This document discusses the commissioning and acceptance testing of a medical linear accelerator (LINAC). It covers regulatory requirements, installation, commissioning, and time planning for the LINAC and radiotherapy facility. It also discusses various technical reports and task group publications that provide guidelines for LINAC quality assurance, including beam data collection and commissioning. Key aspects of the commissioning process involve mechanical, radiation, dosimetry, and quality assurance checks of the LINAC. Proper time management is also required to complete the commissioning and acceptance testing.

1. COMMISSIONING OF MEDICAL
LINEAR ACCELARATOR AND THE
ACCEPTANCE TESTS

2. RADIOTHERAPY FACILITY
• Technical specification
• Effective comparison
• Negotiation & finalization
• Regulatory requirements
• Installation &
Commissioning
• Time planning
• Optimum manpower
LINAC
 Machine specification
& scope of supply
 Technical comparison
 Regulatory requirements
 Installation &
commissioning
 Time management
 QA

3. • AAPM TG-40 report still function as the base
lines
• TG-142 – emerging to modern clinical practice
• TG50, TG58, TG76 TG106, TG104, TG100 for
various LINAC QA
• Accelerator beam data & commissioning – TG-
106
• QA for Tomotherapy –TG-148
• QA for Robotic Radiosurgery – TG-135
• QA for Non-Radiographic Radiotherapy
Localization & Positioning Systems – TG-14
• TRS – 398 / TG- 51 for absolute calibration

4. DESIGN TECHNICAL SPECIFICATION
Sl. No. Specification
1 Dose Delivery & Beam Characteristics
Highest Photon dose rate in MU/Min
Highest FFF dose rate in MU/ Min
Highest electron dose rate MU / Min
Field Flatness
2 System Integration
Explain Level of Integration with respect to the linear acclerator, MLC,
Integrated Dosimetry and verification system, 6D Couch, Portal
Imaging, KV imaging System, µMLC, TPS and OIS. Explain how this
integration helps in therapy in terms accuracy, precision and time?
3 System Accuracy in SUB MILLIMETER
Gantry
Couch
Collimeter
4 Portal Imaging
Detector Size
Active Imaging area
Resolution
Dosimetry application , Specify in case of any unique application using
portal Imaging.
5 KV Imaging
Imaging modes available
Detector Size
Active Imaging area
Resolution
Specify other applications
6 Integrated QA and Dosimetry Systems
Specify the features and applications of integrated QA and Dosimetry
Systems
7 Treatment Planning System
Specify the UNIQUE features of TPS, If any..
Planning algorithm used
List of Optimisation softwares provided as standard
8 Oncology Information System
Specify the UNIQUE features of OIS, If any..
9 MLC
Max Field Size
Min Field Size
Number of leaves
Average leaf transmission
Maximum leaf speed
Maximum over center travel distance
Maximum Leaf retracting distance in cm
Leaf position accuracy
Up gradation of MLC's
MLC resolution
Field size range
Leaf span
MLC Leaf width
MLC Leaf thickness
MLC Leakage (Including intra leaf leakage)
MLC Leaf Material
Maximum step size in mm
Light and Xray field coincidence (Congruence)
Penumbra

5. 10 µMLC
Max Field Size
Min Field Size
Number of leaves
Average leaf transmission
Maximum leaf speed
Maximum over center travel distance
Maximum Leaf retracting distance in cm
Leaf position accuracy
Up gradation of µMLC's
µMLC resolution
Leaf span
MLC Leaf width
MLC Leaf thickness
MLC Leakage (Including intra leaf leakage)
MLC Leaf Material
Maximum step size in mm
Light and Xray field coincidence (Congruence)
Penumbra
11 Network Capabilities & Server Configuration
Capability to interface with Hospital PACS
Capability remote access to the plans
DICOM 3 Ready for all activities like store, print, archive, retrieve etc
Specify any other networking feature availble?
12 Motion Management Systems
Specify the details of motion management features availed. Indicate the advantage ?
13 Respiratory Motion Management System
Specify the details of respiratory motion management features availed. Indicate the advantage ?
14 Knowledge based Treatment Planning support algorithms
Details of knowledge based treatment planning and contouring systems which are availed as standard
https://aapm.org/pubs/reports/RPT_106.pdf

