A One Step Model for Online A One Step Model for Online Planning and Treatment for Planning and Treatment for

Palliative Radiotherapy using Palliative Radiotherapy using Cone Beam CTCone Beam CT

David Fitzpatrick, Anita David Fitzpatrick, Anita VloetVloet, Daniel Letourneau, , Daniel Letourneau, Rebecca Wong, Mary Rebecca Wong, Mary GospodarowiczGospodarowicz, David A , David A JaffrayJaffray

5th Annual Toronto Radiation Medicine Conference

Kingbridge Sunday 27 April 2008

BackgroundBackground

• Palliative radiation should be effective yet fast • Uses simple Techniques

– Ant/Post opposed fields – A Direct field

• Conventional CT planning – a multistep process– can take a few hours to 1-2 days

• 2D planning – Quicker than CT planning– But lacks dosimetric information

Cone Beam CT (CBCT)Cone Beam CT (CBCT)

• CBCT scan images can be rapidly acquired on an RT treatment unit

• CBCT established for Image Guided RT Jaffray, Kupelian at al Expert Rev Anticancer Therapy 2007

• CBCT recently developed to permit image quality sufficient for treatment planning Letourneau, Wong et al IJROBP 2007. Sharpe, Moseley et al Med Physics 2006.

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Conventional CT Simulation (PCT) Conventional CT Simulation (PCT) Planning and RT Planning and RT

Volumetric Imaging

Planning

QAand

IGRT

Time: Many Hours to 1-2 Days

Conventional Planning ProcessPLANNING CT

EXPORT IMAGES TO TPS

PHYSICS QA

QA ROOM

TREATMENT UNITPT SET UP + IGRT

TREATMENT DELIVERY

PLANNING +DR APPROVAL

PT WAITS FOR RT

CONTOURING

WEB PUBLISHINGEXPORT PLAN TO RT UNIT

PT HAS RT

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A CBCT enabled Online Treatment StrategyA CBCT enabled Online Treatment Strategy

Volumetric ImagingOnline

Planning

DeliveryQAand

IGRT

Study ObjectiveTo Replace a multistep PCT process by a

1 step 30 min appointment at the treatment unit.

MethodsMethods• Phase A

– Is the image quality adequate for planning? • Spine, Mediastinum, Abdomen/Pelvis• Suitable for CT planning• n = 3x3

• Phase B– Trial on-line planning within the clinical environment – n = 45 (15 spine, 15 thoracic, 15 abdomen/pelvis)

• Phase C– Testing the efficacy of the established on-line planning

system to treat patients. – n = 60 (15 spine + 15 bone, 15 thoracic, 15 abdomen/pelvis)

MethodsMethods• Outcomes

– Agreement between CBCT and PCT defined GTV– Adequacy of coverage of PCT generated PTV by

CBCT plan 90% isodose– Time– Patient satisfaction rates

Phase APhase A

Spine or mediastinum or abdominal disease

For palliative RT

Conventional Conventional Planning CT Planning CT

(PCT)(PCT)

Cone beam capable treatment unit PCTPCT

CBCTCBCT

DRRDRR

UNDERCOVERAGE by CBCT v PCT

OVERCOVERAGE by CBCT v PCT

Overlap

Phase A GEOGRAPHIC AREA COMPARISON

CBCT/DRR PCT/DRR CBCT/PCT

Mean ±SD% Mean ±SD% Mean ±SD%

% UC 46 ±

61 42 ±

47 11

% OC 31 ±

34 29 ±

34 11

% Overlap 57 ±17 57 ±16 80

Phase BPhase BSpine

Mediastinum For Pall RT

Abdomen/Pelvis

PCT plan used to treat patient

During 1 fraction of treatment a CBCTscan acquired images and

CBCT study plan generated

CBCT Plan CBCT Plan vsvs PCT Plan PCT Plan

Spine Mediastinum/lung

Abdomen pelvis

Field Areamean (SD)

n = 16

Field Areamean (SD)

n = 15

Field Areamean (SD)

n = 13*% UC 12 (13) 18 (16) 20 (15)

% OC 15 (21) 21 (24) 10 (13)

% OL 89 (13) 82 (15) 80 (15)

Phase BPhase B

• Adequacy of CBCT plan 90% isodose coverage of PCT generated PTV- Spine - 93 + 11 %- Mediast – 89 + 15%- Abd/Pelvis – 92 + 5%

PTVPCTPCT

CBCT plan 90% isodose line

Phase B Phase B -- Timing resultsTiming results

CBCTPatient or

Institution's perspective

Planning CTPatient's Perspective

Planning CTInstitution's Perspective

Total Time 28+/- 8 min 30 +/- 12 min 149 +/- 78 min

Phase BPhase B

PCT PCT Process:Process:

GTV GTV PCTPCTFields Fields PCTPCTTime Time PCTPCT

Pt satisfaction Pt satisfaction PCTPCT

Phase CPhase C

Bone only to dateBone only to dateMediastinum

Abdomen/Pelvis

Cone beam scan acquired on treatment

unit and CBCT generated plan used to

treat patient

Conventional Planning CT

for Retrospective validation

1 Step ProcessPatient Set Up

CBCT Image Acquisition Images Exported to TPS

Define PTVPlanning

Plan PublishedExport Plan to RT unit

Dr. Approval + QA IGRT CBCT

Treatment Delivery

Task Professional Time (min)

Patient Walk in and Setup MRT(T) 8.3 ± 2.2

CBCT Acquisition and Export MRT(T) and Planner 6.3 ± 2.1

Dr Contouring RO 3.4 ± 1.3Planning / Export / WebPub Planner 9.9 ± 3.0

QA, Approval and CBCT #2 QA_Phys, RO and MRT(T) 8.7 ± 2.6

Treatment Delivery MRT(T) 2.5 ± 0.5

Patient Walk out MRT(T) 2.3 ± 1.0

Total ------ 39.3 ± 6.8

Phase C Elapsed TimePhase C Elapsed Time (10 spine patients)

MRT(T): Therapist, RO: Radiation oncologist and QA_Phys: QA physicist

Phase C Total Elapsed TimePhase C Total Elapsed Time (10 patients)

Satisfaction dataSatisfaction data 1= strongly agree, 2 = agree, 3 neither agree/disagree, 4 disagr1= strongly agree, 2 = agree, 3 neither agree/disagree, 4 disagree, 5 strongly disagreeee, 5 strongly disagree

Median (Range)

Previous XRT 4 Yes 3 no (3 NA)

Planning and treatment process uncomfortable 4 (3-5)

Inconvenient 4 (2-5)Process difficult 4 (4-5)

Difficulty lying in position 3.5 (1-5)Took a long time 3.5 (2-5)

Efficient 2 (1-5)Satisfied with care 1 (1-2)

Clinical Advantages of 1 Step Online Clinical Advantages of 1 Step Online Planning and TreatmentPlanning and Treatment

• 1 step (less handoffs)• Time efficiency from Institutional perspective• Weekend on call

– Minimize pt transfer between units when staff minimal– Do not require staff trained to operate both CT Simulator

and RT treatment unit• Same day Sim + Treatment start• Minimize delays due to sequencing between systems• Could potentially be used in developing countries

for 3D simulation and Planning

Thank You forThank You for Your AttentionYour Attention