PET. Can we afford PET-CT. Positron annihilation. PET-CT scanner. PET detection

(1)

Can we afford PET

-

CT

John Buscombe

PET

-

CT

New technology

Combines

–

–functional information-functional information-PETPET –

–anatomical information-anatomical information-CTCT

Machine able to perform both studies

in single imaging episode

PET imaging depends on positron

decay

PET

Positron Emission TomographyPositron Emission Tomography

Positrons positively charged electronsPositrons positively charged electrons

Travel 0.001-Travel 0.001-1mm hit electron1mm hit electron

Annihilate e=mcAnnihilate e=mc2 2

2 x 511 kev2 x 511 kevgammas produced travel at 180 gammas produced travel at 180

degrees degrees

Detected by a ring of detectorsDetected by a ring of detectors

MainlyMainlyused in cancer imagingused in cancer imaging

Positron annihilation

PET detection

(2)

Inside a PET

-

CT scanner

How a PET

-

CT is used

Total imaging time about 20-30 minutes Low dose whole

body CT PET imaging in 2-4 “blocks” 5-8 minutes long

Use of PET in staging

FDG in Ca oesophagus

What are the costs in

PET

-

CT

The machine (US$ 2.6

-

4million)

–

–Cost depends on CT with machineCost depends on CT with machine –

–For localisation 2 slice sufficientFor localisation 2 slice sufficient

Even though slower because of time taken Even though slower because of time taken with PET imaging will not add much to time

with PET imaging will not add much to time

of total acquisition

of total acquisition –

–For CT perfusion imaging 16 slice betterFor CT perfusion imaging 16 slice better –

–For Cardiac PET-For Cardiac PET-CT 64 slice neededCT 64 slice needed

Example of cardiac CT

Costs of PET

-

CT

InstallationInstallation –

–Needs a big roomNeeds a big room –

–3 phase power supply3 phase power supply –

–AirAir--concon –

–Space for control room, injection room patient Space for control room, injection room patient waiting area (patients may need to be resting for

waiting area (patients may need to be resting for

2 hours between injection and scan so if scan

takes 20 minutes need 6 patient bays (beds not

(3)

Costs of PET

-

CT

Staff Staff

–

–Here South Africa costs are lowHere South Africa costs are low –

–In USA/UK Costs are higher In USA/UK Costs are higher

RadiopharmaceuticalRadiopharmaceutical –

–Most commonly used FMost commonly used F--18 FDG18 FDG –

–Cyclotron producedCyclotron produced –

–2 hour half life2 hour half life –

–Needs quick deliveryNeeds quick delivery –

–Cost US$400Cost US$400--US$800US$800

Delivery of isotope in UK

Though three cyclotrons would cover much of the main cities of SA in terms of delivery times of F-a8 FDG Many provinces would have little or no cover

Delivery of isotope in UK

Though three cyclotrons would cover most of UK In fact 5 sites would cover over 97% of the population

Delivery of isotope in UK

This is the actual situation

Delivery of isotope in UK

This is the Plan for 2010

So how much does it cost

Depends on many factors but price per

scan normally rated at between

US$1000 and US$3000

South Africa will be closer to US$1000

UK in the middle, US and Germany

closer to US$3000

(4)

Can PET

-

CT be

afforbable

Depends on how it is usedDepends on how it is used

Overall sensitivity and accuracy of PET-Overall sensitivity and accuracy of PET-CT is CT is

normally 10

normally 10--20% higher than CT or MRI20% higher than CT or MRI

This means that is may find sites of This means that is may find sites of

unexpected metastatic cancer unexpected metastatic cancer

Prevents expensive and unnecessary Prevents expensive and unnecessary

operations operations

Look at example of lung cancerLook at example of lung cancer

Can we trust PET

-

CT

Prospective comparative study of staging Prospective comparative study of staging

with PET, PET

with PET, PET--CT and CT aloneCT and CT alone

Performed in LeuvanPerformed in LeuvanBelgium (de WeverBelgium (de Weveret et

al

al EurEurRadiolRadiol2006)2006)

50 patients with “50 patients with “curablecurable””NSCLC studiedNSCLC studied

Results compared with pathology at surgeryResults compared with pathology at surgery

Looked at local and distant nodesLooked at local and distant nodes

Local nodes PET-Local nodes PET-CT 80% CT 80% vsvs66% with CT66% with CT

Mets outside chest PET-Mets outside chest PET-CT 98% CT 98% vsvs88% 88%

with CT with CT

Correctly staged lung cancer

De

Wever

Eur

Radiol

2006

PET service in the management of

PET imaging in centres without

NSCLC.Is it cost effective?

O’Rourke E,Gnanasegaran G, Buscombe J R, *Riddleston M, Hilson A J W

Dept of Nuclear Medicine and *Oncology Royal Free Hospital, London

United Kingdom

Material and methods

Eighteen patients [8 males, 10 females] with Eighteen patients [8 males, 10 females] with

histologically proven NSCLC scanned 2004 histologically proven NSCLC scanned 2004

Mean age: 71 yearsMean age: 71 years

All the patients underwent whole body PET All the patients underwent whole body PET

and CT scans

and CT scansof chest and upper abdomenof chest and upper abdomen

Example 1

(5)

Example 1

CT Spiculated mass left upper lobe. CT Spiculated mass left upper lobe.

