Mārtiņš Kazāks, PhD Deputy Group Chief Economist Chief Economist in Latvia Swedbank
Michael Gillin, PhD Professor, Chief of Clinical Services ...
Transcript of Michael Gillin, PhD Professor, Chief of Clinical Services ...
Michael Gillin, PhD Professor, Chief of Clinical Services,
Dept. of Radiation Physics
Michael Gillin - Grandfather
My twin 12 month old grandsons, Arthur and Charles, live in Minneapolis.
UT MDACC > 8,000 New Patient Starts in FY 12
Quality Assurance The Dilemma
• It is simply not possible to insure safe and accurate treatments under all circumstances, but it is expected.
• The systems (TPS, EMR, Network, and treatment delivery) are too complex and are ever changing and responsibility is diverse.
• Comprehensive knowledge of the entire process is limited.
• Time is finite and there are multiple priorities. • What takes Physics so long to commission
versus what are the Physics concerns.
The Unexpected Finding: Would we observe it and understand its importance?
The Unexpected Finding: Would we observe it and understand its importance?
Quality Assurance Extra-ordinary Event
Rinecker Proton Center Event • Summary: 15 fractions delivered without
incident. Fraction 16: The entire prescribed dose was delivered in 1 fraction. This was not understood until the next day when the EMR indicated that the prescribed dose had been delivered.
• Could this happen to us? Can systems be established to guard against a unique set of circumstances? The New York Times.
Quality Assurance Extra-ordinary Event
Rinecker Proton Center Event Possible Lessons
• How many FTE’s should be dedicated to testing, monitoring and attempting to defeat systems, e.g. EMR, delivery, institution SW, ( Anderson filter)? UT MDACC ~ 1 to 2% of QMP’s
• How frequently should QMP’s perform end-to-end testing, i.e. image, plan, QA, and treat a phantom, in the Treatment Mode of the Delivery System? Annually per unique delivery system.
Quality Assurance Extra-ordinary Event
Rinecker Proton Center Event Possible Lessons
• Sensitivity – to general comments – efficient use of time?
• Staffing – Is sufficient priority given to reviewing to routine operations
• Training – In-service to review the entire delivery system – Vendor supplied
Radiation Oncology Systems Safe and Accurate
Multi-vendor, integrated, digital, complex delivery systems. Photons: UT MDACC is evolving from one standard
delivery system to different vendors and different systems from the same vendor (HDMLC, Rx couches, different in-room imaging.)
Protons: Scanning beams and scattered beams Comprehensive knowledge of the entire system is quite
limited. QA lags behind the new systems – slowly implementing
Atlas, a DB which is designed to store QA measurements ∞ Number of tasks, including various combinations Limited amount of time, which must be used wisely.
Radiotherapy Risk Profile Technical Manual World Health Organization Quality assurance (QA) in radiotherapy is all procedures that
ensure consistency of the medical prescription, and safe fulfillment of that prescription, as regards to the dose to the target volume, together with minimal dose to normal tissue, minimal exposure of personnel and adequate patient monitoring aimed at determining the end result of the treatment.
WHO 1988 MDACC averages 7 variances per month in the last 6 months,
zero reportable variances, i.e. 7 less than perfect events per month out of > 10,000 possibilities.
Radiation Oncology Systems Safe and Accurate
Informal Survey 12 Medical Physicists What are the most important safety questions for patient
care in radiation oncology at UT MDACC? Training – Human Error – Don’t know what we don’t
know Oncologists, RTTs, Service Techs, Physicists
Interconnectivity and Communication Stability of network, of applications (as SW changes),
multiple groups (Hospital, Rad Onc IT, Physics, Vendors) Limited time
Commissioning, Maintenance, After repair, Treatment Schedule
Unexpected Failure of Some Aspect of the Delivery System Unknown double failure
Reasonably prudent practice: Completely trust the vendor? Test in Treatment Mode
Did Varian get the control system right?
Introduction of New Systems – Education of Users and Vendors
Somewhere there is a linac. Reasonably prudent practice:
Understand the entire system
Vendors have work to do! Elekta has promised a better schematic.
