Journal Mobile Options
Table of Contents
Vol. 87, No. 1, 2009
Issue release date: February 2009
Section title: Laboratory Investigation
Stereotact Funct Neurosurg 2009;87:1–7
(DOI:10.1159/000177622)

Analysis of Factors Associated with Volumetric Data Errors in Gamma Knife Radiosurgery

Yang D.-Y. · Sheehan J. · Liu Y.-S. · ChangLai S.-P. · Pan H.-C. · Chen C.-J. · Chou M.-C.
Departments of aNeurosurgery and bRadiology, Chang Bing Show Chwan Memorial Hospital, Changhua, Taiwan; cDepartment of Neurosurgery, University of Virginia, Charlottesville, Va., USA; dDepartment of Mechanical and Computer Aided Engineering, Feng Chia University, eDepartment of Neurosurgery, Taichung Veterans General Hospital, fInstitute of Medical Technology, National Chung Hsing University, and gInstitute of Medicine, Chung-Shan Medical University, Taichung, Taiwan

Do you have an account?

Register and profit from personalized services (MyKarger) Login Information

Please create your User ID & Password





Contact Information









I have read the Karger Terms and Conditions and agree.

Register and profit from personalized services (MyKarger) Login Information

Please create your User ID & Password





Contact Information









I have read the Karger Terms and Conditions and agree.

To view the fulltext, please log in

To view the pdf, please log in

Buy

  • FullText & PDF
  • Unlimited re-access via MyKarger (new!)
  • Unrestricted printing, no saving restrictions for personal use
  • Reduced rates with a PPV account
read more

Direct: USD 38.00
Account: USD 26.50

Select

Rent/Cloud

  • Rent for 48h to view
  • Buy Cloud Access for unlimited viewing via different devices
  • Synchronizing in the ReadCube Cloud
  • Printing and saving restriction apply

Rental: USD 8.50
Cloud: USD 20.00

Select

Subscribe

  • Automatic perpetual access to all articles of the subscribed year(s)
  • Unlimited re-access via Subscriber Login or MyKarger
  • Unrestricted printing, no saving restrictions for personal use
read more

Subcription rates


Select


Article / Publication Details

First-Page Preview
Abstract of Laboratory Investigation

Published online: 11/27/2009

Number of Print Pages: 7
Number of Figures: 3
Number of Tables: 5

ISSN: 1011-6125 (Print)
eISSN: 1423-0372 (Online)

For additional information: http://www.karger.com/SFN

Abstract

Object: Gamma knife (GK) surgery is an important part of the treatment armamentarium for benign and malignant brain tumors. In general, quantitative volumetrical analysis of the tumor on neuroimaging studies is the most reliable method of assessment of the tumor’s response and is critical for accurate dose planning. This study evaluated various factors contributing to volumetric data error of tumors treated with GK radiosurgery. Method: Three differently shaped phantoms (spherical, rectangular, and irregular morphology) were created by immersing like shaped objects into 2% agarose gel. The volumes of phantoms were measured by laser scanning with errors <1%. MRI sequence and parameters including time of flight (TOF), T1, T2, different slice thickness, size of field of view (FOV), phase FOV as well as different position and axis of phantoms were retrieved and transferred to a Perfexion Gamma Knife Workstation (PGK-WS) and Picture Archiving and Communication System (PACS) for data analysis. The volumetric data errors were presented as the volume difference between those computed on the PGK-WS and actual volume measured by laser scanning divided by the actual laser scanning volume. The systemic error was defined as volume discrepancy between Perfexion and PACS over that in Perfexion. One-way ANOVA was used for evaluation of data errors between different methods as well as for factor analysis. Results: The MRI-computed volume of the various phantoms approached the laser-scanned volume within 2% when the slice number was ≥30. The volumetrical data errors (10/5 slices) associated with various MRIs for phantoms were 6.94 ± 0.04%/9.45 ± 0.35% (spherical phantom), 12.3 ± 0.2%/ 20.06 ± 0.7% (rectangular phantom), and 9.29 ± 0.078%/ 15.67 ± 0.6% (irregular phantom) (p < 0.001 and p < 0.001), respectively. The system errors (10/5 slices) associated with various MRIs for the phantoms were 3.17 ± 0.11%/3.9 ± 0.13% (spherical phantom), 3.61 ± 0.12%/4.01 ± 0.12% (rectangular phantom), and 4.39 ± 0.07%/4.75 ± 0.13% (irregular phantom) (p < 0.001 and p = 0.01), respectively. The volumetric data errors were related to the number of slices and the shape of phantom, but the systemic errors were only related to the irregularity of phantom morphology. The volumetrical data errors were not related to size of the FOV, phase FOV, sequence of T1, T2, TOF, and position of phantom. For the rectangular phantom, the data error was related to slice orientation of imaging acquisition (p < 0.001). Conclusion: Volume discrepancies existed between those volumes computed by the PGK-WS and volumes determined by laser scanning. The volumetric data errors were reduced through the acquisition of more slices through the phantom and a more spherical morphology of the phantom. Relatively few system volume errors were observed between those by the PGK-WS and PACS except for a significant discrepancy for the irregular surface phantom. For the rectangular-shaped phantom, the volumetric data errors were significantly related to slice orientation of measurement. When measuring the tumor response in GK radiosurgery or follow-up, an error of as large as 20% is possible for irregularly shaped object and with MRIs using ≤5 slices through the region of interest.


Article / Publication Details

First-Page Preview
Abstract of Laboratory Investigation

Published online: 11/27/2009

Number of Print Pages: 7
Number of Figures: 3
Number of Tables: 5

ISSN: 1011-6125 (Print)
eISSN: 1423-0372 (Online)

For additional information: http://www.karger.com/SFN


Copyright / Drug Dosage

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.