8. Clinical Setups

9. Dosimeter Equipments - (Scope of Supply)- Procurement approval
1 Radiation Field Analyser
a) 3D Scanner
b) Lift (Motorized)
e) with +/- 0.1 mm resolution in each axis, good electrometer resolution, etc.
2 Detectors
a) 0.125 / 0.13 cm³ scanning ion Chamber (2 Nos)
b) 0.6 cm³ Farmer Photon Ion Chamber (2 No) - cylindrical, water proof with one electrometer
d) Scanning Micro chamber 0.015 / 0.01 cm³ Stereotatic Ionisation Chamber (1 No)
e) Edge Detectors (Solid State Detector) (2 No)
g) Parallel plate ionization chamber for high energy electrons - 0.4 cc volume, water proof.
h) Vented Well type ionization chamber for brachytherapy calibration and associated electrometer.
i) Daily beam checker with integrated buld -up
3 Real time Water Slab Phantom
a) Slab Phantom 30 x 30 cm ( With various thicknesses, 5.0 cm, 2.0 cm, 1.0 cm, 0.5 cm, 0.2 cm and 0.1 cm.)
e) 30 X 30 X 30 water (mini phantom) & D20 / D10 Phantom
4
Cylindrical Detector with good isocentric resolution (chamber insertion desirable)
with 3D dose comparison software or
Array detector with Gantry Mount for VMAT commissioning and with necessary Phantom.
5 OSL detector and readout system
6 Radiation Survey Meter for Photons (Pressurized ionization chamber based prefereble)
8 Respiratory Gating Phantom
10 Film – radiographic and chromic, analysis software
14 A comprehensive quality assurance kit for Diagnostic radiology
Catphan phantom for CT
QA tool for radiography and fluoro machines including KVp meter, Dosimeters (separate for mamo, etc.

10. COMMISSIONING DATA FOR LINAC
Khan, F. M. (2010). The physics of radiation therapy. Philadelphia: Lippincott Williams & Wilkins.

11. Mechanical checks
Quality Control of Medical Electron Accelerators . Swiss Society of Radiobiology and Medical Physics . Recommendations No. 11

13. Dial Indicator – checks jaw
symmetry
Khan, F. M. (2010). The physics of radiation therapy. Philadelphia: Lippincott Williams & Wilkins.

16. Collimator rotation
Gantry rotation
Determination of mechanical Isocenter
Khan, F. M. (2010). The physics of radiation therapy. Philadelphia: Lippincott Williams & Wilkins.

17. RADIATION ISOCENTER CHECK
a.Collimator rotation
b.Table rotation
c.Gantry rotation

18. MULTIPLE BEAM ALIGNMENT CHECK

19. MLC
These parameters below should be quantified for each
photon energy and a minimum of 4 gantry
angles(0,90,180,360 degrees) to examine the effect of
gravity on leaf motion
• Light and radiation field congruence
• Interleaf leakage(leakage b/w 2 leaves)
• Intraleaf leakage(Transmission through a leaf)
• penumbra

20. RADIATION CHECKS

22. Quality Control of Medical Electron Accelerators . Swiss Society of Radiobiology and Medical Physics . Recommendations No. 11

23. c

24. TG45 – commissioning electron beam
Commissioning Electron Beams
• calibration of beam output;
• central-axis depth dose curves in water;
• isodose charts in water;
• cross beam profiles in water;
• output factors;
• corrections for field shaping; and
• corrections for air gap

25. RADIATION CHECKS:
ELECTRONS

30. MLC
These parameters below should be quantified for each
photon energy and a minimum of 4 gantry
angles(0,90,180,360 degrees) to examine the effect of
gravity on leaf motion
• Light and radiation field congruence
• Interleaf leakage(leakage b/w 2 leaves)
• Intraleaf leakage(Transmission through a leaf)
• penumbra

31. Current VMAT and QA Options
•Some Existing Planning Systems
•Eclipse (Varian)
•ERGO++/Monaco (Elekta)
•Pinnacle SmartArc (Philips)
•Prowess (Prowess)
•Some Existing Delivery Systems
•VMAT/RapidArc (Varian)
•VMAT (Elekta)
•Some Existing QA Systems
•Film or film equivalent
•2-D ion chamber/diode array (i.e., Matrixx,Octavius, Mapcheck, …)
•3-D diode matrix (Delta 4, ArcChecker,Octavius, Gel/Presage,…)
•Some of 3-D devices could be potentially used for 4-D measurement
Specials Considerations for VMAT
•Due to necessary synchronization of both dose rate and gantry motion with MLC
movement, it is clear that VMAT involves new and different QA steps relative to
conventional IMRT
•This should be reflected in Acceptance Testing (AT), Commissioning (COM), and Routine
QA for VMAT

32. Mechanical Testing of DMLC
• Leaf speed stability-film
• Dose profile across adj.leaves
• Leaf Acceleration and
Decceleration
• Positional accuracy of Leaves
• Routine Mechanical Check
Dosimetric Checks
• MLC transmission
• Head Scatter
• Treatment Verification
Khan, F. M. (2010). The physics of radiation therapy. Philadelphia: Lippincott Williams & Wilkins.

