Outline. NCRP Scientific Committee 6-2

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Magnitude of Medical Radiation Exposures to US population Mahadevappa Mahesh, MS, PhD, FAAPM.

Morgan Department of Radiology and Radiological Science AAPM Annual Meeting, Houston, TX 2008 Outline

Discussions & Conclusions NCRP Scientific Committee 6-2 Kenneth R.

SC 6-2: Purpose To update NCRP Report 93 published in 1987 Evaluate total effective dose equivalent to

public exposed annually from Medical sources Radon Cosmic and Terrestrial Radiation Consumer Products and

NCRP SC 6-2: Radiation Exposure of U.S. population Dennis M. Quinn - Chairman Kenneth L.

1 Magnitude of Medical Radiation Exposures to US population Mahadevappa Mahesh, MS, PhD, FAAPM. Assistant Professor of Radiology & Cardiology Chief Physicist - Johns Hopkins Hospital The Russell H. Morgan Department of Radiology and Radiological Science AAPM Annual Meeting, Houston, TX 2008 Outline Purpose and Goals of NCRP SC 6-2 Data Sources & Results* How should regulatory agencies react? Discussions & Conclusions NCRP Scientific Committee 6-2 Kenneth R. Kase - Chairman Subcommittees: Industrial Exposures Occupational exposures Medical Patient Exposures NCRP SC 6-2: Purpose To update NCRP Report 93 published in 1987 Evaluate total effective dose equivalent to members of U.S. public exposed annually from Medical sources Radon Cosmic and Terrestrial Radiation Consumer Products and Other Radiation Sources (occupational, nuclear fuel cycle, radioactive fallout and miscellaneous sources) NCRP SC 6-2: Radiation Exposure of U.S. population Dennis M. Quinn - Chairman Kenneth L. Miller - Chairman Medical Bruce Thomadsen - Chairman Natural Background Radiation Consumer Products and Miscellaneous Sources Occupational Published in 1987 Daniel J. Strom - Chairman Orhan H. Suleiman - Chairman Natural Technologically enhanced New report expected to be published in 2008

NCRP Report 93*: Annual effective dose equivalent to US population circa 1980-82 1987 Purpose 1989 Natural Sources 3.0 msv Radon 2.0 msv Other 1.0 msv Man-made Sources 0.

2 NCRP Report 93*: Annual effective dose equivalent to US population circa Purpose 1989 Natural Sources 3.0 msv Radon 2.0 msv Other 1.0 msv Man-made Sources 0.6 msv Occupational, Consumer products, nuclear fuel cycle and other miscellaneous products 0.07 msv Medical 0.53 msv X-rays 0.39 msv Nuclear Medicine 0.14 msv Natural 82% Man-made 18% * Published in 1987 To update NCRP Report 93 published in 1987 and NCRP report 100 published in 1989 Last major medical data used in NCRP Report No. 93 are from 1982 or earlier Evaluate the current total effective dose to members of U.S. public exposed annually from Medical Radiation Exposures NCRP SC 6-2: Medical Subgroup Members Chairperson: B. Thomadsen,University of Wisconsin M. Bhargavan D. Gilley J. Gray J. Lipoti M. Mahesh J. McCrohan F. Mettler T. Yoshizumi M. Rosenstein K. Kase American College of Radiology State of Florida DIQUAD, LLC State of New Jersey Johns Hopkins University US FDA Univ of New Mexico VA Duke University Scientific NCRP Consultant Stanford SC 6-2 Chair Goals Estimate current radiation exposure to US population Number and types of medical procedures Effective radiation dose per procedure Examine past and future trends of medical exposures Modalities Radiography, Fluoroscopy, Mammography, Dental Interventional CT Nuclear Medicine Radiation Therapy Methods Collective doses estimated independently for each modality Modality groups: CT, Nuclear medicine, Radiography & Fluoroscopy, Mammography, Interventional, Dental, Chiropractic Radiology, Bone Densitometry, and Radiation Therapy Procedures within each modality categorized by body part or organ system Assumptions Benefit exceeds risk: Issue not examined in this report Data sources: Multiple data sets Incomplete data sets required assumptions and cross checking between data sets Weighting Factors: Used ICRP 60 (1990). Past reports used older ICRP 26 (1977) and new factors are suggested

Modalities & procedures considered in the report Computed Tomography (CT) Nuclear Medicine Procedures Radiography and Fluoroscopy Interventional Radiography Mammography Dental and Chiropractic Bone

