What the Physicist needs to Educational Objectives Know ... · What the Physicist needs to Know and Do in Stereotactic ... • Overcall? • Desired goal is ... • ACR SBB QC manual

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What the Physicist needs to What the Physicist needs to Know and Do in Stereotactic Know and Do in Stereotactic

Breast BiopsyBreast Biopsy

Maynard High, PhDNew York Medical College

Educational ObjectivesEducational Objectives

• SBB role in breast cancer management• SBB Technologist and Physicist QC• VAB localization accuracy details • Image quality and dose in SBB• Brachytherapy application

To make a definitive diagnosis about whether a breast abnormality is benign

or malignant, a biopsy must be performed.

80% are benign

Breast Cancer Diagnosis Breast Cancer Diagnosis and Biopsiesand Biopsies

Brown ML, Houn F, Sickles EA, Brown ML, Houn F, Sickles EA, Brown ML, Houn F, Sickles EA, Brown ML, Houn F, Sickles EA, et alet alet alet al....

Screening Mammography in community practice; positive predictiveScreening Mammography in community practice; positive predictiveScreening Mammography in community practice; positive predictiveScreening Mammography in community practice; positive predictive value of value of value of value of abnormal findings and yield of diagnostic proceduresabnormal findings and yield of diagnostic proceduresabnormal findings and yield of diagnostic proceduresabnormal findings and yield of diagnostic procedures....

AJR Am J Roentgenol 1995; 165: 1373AJR Am J Roentgenol 1995; 165: 1373AJR Am J Roentgenol 1995; 165: 1373AJR Am J Roentgenol 1995; 165: 1373----77777777

Indications for Breast BiopsyIndications for Breast BiopsyCategory 3Probably Benign Finding

• anxious patient• strong family

history of breast ca

• compliance with a recommendation for 6-month follow-up is unlikely

Category 4SuspiciousAbnormality

• can differentiate those patients requiring surgical management from those who can be managed using clinical and mammographic follow-up

Category 5Highly Suggestive of Malignancy

• used preoperatively to confirm diagnosis and expedite surgical planning and therapy

Bassett LW, Winchester DP.Bassett LW, Winchester DP.Bassett LW, Winchester DP.Bassett LW, Winchester DP.

Stereotactic coreStereotactic coreStereotactic coreStereotactic core----needle biopsy of the breast: a report of the Joint Task Force ofneedle biopsy of the breast: a report of the Joint Task Force ofneedle biopsy of the breast: a report of the Joint Task Force ofneedle biopsy of the breast: a report of the Joint Task Force of the ACR, ACS and College of American the ACR, ACS and College of American the ACR, ACS and College of American the ACR, ACS and College of American PathologistsPathologistsPathologistsPathologists

CA Cancer J Clin 1997; 47:171CA Cancer J Clin 1997; 47:171CA Cancer J Clin 1997; 47:171CA Cancer J Clin 1997; 47:171----190190190190

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Breast Biopsy OptionsBreast Biopsy Options

Vacuum Assisted Core NeedleBreast Biopsy

Core NeedleBreast Biopsy

Open SurgicalBreast Biopsy

Minimally Invasive Invasive

Image courtesy of ETHICON ENDOImage courtesy of ETHICON ENDOImage courtesy of ETHICON ENDOImage courtesy of ETHICON ENDO----SURGERYSURGERYSURGERYSURGERY

- Stereotactic x-ray guided- Ultrasound guided

Minimally Invasive AdvantagesMinimally Invasive Advantages

�Outpatient procedure� Local anesthesia; No post-procedure disability� Improved cosmesis; No stitches� Eliminates distortion of breast tissue that might

make interpretation of a mammogram difficult� Permits optimal preoperative planning when

there is a definitive diagnosis of cancer� Lower cost

Indicated Targets for SBBIndicated Targets for SBB

Mammographic Abnormalities including• Solid, spiculated, nonpalpable Mass• Suspicious Micro-calcifications• Solid, circumscribed Mass that is

dominant (usually larger than 1 cm)• Architectural distortion• Asymmetry

Bassett LW, Winchester DP.Bassett LW, Winchester DP.Bassett LW, Winchester DP.Bassett LW, Winchester DP.

