sbrt and pancreas cancer la belle et la bête€¦ · – 23 lapc – 3 lrpc • mean age 70 (range...

SBRT and Pancreas Cancer

La Belle et la Bête

Gert Meijer

la Bête

Controversial role of radiotherapy

• OS was not improved with CRT, 16.5 m vs. 15.3 m

(HR = 1.03[0.79-1.34], p=0.83)

How about the radiotherapy in LAP07?

• All patients treated with 3D-CRT

• Margin on GTV was 3 cm sup-inf and 2 cm radially

• No prophylactic RT to the nodes

• The investigators conclude in the presentation that RT still has an important role in LAP, however they advocate for novel delivery modalities

How about the SBRT?

• patient friendly • non-invasive • hypofractionated

• high dose to central • low dose to organs at risk

How about the SBRT?

How about the SBRT?

How about the SBRT?

Can we cure all patients? - NO!

Can we cure a few patients? - Maybe…. How about palliation? - Hopefully…

poor target definition

poor OAR definition

poor online image guidance

target moves

OARs move too

closeby radiosenstive OARs

What hurdles to take?

poor target definition

poor OAR definition

poor online image guidance

target moves

OARs move too

closeby radiosenstive OARs

What hurdles to take?

poor target definition

poor OAR definition

poor online image guidance

target moves

OARs move too

closeby radiosenstive OARs

What hurdles to take?

Heerkens et al. R&O 2014

poor target definition

poor OAR definition

poor online image guidance

target moves

OARs move too

closeby radiosenstive OARs

What hurdles to take?

Pancreas cancer has been identified as one of key tumor sites within MR-linac consortium

? Sept 2015 Houston

MRI-guided SBRT with for locally advanced pancreatic cancer: a feasibility and safety study Add MRI for target definition and definition organs at risk

1

MRI-guided SBRT with for locally advanced pancreatic cancer: a feasibility and safety study Use gold markers for image guidance during treatment

Acknowledgements Eelco Lens AMC Amsterdam

2

MRI-guided SBRT with for locally advanced pancreatic cancer: a feasibility and safety study Use abdominal corset to reduce motion and measure residual motion with cine MRI

3

MRI-guided SBRT with for locally advanced pancreatic cancer: a feasibility and safety study Create SBRT plan with 3-mm GTV-PTV margins to 3x8Gy

4

MRI-guided SBRT with for locally advanced pancreatic cancer: a feasibility and safety study Blur dose with respiratory motion kernel to estimate effect breathing

breathing pattern 3 x breathing pattern 10 x breathing pattern

5

MRI-guided SBRT with for locally advanced pancreatic cancer: a feasibility and safety study

6

Results

Results

80% intrafraction motion < 3 mm

• 26 patients

– 23 LAPC

– 3 LRPC

• mean age 70 (range 50 -85)

• 13 patients died

• 7 patients developed metastases (1 is still alive)

• No treatment related grade 3 toxicity within 90 days

• One grade 2 pancreatitis due to seed procedure

Results

• Our SBRT regimen is very well tolerated

• No improvement in LC/survival

• Increase dose!

So.....

4D MRI Coronal

Sagittal

Transverse

CC

mo

tio

n (

mm

)

Pancreatic motion

1) Stemkens B et al. ISMRM, 2013 2) Roujol S et al. IEEE TMI, 2011

Flow chart

Pre

-be

am

imag

ing

Rad

iati

on

Transform 3D volume, based on 2D images, using

motion model

Full FOV 3D motion

information (x,y,z,t)

4D MRI acquisition (x,y,z,φ) Motion model

Acquire 2D cine MR images

Warped 3D volume (model)

2D coronal slice (acquired)

So in the end with the MR-linac we are working towards dose deliveries to pancreas tumors with the same accuracies as we currently do in brain Hopefully this will result in a clinical benefit for (a subset of) LAPC patients

Acknowledgements: Hanne Heerkens Bjorn Stemkens Rob Tijssen Marco van Vulpen

Baudouin Denis de Senneville Nico van den Berg Jan Lagendijk Eelco Lens (AMC)

Beth Erickson (MCW) William Hall (MCW)