3 Modalities & procedures considered in the report Computed Tomography (CT) Nuclear Medicine Procedures Radiography and Fluoroscopy Interventional Radiography Mammography Dental and Chiropractic Bone Densitometry Radiation Therapy Major and minor data sources Commercial (IMV Benchmark) Medicare payment data ( ) VA Health Care System Claims data from large national employer plan US FDA CRCPD State radiation programs Large hospitals American College of Radiology Literature IMV Benchmark Reports Based on responses from hospitals and estimated to identified universe of US hospitals (~7000) Surveys had high response rates (~60%) Reports used: CT, nuclear medicine, cardiac catheterization, radiography-fluoroscopy, angiography, mammography, PET and radiation therapy Reports between Data includes all ages Medicare Payment Data Claims data for Medicare fee-for-service enrollees Summarized procedure counts for each modality and sorted by Common Procedure Coding System (HCPCS) Common Procedural Terminology (CPT) code 100% medical claims from Accounts for nearly 40 million enrollees Mainly covers persons >65 years old and disabled Represents one-third of all utilization and one-seventh of US population Veterans Administration (VA) Procedure counts available for Grouped by HCPCS-CPT, patient age and gender Summarized data for used for comparisons 4 to 7 million enrollees, mostly male Women and children under-represented Large National Employer Program (LNEP) Claims data available for 2003 Data summarized by modality and body part 4 millions nationally distributed All ages and gender included Data used for spot-check distributions of procedures for certain modalities

Data: Reconciliations and Limitations Results Procedure counts and distribution from IMV reports Distribution of

available on volumes of chiropractic and dental imaging Computed Tomography (CT) Annual growth over 1993-2006: CT

correlated to nearly 7649 hospitals in US Pediatric CT ~ 8-10% of total procedures Number of CT procedures in US

4 Data: Reconciliations and Limitations Results Procedure counts and distribution from IMV reports Distribution of procedure counts across body part or organ system was matched with data from other data sources Limited data available on volumes of chiropractic and dental imaging Computed Tomography (CT) Annual growth over : CT Procedures > 10% vs US population < 1% Computed Tomography Nearly 67 million CT procedures in US in 2006 Data correlated to nearly 7649 hospitals in US Pediatric CT ~ 8-10% of total procedures Number of CT procedures in US Categories of CT procedures (62.0 million in 2006) IMV Benchmark Report on CT, 2006 HCAP: ~80% of all CT procedures IMV 2006

Distribution Pattern of CT Scanners in US* CT scans of Abdomen and

population >55 years, receives >55% of CT scans * LNEP 2003

Number (millions) % Collective dose Person Sv % Head 19.

4 38 254,000 58.0 Extremity 3.5 5 500 0.1 CT Angiogram 4.

4 TOTAL 67 438,000 Collective dose Effective dose per person from CT

46 msv Preliminary results not yet reviewed and approved by NCRP

Council Radiation dose from CT: Then (1980) and Now (2006) According

5 Distribution Pattern of CT Scanners in US* CT scans of Abdomen and Pelvis Exam distribution vs US Population* IMV 2006 ~ 20% of population >55 years, receives >55% of CT scans * LNEP 2003 Preliminary Results for CT (2006) CT: Procedures vs Collective Dose Number (millions) % Collective dose Person Sv % Head , Chest , Abd/Pelvis , Extremity CT Angiogram , % Miscellaneous , TOTAL ,000 Collective dose Effective dose per person from CT ~438,000 person Sv ~1.46 msv Preliminary results not yet reviewed and approved by NCRP Council Preliminary results not yet reviewed and approved by NCRP Council Radiation dose from CT: Then (1980) and Now (2006) According to NCRP report 100 Collective dose for CT 3,700 person Sv According to current estimations Collective dose for CT Effective dose per capita 440,000 person Sv ~1.5 msv and some radiation exposure

Nuclear Medicine Nuclear Medicine Annual growth over 1993-2005: Nuclear Medicine Procedures > 5% vs US population < 1%

increases in cardiac procedures 1% in 1973 to 57% in 2005 Number of nuclear medicine procedures in US Type of Nuclear

Results for Nuclear Medicine (2005) Procedures by categories (%) Collective dose Effective dose per person Collective dose

1 Thyroid < 0.1 <2 400 0.2 Lung 0.74 4 2,000 0.9 Cardiac 9.80 57 188,000 85.2 GI 1.21 7 3,500 1.6 Renal 0.47 3 650 0.

6 Nuclear Medicine Nuclear Medicine Annual growth over : Nuclear Medicine Procedures > 5% vs US population < 1% Nearly 17 million nuclear medicine procedures in US in 2005 Data correlated to nearly 7200 hospitals in US Largest increases in cardiac procedures 1% in 1973 to 57% in 2005 Number of nuclear medicine procedures in US Type of Nuclear Medicine Procedures IMV Benchmark Report on NM, 2005 IMV 2005 Nuclear Medicine: Procedures vs Collective Dose Preliminary Results for Nuclear Medicine (2005) Procedures by categories (%) Collective dose Effective dose per person Collective dose by categories (%) ~231,000 person Sv ~0.80 msv Number millions % Collective dose Person Sv Brain <0.1 < Thyroid < 0.1 < Lung , Cardiac , GI , Renal Bone , Infection , Tumor , Total ,500 % Preliminary results not yet reviewed and approved by NCRP Council