33. Commissioning VMAT Equipment
There Are Different Ways Of Performing Testing
• There Are Also Different Phantom/Measurement Devices Available For
VMAT Testing
• Different Devices May Need Different Ways Of Operation And
Measurements. However, The Tolerances Against Baselines Should Be
Comparable
They Must Provide Equivalent Information:
• Beam Flatness And Symmetry
• MLC Leaf Calibration
• Sliding Window Dose
• Rotational Accuracy
• Beam Interruption And Termination

34. Three variables during VMAT Delivery: How to check
the variables
• MLC leaf motion: The projection position
of the tip for each MLC leaf on the
MatriXX device can be used to determine
the MLC leaf motion accuracy
• Gantry angle: The projection width of the
1cm gap between MLC leaves on the
MatriXX device can be used to determine
the gantry angle
• Dose rate: The absolute dose measured in
the open area from each 0.1s sample can
be used to determine the actual dose rate

35. A special VMAT plan with specific MLC leaf motion
patterns and dose rate variations was developed to
check all three major variables
• Gantry continue rotates while the
MLC leaves are moving.
• Dose rate also varies while gantry
is rotating.
• The plan was measured using a
MatriXX 2D ion chamber inserted
in a MULTICube phantom.
• The data were recorded in movie
mode with 0.1 second sampling
time.
2010 ACMP Annuall Meetiing,, San Antoniio

36. • ArcCHECK detectors are always facing the delivery beam regardless of gantry angle. The
detector geometry relative to the BEV remains constant. Detection of very small gantry angle
errors is possible. In contrast, when a 2D array is irradiated obliquely, the geometry collapses to
1D. Even when there is no detector shadowing effect, significant information is lost on a 2D
array, and errors up to 10° are missed 75% of the time
• With ArcCHECK, gantry angle, leaf-end position, absolute dose, and time (4D) are measured
and correlated to identify sources of error. Dose accuracy is improved and errors can be traced
to the treatment planning system, the delivery system, or the imaging system
2D Array Measurement
An inherent limitation of 2D arrays is an inability
to capture all of the dose information for
rotational deliveries.
ArcCHECK Measurement
ArcCHECK displays BEV dose distribution throughout
the entire arc delivery. More data is available to
perform a more thorough QA analysis.

37. 2D DIODE ARRAY
A MapCheck device inserted into a
MapPhan
Arc Check – Sun Nuclear
•1386 diode detectors arranged in cylindrical
geometry
•Measures entrance and exit dose
•The QA can be done in composite or per control
point
•DICOM RT Dose is imported and ArcCHECK software
then extracts 3D dose corresponding to detector
locations, and performs a comparison
All data files from ArcCHECK are open format for
easy export
2012 AAPM Annual Meeting, Charlotte

38. MatriXX system has 1020 vented ion chambers with
an active area of 24.4cm x 24.4cm.
The size of each ion chamber is 4.5cm (diameter) x
5cm (height). The raw pixel size is 7.62mm, which
can be interpolated down to 1mm.
Laser is used to align system. Dose from both
coronal and sagittal planes can be measured
depending on the phantom.
Inclinometer
2012 AAPM Annual Meeting, Charlotte

39. Commissioning Related to VMAT
• Mechanical-specific tests
– MLC position test - static gantry
– MLC position test - rotating gantry
– MLC error detection test during rotation
• Dosimetry-specific tests
• Dose profile test at different gantry positions
– MLC dosimetry test at different gantry positions
– MLC dosimetry test with changing gantry speed and dose rate
– MLC dosimetry test with changing leaf speed during rotation
• Interruption/resumption test
• End-to-end tests
– Data transfer
– Patient specific
End-to-End Tests
• Dosimetry and positioning verification from simulation to delivery for phantoms
• End-to-end test for benchmark cases (for example, test cases from AAPM Task Group 119)
• Perform patient-specific QA measurements prior to the start of treatment and for any plan change
• Tolerance: 95% of points in agreement to 4% and 4 mm. Other tolerances may be accepted if there is
a reasonable justification