Stereotactic coreStereotactic coreStereotactic coreStereotactic core----needle biopsy of the breast: a report of the Joint Task Force ofneedle biopsy of the breast: a report of the Joint Task Force ofneedle biopsy of the breast: a report of the Joint Task Force ofneedle biopsy of the breast: a report of the Joint Task Force of the ACR, ACS and College of American the ACR, ACS and College of American the ACR, ACS and College of American the ACR, ACS and College of American PathologistsPathologistsPathologistsPathologists

CA Cancer J Clin 1997; 47:171CA Cancer J Clin 1997; 47:171CA Cancer J Clin 1997; 47:171CA Cancer J Clin 1997; 47:171----190190190190

Trends in SBB Usage:Trends in SBB Usage:

INCREASING?

• Use of CAD makes calcsmore suspicious

• Reimbursement,self-referral?

GurGurGurGur D, Wallace LP, D, Wallace LP, D, Wallace LP, D, Wallace LP, KlymKlymKlymKlym AH, Hardesty LA, Abrams GS, Shah R, AH, Hardesty LA, Abrams GS, Shah R, AH, Hardesty LA, Abrams GS, Shah R, AH, Hardesty LA, Abrams GS, Shah R, SumpkinSumpkinSumpkinSumpkin JHJHJHJH

Trends in Recall, Biopsy and Positive Biopsy Rates for ScreeningTrends in Recall, Biopsy and Positive Biopsy Rates for ScreeningTrends in Recall, Biopsy and Positive Biopsy Rates for ScreeningTrends in Recall, Biopsy and Positive Biopsy Rates for Screening Mammography in an Academic PracticeMammography in an Academic PracticeMammography in an Academic PracticeMammography in an Academic Practice

Radiology 2005; 235: 396 Radiology 2005; 235: 396 Radiology 2005; 235: 396 Radiology 2005; 235: 396 ---- 401401401401

Figure 3. Plot shows the stereotactic (11-gauge) vacuum-assisted core biopsy rates per 1000 screening examinations for each calendar quarter.

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Success Trend in SBB Usage:Success Trend in SBB Usage:

DECREASING?

• Overcall?• Desired goal is 25-40% * of recommended biopsies be malignant (PPV2)

GurGurGurGur D, Wallace LP, D, Wallace LP, D, Wallace LP, D, Wallace LP, KlymKlymKlymKlym AH, Hardesty LA, Abrams GS, Shah R, AH, Hardesty LA, Abrams GS, Shah R, AH, Hardesty LA, Abrams GS, Shah R, AH, Hardesty LA, Abrams GS, Shah R, SumpkinSumpkinSumpkinSumpkin JHJHJHJH

Trends in Recall, Biopsy and Positive Biopsy Rates for ScreeningTrends in Recall, Biopsy and Positive Biopsy Rates for ScreeningTrends in Recall, Biopsy and Positive Biopsy Rates for ScreeningTrends in Recall, Biopsy and Positive Biopsy Rates for Screening Mammography in an Academic PracticeMammography in an Academic PracticeMammography in an Academic PracticeMammography in an Academic Practice

Radiology 2005; 235: 396 Radiology 2005; 235: 396 Radiology 2005; 235: 396 Radiology 2005; 235: 396 ---- 401401401401

Figure 2. Plot shows the percentage of malignant biopsies for each calendar quarter*DHSS Agency for Health *DHSS Agency for Health *DHSS Agency for Health *DHSS Agency for Health

Care Policy Clinical Care Policy Clinical Care Policy Clinical Care Policy Clinical Practice Guideline #13Practice Guideline #13Practice Guideline #13Practice Guideline #13

Accuracy of SBB:Accuracy of SBB:“Accuracy” means correlation with surgical biopsy and depends on several issues:

• Sampling localization accuracy• Sample volume size• Type of cancer

Accuracy of SBB Accuracy of SBB --Localization:Localization:Sampling Localization Accuracy depends on:

1. Image quality• QC item

2. Mechanical accuracy of unit• QC item

3. Skill of operator• Training and experience

Accuracy of SBB Accuracy of SBB –– Sample Size:Sample Size:Correlation

with surgical biopsy improves with sample volume size:


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Accuracy of SBB Accuracy of SBB –– Cancer Stage:Cancer Stage:

Accuracy is lower for ADH than for DCIS

- ie, there may be “upstaging” at surgery from ADH to DCIS

NOT Breast CancerNOT Breast Cancer

In a normal duct In a normal duct the cells lining the cells lining the duct will be the duct will be one or two layers one or two layers thick. thick.

