AAPM REPORT NO. 54 STEREOTACTIC RADIOSURGERY Report of Task Group 42 Radiation Therapy Committee ,:. Michael C. Schell (Chairman) Frank J. Bova David A. Larson (Consultant) Dennis D. Leavitt Wendell R. Latz Ervin B. Podgorsak Andrew Wu ! June 1995 Published for the AmericanAssociation of Physicists in Medicine by the American Institute of Physics STEREOTACTIC RAD1OSURGERY Table of Contents I. INTRODUCTION .................................................................................. 1 A. Clinical Introduction ..................................................................... 1 B. Introduction For Administrators ................................................... 3 If. RATIONALE FOR RADIOSURGICAL TREATMENTS ................... 4 A. Non-Malignant Lesions ................................................................. 5 B. Malignancies .................................................................................. 5 III. THE ACCURACY OF STEREOTACTIC RADIOSURGERY .......... 6 IV. STEREOTACTIC RADIOSURGERY TECHNIQUES ...................... 8 V. ACCEPTANCE TESTING ................................................................. 1 I ,',• A. Introduction .................................................................................. 1 1 B. Accurate Localization .................................................................. 1 1 DISCLAIMER: This publication is based on sources and information C. Mechanical Precision ................................................................... 1 1 believed to be reliable, but the AAPM and the editors disclaim any 1. Linac Gantry, Collimator, and Couch (PSA) ....................... 12 warranty or liability based on or relating to the contents of this 2. Lasers ...................................................................................... 12 publication. 3. Patient Docking Device ........................................................ 13 4. Frame Syste m :....... .:............................................................... 13 TheAAPMdoesnotendorseanyproducts, manufacturers, orsuppliers. 5. Target Verification Devices .................................................. 13 Nothing in this publication should be interpreted as implying such 6. SRS System Verification Test ............................................... 13 endorsement. D. Dose Delivery ............................................................................... 15 E. Patient Safety/Machine Interlocks ............................................. 15 Further copies of this report ($10 prepaid) may be obtained from: E Gamma Knife Acceptance Tests .................................................. 15 VI. DOSIMETRY .................................................................................... 16 A. Linac Systems ............................................................................... 16 American Association of Physicists in Medicine 1. Dose Measurements .............................................................. 16 One Physics Ellipse • Off-Axis Ratios .............................................................. 20 College Park, MD 20740-3843 • Scatter Correction Factors ............................................ 21 • Collimator Scatter .......................................................... 21 International Standard Book Number: 1-56396-497-X • Tissue-Maximum Ratios ............................................... 21 International Standard Serial Number: 0271-7344 B. Measurement Summary ............................................................... 21 1. Linacs ...................................................................................... 21 ©1995 by the American Association of Physicists in Medicine 2. Gamma Knife Units ............................................................... 22 3. Phantoms ................................................................................ 22 All rights reserved. No part of this publication may be reproduced, 4. Dosimetry Calculation .......................................................... 22 storedinaretrievalsystem, ortransmittedinanyformorbyanymeans • Planning Parameters ...................................................... 24 (electronic, mechanical, photocopying, recording, or otherwise) • Gamma Knife ................................................................. 25 without the prior written permission of the publisher. VII. QUALITY ASSURANCE ............................................................... 26 A. Introduction .................................................................................. 26 Published by the American Institute of Physics, Inc. B. Probable Risk Analysis and QA .................................................. 27 500 Sunnyside Blvd., Woodbury, NY 11797 C. Treatment QA ................................................................................ 28 1. Check Lists ............................................................................. 28 Printed in the United States of America 2. Target Position Verification .................................................. 30 ii i iii 3. Laser Check ............................................................................ 30 2. Couch-Mounted Frame System ............................................ 63 4. Pedestal Mount System ......................................................... 31 • Dynamic Stereotactic Radiosurgery 5. "Known" Target Test During Localization: Recommendation to SRS Manufacturers ............................. 31 at McGill University ...................................................... 63 6. Head Ring Movement Test ................................................... 32 C. Dedicated Radioisotope SRS Unit--The Gamma 7. Verification of Treatment Setup ........................................... 32 Knife Technique ........................................................................... 64 8. Secondary Test ....................................................................... 33 1. Apparatus ................................................................................ 64 D. Stereotactic Couch Mount ........................................................... 33 2. Target Localization ............................................................... 66 1. Overview ................................................................................ 33 3. Dose Calibrations and Measurements ................................. 66 2. Target Verification/The Joint Center for 4. Absorbed Dose Profiles ........................................................ 67 Radiation Therapy .................................................................. 34 5. Mechanical Alignment Accuracy ......................................... 70 3. Patient Alignment .................................................................. 35 6. Results .................................................................................... 70 4. Alignme_ht Verification of a Couch-Mounted XVI. Appendix V. EXAMPLE GAMMA-KNIFE QA PROGRAM .....71 Frame (McGill) ....................................................................... 36 XVII. Appendix VI. EXAMPLE RAD1OSURGERY E. Routine QA .................................................................................. 37 PROCEDURES AND CHECKLISTS ........................................ 72 E QA Program for a Gamma Knife ................................................. 39 XVIII.APPENDIXVII. DYNAMIC STEREOTACTIC BRAIN G. Stereotactic Frames and Quality Assurance .............................. 42 IRRADIATION PATIENT CHART (SAMPLE) ........................ 81 VIII. FUTURE DIRECTIONS ............................................................... 43 REFERENCES ............................................................................ 83 A. Image Correlation ........................................................................ 43 B. Multiple Fractionation ................................................................. 44 C. Real-Time Portal Imaging ............................................................ 45 D. Conformal SRS ............................................................................. 45 E. Robot-Guided Linac ..................................................................... 49 IX_ SUMMARY ...................................................................................... 49 X. ACKNOWLEDGEMENTS ................................................................ 50 XI. APPENDIX L PROBABLE RISK ANALYSIS FLOWCHART: EXAMPLE ........................................................................................ 5 I XlI.APPENDIX II. PROBABLE RISK ANALYSIS FLOWCHART: EXAMPLE ...................................................................................... 5 I XIII. APPENDIX Ilia. SRS QA SCHEDULE ....................................... 52 XlV. APPENDIX lllb, LINAC QA SCHEDULE ................................... 52 XV. APPENDIX IV. STEREOTACTIC RADIOSURGERY TECHNIQUES ................................................................................. 53 A. Heavy-Charged-Particle Therapy .............................................. 53 1. Heavy lons--LBL .................................................................. 53 2. ISAH: Irradiation Stereotactic Apparatus for Humans ...... 53 3. Beam Characteristics ..................................... ........................ 53 4. LBL Stereotactic Frame ................................ _....................... 54 5. Treatment ................................................................................ 56 B. Linear Accelerators in Radiosurgery ........................................