Radiation doses from Nuclear Medicine: Then (1980) and Now (2006) According to NCRP report 100 Collective dose for Nuclear

80 msv 32,000 person Sv 231,000 person Sv Radiography & Fluoroscopy Radiography & Fluoroscopy Radiography: Procedures vs

radiographic procedures, bone densitometry & certain fluoroscopy procedures Limited data available for dental and chiropractic

30 msv Preliminary results not yet reviewed and approved by NCRP Council Radiation dose from conventional radiography and

7 Radiation doses from Nuclear Medicine: Then (1980) and Now (2006) According to NCRP report 100 Collective dose for Nuclear Medicine According to current estimations Collective dose for Nuclear Medicine Effective dose per capita ~0.80 msv 32,000 person Sv 231,000 person Sv Radiography & Fluoroscopy Radiography & Fluoroscopy Radiography: Procedures vs Collective Dose Procedures by categories (%) Collective dose by categories (%) Data includes mammography, dental, chiropractic radiographic procedures, bone densitometry & certain fluoroscopy procedures Limited data available for dental and chiropractic procedures Collective dose Effective dose per person from Radiography ~98,000 person Sv ~0.30 msv Preliminary results not yet reviewed and approved by NCRP Council Radiation dose from conventional radiography and fluoroscopy: Then (1980) and Now (2006) According to NCRP report 100 Collective dose 71,000 person Sv According to current estimations Collective dose 98,000 person Sv Effective dose per capita ~0.32 msv Interventional

Interventional Fluoroscopy Procedures considered Non-coronary angiography diagnostic and therapeutic procedures Cardiac catheterization procedures Other interventional fluoroscopy procedures such as

catheterization Other interventional fluoroscopy Number (millions) % Collective dose Person Sv 1.7 10 12,900 10 1.4 9 21,930 17 4.6 28 63,210 49 9.0 53 30,960 24 TOTAL 16.

Therapy Collective dose Effective dose per person ~129,000 person Sv ~0.

8 Interventional Fluoroscopy Procedures considered Non-coronary angiography diagnostic and therapeutic procedures Cardiac catheterization procedures Other interventional fluoroscopy procedures such as ERCP, Urinary studies, Effective dose estimations varies by order of magnitude Preliminary Results for Interventional Procedures Non-coronary diagnostic Non-coronary therapeutic Cardiac catheterization Other interventional fluoroscopy Number (millions) % Collective dose Person Sv , , , , TOTAL ,000 % Preliminary results not yet reviewed and approved by NCRP Council Interventional: Procedures vs Collective Dose Procedures by categories (%) Collective dose by categories (%) Radiation Therapy Collective dose Effective dose per person ~129,000 person Sv ~0.4 msv Preliminary results not yet reviewed and approved by NCRP Council Radiation Therapy Different source of exposure to population than other medical exposures Form of risks are different from diagnostic applications Concern for failure of function of target organ due to high dose Likelihood of secondary cancer Even though data on number of radiation therapy procedures are available, the dose delivered varies widely and often unknown Uncertainty in estimating an average dose is very high, therefore not included in final estimation of radiation exposure to US population Modalities Preliminary Results* Number Procedures % Collective dose (Person-Sv) % Per capita (msv) CT 67 million , Nuclear Medicine Radiography & Fluoroscopy 18 million 4 231, million 76 99, Interventional 17 million 4 129, Total ~426 million 899,000 ~3.0 *NCRP SC 6-2

Procedures vs Effective dose contributions Percent Procedures Effective Dose Contributions Effective dose per capita from medical radiation exposure is ~ 3.

54 msv per capita According to current estimations Collective dose Effective dose 899,000 person Sv 3.

9 Procedures vs Effective dose contributions Percent Procedures Effective Dose Contributions Effective dose per capita from medical radiation exposure is ~ 3.0 msv Radiation dose from Medical Exposure: Then (1980) and Now (2006) According to NCRP report 93 Collective dose 123,000 person Sv Effective dose 0.54 msv per capita According to current estimations Collective dose Effective dose 899,000 person Sv 3.0 msv per capita * Includes mammography & dental procedures Results not yet reviewed and approved by NCRP Council NCRP SC 6-2 Preliminary Results*: Medical Radiation Exposure to US population Per capita radiation dose has increased ~ 500% Radiation exposure to US population from all sources The new pie chart! US 1982 (NCRP 93) US msv x 5.5 = 3.0mSv 3.2 msv Medical 0.54 msv per capita Total 3.6 msv per capita Medical 3.0 msv per capita Total 6.25 msv per capita CT contribution ~1.5 msv * These results have not been reviewed and approved by Council Not to be disseminated or referenced These results have not been reviewed and approved by NCRP Council Not to be disseminated or referenced Discussions Results are snapshots, however, provides insight regarding current and future trends Doses for procedures are averages and individual doses may vary by a factor of 3-20 Final report expected in 2008 Probable causes for increase in medical exposures Advances in medical technology Demand of improved patient care Challenges in early diagnosis Demand for improved temporal and spatial resolution Easy to use - Out of the box solution, for ex: CT Accessibility Emergency Rooms - Outpatient - Doctor s offices - Economics in medical imaging