These cells will These cells will have similar size have similar size and shape.and shape.

A condition with A condition with excess growth of excess growth of cells is referred to cells is referred to as as hyperplasiahyperplasia..

Latin termLatin termexcess = excess = hyper hyper growth = growth = plasiaplasia

Excess growth within the Excess growth within the duct includes abnormal or duct includes abnormal or atypical atypical cells. cells.

The presence of this The presence of this condition increases the condition increases the risk of developing breast risk of developing breast cancer. cancer.

Atypical Ductal Hyperplasia (ADH)

Normal Ductal Hyperplasia


Breast CancerBreast Cancer

The entire duct may The entire duct may be filled with be filled with abnormal, abnormal, atypicalatypicalcells. cells.

This condition is This condition is actually an early actually an early breast cancer.breast cancer.

Cancer cells that break Cancer cells that break out of the duct and out of the duct and invade the breast invade the breast tissue. tissue.

Ductal Carcinoma In Situ (DCIS) Invasive Ductal Carcinoma (IDC)


Accuracy of SBB:Accuracy of SBB:Radiologist’s Bottom line:

• “SBB is equivalent to surgical biopsy in accuracy”

Surgeon’s Bottom line:• “SBB results are often

upstaged at surgery”

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QC Testing NeedsQC Testing Needs

Mammography

• Image quality

• Patient dose

Stereotactic Breast Biopsy

• Image quality• Sampling

accuracy• Patient dose

QC Testing Recommendations QC Testing Recommendations for SBB Unitsfor SBB Units

• ACR Practice Guideline

• ACR SBB accreditation

• State requirements (not MQSA!)

• Manufacturer’s recommendations

• Technologist & Physicist QC Components in each category above

ACR Practice GuidelineACR Practice Guideline

“ACR Practice Guideline for the Performance of StereotacticallyGuided Breast Interventional Procedures” -effective 10/05

• QC testing same as ACR accreditation

• Establishes Qualified MP as one who meets MQSA requirements

ACR Accreditation ACR Accreditation QC Testing RecommendationsQC Testing Recommendations

• ACR SBB QC manual– Full description of tests– Sample report forms

• All MP’s should have a copy

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• ACR.org > ACR Store > Quality and Safety > QC Manuals > Stereotactic Biopsy

• Stereotactic Breast BiopsyQuality Control Manual

• Product Code: P-SBQCMPrice: $57.50

How to Order ManualHow to Order Manual State Requirements for SBBState Requirements for SBB

• MQSA does not apply to SBB units

• Some states have implemented their own requirements

ManufacturerManufacturerQC Testing RecommendationsQC Testing Recommendations

• Manufacturer may recommend tests specific to the unit.

Technologist QC TestsTechnologist QC Tests

• Reviewed by physicist

• Physicist must know how to perform tests to properly review

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Technologist Daily QC Technologist Daily QC

Localization accuracy in air< 1.0 mm sphere

• Lorad requires Z=0 alignment before each patient

D Technologist Weekly QC Technologist Weekly QC

• Track phantom object scores• Track AEC mAs• Track system gain (ROI)• Artifacts

W

MINI MAP

Images courtesy of BOB PIZZUTIELLOImages courtesy of BOB PIZZUTIELLOImages courtesy of BOB PIZZUTIELLOImages courtesy of BOB PIZZUTIELLO

Minimum Passing Phantom Minimum Passing Phantom Image Object ScoresImage Object Scores

FibersSpecksMasses

ACR-MAP

Screen/film

4.03.03.0

ACR-MAP

SBB Digital

5.04.03.5

Mini-Phantom

SBB Digital

3.03.02.5

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Technologist Monthly QC Technologist Monthly QC

