - Bauer-Novotny, Kwei-Yuang

AU - Pötter, Richard

AU - Georg, Petra

PY - 2016/9/1

Y1 - 2016/9/1

N2 - BACKGROUND AND PURPOSE: Target and organ movement motivate adaptive radiotherapy for cervix cancer patients. We investigated the dosimetric impact of margin concepts with different levels of complexity on both organ at risk (OAR) sparing and PTV coverage.MATERIAL AND METHODS: Weekly CT and daily CBCT scans were delineated for 10 patients. The dosimetric impact of organ shape variations were evaluated for four (isotropic) margin concepts: two static PTVs (PTV6mm and PTV15mm), a PTV based on ITV of the planning CT and CBCTs of the first treatment week (PTVART ITV) and an adaptive PTV based on a library approach (PTVART Library).RESULTS: Using static concepts, OAR doses increased with large margins, while smaller margins compromised target coverage. ART PTVs resulted in comparable target coverage and better sparing of bladder (V40Gy: 15% and 7% less), rectum (V40Gy: 18 and 6cc less) and bowel (V40Gy: 106 and 15cc less) compared to PTV15mm. Target coverage evaluation showed that for elective fields a static 5mm margin sufficed.CONCLUSION: PTVART Library achieved the best dosimetric results. However when weighing clinical benefit against workload, ITV margins based on repetitive movement evaluation during the first week also provide improvements over static margin concepts.

AB - BACKGROUND AND PURPOSE: Target and organ movement motivate adaptive radiotherapy for cervix cancer patients. We investigated the dosimetric impact of margin concepts with different levels of complexity on both organ at risk (OAR) sparing and PTV coverage.MATERIAL AND METHODS: Weekly CT and daily CBCT scans were delineated for 10 patients. The dosimetric impact of organ shape variations were evaluated for four (isotropic) margin concepts: two static PTVs (PTV6mm and PTV15mm), a PTV based on ITV of the planning CT and CBCTs of the first treatment week (PTVART ITV) and an adaptive PTV based on a library approach (PTVART Library).RESULTS: Using static concepts, OAR doses increased with large margins, while smaller margins compromised target coverage. ART PTVs resulted in comparable target coverage and better sparing of bladder (V40Gy: 15% and 7% less), rectum (V40Gy: 18 and 6cc less) and bowel (V40Gy: 106 and 15cc less) compared to PTV15mm. Target coverage evaluation showed that for elective fields a static 5mm margin sufficed.CONCLUSION: PTVART Library achieved the best dosimetric results. However when weighing clinical benefit against workload, ITV margins based on repetitive movement evaluation during the first week also provide improvements over static margin concepts.

KW - Female

KW - Humans

KW - Movement

KW - Organ Sparing Treatments/methods

KW - Organs at Risk/radiation effects

KW - Radiation Dosage

KW - Radiometry/methods

KW - Radiotherapy Dosage

KW - Radiotherapy Planning, Computer-Assisted/methods

KW - Rectum/radiation effects

KW - Tomography, X-Ray Computed

KW - Urinary Bladder/diagnostic imaging

KW - Uterine Cervical Neoplasms/diagnostic imaging

KW - Uterus/diagnostic imaging

KW - Workload

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U2 - 10.1016/j.radonc.2016.08.004

DO - 10.1016/j.radonc.2016.08.004

M3 - Journal article

C2 - 27528119

SN - 0167-8140

VL - 120

SP - 526

EP - 531

JO - Radiotherapy and Oncology

JF - Radiotherapy and Oncology

IS - 3

ER -

Impact of organ shape variations on margin concepts for cervix cancer ART

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