8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 1 Use-Case on treatment planning at HIMAC Koichi Murakami KEK 1 st Workshop on the Italy-Japan Collaboration on Geant4 Medical Application 8/Mar./04, INFN Genova

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 2 Introduction  Our project was just started and we are not yet familiar with practical use-cases in medical application.  It is important to collect practical use-cases and requirements for medical users.  We had hearing for treatment planning system at HIMAC (NIRS) on last Dec. with a brief demonstration of the system. collecting use-cases and documentation picking up requirements from use-cases

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 3 Basic Flow of Radiation Treatment  Diagnosis Prescription according to the treatment protocol.  Treatment planning (our scope)  Discussion based on the results of treatment planning  Treatment

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 4 Input/Output of the system  At first, we list up items taking part in the system.  Diagnosis (input) “ Treatment protocol ” to be applied Image data (CT) of a patient  DICOM format Specification of ROI (Region Of Interest)  Identification of organs  Specification of target (cancer) volume  Parameters of treatment system beam energy, parameters of beam line (input) parameters of collimators (range shifter, MLC, Bolus) (i/o)  Discussion based on the results of treatment planning (output) Dose distribution DVH (Dose Volume Histogram)

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 5 Image Data (CT)  DICOM format “ Dr. View ” is used as visualization tools.  Resolution 512x512 pixels of 0.7mm 2 in xy-plane  21cm x 15cm (at MLC in HIMAC) dz=3/5 mm along z-direction, 30cm in total  Correction position smoothing density (removal of artifact)  Conversion from CT-value to density material is defined as “ water ”.

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 6 Specification of ROI  ROI (Region Of Interest) region for scoring DVH OAR (Organs At Risk) Tumor (Target) Volume  GTV < CTV < PTV  GTV (Gloss Tumor Volume)  CTV (Clinical Target Volume)  PTV (Planning Target Volume)  TV = PTV + 6mm (HIMAC)  Operation is carried out by doctors. Marking ROI for each sliced CT image by hand Automatic identification of organs is possible with commercial tools.

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 7 Parameters of Treatment System  Beam energy depending on the depth to tumor  Parameters of magnets making laterally uniform beam area Wobbler magnet and scatterer thickness  Ridge filter forming SOBP (Spread Out Bragg Peak)  Range Shifter adjusting range  Collimators Ring collimators MLC (multi leaf collimator)  Bolus being sculpted for tumor depth  Control protocols of hardware GPIB Original format

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 8 Discussion for Treatment  Treatment team has discussion based on the results of treatment planning.  Dose Distribution Spatial resolution  2 times larger size of cells than CT image (1.4mmx1.4mm)  same size along z-direction  more fine resolution in other facilities  DVH (Dose Volume Histogram) Integrated volume having dose more than given over ROI. DVH in TV vs. DVH in OAR (Organ At Risk)

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 9 Documentation

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 10 Documentation  Making formatted documentation was just started for our situation.  Digging out actors (list of actors)  Breaking down to sub-systems (tentative)  Glossary of terminology  Description of use-cases

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 11 Digging out Actors  List of Actors Doctors MRT (Medical Radiation Technologists) as Operators/Planners This is our (japanese) situation. Situation can be different between countries.  Other concerned participants Patients QA of system (design/study/evaluation)

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 12 System Component  Breaking down to sub-systems This is currently tentative. A) Modeling / Visualization B) Management of Geometry and Parameters C) Dose Calculation D) Analysis

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 13 Scope of System Component (1) Modeling / Visualization  I/O of image data  Interface with CT-system and image servers  Visualization of image data  Image processing in medical use automatic detection of organs editing CT-values modeling of human body production of DRR (Digitally Reconstructed Radiograph)  (Graphical) user interface

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 14 Scope of System Component (2) Management of Geometry and Parameters  I/O and management of geometry and parameters beam line parameters and (Geant4) geometry information of patients  converted from CT images to a suitable for planning (e.g. Geant4 geometry)  Calculation and management of parameters of instruments forming exposure area collimators/filters interface with CAD/CAM system  (Graphical) user interface

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 15 Scope of System Component (3) Dose Calculation / Analysis  Dose Calculation Dose calculation engine  non-MC base code  MC code (e.g. Geant4) Scoring (Tally) package  Analysis Analysis (histogramming) package Interface with visualization of result (Graphical) user interface

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 16 Description of Use-cases  Items in each use-case Identifier Goals in Context Scope  System / Sub-system / Component  as Black Box / White Box Level  Summary / User-goal / Function (according to abstraction level) Actors Pre-condition Guarantees Scenario Extensions  branches for main scinario  alternatives in cases of failure  variations of what to do for main scenario Technology and Data Variation  variations of how to do for main scenario Notes

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 17 Documentation of Use-Case  We ’ ve made documentation for higher level of use-cases. 1 summary level of use-case and 4 user-goal level of use-cases for sub-systems  Use-Case: Planning radiation treatment Making treatment plan with treatment planning system. summary (top) level scope : radiation treatment planning system  sub-systems are used as black boxes.

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 18 User-goal level of Use-Cases (1)  Input of treatment information Scope : Visualization / Modeling (White Box) Processing CT image of a patient and setting information of treatment  Input of exposure condition Scope: Management of geometry and parameters (WB) Setting exposure condition of the system  beam line parameters  exposed dose

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 19 User-goal level Use-Cases (2)  Calculation of parameters of instruments Scope: Management of geometry and parameters (WB) Calculating parameters of instruments forming exposed area  ridge filter  range shifter  bolus  MLF (Multi Leaf Collimator)  Calculation of Dose Distribution Scope : Dose Calculation (WB) Calculating dose distribution in ROI under the given condition

8/Mar./041st Workshopon the Italy-Japan Collaboration on Geant4 Medical Application 20 Future Direction  Collecting Use-Cases for as many facility / system of treatment planning system as possible  Documentation of Use-Cases  Breaking down to well-defined sub- systems  Finding components which can be shared between different system.  Picking up requirements