The multi-vendor challenge. Vendor A points to vendor B who points to vendor C, who did not realize there was an issue.
ASTRO – U.S. Perspective
Radiation Oncology Treatment Delivery Systems
CT Simulators – 4 different models of CT simulators Treatment Planning Systems
Photons – Pinnacle Protons – Eclipse HDR (3), PDR (4), Prostate, Eye, etc.
Electronic Medical Record - Mosaiq Treatment Delivery Systems with in-room imaging
Varian linacs (16 units + Gamma Knife) Main Campus 8 in RCCs Hitachi Proton System (4 scattered beam lines + 1 spot beam line)
Digital systems do have internal monitoring functions. Emails from the delivery systems –TrueBeam or Hitachi
sending out emails stating the results of various internal tests?
What version of SW will the device alert the user that some parameter has changed? 2014, 2015, 2016 ?
G3 Scan Beam Weekly Output Checks**
2012 Data • Range Average SD • 30.6 cm 98.5% (1.0) 0.68% • 20.0 cm 93.1% (.94) 0.24%* • 14.0 cm 80.8% (.82) 0.50%*
• * Incorrect baseline data corrected in the
summer 2012 • ** Technique changed from 5/10 phantom to
Tracker Lack automatic processes to collect and analyze this data taken weekly. A great
need is to develop processes to automatically analyze QA data.
Clinical Physics Staffing UT MDACC
Clinical Qualified Medical Physicists - 36 Medical Physicists working towards certification – 6
Total ~42 Physicist Assistants
Main campus – 6 each PTC H - 5 each
Service Personnel Main campus – 8 PTC H - 5
There are other physicists whose primary responsibilities are research, education, RCCs, and RPCs.
Clinical Physics Staffing
~ 1.5 physicist per external beam delivery system PTC H is staffed by a QMP from 7 am until mid-night, 5
days per week PTC H is staffed every Saturday by several QMPs Photons – limited staffing on weekends – weekdays
staffing from 7 AM until 9 PM
~ 1.5 physics support person per external beam delivery system plus support from vendors (Varian, Hitachi, Elekta, etc.)
Clinical Physics Staffing
Estimated QMP Machine QA FTE per delivery system: Protons – 1 FTE per beamline for machine QA
G1 – 16 beams G2 – 23 beams G3 – 94 beams
Photons - 0.1 FTE per linac for machine QA TrueBeam – 3 photon beams and 5 electron beams
Multiple photon systems, one proton system.
IMRT QA Photons
This is basically just a physics service. We do not use this data to identify issues to be addressed.
MDACC Issues: Highly modulated fields, split fields, and couch kicks
IT Staffing Infrastructure IT, Application Physics
Radiation Oncology Mosaiq, InfoSec, Desktop
MDACC Network InfoSec
Vendor Elekta – one on-site person Eclipse – one on-site person
The division of responsibilities between medical devices, infrastructure support, and information security is evolving, as priorities and standards keep changing. There are very different cultures in IT and clinical physics.
Peer Review A Developing Discipline
Peer review within Physics Define expectation of independent physics review
‘Peer’ review within the Radiation Oncology practice Opportunity to review before a new
device/version/procedure is used Executive summary for CQI Committee who must
respond in some fashion.
RPC services
Recent QA Issues Error in Image Association, which appears to be a network
issue with time delays as data is sent to the Server. Confusion in the EMR definition of a fraction, with
potential patient underdose Failure to deliver the entire dose with spot scanning and
with x-rays Custom coding for electron apertures, two years to
implement, due to design and other issues (vendor support)
Appropriate integration of different systems, e.g. TrueBeams with 15 MV, HDMLC, 3 different types of treatment couches, and soon Elekta linacs into one practice.
Off-label use of device without any review
UT MDACC Standards Responsibility for Equipment Quality Control
“The Quality Control Officer is responsible for assuring that all equipment quality control procedures are adhered to, and that appropriate documentation is maintained. The Radiation Treatment Quality Assurance Committee monitors equipment quality control activities and indicator of equipment performance arising from quality control activities.”