1. Hardcopy output quality– Print SMPTE or stored Phantom Image– Measure OD in consistent locations– Compare hardcopy with monitor

2. Visual checklist– Lights, switches, motion, accessories– Opportunity to document items needing

repair

M Technologist SemiTechnologist Semi--Annual QCAnnual QC

1. Compression force

2. Repeat analysis– Count repeated and rejected images by

category and tabulate – Document analysis and corrective action -– Repeat rate will typically be higher than

for mammography

S

Ongoing QAOngoing QA

Medical audit:• # of cancers diagnosed• # of complications needing treatment• # and reason for repeated biopsies• Rate of compliance with recommended

follow-up in women with benign SSB results

Everyday PhysicistPhysicist’’s Annual Surveys Annual Survey

1. SBB Unit Assembly Evaluation2. Collimation Assessment3. Focal Spot / System Limiting Resolution4. kVp Accuracy and Reproducibility5. Beam Quality Assessment (HVL)6. AEC / Manual Exposure Assessment7. Image Receptor Uniformity8. Breast ESE, AGD, AEC Reproducibility9. Image Quality Evaluation (phantom)10.Artifact Evaluation11.Localization Accuracy

A

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1) Unit Assembly Evaluation:1) Unit Assembly Evaluation:

Key Items for SBB:• Mechanical and safety• Breast thickness indicator accuracy• Needle holder and guides assure

1 mm accurate support.• Operator technique charts posted

2) Collimation Assessment:2) Collimation Assessment:

a. X-Ray Field should extend beyond Image Receptor on all 4 sides

b. X-ray Field should extend < 5 mm beyond image receptor on any side

c. Does the biopsy window align with the image field of view?

LoradLorad Collimation Assessment:Collimation Assessment:

BIOPSY WINDOW in compression paddle

Film cassette behind compression paddle

LoradLorad Collimation Assessment: Collimation Assessment: Digital ImageDigital Image

• Measure visible diameter of coin with TOOLS/CALIPERS.

• Anterior missing image is 19.0 – 17.6 = 1.4 mm

• Should be <5 mm19.0 mm

17.6 mm

Anterior

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BUTBUT…… How about the XHow about the X--Ray Field ?Ray Field ?

Film behind steel compression paddle does not show full extent of x-ray field.

CHEST WALL

Incorrect collimator aperture

2 Exposures on Same Cassette:2 Exposures on Same Cassette:1 with paddle; 1 without1 with paddle; 1 without

Shows: 1) x-ray field too large2) not centered to biopsy window

3) System Resolution Test:3) System Resolution Test:

• Need to measure in BOTH:– 512 matrix– 1024 matrix

• Need to measure BOTH:– Parallel to A-C axis– Perpendicular to A-C

Must ZOOM Image:Must ZOOM Image:

5.6 lp/mm (512 mode)7.1 lp/mm (1024 mode)

Typical with this Test object (Lorad):

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4, 5) 4, 5) kVpkVp and HVL Tests:and HVL Tests:

• Can make exposures without digital acquisition from generator console

• HVL measurement thru biopsy aperture, ie, through hole in paddle

– HVL > kVp / 100

6) AEC or Manual Exposure 6) AEC or Manual Exposure Assessment :Assessment :

• Evaluate signal (ROI) using clinical technique for 4, 6, 8 cm phantom.

• Performance Criteria (ACR):- 6, 8 cm ROI value should be

within 20% of 4 cm. - exposure time should be <2 sec

LoradLorad Manual Exposure Manual Exposure Recommendation :Recommendation :

• Performance Criteria (Lorad):- ROI signal = 4000 in 512 mode- ROI signal = 6000 in 1024 mode

• No AEC – Technique chart critical

Source: Source: Source: Source: Lorad/Trex/HologicLorad/Trex/HologicLorad/Trex/HologicLorad/Trex/Hologic Applications SupportApplications SupportApplications SupportApplications Support

LoradLorad Manual Exposure Manual Exposure Assessment :Assessment :

-36%2462350 (max)3410248 cm

-12%34072663210246 cm

38761922810244 cm

-21%3086322325128 cm

-1%3860273295126 cm

389996285124 cm

from 4 cmat image center

% DifferenceDigital signal mAskVpMatrixPhantom

Thickness Performance:

