WE‐D‐351‐08

Integrated Subvolume Boosting Technique to Reduce Normal Tissue Irradiation During SBRT Treatment Planning Using Helical Tomotherapy

A. Gutiérrez, Wolfgang A. Tome, S. Stathakis, N. Papanikolaou

Research output: Contribution to journalArticle

Abstract

Purpose: To characterize the reduction in normal tissue volume irradiated in a SBRT treatment plan by delivering an inhomogeneous dose to the PTV—via integrated subvolumes prescribed to increasing doses above prescription dose—instead of a homogeneous dose using helical tomotherapy. Method and Materials: Three patients were retrospectively planned using helical tomotherapy with two treatment plans: (1) homogenous plan delivering a uniform prescription dose to the PTV and (2) inhomogeneous plan delivering a non‐uniform dose to the PTV. Subvolumes were created by volumetrically contracting the PTV by 4mm resulting in three subvolumes within the PTV (PTVi, PTVii, and PTViii). Dose prescriptions to the various targets were as follows: Homogenous: PTV: 95% of volume to receive 60.0Gy; Inhomogeneous: PTViii: 20% of volume to receive 80.0Gy, PTVii: 50% of volume to receive 75.0Gy, PTVi: 50% of volume to receive 70.0Gy, PTV: 95% of volume to receive 60.0Gy. The homogenous and inhomogeneous plans were compared on the basis of normal tissue volume reductions to various dose levels assuming identical target coverage of the PTV. Results: A significant reduction in the volume of normal tissue irradiated to high doses was achieved for all patients. Average reduction of V90%, V80%, V50%, and V20% were 18, 15, 9, and 7%, respectively. It was noted that as the dose level decreases, the percent volume reduction between the homogeneous and inhomogeneous plans decreases. Conclusion: The study served to quantify the volumetric reduction of normal tissue irradiated during lung SBRT treatments with helical tomotherapy when delivering non‐uniform doses to the PTV as compared to uniform doses. Our results indicate that an inhomogeneous dose distribution generated by the creation of integrated subvolumes prescribed to higher doses within the PTV significantly reduces the volume of normal tissue irradiated, especially at higher doses (>50% of prescription dose).

Original languageEnglish (US)
Pages (from-to)2947
Number of pages1
JournalMedical Physics
Volume35
Issue number6
DOIs
StatePublished - 2008
Externally publishedYes

Fingerprint

Intensity-Modulated Radiotherapy
Prescriptions
Therapeutics
Lung

ASJC Scopus subject areas

  • Biophysics
  • Radiology Nuclear Medicine and imaging

Cite this

WE‐D‐351‐08 : Integrated Subvolume Boosting Technique to Reduce Normal Tissue Irradiation During SBRT Treatment Planning Using Helical Tomotherapy. / Gutiérrez, A.; Tome, Wolfgang A.; Stathakis, S.; Papanikolaou, N.

In: Medical Physics, Vol. 35, No. 6, 2008, p. 2947.

Research output: Contribution to journalArticle

@article{bbac81d1d17945fd9726240534b65754,
title = "WE‐D‐351‐08: Integrated Subvolume Boosting Technique to Reduce Normal Tissue Irradiation During SBRT Treatment Planning Using Helical Tomotherapy",
abstract = "Purpose: To characterize the reduction in normal tissue volume irradiated in a SBRT treatment plan by delivering an inhomogeneous dose to the PTV—via integrated subvolumes prescribed to increasing doses above prescription dose—instead of a homogeneous dose using helical tomotherapy. Method and Materials: Three patients were retrospectively planned using helical tomotherapy with two treatment plans: (1) homogenous plan delivering a uniform prescription dose to the PTV and (2) inhomogeneous plan delivering a non‐uniform dose to the PTV. Subvolumes were created by volumetrically contracting the PTV by 4mm resulting in three subvolumes within the PTV (PTVi, PTVii, and PTViii). Dose prescriptions to the various targets were as follows: Homogenous: PTV: 95{\%} of volume to receive 60.0Gy; Inhomogeneous: PTViii: 20{\%} of volume to receive 80.0Gy, PTVii: 50{\%} of volume to receive 75.0Gy, PTVi: 50{\%} of volume to receive 70.0Gy, PTV: 95{\%} of volume to receive 60.0Gy. The homogenous and inhomogeneous plans were compared on the basis of normal tissue volume reductions to various dose levels assuming identical target coverage of the PTV. Results: A significant reduction in the volume of normal tissue irradiated to high doses was achieved for all patients. Average reduction of V90{\%}, V80{\%}, V50{\%}, and V20{\%} were 18, 15, 9, and 7{\%}, respectively. It was noted that as the dose level decreases, the percent volume reduction between the homogeneous and inhomogeneous plans decreases. Conclusion: The study served to quantify the volumetric reduction of normal tissue irradiated during lung SBRT treatments with helical tomotherapy when delivering non‐uniform doses to the PTV as compared to uniform doses. Our results indicate that an inhomogeneous dose distribution generated by the creation of integrated subvolumes prescribed to higher doses within the PTV significantly reduces the volume of normal tissue irradiated, especially at higher doses (>50{\%} of prescription dose).",
author = "A. Guti{\'e}rrez and Tome, {Wolfgang A.} and S. Stathakis and N. Papanikolaou",
year = "2008",
doi = "10.1118/1.2962752",
language = "English (US)",
volume = "35",
pages = "2947",
journal = "Medical Physics",
issn = "0094-2405",
publisher = "AAPM - American Association of Physicists in Medicine",
number = "6",

