LUND UNIVERSITY QA procedures needed for advanced RT techniques and its impact in treatment outcome Tommy Knöös Sven ÅJ Bäck, Hunor Benedek, Per Wendel, Börje Blad Skåne University Hospital and Lund University (with a little help from our friends…) 1 LUND UNIVERSITY Introduction Varian Elekta Accuray TomoTherapy (6 TrueBeams 2013-2014, C-RAD Catalyst) = 12 Linacs 2 QA-Workflow? LUND UNIVERSITY Patient safety first Each individual employee shall help to ensure the patient safety culture 3 LUND UNIVERSITY QA/Patient Safety 4 LUND UNIVERSITY Reason’s Swiss cheese model of failure propagation Successive layers of defences, barriers, and safe guards Some holes due to active failures Chart checks Commissioning, benchmarking QA, PMI etc In-vivo dosimetry/EPID/IMRT QC Other holes due to latent conditions 5 When holes line up an error will occur! LUND UNIVERSITY Some recent publications… NORDSTRÖM, F (2012): Quality Assurance in Radiotherapy: Development and evaluation of new tools for improved patient safety in external beam therapy. PhD Thesis, Lund University, Malmö NORDSTRÖM F, AF WETTERSTEDT S, JOHNSSON S, CEBERG C & BÄCK SÅJ (2012): Control chart analysis of data from a multicenter monitor unit verification study. Radiother Oncol, 102: 364-370 NORDSTRÖM F, CEBERG C, BÄCK SÅJ (2012): Ensuring the integrity of treatment parameters throughout the radiotherapy process Radiother Oncol doi:10.1016/j.radonc.2012.01.004 6 LUND UNIVERSITY Evolution/principles 1994 2014 http://curiousphotos.blogspot.co.at/ Increased complexity... 7 LUND UNIVERSITY Increased complexity... 8 LUND UNIVERSITY Increased complexity... • Conventional QC introduce a false security? Catch the big elephants? • Patients are 3D/4D? QA methods? • Complementary methods, conventional/new Nordström, PhD thesis, Lund University, 2012 • End to end tests «E2E» • (Legal aspects, Sweden, France…) 9 LUND UNIVERSITY New results 2013-2014 (eg.) InterPlay effects TomoTherapy and motion Polymer gel and MRI Ljusberg, MSc thesis, Lund University, 2013 z α 10 From the workshop on “Setting the scene for the next decade” organised by IAEA/WHO 2012 From the Summery and Conclusion by W Hendee (Editor of Med Physics) T Knöös NKI-AVL: in vivo EPID dosimetry by back-projection - 3D approach 1) calculate plan 2) measure EPID dose 3) reconstruct dose in many planes for all gantry angles 4) compare plan and reconstructed patient dose patient (CT) With courtesy of B Mijnheer T Knöös 3D in vivo dose reconstruction • 5-field IMRT prostate cancer treatment • 18 MV beam • 3D g-evaluation with criteria: • 3% of dose at isoc. and 3 mm DTA CT Abs. dose With courtesy of B Mijnheer γ-index T Knöös LUND UNIVERSITY Patient Safety or Clinical Outcome? 14 H & N study Overall Survival Eight hundred sixty-one patients were accrued from 89 sites in 16 countries TROG 02.02 HeadSTART Richins et al J Clin Oncol 2010 Peters et al J Clin Oncol 2010 T Knöös H & N Study Loco-regional Failure TROG 02.02 HeadSTART Richins et al J Clin Oncol 2010 Peters et al J Clin Oncol 2010 T Knöös 2012 “These QA data stemming from prospective clinical trials show undisputedly that non adherence to protocol specified RT requirements is associated with reduced survival, local control and potentially increased toxicity.” T Knöös 2012 “These QA data stemming from prospective clinical trials show undisputedly that non adherence to protocol specified RT requirements is associated with reduced survival, local control and potentially increased toxicity.” Quality Improves Patient Safety T Knöös 19 One of the goals of Quality Assurance in Radiotherapy (QART) is to reduce the variability and uncertainties related to treatment planning and delivery. Seminarium 17/10 T Knöös Barriers (Defence in Depth)  Multiple barriers or QC to ensure that any errors are detected and corrected before initiating therapy.  Many barriers, however, is dependent on human judgement and interpretations which makes them sensitive to individual variations and temporary conditions. T Knöös Varian Daily Profiles MU/Gy MLC dynamic Monthly MLC dynamic Annually MU/Gy Energy Energy MU/Gy Profiles Elekta Daily MU/Gy Energy Profiles Monthly Biweekly MLC dynamic Annually MU/Gy Energy MU/Gy Energy Energy Profiles Profiles Tomo Daily MU/Gy Energy Air scan, calibrating detector Monthly Biweekly Quarterly Annually Energy MU/Gy MVCT, HU Couch Profiles speed MVCT, Dose Couch Geometry MLC dynamic Energy Profiles MU/Gy After service Planned Service Routine QA (previous slides) Unplanned Service/ repairs QA depending on what repairs, discussion between physicist and engineers Routine QA /parts of Acceptance tests Machine Clinical Daily QA IBA StarTrack • 453 ion chambers • 27x27 cm2 • detector spacing along main axis 5 mm, along diagonals 7 mm. Iso verification MonthlyBiweekly QA MLC tests on EPID Output in polystyrene phantom Energy with extra block Annually QA • • • • Energy Water tank ION chambers / diodes Scanning profiles and PDD Dose determination Profiles MU/ Gy Pre treatment verification (patient specific QA) • For IMRT / VMAT /Tomo • Measurement in phantom geometry Patient QA Machine QA Swedish Society of Radiation Physics Report 2014:1 Acknowledgement Sofie Ceberg Fredrik Nordström Crister Ceberg Annelie Edvardsson (et al.)