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Fischer AEC Exposure Fischer AEC Exposure Recommendation :Recommendation :

• Performance Criteria (Fisher):

- ROI signal = 1800 – 2000 (Standard)

• AEC: Technique chart important for proper kVp

Source: Fischer Technical SupportSource: Fischer Technical SupportSource: Fischer Technical SupportSource: Fischer Technical Support

7) Digital Receptor Uniformity: 7) Digital Receptor Uniformity:

• 4 cm lucite or BR-12 • Expose with clinical technique• Measure SNR = Mean/SD in center and

each corner AND suspicious areas

• Performance Criteria:Corner SNR’s within 15% of Center SNR

• If SNR not available, use signal

SNR

SNR

SNR

SNR

SNR

Digital Receptor Uniformity:Digital Receptor Uniformity:LoradLorad ProtocolProtocol

(100, 100)

(100, 400) (400, 400)

(400, 100)

(256, 256)

SNR

UL

SNR

LL

SNR

UR

SNR

LR

SNR

Centr

• 28 kVp• mAs for Sig =4000• Measure SNR’s at

specified locations.• 32 x 32 pixel ROI

–set with trackball.• Lorad spec +/-20%

of SNR(center).

Source: Source: Source: Source: Lorad/Trex/HologicLorad/Trex/HologicLorad/Trex/HologicLorad/Trex/Hologic Technical SupportTechnical SupportTechnical SupportTechnical Support

Effect of Collimation on UniformityEffect of Collimation on Uniformity

No Biopsy Paddle

This is how Loradcalibrates “white

field”

With Biopsy Paddle

(x-ray field not well centered to

paddle aperature)

With Biopsy Paddle

(After re-centering x-ray field to

paddle aperature)

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Digital Receptor Uniformity:Digital Receptor Uniformity:Fischer ProtocolFischer Protocol

• Signal uniformity only

• Fischer phantom

• 26 kVp, AEC

Fischer Fischer Fischer Fischer MammotestMammotestMammotestMammotest Service Manual, 2005, or Technical Service Manual, 2005, or Technical Service Manual, 2005, or Technical Service Manual, 2005, or Technical SupportSupportSupportSupport

8) Average Glandular Dose: 8) Average Glandular Dose:

• Depends on matrix size (Lorad)• Depends on signal (ROI value)

– Manual technique – AEC setting (Low, Standard, High)

• Depends on kVp– Do not use same kVp for all thickness!

• Performance Criteria:– <300 mrad (3 mGy) for 4.2 cm breast

28 kVp,28 kVp,140 140 mAsmAs,,227 227 mradmrad



Effect of Effect of mAsmAs on on Image Quality and Dose:Image Quality and Dose:

Images courtesy of Andrew MaidmentImages courtesy of Andrew MaidmentImages courtesy of Andrew MaidmentImages courtesy of Andrew Maidment

9) Image Quality Evaluation:9) Image Quality Evaluation:

• 512 and/or 1024 ?

• Site mAs technique

• Site kVp

• Be consistent with technologist test

• Opportunity to show site images at lower dose

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10) Artifact Evaluation:10) Artifact Evaluation:

Typical artifacts:• Dust (camera, screen, lens, mirror)• Pixel defects ( dropouts)• Non-uniformities (light pipe stucture, vignetting, linear shading)– corrected by white-fielding

• Clipping (dose too high)

On On LoradLorad,, ““WhiteWhite--FieldField”” is is a service procedure:a service procedure:

• Can correct some non-uniformities• Consists of the average of several exposures on uniform lucite phantom

• Correction formula (Lorad) is:

• On Fischer, is a Daily procedure

(Image – Dark Field)

(White Field – Dark Field)

““MovedMoved”” Dust ArtifactsDust Artifacts

White Speck next to Black Speck

• Dust on mirror or screen moved AFTER white-field calibration

11) Localization Accuracy: 11) Localization Accuracy: (Gelatin Phantom)(Gelatin Phantom)

