pmp Progress in Medical Physics Progress in Medical Physics 2508-4445 2508-4453 Korean Society of Medical Physics 10.14316/pmp.2018.29.4.123 pmp-29-123 Original Article Guideline on Acceptance Test and Commissioning of High-Precision External Radiation Therapy Equipment KimJuhye ∗ ShinDong Oh† ChoiSang Hyoun‡ MinSoonki† KwonNahye§ JungUnjung ∗ KimDong Wook ΙΙ Research Institute of Clinical Medicine, Kyung Hee University Hospital at Gangdong Department of Radiation Oncology, Kyung Hee University Hospital Division of Medical Radiation Equipment, Korea Institute of Radiological and Medical Sciences, Seoul Department of Nuclear Engineering, Kyung Hee University, Yongin Department of Radiation Oncology, Kyung Hee University Hospital at Gangdong, Seoul, Korea Corresponding author Dong Wook Kim (joocheck@gmail.com) Tel: 82-2-440-7398 Fax: 82-2-440-7393 012018 19012018 294123 136 20112018 13122018 14122018 Copyright © 2018 Korean Society of Medical Physics 2018 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

The complex dose distribution and dose transfer characteristics of intensity-modulated radiotherapy increase the importance of precise beam data measurement and review in the acceptance inspection and preparation stages. In this study, we propose a process map for the introduction and installation of high-precision radiotherapy devices and present items and guidelines for risk management at the acceptance test procedure (ATP) and commissioning stages. Based on the ATP of the Varian and Elekta linear accelerators, the ATP items were checked step by step and compared with the quality assurance (QA) test items of the AAPM TG-142 described for the medical accelerator QA. Based on the commissioning procedure, dose quality control protocol, and mechanical quality control protocol presented at international conferences, step-by-step check items and commissioning guidelines were derived. The risk management items at each stage were (1) 21 ionization chamber performance test items and 9 electrometer, cable, and connector inspection items related to the dosimetry system; (2) 34 mechanical and dose-checking items during ATP, 22 multileaf collimator (MLC) items, and 36 imaging system items; and (3) 28 items in the measurement preparation stage and 32 items in the measurement stage after commissioning. Because the items presented in these guidelines are limited in terms of special treatment, items and practitioners can be modified to reflect the clinical needs of the institution. During the system installation, it is recommended that at least two clinically qualified medical physicists (CQMP) perform a double check in compliance with the two-person rule. We expect that this result will be useful as a radiation safety management tool that can prevent radiation accidents at each stage during the introduction of radiotherapy and the system installation process.

 External radiation therapy equipment Acceptance test Commissioning IMRT Risk management REFERENCESGary A Ezzell Calvin James M. Low Daniel Rosen Isaac Sharpe Michael B. Xia Ping Guidance document on delivery, treatment planning, and clinical implementation of IMRT: Report of the IMRT subcommittee of the AAPM radiation therapy committee Med. Phys. 2003308 20892115 IAEA Human Health Series No.25: Roles and Responsibilities, and Education and Training Requirements for Clinically Qualified Medical Physicists International Atomic Energy Agency. 2013 IAEA TRS-398 report: Absorbed Dose Determination in External Beam Radiotherapy: An International Code of Practice for Dosimetry based on Standards of Absorbed Dose to Water International Atomic Energy Agency. 2006 Almond P. R. Biggs P. J. Coursey B. M. Hanson W. F. Saiful Huq M. Nath Ravinder AAPM's TG-51 protocol for clinical reference dosimetry of high-energy photon and electron beams Med. Phys. 1999269 18471870 Gerald J Kutche Coia Lawrene Gillin Michael Hansom Wiliam F. Leibel Steven Morton Robert J. Comprehensive QA for radiation oncology y: Report of AAPM Radiation Therapy Committee Task Group 40 Med. Phys. 1994214 581618 Eric E Klein Hanley Joseph Bayouth John Yin Fang-Fang Simon Wiliam Dresser Sen Task Group 142 report: Quality assurance of medical accelerators Med. Phys. 2009369 41974212 Indra J Das Cheng Chee-Wai Watts Ronald J. Ahnesjö Anders Gibbons John Allen Li X. Accelerator beam data commissioning equipment and procedures: Report of the TG-106 of the Therapy Physics Committee of the AAPM Med. Phys. 2008359 41864215 Gary A Ezzell Burmeister Jay W. Dogan Nesrin LoSasso Thomas J. Mechalakos James G. Mihailidis Dimitiris IMRT commissioning: Multiple institution planning and dosimetry comparisons, a report from AAPM Task Group 119 Med. Phys. 20093611 53595373 ESTRO booklet no.9: Guidelines for the verification of IMRT 2008 Daniel A Low, Jean M. Moran, James F. Dempsey, Lei Dong, Mark Oldham, Dosimetry tools and techniques for IMRT Med. Phys. 2001383 13131338 Oh Yoonjin Shin Dong Oh Kim Juhye Kwon Nahye Lee Soon Sung Choi Sang Hyoun Proposal on Guideline for Quality Assurance of Radiation Treatment Planning System Progress in Medical Physics. 2017284 197206 L J. Humphries and J A. Purdy, In Advances in Radiation Oncology Physics Dosimetry, Treatment Planning, and Brachytherapy. 1992 AAPM Monograph Vol. 19, edited by J. A. Purdy AAPM. Per H Halvorsen Das Indra J. Fraser Martin Jay Freedman D. Robert E. Rice III lbbott Geoffrey S. AAPM Task Group 103 report on peer review in clinical radiation oncology physics Journal of Applied Clinical Medical Physics. 200564 5064 Figures and Tables