Quality Assurance Guidance for Canadian Radiation Treatment Programs, April 3, 2011
TJC requires a Quality Officer for each clinical department, but with different responsibilities, 0.1 FTE.
UT MDACC Standards Quality Control Officer
“A qualified individual is designated as having primary responsibility for assuring that all equipment quality control procedures are adhered to, and that appropriate documentation is maintained. The Quality Control Officer reports to the Organization’s CEO either directly or through the Cancer Program or Organization’s quality committee or equivalent, on matters relating to quality assurance within the Radiation Treatment Program.”
Quality Assurance Guidance for Canadian Radiation Treatment Programs, April 3, 2011
Quality Officer reports independent of the radiation treatment program head. (In the US, radiation safety is structured this way.)
Institution Patient Safety Processes Historically patient safety processes in Radiation
Oncology have been independent of institution wide processes.
This will eventually change at UT MDACC, which is an important step, in my opinion.
Senior radiation oncologist “Mike, we trust you.”
UT MDACC Standards Equipment Quality Control Procedures
“Commissioning of equipment is independently reviewed, and checked with measurement as necessary, by a qualified individual, normally a medical physicist who was not involved in the commissioning process. Commissioning is not considered complete until this independent verification has been performed.” RPC TLD Report is required before the first treatment.
Quality Assurance Guidance for Canadian Radiation Treatment Programs, April 3, 2011
UT MDACC Standards Introduction of New Equipment
“Before new equipment is introduced into clinical service, a complete safety analysis is performed, a quality control procedure is implemented and tested and all personnel involved in the calibration, operation or maintenance of the device are trained in the operation of the device.”
Quality Assurance Guidance for Canadian Radiation Treatment Programs, April 3, 2011
MDACC performs an independent safety analysis and independent safety tests on each new piece of equipment before first clinical use.
Clinical physicists have not been trained to perform complete safety analysis, but are learning.
UT MDACC Standards External Dosimetry Audit
“An independent machine dosimetry audit, available from the Radiological Physics Center (RPC) in Houston, Texas, is conducted on an annual basis. The audit results are reviewed by the Radiation Treatment Program Head, the Radiation Quality Assurance Committee, and the heads of the radiation oncology, medical physics and radiation therapy departments.”
Quality Assurance Guidance for Canadian Radiation Treatment Programs, April 3, 2011
MDACC shares the results of these audits with the physics team leads.
RPC External Audit Results
6 MV Variation + 2% over 6 years
2108
6, 9, and 12 MeV Electrons
Variation + 3% over 6 years 2109
RPC External Audit Protons Spot Scanning Beam
In the middle of a 10 cm x 10 cm x 10 cm volume, maximum range 30.6 cm, uniform dose with 8 mm spot spacing, 1 cGy = 1 MU
TLD/Inst ratio 0.965 to 1.005
RPC Liver Phantom Spot Scanning
Eclipse PTV1 RPC vs Inst 0.93
PTV2 RPC vs Inst 0.95 Not the best agreement – what can be learned from this?
Quality Assurance in Treatment Delivery
• Routine (TG 40, TG 142) – Limited time by QMP – Machine: Daily, Weekly, Monthly, Annual – Patient: Pre-treatment review, end of treatment
review, weekly reviews – After repairs – improvement needed to define
minimum tests after specific repairs • Extra-ordinary – Highly specific issues – Time
consuming – Limited Vendor Support – Aborts during G3 treatments – EMR definition of a fraction
• Commissioning – New versions of SW – Eclipse 1 man year, Pinnacle
0.5 man year (multiple scripts, DICOM changes, etc.) – New systems of HW or SW – EMR multiple
disciplines – 4 to 6 months of testing
Role of QMP Routine QA • Machine
– Define measurements to be done – Analyze measurements - new systems
needed to track measurements. – Make measurements (PA and QMP)
• Patient – Pre-Rx chart review – changes several
percent. Important service – Post-RX chart review – Zero issues identified – Weekly reviews (CMD and QMP) –Not
important, especially with EMR.