• Technologist test observed by physicist

• Performance Criteria:a) Pre- and Post-fire images to be as

recommended by biopsy device makerb) Phantom lesion material is collected by

biopsy deviceImage courtesy of BOB PIZZUTIELLOImage courtesy of BOB PIZZUTIELLOImage courtesy of BOB PIZZUTIELLOImage courtesy of BOB PIZZUTIELLO

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Core Needle PreCore Needle Pre--Fire Images:Fire Images:Correct placement for needle:Correct placement for needle:

TargetLesion

Core Needle PostCore Needle Post--Fire Images:Fire Images:Illustrating Illustrating ““Needle DiveNeedle Dive””

TargetLesion

1. Position Probe under Lesion1. Position Probe under Lesion

Probe aligned with target

How a Vacuum Assisted Biopsy How a Vacuum Assisted Biopsy Device Works (Device Works (MammotomeMammotome):):


Cutter rotates and vacuum is applied simultaneously

2. Vacuum Tissue into Aperture2. Vacuum Tissue into Aperture



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3. Transect Tissue3. Transect Tissue

Cutter blade moves forward, tissue is cut



4. Transection Completed4. Transection Completed



Tissue sample transported to specimen chamber for removal

5. Transport Tissue5. Transport Tissue



Pre-Fire Images

Correct Probe Position

-15o +15o

VAB Probe Positioning:VAB Probe Positioning:


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PrePre--Fire Pair FischerFire Pair Fischer::


PrePre--Fire Pair Fire Pair LoradLorad::


Post-Fire Images

-15o +15o

Correct Probe Position

VAB Probe Positioning:VAB Probe Positioning:


PostPost--Fire Pair FischerFire Pair Fischer::


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PostPost--Fire Pair Fire Pair LoradLorad::


Probe Positioning Errors:Probe Positioning Errors:

-15o +15o

Probe aperture is above the center of the lesion on both the (-) and (+) 15o images.

Sampling should be increased between 9:00 – 3:00 going through 6:00

-Y/Vertical Error

-Y/Vertical ErrorPost-Fire Images


Points to Observe during Points to Observe during Localization Accuracy Test:Localization Accuracy Test:

• “Z” zeroing of needle (and X,Y zero)• “Pull-Back” of needle• Needle guide close to skin• Targeting on image, especially for

calcs• Visibility/Marking of alignment hole• Transmission of coordinates to

biopsy gun movable stage

Localization Accuracy: Localization Accuracy: (Gelatin Phantom)(Gelatin Phantom)

• Biopsy needles are expensive – have site save one for this test.

• Performance Criteria:a) Pre- and Post-fire images to be as

recommended by biopsy device makerb) Phantom lesion material is collected by

biopsy device

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Breast Cancer ManagementBreast Cancer Management

• Screening - Mammography

• Diagnosis – U/S, MRIBiopsy

• Treatment – SurgeryChemotherapyIMRT/Brachytherapy

Types of Brachytherapy

Intracavitary

• MammoSite

Interstitial

• Kuske Grid and Comfort Catheter System

Slide courtesy of Fischer Imaging & Robert Slide courtesy of Fischer Imaging & Robert Slide courtesy of Fischer Imaging & Robert Slide courtesy of Fischer Imaging & Robert KuskeKuskeKuskeKuske, MD, MD, MD, MD

Template positioned with mild compression

Using SBB Unit for Brachytherapy:Using SBB Unit for Brachytherapy:

Slide courtesy of Fischer ImagingSlide courtesy of Fischer ImagingSlide courtesy of Fischer ImagingSlide courtesy of Fischer Imaging

Breast image with template, AOI drawn around the lumpectomy cavity



Non-ionic contrast in the lumpectomy cavity with the imaging arm underneath the table clearly defines the target

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Coordinates chosenFor catheter insertion



Brachy Needles inserted



In conclusion.....In conclusion.....

• Medical Physicists have an important role in optimizing accuracy in SBB

– Review technologist QC– Perform physics QC survey– Optimize image quality & dose

Thank You for Your Attention

Documents

What the Physicist needs to Educational Objectives Know ... · What the Physicist needs to Know and Do in Stereotactic ... • Overcall? • Desired goal is ... • ACR SBB QC manual