Clinical experience with ProteusONE imaging systems at WKCC

Kuan Ling (Gwen), Chen, Ph.D.

September 25, 2017

Willis-Knighton Proton Therapy Center

Willis-Knighton Health System 4 Hospitals in Shreveport/Bossier City, Louisiana

IBA ProteusONE

Partial gantry rotation 220 degree

Treatment field size Maximum 20 x 24 cm2

Beam delivery modality Pencil beam scanning (PBS) only

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WKCC IBA ProteusOne Timeline

Entered Negotiations May 2011

Contract Signed Sep. 2011

Groundbreaking Feb. 2012

Cyclotron and Gantry Arrival Aug.- Oct. 2013

Started Beam Tuning Dec. 2013

Started PBS Calibration Feb. 2014

Acceptance Test and Commission Jul. 1st, 2014

First Patient Treated Sep. 9th, 2014

CBCT Installed Sep. 24th, 2015

Upgraded to AI2.0 (CBCT LFOV) Jun. 2017 (not clinical yet)

358 patients treated Sep. 17th, 2017

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To Date Proton Treatment Statistics

Re-treat – 8%4

GU-Prostate43%

Brain15%

H/N12%

Lung8% GI

6%

GU-GYN6%

Breast/CW4%

Lymphoma2%

Spine2%

Sacroma1%

GU-other1%Other

6%

IBA Image-Guided Therapy System

Software adaPTinsight

Hardware Stereoscopic X-ray system

(dual source mode)

2D oblique (OB1-OB2)

Nozzle Imager

3D CBCT

2D orthogonal (single source mode)

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IBA Imaging System Specification

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Stereoscopic X-ray system Nozzle imager

X-Ray Tube Flat Panel

Stereo X-ray

Flat Panels

X-Ray Tubes

Under Ground

IBA Imaging System Specification

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Specifications Stereo Oblique Nozzle Imager

Flat Panel Type Amorphous silicon Amorphous silicon

Image Mode 2D 2D, 3D

Scan Diameters (FOV) n/a 25cm (currently)

Scan Length (S-I FOV) n/a 26 cm

Source to Axis Distance 250 cm 100 cm

Imager to Axis Distance 82 cm 55 cm

Flat Panel Array 1440 x 1560 px 2881 x 2881 px

Flat Panel Physical Size 38.0 x 32.8 cm2 50.8 x 51.8 cm2

Panel Sensitive Area at ISO 22 x 20 cm2 28 x 28 cm2

Pixel Size at Isocenter 0.1 mm 0.1 mm

Max. Gantry Speed (CBCT) n/a 3, 6 deg/s

CBCT Frame Rate n/a 7.5 fr/s

Elekta Versa XVI

Amorphous silicon

2D, 3D and 4D

27, 41 & 50 cm

Up to 27cm

100 cm

54 cm

1024 x 1024 px

42.5 x 42.5 cm2

27 x 27 cm2

0.25 mm

1 deg/s

5.5 fr/s

IBA Imaging System – CBCT Dose

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Scan

ProtocolFOV

Acquisition

Angle

Gantry

Speed (°/s)

Scan Parameters CTDIweighted

(mGy)kVp mA ms

Head HD Small 205 3 100 25 12 8.2

Head SD Small 205 6 100 25 12 4.4

Thorax Small 205 3 110 25 12 6.4

Pelvis Small 205 3 120 40 12 12.5

AI 2.0 (Large FOV)

Thorax Large434

(dual half scan)6 110 50 12 10.6

Pelvis Large434

(dual half scan)6 120 64 12 15.7

WKCC Current Clinical Application

Site Stereo Oblique CBCT 2D Orthogonal

Brain V A A

Head/Neck V A A

Thorax/Lung V A A

Thorax/Lung (BH) V A* A

Breast/ Chest Wall V A --

Abdomen (BH) V A* A

Pelvis V A --

Prostate A & V A (weekly) --

Prostate Bed V A A

Extremities V A A

– A: Patient Position Alignment – V: Patient Position Verification – *not used clinically

Brain

CBCT is best for alignment

Stereo oblique is difficult for alignment (rotational uncertainty)

Oblique Ortho

CBCT

Head/Neck

CBCT is best for alignment

Stereo oblique is difficult for alignment (rotational uncertainty)11

ObliqueCBCT

Lung

Free breathing CBCT

Breath hold CBCT for BH is feasible

but not used clinically currently

CBCT

Oblique

Lung

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CBCT

re-CT

Planning CT

Pelvis

Landmark Bony structures

Both CBCT and stereo oblique are good for setup

CBCT Oblique

Prostate

Landmark Fiducial

Stereo oblique is good for daily alignment

Weekly CBCT

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CBCT

Oblique

Prostate Bed

Landmark Rectal balloon w/ contrast

Bony structures

CBCT SI direction w/ balloon

AP, RL direction w/ bone

CBCT

Ortho

WKCC Experience Summary

CBCT essential for H/N, thorax, abdomen, pelvis (prostate bed)

LFOV is useful for breast, pelvis

Stereo Oblique Bony structure

Fiducials

Video of LFOV

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Questions?

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