Spectroscopic Window on Spectroscopic Window on Tumor MetabolismTumor Metabolism

Michael Garwood, Ph.D.Michael Garwood, Ph.D.Univ. of MinnesotaUniv. of Minnesota

Role of MRS in the Clinical Management of Cancer

• Diagnosis: guide biopsy avoid unnecessary/risky biopsies ascertain aggressiveness/stage/prognosis

• Treatment: guide choice of treatment identify non-responders early

→ alter treatment regime tool for follow up

Ackerstaff et al., J Cell Biochem 2003

High Res 1H MRS of CellsNon-Malignant cells Malignant cells

extract

in vitro

GPC → PCho switchAboagye et al., Cancer Res 1999

R-CH2-CH2-N-CHH

H

CH H H

-

H H H

-

C

+

Choline-containing compounds

lipids

suppressed water

lipid

Cholinecompounds

(tCho)

Frequency (ppm)

1H MRS

invasive ductal carcinoma

MRI

CMRR 4 Tesla

In vivo 1H MRS of breast cancerFirst reported studies: Roebuck et al, Radiol 1998; Gribbestad et al, JMRI 1998

Jacobs MA, Barker PB, et al. Proton magnetic resonance spectroscopic imaging of human breast cancer: a preliminary study. J Magn. Reson Imaging. 2004 Jan;19(1):68-75

BenignFocalFibrosis

Infiltrating ductal carcinoma P < 0.0008

Membrane Choline Phospholipid Metabolism

Adapted from Aboagye EO, Bhujwalla ZM. Cancer Res 59:80-84 1999

Lysophosphatidic acid

Mechanisms of increased PC in cancer:

• Increased expression and activity of choline kinase [Ramirez de Molina et al., Oncogene 2002]

• Higher rate of choline transport [Katz-Brull & Degani, AntiCancer Res. 1996]

• Increased PLD activity [Noh et al., Cancer Lett. 2000]

• Increased PLA2 activity [Guthridge et al., Cancer Lett. 1994]

Glioblastoma Multiforme (High Grade Tumor)

Cho

NAA Lac

FLAIR

PPM 4.0 3.0 2.0 1.0

T1

Cho

CrNAA

Right

Left

slide courtesy of Peter Barker, Johns Hopkins U

Prostate Cancer

Normal human prostate

Tumor-bearing prostate

Cheng LL, FEBS Lett. 2001

MRI/MRSI Targeted, TRUS-Guided Biopsies

PSA - 12 ng/mlTwo prior negative biopsies

The sensitivity of TRUS guided biopsy is reduced in large prostates and when the cancer is located in difficult locations such as the apex or in the anterior or lateral aspects of the prostate.

555 5 5

MR targeted TRUS guided biopsy positive

Journal Urology 2000, 164(2) 400-404

The accuracy of cancer detection of MRI/MRSI targeted biopsy in men with prior negative biopsy ≈80%. (Yuen et al, J. Urol. 2004; Prando et al, Radiology 2005)

courtesy of J.Kurhanewicz, UCSF

13

Chemical Shift: Minimized with higher BW pulses

X Y Z

RF

Gra

die

nts

90 180 180

1800

Standard pulses

900

Spectrum

Center Frequency (-235 Hz)

F F

%CS : F / BWRF

F

Broadband pulses

Courtesy of: G. Metzger

14

OVS with over-prescription

Courtesy of: G. Metzger

15

Prostate Spectroscopy at 3T: Single Voxel Echo Time, Coupling and SNR

TE = 260 ms

TE = 100 ms

Courtesy of: P. Choyke & G. Metzger

16

Case Study: Slice 5

Cho

Sp

CreCit

Courtesy of: P. Choyke & G. Metzger

Quantification

• Metabolite ratios (eg, tCho/NAA, (tCho+Cr)/Cit)

• External reference (eg, phantom of known conc)

• Reference to tissue water signal

a)

0123456

b)

tCho

3 Tesla

Normal breastMRI Devices 4-ch coil

3x3x3 cm voxel

LASER Localization

TE Averaging (60-300ms in 128 increments)

NEX=2

Breast Anatomy

• Anatomy varies greatly

• Tissues are distributed heterogeneously

Intravoxel lipids are inevitable

Lobules

Fat StromaTavassoli, 1999

Adipose tissue

Fibroglandular tissue

Netter, 1997

Internal Referencing with Water

1 2

1 2

1[tCho]

gain T TtCho water water

water tCho watergain T T tCho

f f fA

A MWf f f

1 2

, # /

gain

T T

water tCho

water

A Time domain amplitude

f receiver gain correction

f f relaxation correction

nuclei molecule

MW molecular wt

[tCho] expressed in molal units (mmol tCho/kg water)

No assumptions about volume or density

• NOT assuming constant water concentration

• Assuming a two-compartment model (water & fat) and all tCho is in the aqueous compartment

Bolan et al., MRM 2003

Spectral Fitting

Adapted TDFDFit (Slotboom et al., MRM 1998)

Time-Domain Model:

