A Cylindrical 3D Water A Cylindrical 3D Water Scanner – Scanner –

First Experiences and Results First Experiences and Results

Karen FeyenKaren Feyen

AZ St-Maarten Duffel, BelgiumAZ St-Maarten Duffel, Belgium

A.Z. Sint-Maarten – RT A.Z. Sint-Maarten – RT department - Linacsdepartment - Linacs

– SLi 18 (installed 2002), conformal treatmentsSLi 18 (installed 2002), conformal treatments• 6MV/15MV photons6MV/15MV photons• 5 electron energies5 electron energies• MLCi with 1 cm leaves, max field size 40 MLCi with 1 cm leaves, max field size 40

cm x 40 cmcm x 40 cm• Short physics duct from control area to Short physics duct from control area to

linac technical area : no fixed cablinglinac technical area : no fixed cabling– Synergy platform (installed 2007), IMRTSynergy platform (installed 2007), IMRT

• 6MV/15MV photons6MV/15MV photons• Beam modulator with 4 mm leaves, max Beam modulator with 4 mm leaves, max

field size 21 cm x 16 cmfield size 21 cm x 16 cm• Physics duct about 25 m, fixed cabling Physics duct about 25 m, fixed cabling

and connectors in bunker and control and connectors in bunker and control areaarea

– EPID based IGRT on both systemsEPID based IGRT on both systems• Iview GTIview GT• Vanderwilt remote table controlVanderwilt remote table control• Offline/online protocols, no CBCTOffline/online protocols, no CBCT

– ± 1000 new patients/year± 1000 new patients/year

A.Z. Sint-Maarten – RT A.Z. Sint-Maarten – RT department department

• CT simulationCT simulation– Siemens Definition CT (medical imaging Siemens Definition CT (medical imaging

department)department)– A2J CT-Sim lasersA2J CT-Sim lasers– Medio 50 CP simulator used for some Medio 50 CP simulator used for some

palliative palliative • Medio 50 CP simulatorMedio 50 CP simulator– Some palliative treatmentsSome palliative treatments

• Main TPS = PinnacleMain TPS = Pinnacle• Brachy:Brachy:

– Nucletron HDR / Oncentra MasterplanNucletron HDR / Oncentra Masterplan– PBT inhouse/other centers : Bard / VariseedPBT inhouse/other centers : Bard / Variseed

• Other equipmentOther equipment• More than 40 PC’s and workstations for about More than 40 PC’s and workstations for about

20 people20 people• A lot of cables and a lot of heatA lot of cables and a lot of heat

Dosimetry material Dosimetry material

• Abolute DosimetryAbolute Dosimetry– FC-65-G cylindrical FC-65-G cylindrical

reference chamberreference chamber

– PPC-40 parallel plate PPC-40 parallel plate chamberchamber

– Dose-1 electrometerDose-1 electrometer

– WP1D motorised WP1D motorised waterphantomwaterphantom

• Machine QA - SNCMachine QA - SNC– Switching to IC-profiler or Switching to IC-profiler or

Profiler 2 (still to be Profiler 2 (still to be decided)decided)

– Daily QA3 (wireless)Daily QA3 (wireless)

• Patient QAPatient QA– MatrixxMatrixx

– InvidosInvidos

• Brachy QABrachy QA

– Unidos E and Sourcecheck Unidos E and Sourcecheck (PBT)(PBT)

– Nucletron/Standard Nucletron/Standard Imaging and PTW well Imaging and PTW well chamber (HDR)chamber (HDR)

3DS – How did we decide ?3DS – How did we decide ?

• Motivation :Motivation :• WP700 system dates from 1989 and was WP700 system dates from 1989 and was

in need for replacementin need for replacement• ““New” project : commission Sli 18 for New” project : commission Sli 18 for

IMRT, we wanted this done without IMRT, we wanted this done without doubts about the measurement data doubts about the measurement data qualityquality

• Increase time efficiency of water tank Increase time efficiency of water tank measurementsmeasurements

• Reduce threshold to use of water tankReduce threshold to use of water tank

• Obtained budget approval 04/2010Obtained budget approval 04/2010

3DS – How did we decide ?3DS – How did we decide ?