Ionization chamber performance test.

The risk management items for electrometer, cable and connector check.

The risk management items for acceptance test of external radiation therapy equipment: Mechanical and dosimetry test.

The risk management items for acceptance test of external radiation therapy equipment: MLC.

The risk management items for acceptance test of external radiation therapy equipment: Imaging system.

The risk management items for commissioning of external radiation therapy equipment: preparation of beam measurement.

The risk management items for commissioning of external radiation therapy equipment: beam measurement.

The derived risk management items were compared for the correlation with TG-142 quality assurance items.

Step Mechanical and Dosimetry check
Sub-step Risk management items TG-142 Quality assurance items Period IMRT Tolerance Remark
Mechanical test Mechanical isocenter variation (with collimator, gantry, couch rotation) Gantry/collimator angle indicators (digital only) Monthly 1° Cardinal angles
Treatment couch position indicator Monthly 2 mm/1°
Collimator rotation isocenter Annual ±1 mm Change from baseline
Gantry rotation isocenter Annual ±1 mm Change from baseline
Couch rotation isocenter Annual ±1 mm Change from baseline
Cross-hair check Cross-hair centering (walkout) Monthly 1 mm
Digital display indicator calibration Collimator size indicator Daily 2 mm
 (Jaw position, gantry, collimator rotation) Gantry/collimator angle indicators (digital only) Monthly 1° Cardinal angles
Jaw position indicators (symmetry) Monthly 2 mm
Jaw position indicators (asymmetry) Monthly 1 mm
Couch movement (rotation, Treatment couch position indicator Monthly 2 mm/1°
longitudinal, lateral, vertical) Table top sag Annual 2 mm Change from baseline
Table angle Annual 1°
Table travel maximum range movement Annual ±2 mm
in all directions
Optical distance indicator (ODI) Distance indicator (ODI) at isocenter Daily 2 mm
verification Distance check device for lasers Monthly 1 mm
compared with front pointer
Radiation isocenter Spoke shot (Gantry rotation) Coincidence of radiation and mechanical l Annual ±2 mm Change from baseline
check isocenter
Winston-Lutz test (with gantry/ Collimator rotation isocenter Annual ±1 mm Change from baseline
collimator/couch rotation) Gantry rotation isocenter Annual ±1 mm Change from baseline
Couch rotation isocenter Annual ±1 mm Change from baseline
Coincidence of light field and X-ray Light/radiation field coincidence Monthly 2 mm or 1%
field (symmetry)
Light/radiation field coincidence Monthly 1 mm or 1%
(asymmetry)
Laser guard collision Protection zone area verification Laser guard-interlock test Monthly Functional
protection system Protection zone tilt verification
Motion stop function verification
Power key switch and override function verification
Beam performance Photon PDD X-ray beam quality (PDD10 or TMR20,10) Annual ±1% Change from baseline
test Photon field flatness/symmetry Photon beam profile constancy Monthly 1%
X-ray flatness change from baseline Annual 1%
X-ray symmetry change from baseline Annual ±1%
Electron PDI Electron energy constancy Monthly 2%/2 mm
Electron beam quality (R50) Annual ±1 mm Change from baseline
Electron field flatness/symmetry Electron beam profile constancy Monthly 1%
Electron flatness change from baseline Annual 1%
Electron symmetry change from baseline Annual ±1%
Symmetry interlock check Follow manufacturer's test procedure Annual Functional
Beamstopper interlocked angles Follow manufacturer's test procedure Annual Functional
Dosimetry Dose reproducibility X-ray output constancy Daily 3% All energies
Monthly 2% All energies
Electron output constancy Daily 3%
Monthly 2%
Backup monitor chamber constancy Monthly 2%
X-ray/electron output calibration (TG-51) ) Annual ±1% Absolute dosimetry
Spot check of field size dependent output Annual 2% Two or more field size
factors for X-ray <4×4 cm2 check
1% ≥4×4 cm2
Output factors for electron applicators Annual ±2% - Change from baseline
- Spot check of on