Minimize residuals in frequency-domain over narrow (0.4 ppm) band

• Fit 3 peaks independently: tCho, water, 1.3 ppm lipid

• Errors from Cramer-Rao Minimum Variance Bound; used for detection threshold

model

data

residual

2 2( ) exp( )s t A i t i t t

6 4 02ppm

Bolan et al., MRM 2003

Normal gland (Presumed) [tCho] = 0.75 ± 0.07 mmol/kg

volume = 13.0 mLlipid fraction = 3.5%

Invasive Ductal Carcinoma[tCho] = 6.8 ± 0.1 mmol/kg

volume = 6.8 mLlipid fraction = 8%

Atypical Hyperplasia[[tCho] = 1.5 ± 0.8 mmol/kg

volume = 1.1 mLlipid fraction = 15%

Bolan et al., MRM 2003

6 5 4 3 2 1 0 -1 -2Frequency (ppm)

invasive ductal carcinoma

no C

ho

6 5 4 3 2 1 0 -1 -2

Frequency (ppm)

Reason for false negative? Spurious lipid sideband peaks!

invasive ductal carcinoma

Sideband Artifacts

-500 -500Hz-300 -100 100 300

TE

(m

s)

45

57

sidebands

water

sidebands

Sidebands have coherent, TE-dependent phase

Averaging causes destructive interference

Bolan et al., MRM 2002

• Antisymmetric side peaks

• Amplitude >1%

• Caused by B0 oscillation

Echo-time Averaging

ppm-20468

Conventionalsingle TE

TE averaging

NotCho

tCho?NEX=64

TE=45ms

TE=45-196ms64 increments

2

Bolan et al., MRM 2002

In vivo 1H spectrum of a voxel containing mainly adipose tissue

[Cho] = 0.642 mmol/kg

Voxel o

f just

the

enhancing re

gion[Cho] = 0.910 mmol/kg

[Cho] = 0 mmol/kg

Voxel of just the non enhancing

region

Day 127 (AC x 4 followed by Taxotere x 3)size = 3.0 x 2.7 x 3.0 cm3

[tCho] = 0 ± 1.73

Lipid

H2O Lipid

Lipid

7 123456 -10ppm

All 4 readers maintained their decision to biopsy

Invasive Ductal Carcinoma

SI

time (sec)

4

2

3

00

1

0 1 32 4 5

Precontrast Postcontrast Subtraction

tCho

time (min)

Meisamy et al, Radiology 2005

Conclusions about MRS for breast cancer diagnosis:

Adding quantitative 1H MRS to breast MRI improves sensitivity, specificity, and accuracy, over MRI alone

Quantitative 1H MRS is particularly useful in cases where lesion morphology and time-intensity curves are indeterminate

Meisamy et al, Radiology 2005

Treatment Planning and Monitoring

MRSI for Radiation Treatment Planning of Brain Tumor

Cho/Cr Grade Dose painting

<1 0

≥1-2 1 5040

≥2-3 2 5940

≥3 3 7020

MRSI-based radiation dose painting using the IMRT method

Thakur, Chang, Huang, Koutcher, NarayanaMemorial Sloan-Kettering Cancer Center

Models of tCho response

Measured acute response to PX-478 (inhibits HIF1-alpha production) in mouse xenografts of HT-29 (colon)

Methods: in vivo MRS at 4.7T, ex vivo validation

Results: tCho dropped significantly at 12 and 24 hrs

Jordan et al., NMR Biomed 2006 Al-Safar et al., Cancer Res 2006

Measured acute response to MN58b (inhibits CK) in mouse xenografts of MDA-MB-231 (breast) and HT-29 (colon)

Methods: in vivo MRS at 4.7T, ex vivo validation

Results: tCho dropped significantly at 48hrs in both models

PCho

CK

cell density

Neoadjuvant chemotherapy (primary systemic therapy, PST) is the preferred treatment for locally advanced breast cancer (Fisher et al. J Clin Oncol 1997, 1998)

Advantages:

Tumor shrinkage; possible breast conserving procedures

In vivo monitoring of chemo-sensitivity

(customize Tx complete pathologic response)

Treatment Monitoring in Breast Cancer

4T Tx Monitoring in Breast Cancer: Results to Date

• 14/18 Responders had a decrease in [tCho] at Day 1

• 9/10 Non-responders had a increase in [tCho] at Day 1

• Day 1 Rule: 82% accuracy in 28 subjects

0

1

2

3

4

5

6

7

8

9

[tC

ho

] (

mm

ol/

kg

)

0

1

2

3

4

5

6

7

8

9

Baseline Day 1 Baseline Day 1

Responders Non-Responders

[tC

ho

] (

mm

ol/

kg

)

Meisamy et al, Radiology 2004

Pre PST 24 hrs AC X 1 AC X 4

[tCho] = 4.6LD = 4.0 cm

[tCho] = 3.7LD = 4.0 cm

[tCho] = 0.9LD = 1.7 cm

Responder to AC

Meisamy et al, Radiology 2004

Pre PST 24 hrs AC X 1 AC X 4 Taxol X 2

[tCho] = 4.1LD = 1.7 cm

[tCho] = 4.6LD = 4.0 cm

[tCho] = 3.7LD = 4.0 cm

[tCho] = 0.9LD = 1.7 cm

Responder to AC, but not Taxol

Meisamy et al, Radiology 2004

cholinecitrate

Therapeutic Selection and MonitoringBaseline

Metabolic Atrophy

1 year

Metabolic Atrophy

5 years

courtesy of J.Kurhanewicz, UCSF

Is it possible to predict response from baseline MRS data?

