Model-based selection of breast cancer patients for proton ......Apr 29, 2019  · Erik Korevaar, ir, PhD Jan Hietkamp Patrick Kalk Julius Center Utrecht Ewoud Schuit, PhD National

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Model-based selection of breast cancer

patients for proton therapy

Anne Crijns, MD, PhD

Department of Radiation Oncology

University Medical Center Groningen

Groningen

The Netherlands

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Disclosures

COI status Names of companies / organizations

① Post of executive / consultant No

② Stocks No

③ Patent royalties No

④ Stage moneys No

⑤ Manuscript fees No

⑥ Grant / Research funding YES Department of Radiation Oncology has research collaborations

with IBA, RaySearch, Siemens and Mirada

⑦ Other rewards No

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CASE 1

• BC patient of 61 years

- No cardiac risk factors

- Breast conserving surgery of the left

breast + sentinel node: pT1cN1mi(sn)M0

invasive carcinoma

- Parasternal uptake on scintigraphy

- Treatment

- Locoregional RT including internal

mammary chain

Photons: MHD 6.39

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CASE 2

• BC patient of 40 years

- Cardiac risk factor: BMI >30

- Breast conserving surgery of the left

breast + SN: pT1bN0(i+)M0 invasive

carcinoma

- Treatment

- Local RT

Photons: MHD 2.56

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CASE 3

• BC patient of 63 years

- Cardiac risk factors: BMI >30, diabetes,

hypertension, hypercholesterolemia

- Breast conserving surgery of the left

breast + SN: pT1cN1ma(sn)M0 invasive

carcinoma

- Treatment

- Locoregional RT

Photons: MHD 1.61

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• Proton therapy is an expensive treatment

• Limited available in the Netherlands

Model-based selection of breast cancer patients for

proton therapy based on model for acute coronary

events (ACE)

Indication for proton therapy?

Source: National Indication Protocol Proton Therapy Breast Cancer (The Netherlands, 2018)

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Model for acute coronary events

• Relative risk increases linearly by 7.4% / Gy MHD

• No dose threshold

• < 5 years after RT

Darby, N Engl J Med 2013

How to translate the relative risk

of 7.4 % / Gy into an excess risk

for an individual patient?

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Risk on ACE Excess risk in relation to baseline risk Dutch population

0%

5%

10%

15%

20%

25%

30%

35%

40%

0 1 2 3 4 5 6 7 8 9 10

Ris

k o

n A

CE

Mean heart dose (Gy)

Male with risk factors

Male without risk factors

Female with risk factors

Female without risk factors

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0%

5%

10%

15%

20%

25%

30%

35%

40%

0 1 2 3 4 5 6 7 8 9 10

Ris

k o

n A

CE

Mean heart dose (Gy)

Male with risk factors

Male without risk factors

Female with risk factors

Female without risk factors

Baseline risk

21%

5%

If dose = 10 Gy

If dose = 10 Gy

Excess risk: 3.8%

Excess risk: 15.6%

Risk on ACE Excess risk in relation to baseline risk Dutch population

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Ph

oto

ns

P

roto

ns

∆NTCP ≥2%

according

criteria

National

Indication

Protocol ?

Photons no

Protons yes

How does model-based selection work?

Plan comparison

MHD

PHOTON

plan

MHD

PROTON

plan

NTCP-model Selection

Source: National Indication Protocol Proton Therapy Breast Cancer (The Netherlands, 2018)

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CASE 1 pT1cN1mi(sn)M0 invasive carcinoma

Photons Protons

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CASE 2

pT1bN0(i+)M0 invasive carcinoma

Photons Protons

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CASE 3

pT1cN1ma(sn)M0 invasive carcinoma

Photons

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• Model for ACE will be further optimized

• Models for other late (cardiac) complications

- Heart failure

- Pneumonitis

- Secondary tumors

Better selection of BC patients for proton therapy

Model-based selection protons

UMC Groningen Protonen Therapie Centrum (GPTC) Acknowledgements

Department of Radiation Oncology

Prof. Hans Langendijk, MD, PhD

John Maduro, MD, PhD

Marleen Woltman, MD

Dianne Busz, MD

Max Beijert, MD

Olga Chouvalova, MD

Gertjan Stiekema, PA

Estelle Batin, ir, PhD

Erik Korevaar, ir, PhD

Jan Hietkamp

Patrick Kalk

Julius Center Utrecht Ewoud Schuit, PhD

National Platform Radiotherapy

Breast Cancer

National Platform Proton Therapy

a.p.g.crijns@umcg.nl