Undue Exposure to Ionizing Radiation Presentation to Alabama Hospital Association Oct 16, 2018 Jim Duncan, MD PhD FSIR Vice Chair for Quality and Safety Mallinckrodt Institute of Radiology Washington University in St Louis
Objectives By the end of this presentation, participants will: List three causes for undue exposure Studies/Illness; Images/Study; Dose/Image Describe two risks of undue exposure Carcinogenesis; Skin burns List new requirements regarding ionizing radiation Oversight of CT and fluoro
3 Common Scenario Your son or daughter falls Visible contusion Screaming uncontrollably What do you do? As a father who happened to be a radiology resident I drove my son frantically to the ER Jonathan needs an urgent head CT St Louis Children s Hospital ER They recommended watch and wait I must admit that I felt a bit cheated
Meet Jonathan Duncan Jonathan did not have a serious head injury but each year more young children visit the ER for head trauma CDC Data https://www.cdc.gov/traumaticbraininjury/data/rates_ed_byage.html
Meet Morgan* Previously healthy 11yr old girl with RLQ pain, R/O appy CT abdomen and pelvis (instead of an ultrasound exam) 3.7mm noncalcified nodule unknown malignant potential recommend followup CT without and with contrast Followup Chest CT 3.7mm noncalcified nodule, recommend further followup Referred to Interv Radiology for needle biopsy Original CT One month later *Not her real name
How Can We Improve Medical Imaging? Imaging provides tremendous benefit Live-saving technologies, clear utility However benefits are accompanied by risks Possible to preserve benefits while reducing risks Optimization is the goal Radiation exposure Financial burden Incidental findings
Optimizing Radiation Exposure from Medical Imaging
Ionizing Radiation Damages DNA* Measuring the damage** Collected blood samples after CT scans Stained lymphocytes for histone complex associated with DNA double-strand breaks (DNA-DSBs) Linear relationship between double strand breaks and dose Except head CT where bone serves as a shield *BEIR VII Report, National Academies Press(2006) Lobrich et al, PNAS 102:8984 (2005)
DNA Damage Response Two pathways: Cell death vs repair* Cells with multiple damaged sites (high dose) cell death Cells with few damaged sites (low dose) repair Balter et al Radiology 254:326 (2010)
Visible Injuries Attracted Attention Mad River, 2 yr old receives 151 CT Scans Cedars-Sinai & Huntsville CT Perfusion Skin injuries from fluoro procedures https://www.nytimes.com/2009/10/16/us/16radiation.html https://www.nytimes.com/2010/08/01/health/01radiation.html Balter et al Radiology 254:326 (2010)
Cancer Risk Caused by Errors during DNA Repair Surviving cells attempt to repair the DNA double strand breaks Repair frequently leads to changes in the underlying base sequence* The accumulation of these mutations ( information scars ) can lead to neoplastic transformation** *Chang, Pannunzio, Adachi and Lieber, Nature Reviews: Mol Cell Biol 18:495 (2017); Duncan, Lieber, Adachi and Wahl J Nucl Med 59:1014 (2018) **Martincorena and Campbell Science 349:1483 (2015); Behjati et al Nature Comm 7:12605 (2016)
Balancing Risks vs Benefits of Imaging Diagnosis please: What does this image show? Beta et al J Vasc Interv Radiol 20:769 (2009)
Optimizing the Balance Sigmoidal benefit model where more imaging data does not automatically increase the probability of the desired clinical result. Need to center the curve on the sweet spot and minimize unnecessary variation Duncan & Evens JAMA 301:2383 (2009)
Three Opportunities to Improve More Studies/Lifetime than necessary Imaging instead of observation for minor head trauma Analog: Giving antibiotics for viral infections More Images/study than necessary Dual phase (without/with contrast) CT scans when single phase is enough or repeat runs during fluoro procedures Analog: Multiple different antibiotics when single agent is sufficient More Dose/Image than necessary Pediatric CTs done using adult settings, high dose fluoro imaging Analog: Children receiving adult doses of antibiotics
Dose Budget Part 1: Studies per Lifetime Overuse of CT Head CTs for children with minor head trauma Alternative is observation Abdominal CTs for possible appendicitis For children, the alternative is ultrasound Chest CTs with low likelihood of pulm embolism Focus instead on alternative diagnosis