10 Benefits from Medical Imaging Benefits outweighs the risks! Early diagnosis have led to Increase in life expectancy Decrease in deaths due to cancers, cardiovascular and other diseases Decreases in childhood mortality - not only in US but globally - due to early diagnosis What should we do? Aware of risks of radiation when ordering x-ray based examinations Essential to use most accurate information when making risk benefit decisions Often risks are either underestimated or massively overestimated Well-informed investigative decisions are key! Are more regulations required Yes & No Yes, Appropriate regulations are required to hinder/stop misuse of medical x-ray technology Yes, appropriate regulations are required to ensure x-ray technology is operated at optimal settings with proper QA in place and only qualified individuals operates/uses the technology No, should not curb the development of new technology or protocols or stop clinicians from finding new ways to better care for their patients What can we do? Examine radiation doses for different procedures Identify and optimize factors contributing towards radiation doses Image quality should not be jeopardized when reducing dose Management of radiation dose is key! Effective doses in CT procedures* Computed Tomography * Mettler, Huda, Yoshizumi and Mahesh, Radiology, July 2008

Many patients have more than one CT examination 2002 2003 2004 2004 2005 Sinus CT in Post Bone Marrow Transplant Pediatric Patients Table 1: Number of CT scans performed for various age groups along

2 2 to 5 19 3.8 2 13 16.9 8.8 57.2 6 to 10 10 3.4 2 6 11.2 6.6 19.8 11 to 15 15 3.1 2 7 7.8 5 17.5 16 and above 16 3 2 6 6.6 4.4 13.

11 Many patients have more than one CT examination Sinus CT in Post Bone Marrow Transplant Pediatric Patients Table 1: Number of CT scans performed for various age groups along with the average and range of effective dose estimation. No. of CT scans Effective dose (msv) Age group No of patients Average Minimum Maximum Average Minimum Maximum 0 to to to to and above Radiation Dose Report for a CTA Procedure Recommendations to reduce radiation risk from CT Total effective dose (msv) Effective dose (msv) 2.4 msv 1.0 msv 18.3 msv 21.7 msv Optimize CT settings Reduce tube current (ma) Use dose modulation techniques Increase pitch Reduce number of multiple scans with contrast material Eliminate inappropriate referrals for CT Adopt Image Gently Campaign for lowering dose General Implications What can we do? Advances in technology leads to increase in protocols With technological advances and optimization, often radiation exposure per exam can decrease For example, digital vs screen-film mammography, 64 vs 4 MDCT However, number of exams performed per patient visit seems to increase For example: As scan time becomes shorter, and more information can be gathered per visit, tendency is to add more exams per visit A chest x-ray may be followed by a chest CT scan and chest CT scan may further include with and without contrast scans Similarly, CT Angiography may be followed by CT Perfusion How many of the medical exams are appropriate? Is educating public regarding radiation exposures better? YES Web - can be a useful tool or a distracting tool Delicate balance necessary - educating versus scaring population about radiation exposures Often when patients ask about their medical exposures, clinic pays special attention regarding their protocol settings

12 Conclusions Advances in medical technology, clinical applications, proliferation of imaging systems and easiness to use and many other factors have contributed to the overall increase in medical radiation exposure Justify appropriateness of x-ray imaging procedure Understanding associated radiation dose and risks are essential to obtain optimal benefit Conclusions Results are snap-shot of radiation exposure to US population from various medical procedures Doses for procedures are averages and individual doses may vary by a factor of 3-20 Benefit exceeds risk - however, this issue is not examined in this report Final report is expected in 2008 Conclusions Overall, medical radiation exposure to US population has increased significantly from last report Advances in medical technology, clinical applications, proliferation of imaging systems and easiness to use and many other factors have contributed to the overall increase in medical radiation exposure to US population Slice Wars! Past Present - Future Dose Wars!

Ionizing Radiation Exposure of the Population of the United States. David A. Schauer Executive Director

Ionizing Radiation Exposure of the Population of the United States David A. Schauer Executive Director Key Dates in NCRP s s History 1929: U.S. Advisory Committee on X-ray and Radium Protection 1946: U.S.