Welcome to the

Breast IORT SymposiumClinical and Practice Perspectives

Agenda

6:00 – 6:10 Introduction D. Francescatti, MD

Xoft System Overview

6:10 – 6:20 IORT/Xoft System Physics R. Holt, PhD

6:20 – 7:00 IORT Experience at M. Silverstein, MD

Hoag Hospital

7:00 – 7:30 IORT Experience at B. Schwartzberg, MD

Rose Medical Center

7:30 – 7:45 IORT Reimbursement K. Francisco, Pinnacle

Health Group

7:45 – 8:00 Discussion

Intraoperative Radiation Therapy (IORT)

Radiation Therapy at the Time of Lumpectomy

Breast Cancer: Radiation Therapy Advancement

6 - 7 weeks

of treatment

5 days

twice a day

As little as 8 min.

during surgery

WBRT APBI IORT

1950 - Present 1992 - Present 2000 - Future

MC418R1 4/12

Breast Cancer

U.S. Incidence

MC418R1 4/12

(1)Combined New Invasive, DCIS, LCIS and Regional (2)Combined localized 60% of DCIS patients with unicentric disease

Sources: American Cancer Society; Cancer Facts and Figures 2010 NIH, SEER Incidence Data, 2007. BCT = Breast Conserving Therapy

Lumpectomyw/RT43%

Lumpectomy w/o RT

20%

Mastectomy w/o RT

37%

Localized Stage

54%

Regional or

Distant Stage

25%

DCIS

18%

LCIS

3%

Breast Cancer Statistics – U.S.

Breast Cancer Cases Eligible for Lumpectomy

261,100 Cases 168,000 Eligible Patients

>20% of Potential BCT Patients

NEVER

Receive Radiation Therapy

0%

10%

20%

30%

40%

50%

60%

≤10 10 to 25 25 to 50 >50

Miles from RT Facility

*Impact of Patient Distance to Radiation Therapy on Mastectomy Use in Early Stage Breast Cancer Patients, A.

Schroen et al., Journal of Clinical Oncology, October 1, 2005

% Patients

Opting for

Mastectomy

Mastectomies increase almost 50% for patients living

more than 50 miles from radiation therapy center

Socioeconomic Factors

MC418R1 4/12

**Journal of National Cancer Institute, February 2, 2000 New Mexico Statistics following Breast Conserving Surgery

Socioeconomic Factors

Distance to Radiation Therapy Reduces Patient Compliance

30%

40%

50%

60%

70%

80%

90%

<10 10-24 25-49 50-75 75-100 >100

% of PatientsReceiving Radiation Therapy

Miles Patient Travelled

Xoft Axxent® eBx® System

Xoft Axxent® eBx® SystemA Platform and System of Care

REST OF BODY

BREAST

Miniaturized X-ray Tube The Electronic Brachytherapy Source

The Source Operates

at 50 kV and 300

microamps

(15 Watts)

One System. Multiple Solutions

The Xoft Axxent® Controller is FDA cleared

for use anywhere in the body

Display Screen/

Touch Screen

Control

Well Chamber

Handheld

Barcode

Scanner

Adjustable arm

(in storage

position)

Wheel Brakes

Xoft Axxent® eBx ® Controller Components

Controller Components

Applicator

hub

attachment

Source

connected

to source nest

Source high voltage

cable attachment

Balloon Inflation Valve

Drainage Port Valve

Drainage Holes x 7

Balloon Applicator

Drainage holes

• Seroma management -

potentially reduce infection

• Improve dosimetry

Radiolucent Balloon Wall for

improved visibility while imaging

Sizes:3-4 cm spherical

4-5 cm spherical

5-6 cm spherical

5x7 cm ellipsoidal

Treatment Times for 20 Gy to Surface are 2 - 2.5X Faster with Xoft

Xoft data computed for all balloons by Pacific Crest Medical Physics, May 2010. Plans were optimized to deliver 20 Gy to the surface using TG-43 data on BrachyVision from CT scans of all possible balloon sizes and including a 6% latex wall BaSO4 correction.

40 uA Tx time data and median diameter used in IORT comes from “IORT for Breast Cancer using the Intrabeam system”, Tumori, 91: 339-345, Kraus-Tiefenbacher, et al

Balloon Diam.