}

TY - JOUR

T1 - WE‐D‐351‐08

T2 - Integrated Subvolume Boosting Technique to Reduce Normal Tissue Irradiation During SBRT Treatment Planning Using Helical Tomotherapy

AU - Gutiérrez, A.

AU - Tome, Wolfgang A.

AU - Stathakis, S.

AU - Papanikolaou, N.

PY - 2008

Y1 - 2008

N2 - Purpose: To characterize the reduction in normal tissue volume irradiated in a SBRT treatment plan by delivering an inhomogeneous dose to the PTV—via integrated subvolumes prescribed to increasing doses above prescription dose—instead of a homogeneous dose using helical tomotherapy. Method and Materials: Three patients were retrospectively planned using helical tomotherapy with two treatment plans: (1) homogenous plan delivering a uniform prescription dose to the PTV and (2) inhomogeneous plan delivering a non‐uniform dose to the PTV. Subvolumes were created by volumetrically contracting the PTV by 4mm resulting in three subvolumes within the PTV (PTVi, PTVii, and PTViii). Dose prescriptions to the various targets were as follows: Homogenous: PTV: 95% of volume to receive 60.0Gy; Inhomogeneous: PTViii: 20% of volume to receive 80.0Gy, PTVii: 50% of volume to receive 75.0Gy, PTVi: 50% of volume to receive 70.0Gy, PTV: 95% of volume to receive 60.0Gy. The homogenous and inhomogeneous plans were compared on the basis of normal tissue volume reductions to various dose levels assuming identical target coverage of the PTV. Results: A significant reduction in the volume of normal tissue irradiated to high doses was achieved for all patients. Average reduction of V90%, V80%, V50%, and V20% were 18, 15, 9, and 7%, respectively. It was noted that as the dose level decreases, the percent volume reduction between the homogeneous and inhomogeneous plans decreases. Conclusion: The study served to quantify the volumetric reduction of normal tissue irradiated during lung SBRT treatments with helical tomotherapy when delivering non‐uniform doses to the PTV as compared to uniform doses. Our results indicate that an inhomogeneous dose distribution generated by the creation of integrated subvolumes prescribed to higher doses within the PTV significantly reduces the volume of normal tissue irradiated, especially at higher doses (>50% of prescription dose).

AB - Purpose: To characterize the reduction in normal tissue volume irradiated in a SBRT treatment plan by delivering an inhomogeneous dose to the PTV—via integrated subvolumes prescribed to increasing doses above prescription dose—instead of a homogeneous dose using helical tomotherapy. Method and Materials: Three patients were retrospectively planned using helical tomotherapy with two treatment plans: (1) homogenous plan delivering a uniform prescription dose to the PTV and (2) inhomogeneous plan delivering a non‐uniform dose to the PTV. Subvolumes were created by volumetrically contracting the PTV by 4mm resulting in three subvolumes within the PTV (PTVi, PTVii, and PTViii). Dose prescriptions to the various targets were as follows: Homogenous: PTV: 95% of volume to receive 60.0Gy; Inhomogeneous: PTViii: 20% of volume to receive 80.0Gy, PTVii: 50% of volume to receive 75.0Gy, PTVi: 50% of volume to receive 70.0Gy, PTV: 95% of volume to receive 60.0Gy. The homogenous and inhomogeneous plans were compared on the basis of normal tissue volume reductions to various dose levels assuming identical target coverage of the PTV. Results: A significant reduction in the volume of normal tissue irradiated to high doses was achieved for all patients. Average reduction of V90%, V80%, V50%, and V20% were 18, 15, 9, and 7%, respectively. It was noted that as the dose level decreases, the percent volume reduction between the homogeneous and inhomogeneous plans decreases. Conclusion: The study served to quantify the volumetric reduction of normal tissue irradiated during lung SBRT treatments with helical tomotherapy when delivering non‐uniform doses to the PTV as compared to uniform doses. Our results indicate that an inhomogeneous dose distribution generated by the creation of integrated subvolumes prescribed to higher doses within the PTV significantly reduces the volume of normal tissue irradiated, especially at higher doses (>50% of prescription dose).

UR - http://www.scopus.com/inward/record.url?scp=85024791319&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85024791319&partnerID=8YFLogxK

U2 - 10.1118/1.2962752

DO - 10.1118/1.2962752

M3 - Article

VL - 35

SP - 2947

JO - Medical Physics

JF - Medical Physics

SN - 0094-2405

IS - 6

ER -