• Requirements specifications (highlights):Requirements specifications (highlights):– MustMust

– qualitatively perform as well or better than qualitatively perform as well or better than the old system (of course)the old system (of course)

– work with current detectorswork with current detectors– handle current datahandle current data– export to Pinnacle export to Pinnacle – TMR/TPR capableTMR/TPR capable– Before purchase, we must work with the Before purchase, we must work with the

system to get the look and feelsystem to get the look and feel– ShouldShould

– more user friendlymore user friendly– easier/faster to setupeasier/faster to setup

3DS – How did we decide ?3DS – How did we decide ?

• On site visits at nearby centers May-June On site visits at nearby centers May-June 20102010• PTW MP3-M / Mephysto MCPTW MP3-M / Mephysto MC2 2

• IBA Blue Phantom / OmniPro Accept v7IBA Blue Phantom / OmniPro Accept v7 both very qualitative and well established systemsboth very qualitative and well established systems IBA blue phantom and OmniPro Accept v7 seemed IBA blue phantom and OmniPro Accept v7 seemed

logical successor to our current systemlogical successor to our current system

• No clinical 3DS system available in Europe No clinical 3DS system available in Europe at that timeat that time

• => Visit to SNC factory => Visit to SNC factory

3DS – How did we decide ?3DS – How did we decide ?

• Visit SNC factoryVisit SNC factory• First view on a functional First view on a functional

prototypeprototype• Opportunity to talk to several Opportunity to talk to several

people involved in the people involved in the development of hardware and development of hardware and softwaresoftware

• Enthousiastic team Enthousiastic team determined to deliver a determined to deliver a innovative and qualitative innovative and qualitative product, eager to take input product, eager to take input from (potential) usersfrom (potential) users

• Good overview of hardware, Good overview of hardware, softwaresoftware

• But system released early But system released early 2011, which was later than 2011, which was later than we hoped forwe hoped for

3DS – How did we decide ?3DS – How did we decide ?

• Competitive offers from all partiesCompetitive offers from all parties• Open communication with all distributorsOpen communication with all distributors• Detailed comparison of all specs Detailed comparison of all specs • Choice between solid well established system and Choice between solid well established system and

young innovative systemyoung innovative system• Very much attracted by the novelties of the 3DS Very much attracted by the novelties of the 3DS

systemsystem– Auto setup : objective, time saving (?), Auto setup : objective, time saving (?), – One-cable connection : fast, less fragileOne-cable connection : fast, less fragile– Measurement database instead of filesMeasurement database instead of files– Layered processing with rollback optionsLayered processing with rollback options– Consistent detector orientation (certainly has a positive Consistent detector orientation (certainly has a positive

effect but not thoroughly evaluated at that timeeffect but not thoroughly evaluated at that time))

3DS – How did we decide ?3DS – How did we decide ?

• But no reference and no opportunity to test at But no reference and no opportunity to test at that timethat time

=> Test site agreement=> Test site agreement– Gain experience with new system before it is releasedGain experience with new system before it is released– Opportunity to provide input for new features (wish list !)Opportunity to provide input for new features (wish list !)– Possibly start measurements with test system if all Possibly start measurements with test system if all

works earlier than planned (optimism is good) works earlier than planned (optimism is good)

3DS – the system3DS – the system

3DS – the system3DS – the system

• Main hardware Main hardware differences : differences : – Cylindrical geometry Cylindrical geometry

– movement in (r, theta, z) movement in (r, theta, z) instead of (x, y, z)instead of (x, y, z)

– Look less bulkyLook less bulky– less water needed, less weight less water needed, less weight – scan range is the same for all scan range is the same for all

scans ( i.e. not larger for scans ( i.e. not larger for diagonals) but is large (standard diagonals) but is large (standard 50 cm)50 cm)

– larger scan range possible with larger scan range possible with special detector holderspecial detector holder

Mechanical TestingMechanical Testing

• Relative positioning accuracy using Relative positioning accuracy using laser pointer and chart paperlaser pointer and chart paper– Ring driveRing drive

– Vertical drive Vertical drive

– Diameter driveDiameter drive

• Done using controls box – without Done using controls box – without auto setup measurements (dry auto setup measurements (dry tank)tank)

• Leveling accuracy : Leveling accuracy : ≤≤ 0.1° 0.1° (accuracy of our digital level)(accuracy of our digital level)

• Plumb line of vertical drive using Plumb line of vertical drive using laser level (construction)laser level (construction)

3DS – Setup3DS – Setup

• Platform setup procedure:Platform setup procedure:• Connect power and PDIConnect power and PDI• Calibrate motors platform and tankCalibrate motors platform and tank• Put tank approximately rightPut tank approximately right• Fill tank and adjust height to correct SSDFill tank and adjust height to correct SSD• Leave bunker and run auto setup procedureLeave bunker and run auto setup procedure