(cm) *Xoft 300 µA source (min) 40 µA source (min)

3.0 4.9 24.9

3.5 7.6 18.6

4.0 10.9 26.8

4.5 15.2 36.6

5.0 20.3 48.9

Median (4.2) 12.5 32.4

More Efficient Operating Room - Faster Turnover

Benefits of Selecting Xoft

• Economical

• Mobile

• Versatile - platform technology

• Treat area at greatest risk of tumor recurrence

• Less time in the OR

• Convenient for patient

• Green technology/isotope free

Xoft Axxent ® eBx ® System

Physics

Xoft Miniaturized X-ray Source

Fully disposable device

Rapid treatment times

Miniaturized X-ray Source:

Detailed View

Miniaturized X-ray Source

Cooling

connections

HV connection

X-ray Tube HV Cable

MC418R1 4/12

Radiation Safety: Time, Distance, Shielding

Distance 1 meter 2 meters

Shielding none1 mm rolling

shieldnone

1 mm rolling

shield

C-arm OR

Fluoroscopy

(50 – 120 kV)

120 mR/hr 0.32 mR/hr 30 mR/hr 0.08 mR/hr

50 kV source

w/FlexiShield15 mR/hr 0.04 mR/hr 3.8 mR/hr 0.01 mR/hr

Radiation Safety

TG43 formalism accurately represents the actual source characteristics

34 Red

17 Orange

10.2 Yellow

6.8 Green

5.1 Blue

3.4 Dark Blue

1.7 Magenta

Film 40A01

D (Gy)

34 Red

17 Orange

10.2 Yellow

6.8 Green

5.1 Blue

3.4 Dark Blue

1.7 Magenta

Film 40A01

34 Red

17 Orange

10.2 Yellow

6.8 Green

5.1 Blue

3.4 Dark Blue

1.7 Magenta

Film 40A01

D (Gy)

34 Red

17 Orange

10.2 Yellow

6.8 Green

5.1 Blue

3.4 Dark Blue

1.7 Magenta

40 kV Probe in

BrachyVision®

D (Gy)

34 Red

17 Orange

10.2 Yellow

6.8 Green

5.1 Blue

3.4 Dark Blue

1.7 Magenta

X-ray distribution described mathematically in AAPM TG-43 format

Film measurements compare parameterization to actual

X-ray Source Distribution Pattern

X-ray Distribution On FilmPredicted Distribution From Planning System

Same dose as Iridium-

192 at the prescription

point

Higher dose inside

applicator (absorbed by

saline)

Rapid dose fall off

requires less shielding

Xoft eBx® Radiation

Depth-dose curve similar to 192Ir over region of interest

Illustrated for 5 cm diameter applicator

MC418R1 4/12

High Dose, Low Energy Delivers Less

Radiation to Critical Structures (heart, lung, ribs)

Dickler, et al. “A dosimetric comparison of MammoSite high dose rate brachytherapy and Xoft Axxent electronic brachytherapy,”Brachytherapy (6) 2007, 164-168.. Slide courtesy of Dr. David Wazer

Dose shaping capabilities: Not limited to spherical applicators

• Multiple dwell points allow optimal dose to be shaped as needed

• Typical planning method

– Pre-planned Atlas for all possible balloons, pre-validated by physics

– Appropriate plan chosen during surgery

IORT Dose Shaping Capabilities:

Spherical and Ellipsoidal Applicators

6 cm long x 4 cm ellipsoidal 4 cm spherical

Dose-Volume Histogram (DVH) Comparison of

IORT Plans for Two 50 kV Systems

1. Nairz O, et al. “A dosimetric comparison of IORT techniques in limited-stage breast cancer”. Strahlenther Onkol 2006. 182: 342-348

Intrabeam DVH of PTV: from Nairz

Xoft DVH of PTV, plan A: optimized to match Nairz

Xoft DVH, plan B: opt. to maximize 1 cm dose

PTV = CTV+1 cm

CTV = 4 cm

diameter sphere,

with lumen

Energy Spectra of 50 kV Tungsten and Gold X-rays

0

50

100

150

200

250

300

0

500

1000

1500

2000

2500

0 10 20 30 40 50 60

After 2 cm Water Filtration

Xoft Nist

Amptex Au50

0

2000

4000

6000

8000

10000

0 10 20 30 40 50 60

Xoft Tungsten

0cm

1cm

2cm

3cm

4cm

0

200

400

600

800

1000

1200

1400

0 20 40 60

Amptek Au

0cm

1cm

2cm

3cm

4cm

Energy (kV)

Co

un

ts (

arb

itra

ry)

Co

un

ts (

arb

itra

ry)

Energy (kV)

Energy (kV)