Treatment Prediction / Phenotyping

Inconsistent findings in brain MRS:Tzika, Neuroradiology 2001 – responders had lower tChoPreul, Neurosurgery 2000 – no differenceLazareff, J Neurooncol 1999 – no difference

Baseline [tCho] was higher in responders than in non-responders (p=0.03)

Higher [tCho] @ baseline associated with higher grade & positive nodes

Can MRS identify responders before starting treatment?

0

1

2

3

4

5

6

7

8

9

[tC

ho

] (

mm

ol/

kg

)

0

1

2

3

4

5

6

7

8

9

Baseline Day 1 Baseline Day 1

Responders Non-Responders

[tC

ho

] (

mm

ol/

kg

)

Pretreatment 31P spectrum from nodal disease of a HNSCC patient who experienced partial response

Pre

trea

tmen

t P

ME

/NT

P r

atio

Pretreatment PME/NTP ratios from tumors;complete responders were different from incomplete response group P<0.001

Preliminary results with 31P MRSI

A. Shukla-Dave, et. al. Acad Radiol, 9:688-694, 2002

31P MRS in Bone Sarcoma

Zakian, et. al., Cancer Research 2003 Dec 15;63(24):9042-7

Baseline spectrum

Baseline Energetics Predicts Outcome in Bone Sarcoma

Zakian, et. al., Cancer Research 2003 Dec 15;63(24):9042-7

NTP/Pi predicts longer survival

Future:

• More studies correlating with pathology, immunohistochemistry, and outcomes

• Further studies to assess reliability/reproducibility

• Results of multi-center trials

• Combine with other metrics (DCE-MRI, ADC,…) → multiparametric analyses

• 3T (and higher?)

D a ta e x a m p le

C h o + C rC i

C h o C i

A

B

C

D

E

C h o + C rC i

C h o C iC h o + C rC i

C h o C i

A

B

C

D

E

F ig u re 3 . T h e a x ia l T 2 -w e ig h te d im a g e (A ) is u s e d fo r m a tc h in g v o x e l lo c a t io n s to h is to p a th o lo g ic a l s p e c im e n s (D ) . O n e o f th e s p e c tra l m a p s (B ) , p a r t ia lly e x p a n d e d in (E ) , re f le c ts th e q u a li ty o f th e M R S I d a ta th ro u g h o u t th e s lic e . D e v ia t io n s in th e ( C h o + C r) /C i m e ta b o lite ra t io m a p in (C ) la rg e ly c o rre s p o n d to th e tu m o rlo c a t io n in d ic a te d w ith th e b lu e lin e in (D ) .

Prostate spectroscopy at 1.5T with endorectal coil

IMAPS (1.5T)

The axial T2-weighted image (A) is used for matching voxel locations to histopathological specimens (D). One of the spectral maps (B), partially expanded in (E), reflects the quality of the MRSI data throughout the slice. Deviations in the (Cho + Cr)/Ci metabolite ratio map in (C) largely correspond to the tumor location indicated with the blue line in (D).

Courtesy of T. Scheenen and Prof. A. Heerschap, Radboud University Nijmegen Medical Center, Dept. of RadiologyThe IMAPS community

Slide courtesy of Michael Jacobs, JHU

Current Multiparametric (MRI/DTI/MRSI) Prostate Imaging Exam

Polyamines

Creatine

3.0PPM 2.02.5

Citrate

Choline

CholineCreatine

3.0 2.02.5

Lipid

Healthy Cancer

T2 weighted MRI

Diffusion weighted MRIADC Map

MRSI (0.3 cc)

Elevated cholineReduced citrateReduced polyamines

Decreased Signal Intensity on T2 weighted Imaging

Reduced water diffusion

Slide courtesy J. KurhanewiczUCSF

3T MRSI vs 1.5T MRSI: Improved Detection of Residual Cancer

3T 1.5T

Cho

ChoCho

Cho

Cho

0.16 cc 0.34 cc

Choline

Creatine

U of Minn ResearchersPatrick BolanGreg MetzgerSina MeisamyAdeka McIntoshCurt CorumAngela StyczynskiNate PowellDjaudat IdiyatullinJang-Yeon ParkCarl SnyderJames BoyumDoug YeeMichael NelsonTim EmoryLenore EversonTodd TuttleEvin GulbahceTommy Vaughan

Thanks for Sending SlidesArend HeerschapJason KoutcherJohn KurhanewiczMichael JacobsPeter BarkerWei Huang

Funding SourcesNational Institutes of Health (CA92004, RR08079)

Acknowledgements