Resident Physics Series ACR Mammography Protocols

Who Regulates Radiation in the United States?

Radioactive Material Regulation Because of their potentially hazardous properties, the use of certain radioactive materials must be closely regulated to protect the health and safety of the public and the environment. Toward that end, the responsibility for licensing and regulating the use and handling of these materials is shared by the following governmental organizations: The U.S. Environmental Protection Agency (EPA) The Food and Drug Administration (FDA) The U.S. Nuclear Regulatory Commission (NRC) State Governments

X-Ray Manufacturer Regulation X-ray imaging systems must comply with radiation safety performance standards in Title 21 Code of Federal Regulations (Subchapter J, Radiological Health) Parts 1010 and 1020: 1010 - Performance standards for electronic products: general 1020.30 - Diagnostic x-ray systems and their major components 1020.31 - Radiographic equipment 1020.32 - Fluoroscopic equipment 1020.33 - Computed Tomography (CT) equipment

X-Ray Usage Regulation States regulate almost all medical usage of diagnostic x-ray Regulations vary widely from state to state Georgia requires a full 6 hours of training to take x-rays (unless you’re a physician or dentist in which case you’re assumed to have already gotten it)

X-Ray Usage Regulation: Mammography Mammography controlled by federal government (FDA) 1992 Mammography Quality Standards Act (MQSA)

Mammography Quality Standards Act (MQSA) 1992 “to ensure the safety and reliability of mammography and help detect breast cancer in its earliest, most treatable stages” Mammography practice under federal control (FDA)

MQSA Requirements Yearly physics surveys Yearly FDA inspections Georgia x-ray regulators on contract with FDA FY 2018 No violations: 84.9%

Facility Accreditation by “Accrediting Body” American College of Radiology (ACR) State of Arkansas State of Iowa State of Texas

Acronyms FFDM (also 2D) DBT (also 3D) Full Field Digital Tomography Digital Breast Tomosynthesis

FDA Facility & Procedure Count June, 2006 Mid-2018 % Change Total certified facilities 8850 8726 -1.4 Total accredited units 13588 19242 +41.6 Certified facilities with FFDM units 1027 8622 +739 Accredited FFDM units 1455 12817 +781 Certified facilities with DBT 4526 Certified DBT units 6341 Annual mammography procedures 33,940,037 39,318,393 +15.8

Mammography QC Manual Sections Radiologist Clinical Image Quality Revised Edition, 1999 Sections Radiologist Clinical Image Quality Radiologic Technologist Medical Physicist

New manual now out for FFDM; new manual coming for DBT Mammography QC Manual New manual now out for FFDM; new manual coming for DBT

Quality Assurance (QA) QA should ensure Every imaging procedure is necessary & appropriate to clinical problem at hand images contain information critical to solution of that problem

Quality Assurance (QA) recorded information is correctly interpreted made available to patient’s physician in a timely fashion consistent with image quality objectives, examination results in lowest possible radiation exposure cost inconvenience to the patient

QC is integral part of QA Quality Control (QC) QC is integral part of QA Acceptance Testing detection of defects in equipment that is newly installed or has undergone major repair Baselines Establishment of baseline equipment performance quantitative data when system operating properly

Quality Control (QC) Diagnosis Verification Diagnosis of changes in equipment performance before they become radiologically apparent Verification Verification of correction of causes of deterioration in equipment performance

Facility Responsibility Designate One Lead Interpreting Physician

Lead Physician’s Responsibilities Ensure technologists have adequate orientation based on procedure manual training continuing education Ensure effective QC program

Radiologist’s Responsibilities Designate one technologist responsible for QC QC tech can delegate responsibilities

Radiologist’s Responsibilities Ensure availability of appropriate test equipment Arrange staffing / scheduling to allow time for QC

Radiologist’s Responsibilities provide frequent consistent positive & negative feedback to technologists about film quality & QC Review technologist’s test results no less than every 3 months more often if inconsistent results

Radiologist’s Responsibilities Select a medical physicist administers QC program performs physicist’s tests Review physicist’s test results

Radiologist’s Responsibilities Oversee or designate qualified individual to oversee radiation protection program for employees patients individuals in surrounding area

Radiologist’s Responsibilities Ensure proper maintenance of records in QC procedures manual employee qualifications mammography technique / procedures quality control / safety / protection infection control

Radiologist’s Responsibilities “The radiologist is ultimately responsible for the quality of films produced under his or her direction and bears ultimate responsibility for both proper QC testing and QA procedures in mammography.”

Physicists & Digital Mammography Physicist must insure equipment meets manufacturer’s specifications Equipment specs now defined by manufacturer, not ACR/FDA

Physicist’s Responsibilities Note: All physicist’s tests required annually or after tube replacement or major service

Physicist’s Responsibilities: Mammography Unit Assembly Evaluation mechanical stability / identification of sharp edges receptor stability locks / motions / detents operator shielding thickness scale accuracy indicator lights working technique chart posted

Physicist’s Responsibilities: Mammography Unit Assembly Evaluation Film Cassettes slide smoothly into/out of holder Override available for auto-decompression display must indicate when auto-decompression turned off Manual release of compression if power lost CR

Collimation Assessment x-ray light field alignment beam does not exceed receptor by > 2% SID compression paddle / receptor alignment at chest wall within 1% SID paddle not visible on image Image should fill film Film

Physicist’s Responsibilities Focal Spot Performance limiting resolution pattern kVp accuracy / reproducibility Beam quality (HVL) minimum & maximum minimum: patient dose maximum: image contrast

Automatic Exposure Control (AEC / Phototiming) kVp tracking Thickness tracking image mode tracking (Mag, cassette sizes, w w/o grid) automatic mode tracking unit selects kVp, target, filter density control even steps of ~ 15-20%

Physicist’s Responsibilities: Screen Uniformity AEC Reproducibility Film

Physicist’s Responsibilities Breast Entrance Exposure, Average Glandular Dose, Special “accreditation” phantom used for entrance exposure / average glandular dose / image quality

Breast Average Glandular Dose Limits 0.3 rad (300 mrads, 3 mGy) maximum per view for screen-film receptors using a grid Same for film and digital 0.1 rad (100 mrads, 1 mGy) maximum per view for non-grid screen-film receptors Radiation output rate > 800 mR/sec

Image Quality Evaluation use “accreditation” phantom record fibers speck groups masses optical densities technique New phantom available for FFDM

Phantom Image

Artifact Identification Artifact evaluation / description Done with phantom

Physicist’s Responsibilities Monitor QC Brightness Often automated test Viewing conditions ambient lighting

Technologist’s Responsibilities All QC must not only be performed but must be documented!

Technologist’s Responsibilities Monthly: Visual Checklist SID indicator angle indicator locks field light smooth motions

Technologist’s Responsibilities Monthly: Visual Checklist Compression device & firm compression Smooth edges Holds pressure hand switch placement visibility switches/ lights/ meters cones/ collimators

Technologist’s Responsibilities Quarterly Repeat analysis breakdown by cause motion positioning technique etc.

Semi-Annual Technologist’s Responsibilities Compression can use bathroom scale covered with towel 25 - 40 pounds for automatic systems at least 25 pounds for manual compression

The End Questions?