40. TG RPT 106

41. Need for Periodic - Quality Assurance
• Clinical experience has shown that variations of 10% or more in the
delivered dose can sharply reduce the probability of local tumor control.
• ICRU Report 62 recommends that radiotherapy be delivered within 5% of
the prescribed dose to ensure adequate tumor control.
• The global aim is to achieve the desired tumor control while maintaining
toxicities to normal tissues to a minimum

42. QA of LINAC Based on TG-142
Daily QA Machine type tolerance
Non-IMRT IMRT
1
Dosimetry Photon beam output constancy 3%
Photon beam profile constancy 3%
Electron beam output constancy 3%
2
Mechanical Laser localization 2 mm 1.5 mm
ODI indicator 2 mm 2 mm
3 Safety Door interlock (beam off) Functional
Audiovisual monitor Functional
Beam on indicator Functional
Weekly QA Machine type tolerance
Non-IMRT IMRT
1
Dosimetry Photon beam output constancy 3%
Electron beam output constancy 3%
2
Mechanical Collimator size indicator 2 mm 2 mm
Jaw position indicators (symmetric) 2 mm
Jaw position indicators (asymmetric) 2 mm

43. Monthly QA Machine type tolerance
Non-IMRT IMRT
1 MLC QA MLC transmission factor measurement
Dosimetric leaf gap measurement
Picket fence, garden fence tests
Leaf position accuracy tests in producing complex fields
Leaf speed stability
2
Mechanical Light/radiation field coincidence (symmetric) 2 mm or 1% on a side
Light/radiation field coincidence (asymmetric) 1 mm or 1% on a side
Localizing lasers 2 mm 1 mm
Gantry / collimator angle indicators 1.0o
1.0o
Couch position indicators 2 mm/1o
2 mm/1o
Annual QA Machine type tolerance
Non-IMRT IMRT
1 Dosimetry Photon flatness change from baseline 1%
Photon symmetry change from baseline ±1%
Electron flatness change from baseline 1%
Electron symmetry change from baseline ±1%
Photon / electron calibration (TRS-398) ±1%(absolute)
Photon beam quality (TPR20/10) ±1% from baseline
Electron beam quality (R50) ±1 mm
Photon output constancy vs dose rate ±2% from baseline
Photon output constancy vs gantry angle ±1% from baseline
electron output constancy vs gantry angle ±1% from baseline
2
Mechanical Gantry / collimator /couch rotation isocenter ±1 mm from baseline
Coincidence of radiation and mechanical isocenter ±2 mm from baseline

44. REFERENCES
• Shende, R., Gupta, G., Patel, G., & Kumar, S. (2016). Commissioning of
TrueBeam^TM Medical Linear Accelerator: Quantitative and
Qualitative Dosimetric Analysis and Comparison of Flattening Filter (FF) and
Flattening Filter Free (FFF) Beam. International Journal of Medical Physics, Clinical
Engineering and Radiation Oncology,05(01), 51-69.
doi:10.4236/ijmpcero.2016.51006

45. THANK YOU

46. TIME MANAGEMENT
 SLA approval – 1 month
 Bunker construction – 2 -3 weeks
 TLD application – 40 days (more delay)
 RS0 nomination – 3 days
 Machine – discussion, negotiation & finalization
– 2-3 weeks
 Procurement – 2 weeks
 Machine shipment – 45 days
 Intimation – 1 day

47.  Mechanical Installation – 21 days
 RT COM approval – 15 days ( Man power should be
added before)
 Radiation beam switch on & Survey– 2 days
 Survey approval – 7-10 days
 Beam Tuning – 5 days
 Customer Acceptance Protocol (CAT) – 6 days
 Clinical Approval_ AERB measurements – 10 days
 Beam data measurement for TPS – 3 weeks
 License – 15-20 days

48. ACCEPTANCE: DYNAMIC TREATMENT
 Arc Dynamic Functionality(Load and Deliver plan)
o Check that no interlocks are asserted
o Check that leaf speed is 2.5cm/s
o Check effective MU/degree
o Check gantry position RMS error
o Check MU RMS error
 Sliding Window IMRT Test(Load and deliver plan at G
=90,270)
o Check that no interlocks are asserted
o Leaf position deviation less than 0.15 cm