• Tank Leveling Tank Leveling • Ring center determinationRing center determination• Tank center determination and tank adjustmentTank center determination and tank adjustment• Ring angle offset determinationRing angle offset determination• Hysteresis measurementHysteresis measurement

3DS – Auto setup3DS – Auto setup

3DS – Auto setup – 3DS – Auto setup – calibrate platformcalibrate platform• Platform leveling and x- y- motors need to Platform leveling and x- y- motors need to

be calibrated before they can be usedbe calibrated before they can be used• Best done before aligning the system with Best done before aligning the system with

the the crosswirecrosswire

3DS – Auto setup – 3DS – Auto setup – calibrate platformcalibrate platform• Tank ring drive, diameter drive and vertical Tank ring drive, diameter drive and vertical

drive home positions are determineddrive home positions are determined

3DS – Auto setup3DS – Auto setup

3DS – Auto setup – ring 3DS – Auto setup – ring centercenter• Diameter drive is mounted Diameter drive is mounted

eccentrically to allow for the detector eccentrically to allow for the detector to be in the centerto be in the center

3DS – Auto setup – Ring 3DS – Auto setup – Ring centercenter• To keep the detector in the To keep the detector in the

mechanical center of the tank, it must mechanical center of the tank, it must be positioned correctlybe positioned correctly• In the direction In the direction

orthogonal to the orthogonal to the diameter drive -> specific diameter drive -> specific distance when mounting distance when mounting the detectorthe detector

• In the direction along the In the direction along the diameter drive -> done diameter drive -> done by the system by the system

3DS – Auto setup – Ring 3DS – Auto setup – Ring centercenter• If the ring center would not be If the ring center would not be

determined correctly, the detector determined correctly, the detector would rotate on a circle around the would rotate on a circle around the mechanical centermechanical center

3DS – Auto setup3DS – Auto setup

• Tank adjustTank adjust•The isocenter/beam center is determined fromThe isocenter/beam center is determined from

• Inline and crossline scan at collimator 0°Inline and crossline scan at collimator 0°• Inline and crossline scan at collimator 180°Inline and crossline scan at collimator 180°

•The tank position is shifted to match the beam centerThe tank position is shifted to match the beam center• Angle offsetAngle offset

•The angle of the tank is aligned with the collimatorThe angle of the tank is aligned with the collimator

3DS – Auto setup Checks3DS – Auto setup Checks

• Check after auto setup during test period:Check after auto setup during test period:•Visually check position of detector vs crosswireVisually check position of detector vs crosswire•Take scans at cardinal angles Take scans at cardinal angles •Check correct position of beam edgesCheck correct position of beam edges

• => Part of factory testing=> Part of factory testing

3DS – Setup -timings3DS – Setup -timings

Item Timing (approx.)

Calibrate platform 1’30”

Calibrate tank 45”

Fill tank (old reservoir) 7’

Tank leveling 4’30”

Ring/Tank center & adjust

7’

Ring angle offset 1’45”

Hysteresis 1’30”

3DS – Scan database3DS – Scan database

• Scans are grouped in projects – can be added to multiple Scans are grouped in projects – can be added to multiple projectsprojects

• DB can be searched by building logical expressions of DB can be searched by building logical expressions of various scan parametersvarious scan parameters

• Scan lists can filtered Scan lists can filtered • Scans lists can be groupedScans lists can be grouped

3DS – Scan database - 3DS – Scan database - projectsprojects

3DS – Scan database 3DS – Scan database searchessearches

3DS – Scan database 3DS – Scan database filteringfiltering

3DS – Scan database 3DS – Scan database filteringfiltering

3DS – Scan layered 3DS – Scan layered processingprocessing

3DS – Scan layered 3DS – Scan layered processingprocessing

Experiences – Detectors Experiences – Detectors usedused

Experiences – Easy setupExperiences – Easy setup

Results – Large scan rangeResults – Large scan range

• The standard scan range of 50 cm can be The standard scan range of 50 cm can be extended using the radial offset detector holderextended using the radial offset detector holder

• 40 cm x 40 cm, d=30cm, 5 cm extra => 62cm 40 cm x 40 cm, d=30cm, 5 cm extra => 62cm scanscan