applicator/energy
Dose linearity with MU X-ray monitor unit linearity output Annual ±2% ±5% (2-4 MU)
constancy (≥5 MU)
Electron monitor unit linearity output Annual ±2%
constancy (≥5 MU)
Dose linearity with dose rate Typical dose rate profile constancy Monthly 2%
X-ray output constancy vs. dose rate Annual ±2% Change from baseline
Dose reproducibility with gantry angle X-ray output constancy vs. gantry angle Annual ±1% Change from baseline
Electron output constancy vs. gantry angle Annual ±1%
Mechanical test Field light alignment Setting vs. radiation field for two patterns Monthly 2 mm
Coincidence of light field and X-ray field Monthly ±2 mm All energies
Cross-hair alignment Cross-hair centering (walkout) Monthly 1 mm
Gantry/collimator rotation isocenter Gantry/collimator angle indicators Monthly 1° Cardinal angles
(digital only)
Collimator rotation isocenter Annual ±1 mm Change from baseline
Gantry rotation isocenter Annual ±1 mm Change from baseline
Optical distance indicator (ODI) Distance indicator (ODI) at isocenter Daily 2 mm
verification Distance check device for lasers Monthly 1 mm
compared with front pointer
Collimator rotation readout calibration Gantry/collimator angle indicators Monthly 1° Cardinal angles
(digital only)
Accessory mount Accessory trays (i.e., port film graticle tray) Monthly 2 mm
Latching of wedges, block tray Monthly Functional
Static MLC Leaf position accuracy Qualitative test (i.e., matched segments, Weekly Visual inspection for
aka “Picket fence”) discernable deviations
such as an increase in
interleaf transmission
Leaf position accuracy Monthly 1 mm Four cardinal angles
Leaf position repeatability Leaf position repeatability Annual ±1 mm
Radiation test Collimator spoke shot Leaf spoke shot Annual ≤1.0 mm (radius)
Gantry spoke shot Leaf spoke shot Annual ≤1.0 mm (radius)
Coincidence of light field and X-ray field Coincidence of light field and X-ray field Monthly ±2 mm All energies
Dynamic MLC MLC transmission dose rates MLC transmission (average of leaf and Annual ±0.5% Change from baseline
interleaf transmission) All energies
AutoDynalogs for the Millennium MLC - - - Only Varian
Generate dynalogs for Mark series or - - - Only Varian
m3 MLC
RV modeup - - -
Arc dynamic leaf speed test Travel speed Monthly Loss of leaf speed>0.5
cm/s
Arc dynamic interlock trip test Arc mode (Expected MU, degrees) Annual ±1 mm Change from baseline
Arc dynamic typical plan test Arc mode (Expected MU, degrees) Annual ±1 mm Change from baseline
Segmental IMRT test (Step and shoot) Segmental IMRT (step and shoot) test Annual RMS maximum of
error<0.35 cm
Moving window IMRT test Moving window IMRT Annual RMS maximum of Four cardinal gantry
error<0.35 cm angles
Moving window IMRT typical plan test
OBI Safety test Door interlock - - -
Mechanical kV source positioning test Positioning/repositioning Daily ≤2 mm
position accuracy kV Imager positioning test Positioning/repositioning Daily ≤2 mm
verification
X-ray check Distance measurement demonstration Scaling Monthly Baseline
kV imager panel virtual alignment Imaging and treatment coordinate Daily ≤1 mm
demonstration coincidence
Optical isocenter demostration Imaging and treatment coordinate Daily ≤2 mm Single gantry angle
coincidence Monthly ≤2 mm Four cardinal angles
X-ray X-ray measurement-digital fluoroscopy, Imaging dose Annual Baseline
generator pulsed mode (kVp, mA, mS)
test Digital radiography-dual gain standard Imaging dose Annual Baseline
resolution (kVp, mA, mS)
HVL using Digital fluoroscopy pulsed Beam quality/energy Annual Baseline
mode
High contrast resolution Spatial resolution Monthly Baseline
Gray scale linearity Spatial resolution Monthly Baseline
Low contrast sensitivity Contrast Monthly Baseline
Cone beam CT number (Hounsfield unit) HU constancy Monthly Baseline
CT Spatial linearity measurement Geometric distortion Monthly Baseline
(distance)
Image uniformity measurements Uniformity and noise Monthly Baseline
High resolution Spatial resolution Monthly Baseline
Low contrast resolution Contrast Monthly Baseline