Dose Budget Part 2: Images per Study No free lunch, there is a cost to collecting data More pixels more dose More images more dose Multiple scans of the same region Dual or combination CT scans Without then with IV contrast Double the radiation dose Minimal improvement in Dx accuracy Z-Axis overscanning Top/bottom of CTs for Abd/Pelvis Extra runs during fluoro procedures
Dual Chest CTs in Alabama Medicare outpts Data from CMS Hospital Compare Rates typically <2% Improvement options Protocol review Removing without and with Chest CTs from your list of orderable exams Discussions with referring providers https://fusiontables.google.com/datasource?docid=1rihy1hk AbvvDGjgAryhJebm5LPW2cOzfcXX0XaoO#map:id=3
Dose Budget Part 3: Dose per Image Greenwood et al Radiographics 35:1539 (2015) Image utility rather than image quality Dose budget: Dose/Image x Images/exam x Exams/illness 2.4 microgy at detector 0.24 microgy at detector
Increasing Interest from Regulators Joint Commission New CT requirements: Issued 2013, Effective 2015 New fluoro requirements: Issued 2018, Effective 2019 CMS Partnership for Patients: Ionizing Radiation Standards of Practice: Medical Imaging Clinical Decision Support: Medical Imaging
Jt Commission Requirements CT (July 2015) Monitor dose Review protocols, establish expected ranges Pediatric protocols (dose/image) Review cases that exceed expected range Training Fluoroscopic Procedures* (Jan 2019) Monitor dose Establish expected ranges Review cases that exceed expected range Annual training for anyone who activates fluoro unit *Am Hosp Assoc Webinar (Sept 2018) http://www.healthforum.com/connect/events/518000545
Changing Dose/Image: Pediatric CT Protocols Groundwork Image Gently, installing dose monitoring software, Governing council Step 1: Burning platform July 2015 Jt Commission deadline Step 2: Getting data All CT scanners throughout the system to sending data by Jan 2015 Step 3: Data analysis Use of a pediatric CT protocols identified by protocols that contained a _peds suffix BJC Healthcare 11 Hospital System 5 staffed by academic radiology 6 staffed by private practices
Results McKinstry et al IHI/BMJ Conf Proceedings Pg 234 (2018) https://drive.google.com/file/d/15jxoblipwuo9pg3 Je1ITIQBCeN0XRF/view
Impact of Peds CT Protocols
Peds CT Protocols Summary Importance of collecting and analyzing data Data and its analysis transforms the conversation If we have data, let s look at the data. If all we have are opinions, let s go with mine Jim Barksdale, CEO of Netscape In God we trust, all others bring data W. Edwards Deming Governing body Change management Extension agents who bridge the gap between the conference rooms and frontlines
Fluoroscopic Procedures Dose monitoring Started with manual data entry (2008) Promoted situational awareness (techs & MDs) Additional work for high dose cases First > 60min fluoro time, later >5Gy K a,r ) Std text entered into radiology reports Informational brochure for patients Describes possible skin changes Drawing to indicate region of concern Follow-up and event report Switched to electronic data capture (2011) NCRP Report 168 (2015) Duncan et al J Am Col Radiol 12:617 (2015)
Implemented Low Dose Fluoro Protocols Duncan et al J Am Col Radiol 10:847 (2013)
Summary: Possible Immediate Actions* Start capturing data Dose metrics via manual or electronic Data analysis Start with head CTs: high volume, standardized exam, plot DLP vs age Fluoro procedures: >60 min fluoro time and 5Gy Default settings Low dose protocols: pediatric CTs, fluoro procedures Chest CTs without and with contrast Remove from list of orderables or require approval Minor head trauma in children Post & then track adherence to established decision aids (PECARN**) *What can we do by next Tuesday? (Shamelessly stolen from IHI) **Kupperman et al Lancet 374:1160 (2009)
Summary Undue exposure to radiation Clear need to improve Esp for children Improvement is possible Hierarchy of dose budgets Dose/image, images/study, studies/illness or lifetime Tools for improvement Measurement Transparency Extension agents Default settings