MDACC IMRT QA 2012
2012 – performed 3035 IMRT QA Plans 98.7% passed ion chamber tests using a 5% criteria.
Oncologists expect high passing rates.
How valuable is this point dose test? How would oncologists react if physics designed tests
which had a 90 or 95% passing rate with the goal of identifying weaknesses in the system?
Should we be reporting dose to a point or dose to a volume to state the estimated minimum dose,
e.g. the CTV received 85% of the prescribed dose?
IMPT MFO Planning and Patient QA
» Chordoma – 34 yo female
• Three Fields: 70 Gy in 35 Fxs • Field Range(cm) SOBP(cm) Layers Spots MU • LAO 12.57 7.64 27 494 12.59 • RAO 11.97 7.16 33 595 15.89 • Vertex 15.03 5.42 16 637 20.16
Depth Dose Curves
Red diamonds are the Matrixx measurements in plastic water.
Error bars correspond to 2% and 2mm.
There are time constraints which limit the measurements to be made.
RAO FIELD Depth 5 cm
• Gamma analysis for field BRAPB (Gantry = 282o). Upper left pane: measured dose plane; lower left pane: calculated dose plane; upper right pane: isodose line-comparison; lower right pane: gamma index map, 99.5% passes for 2% and 2 mm criteria.
MDACC RPC Photon Phantoms 2011 - 2012 Activities
Lung – SBRT H&N – Segmental and VMAT Prostate – Segmental and VMAT Spine – Segmental Liver – Segmental
All passed national standards.
MDACC RPC Proton Phantoms
• Prostate – Scattered beam June, ’11 Passed – Spot scanned July, ’12 Passed
• Lung – Scattered beam May, ’11 Passed – Spot scanned Jan, ’12 Passed
• H&N – Scattered beam Not irradiated – Scanned beam May,’12 Passed both
SFO an MFO • Spine
– Scattered beam Oct, ’12 Failed retry Spring 13
– Scanned beam Not irradiated Need to do
Patient Safety and Technical QA Strengths
Well defined standards High quality delivery systems
Weaknesses Continuous training on all systems 1% per year of cost? Pay
the vendor to come annually. Complexity of systems and lack of analytic tools Disconnect between therapists and physicists/service – maintain
the schedule, which will keep patients happy vs. fix the unit Opportunities
Better interface with vendors Better systems for analyzing routine data
Threats Groups outside of Radiation Oncology Economic pressures to treat patients
Patient Safety and Technical QA Summary
Radiation Oncology – very complex systems
Regulations/Standards – addressing traditional issues
Limited tools for analyzing the QA results
Difficult to define appropriate tests for the entire process
Comfort in the established routines which provide expected results
Discomfort when different questions or issues are raised, e.g. reviewing risk issues with use of equipment or thinking in terms of dose to volume or robustness of plan.
Arthur and Charles: 10 months old,
Focused on the essentials.
Regulatory Environment In U.S. modest effort
Federal Source tracking FDA devices HIPPA Information Security
State of Texas Radioactive sources, specific limited QA requirements Devices – specific daily, weekly, annual requirements
Atlas summary RPC phantom list – protons and photons RPC output Proton daily check Photon daily check Changes in last 5 years – independent safety
review, exe summaries, greater reliance on RPC phantoms
Risk analysis
Recommendations – recent Processes – new EMR, new TPS, new delivery Environment of Safety
Scanning Beam Energy Absorber Measurements, TPS, EMR
Blank EA AL0 – large snout AM0 – medium snout AS0 – small snout
EA in aperture slot AL67 – large snout AM67 – medium snout AS67 – small snout
EA setting from Eclipse
Only 1 aperture slot is used
Any change in the delivery system, also involves changes in other systems.
Physics Patient Specific Services
External Beam SRS (gamma knife jail) and SBRT IMRT QA, before the first treatment Proton patient QA, especially spot scanning – 2 methods
of determining the MUs.
Brachytherapy Afterloading units, including IOHDR Prostate brachy, eye plaques, misc.