Diapositiva 1

REAL-TIME MODEL FOR ADAPTIVE RADIATION THERAPY: A BIOMECHANICAL APPROACH USING A LEGO MINDSTORMSGabriele GUIDI Medical Physicist Medical Physics Dpt, University Hospital Policlinico, MO

N Maffei, C Vecchi, G BaldazziPhysics Dpt, University of Bologna

G M Mistretta, A Ciarmatori, T CostiMedical Physics Dpt, University Hospital Policlinico, Modena

DisclosuresNo conflicts of interest to disclose

Co-Funding: Italian Ministry of Health (MoH2010, GR-2010-2318757)Dose warping methods for IGRT and AdaptiveRT: dose accumulation based on organ motion and anatomical variations of the patients during radiation therapy treatments

Tecnologie Avanzate S.r.l. (Italy): Co-Partner of MoH2010, GR-2010-2318757

NO CONFLICTS OF INTEREST TO DISCLOSE

Adaptive Radiation Therapy (ART) is a state-of-the-art approach that uses a feedback process to account for patient-specific anatomic and/or biological changes, thus, delivering highly individualized radiation therapy for cancer patients.Needs for Clinical Practice:Image Guided SystemFast Re-ContouringFast Re-calculationTools for Real-Time QA or SimulationPredictive Tools for Biomechanical Approach [Malone 2014] Malone C, Rock L, Skourou C, Efficacy evaluation of retrospectively applying the Varian normal breathing predictive filter for volume definition and artifact reduction in 4D CT lung patients, Journal of Applied Clinical Medical Physics, vol 15, num 3.What is Available?Daily Setup Images (e.g. MVCT/kVCT)Automatic PTV/OARs contouring DIR and/or Warping methodsHybrid deformable algorithmsDose Accumulation algorithmWorkflow automation (Scripting, GPU, Cluster, iCloud)Tracking/Robotic Systems (e.g.VisionRT, CyberKnife, ExaPot, X-Ray)Predictive analysisNeural NetworksBayesian Network validation

ADAPTIVE RADIATION THERAPYMissing?

XRayXRay

Tracking

WHAT IS THE PROBLEM?BREATHINGMOTIONApproximate localization of TUMOR & OARWith 4DCT and/or Gating SystemBreathing PhaseReconstruction With Standard CT(Mean Object Positions)Correlation between External & Internal Motion ??

4DCTBreathing MotionContour GTV Spatial-time position4D function correlate to BPM

Simulate irregular BREATHING + GTV spatial positions phases

Vision RTAim:BIOMECHANICAL APPROACH

InfraRed /UltraSound SENSOR8 RIBs with 4 angular speedPrototype LINAC 2 TUMOR with 4 DOFEV3 BRICK: Linux wireless CPU, LabVIEW programmable

30 cm24 cm[Jeong 2011] Jeong H S, Han Y, Kum O et al., Development And Evaluation of a Phantom for Multi-purpose Dosimetry in IMRT, Nuclear Engineering And Technology, Vol.43 No.4 , 2011.REAL-TIME ROBOT

Freedom offered by building bricks

Low-cost/home-made solution

Pediatric scale

Plastic materials avoid artifacts

Complete versatility with LabVIEW dedicated software [Cruz-Martn 2012] Cruz-Martn A, Fernndez-Madrigal J A, Galindo C et al., A LEGO Mindstorms NXT approach for teaching at Data Acquisition, Control Systems Engineering and Real-Time Systems undergraduate courses, Computers & Education 59 (2012) 974988.

ADVANTAGES FROM LEGO APPROACH

Human 4D simulation reproducible

4DCT, MESH RECONSTRUCTION AND OBJECT TRACKING/CONTOURING

Quasar phantom, interfaced with VisionRT software, reproduces BPM Through sensors, the ROBOT emulates in real-time patients breathing motion

BREATHING REAL-TIME SIMULATION

4D Breathing SimulationTracking Tumor Simulation

(12 BPM)

[Castillo 2014] Castillo S J, Castillo R, Balter P, et al., Assessment of a quantitative metric for 4D CT artifact evaluation by observer consensus, Journal of Applied Clinical Medical Physics, vol 15, num 3. PRELIMINARY RESULTS

PROTOTYPE TARGET MOTION SIMULATION vs. 4DCT ACQUISITION

We can move and reproduce the 4D motion using surrogate signals 4D Motion QA (Quality Assurance) and biomechanical analysis is feasible

Organ motion and deformation can lead divergence of treatments compared to the initial constraints

Standard CT freeze images of Tumor and OARAn anthropomorphic phantom can simulate the human physiology to follow and predict changes in morpho-dosimetry using external surrogate

4DCT allows to follow dynamics parameters of breathing (spatial time localization)CONCLUSIONSLEGO MINDSTOMRS can help to prototype idea and make some experimental with low cost

Adaptive Radiation Therapy for LUNG disease requires adequate representation of the anatomical ROI for a correct calculation of the amount of dose delivered

A correlation between internal organ motion and the breathing sinogram is fundamental

Creation of real models in conjunction with predictive analysis could increase accuracy of treatments and ensuring that dose distributions are aligned with therapeutic targets

Internal External correlation can be investigated using surrogate and anthropomorphic phantom (or using LEGO solutions)TAKE HOME MESSAGE

GR-2010-2318757 - G.Guidi - 2010 Ricerca Finalizzata e Giovani Ricercatori - Ministero della Salute

Thats too much!!!(Praha 2009 : Tomotherapy Meeting)THANK YOU FOR YOUR ATTENTION

ACKNOWLEDGE

14

Suggestions Questions?MOST VALUABLE? ..RESEARCH TEAM