No obvious mediastinal disease No obvious mediastinal disease

Example 1

18 FDG 347

18 FDG 347 MMBqBq

FDG

FDG--avid lesion LUL; FDGavid lesion LUL; FDG--avid lesion right hilumavid lesion right hilum

Lung cancer upstaged

Lung cancer upstaged --> inoperable> inoperable

Example 2

Mass Left Base Mass Left Base

Example 2

Mass left lower lobe, enlarged nodes AP window

Example 2

18 FDG PET 350 18 FDG PET 350MBq MBq

Outcome of 18 patients with potentially curable non-small cell lung cancer

18 patients with curable disease?

PET-CT scan 10 positive for metastases on PET-CT no operation 8 operated on 2 PET-CT positive in mediastinum 6 PET-CT negative for metastasis

(6)

Conclusion

PET was shown to change patientPET was shown to change patient’’s operability s operability

state in 7/18 (39%) state in 7/18 (39%)

Total saving of approx US$60,000 in this small Total saving of approx US$60,000 in this small

patient group

patient group ––US$3,300 per patientUS$3,300 per patient

If systematically used in UK would save US$20 If systematically used in UK would save US$20

million/year million/year

PET is a cost effective method in the PET is a cost effective method in the

management of NSCLC even in units where management of NSCLC even in units where there is no on site PET service available there is no on site PET service available

How does this compare

with other centres

Using PET to prevent surgery on

inoperable patients

Sloka

et al Newfoundland Canada,

Med

Sci

Monitor 2004

Using F

-

18 FDG PET in pre

-

op

assessment of NSCLC

Using PET/CT to correctly identify

curable patient saves US$1500/patient

Results from Australia

Yap et al EJNM 2005 Austin MelbourneYap et al EJNM 2005 Austin Melbourne

Looked at 200 patients with potentially Looked at 200 patients with potentially

operable NSCLC operable NSCLC

100 staged with mediastinoscopy100 staged with mediastinoscopy

100 with FDG PET and medistinoscopy100 with FDG PET and medistinoscopyif if

PET positive PET positive

Even though sensitivity of FDG PET was Even though sensitivity of FDG PET was

only 3% higher than CT and there was only only 3% higher than CT and there was only a 5% reduction on futile

a 5% reduction on futile medistinoscopiesmedistinoscopies

Total saving per patient was still US$2000Total saving per patient was still US$2000

Other cancer sites in which

PET_CT can be used in

staging

Oesophagus

Stomach

Colon

Ovary

Not useful for

– –ProstateProstate – –BreastBreast – –Pancreas, HCCPancreas, HCC

How else to save money

with PET

-

CT

Many treatments for cancer are expensiveMany treatments for cancer are expensive

Those that work are more expensiveThose that work are more expensive –

–RituximabRituximabUS$32,000 per yearUS$32,000 per year

–

–GemcitabineGemcitabineUS$24,000 per yearUS$24,000 per year –

–Also these drugs have marked side effectsAlso these drugs have marked side effects

PET can be used to predict early on in the PET can be used to predict early on in the

treatment if it is likely to work treatment if it is likely to work

If evidence no working treatment should be If evidence no working treatment should be

Has the treatment

worked

Treatments for haematological

malignancies expensive

Side effects severe including a

deth

rate of about 10

-

15%

Need to know was the treatment

worth it?

(7)

Residual mass in

axilla

POST

-

TREATMENT EVALUATION

Jerusalem et al, Blood, 1999

54 patients (NHL + HD)

Median follow-

Median follow

-up: 23 months

up: 23 months

Positive predictive value: 100%

Negative predictive value: 83%

0 10 20 30 40 50 0 20 40 60 80 100 P<0.0001 Negative PET Positive PET Duration (months) P rop or ti o n sur v iv in g pr og ress io n -f ree ( % )

Progression free survival related to PET response

EARLY TREATMENT

EVALUATION

PET predicts prognosis after

1 cycle

KostakogluKostakogluet al, et al, J.Nucl.MedJ.Nucl.Med., 2002., 2002

1 1-

-2 cycles

2 cycles

TorizukaTorizukaet al, EJNMMI, 2003et al, EJNMMI, 2003

2 cycles

ZijlstraZijlstraet al, et al, Br.J.HaematolBr.J.Haematol., 2003., 2003

2 2-

-3 cycles

3 cycles

Jerusalem et al, Jerusalem et al, HaematologicaHaematologica, 2000, 2000

2 2-

-4 cycles

4 cycles

MikhaeelMikhaeelet al, et al, LeukLeuk. Lymphoma, 2000. Lymphoma, 2000

3 3-

-4 cycles

4 cycles

SpaepenSpaepenet al, Ann. et al, Ann. OncolOncol., 2002., 2002

F-18 FDG PET after 1st cycle in ABVD in HD

After 1 cycle After completion Category 18_F-FDG PET+ 18_F-FDG PET-18_F-FDG PET+ 18_F-FDG PET-Relapse Remission Total Median PFS (mo) 9 1 10 5 2 11 13 Not 5 1 6 0 6 11 17 Not 18

18

_F

_-

_{FDG PET after 1 cycle}

_vs

_after

completion of chemotherapy

(8)

Potential savings

CR rate in HD about 60-CR rate in HD about 60-70%70%

Therefore at least 30% chemo wastedTherefore at least 30% chemo wasted

Cost per cycle about US$2000 including Cost per cycle about US$2000 including

drugs and administration (not side effects) drugs and administration (not side effects)

If chemo not given after 1If chemo not given after 1ststcycle if Fcycle if F--18 18

FDG positive saving per patient is US$10000 FDG positive saving per patient is US$10000

On average saving in 100 HD patients would On average saving in 100 HD patients would

be US$100,000 be US$100,000