Results – Large scan rangeResults – Large scan range

• Radial offset detector offsets the detector from the Radial offset detector offsets the detector from the center of the carriage, brings it closer to the tank wallcenter of the carriage, brings it closer to the tank wall

• Diameters driver rotates by 180° when detector is in Diameters driver rotates by 180° when detector is in the centerthe center

Results – Consistent Results – Consistent detector orientationdetector orientation

• The cylindrical design The cylindrical design ensures a consistent ensures a consistent orientation of the orientation of the detector : the motion detector : the motion always occurs transverse always occurs transverse to the axis of the detectorto the axis of the detector

Results – Consistent Results – Consistent detector orientationdetector orientation• Intuitively important forIntuitively important for

• extended detectorsextended detectors

• detectors with different dimensions along their respective axisdetectors with different dimensions along their respective axis

• Tested with 3 types of detectorsTested with 3 types of detectors• elongated ICelongated IC

• ““spherical” IC (CC13)spherical” IC (CC13)

• diodediode

• Compared scans with axis Compared scans with axis • transverse to motiontransverse to motion

• along the directionalong the direction

Results – Consistent Results – Consistent detector orientation – detector orientation – elongated ICelongated IC

Results – Consistent Results – Consistent detector orientation – detector orientation – elongated ICelongated IC

Effect clearly visible

Results – Consistent Results – Consistent detector orientation – CC13detector orientation – CC13

Results – Consistent Results – Consistent detector orientation – CC13detector orientation – CC13

Effect present but less visible

Results – Consistent Results – Consistent detector orientation – diodedetector orientation – diode

Results – Consistent Results – Consistent detector orientation – diodedetector orientation – diode

Effect invisible

Results – Evaluation of scan Results – Evaluation of scan parametersparameters

•Set of scans for various field sizes Set of scans for various field sizes and various scan settings – CC13and various scan settings – CC13

Results – Evaluation of scan Results – Evaluation of scan parametersparameters

•Set of scans for various field sizes Set of scans for various field sizes and various scan settings – Edge and various scan settings – Edge (diode)(diode)

Results – Detector choice – Results – Detector choice – small fieldssmall fields• Set of scans Set of scans

for various for various detectors and detectors and optimal scan optimal scan settingssettings

• ““Sharp” vs Sharp” vs noisynoisy

Results – Detector choice – Results – Detector choice – large fieldslarge fields• Set of scans Set of scans

for various for various detectors and detectors and optimal scan optimal scan settingssettings

• ““Sharp” vs Sharp” vs noisynoisy

Results – Scans with offsetResults – Scans with offset

• Achieved by eitherAchieved by either• Software controlled shift of platform (offsets ~ 1cm)Software controlled shift of platform (offsets ~ 1cm)

• By combination of radial and angular movement (larger By combination of radial and angular movement (larger offsets)offsets)

Results – Scans with offsetResults – Scans with offset

• Check off-axis shiftCheck off-axis shift

• Collimator 45°Collimator 45°

• Scan with no offset / Scan with no offset /

• Scan with 1 cm offsetScan with 1 cm offset

Results – Scans with offsetResults – Scans with offset

• Check detector Check detector position ? position ?

0 cm offset

1 cm offset

delta cm

Edge - 7.02 6.1 0.92

Edge +

6.99 6.07 0.92

Results – Currently Results – Currently performing commissioning performing commissioning measuringmeasuring

Results – Currently Results – Currently performing commissioning performing commissioning measuringmeasuring

Summary of my findingsSummary of my findings

• 3DS is a nice innovative system to work with : no 3DS is a nice innovative system to work with : no more dreading to use itmore dreading to use it– Less bulky, less heavy, practical designLess bulky, less heavy, practical design

– Auto setup : objective, fast(er)Auto setup : objective, fast(er)

– One-cable connectOne-cable connect

– Database of measurement : very helpful during Database of measurement : very helpful during comissioningcomissioning

– Layered processingLayered processing

=> Faster, more frequent use=> Faster, more frequent use

• Still being optimised and developped further Still being optimised and developped further based on user feedback => real strength of SNCbased on user feedback => real strength of SNC

AcknowledgementsAcknowledgements

• My colleague My colleague physicists, for all physicists, for all extra work during extra work during evenings and evenings and weekends: weekends:

• Natalie BalNatalie Bal

• Charlotte BauwensCharlotte Bauwens

• Our department Our department head dr. Ph. Spaashead dr. Ph. Spaas

Thank you !Thank you !

3DS – the system3DS – the system

3DS – the system3DS – the system