PET/CT

PET/CT imaging : 

PET/CT imaging

Why PET/CT? (Positron Emission Tomography) : 

Why PET/CT? (Positron Emission Tomography) Dual opposing photons allow localization without collimators-better sensitivity than SPECT. Positron emitters can be tagged to basic physiological compounds like glucose. Covers essentially different clinical territory to most of standard Nuclear Medicine. Shows tumour metabolism. Addition of CT improves localization, attenuation correction.

Basic Applications for 18FDG : 

Basic Applications for 18FDG Carcinoma, lymphoma staging and follow up. Other uses – myocardial viability - gold standard but MIBI more cost-effective. Cerebral metabolism – epilepsy. Limited application. Assist in radiotherapy planning Absolute quantitation possible.

Referral Trends : 

Referral Trends Roll out of regional radiotherapy services not matched by oncology diagnostic support such as MR and PET. Metropolitan centres at full capacity- many country patients. Ideal positioning in existing oncology centre (Morris, 1999). Captive market- whole of catchment area will have comprehensive oncology service without travelling. In-town Oncologist support- referring levels guaranteed. Reduction in treatment delays possible.

Problems : 

Problems Supply and cost of 18FDG – 1 hour from cyclotron is feasible for moderate daily workload taking decay into account. Half life under 2 hours. Capital cost – Shielding for 511 keV plus equipment. Profitability – dependent on Medicare site rebateability. Hybrid PET/CT machine can fall back to diagnostic CT only function. Staffing – lead time for training, shortage of physicians.

P.E.T. Adding value in oncology services. : 

P.E.T. Adding value in oncology services. Proven value in Australia in various oncology applications (Hicks et al., 1999). Staging and follow up, response to therapy. Ca lung, melanoma, head & neck, gastrointestinal. In up to 60% of Ca lung patients, management significantly influenced by the PET scan result (Hicks et al., 1999). Clinical service model rather than research.

Cost Effectiveness : 

Cost Effectiveness Proven clinical benefits versus cost involved in major applications (Gambhir et al., 1999). Partially due to reduction in unnecessary surgery in Ca lung (Verboom et al., 2003). Flow-on effect to other imaging modalities as patients stay in town for complete workup and therapy - increased revenue offsets PET costs.

Economic Viability : 

Economic Viability Only do for major clinical indications – core clinical service to improve fiscal viability. Success dependent on availability of Medicare rebate for site. Recent Government reviews flag increased funding. Reviews rely on evidence base (Ware et al., 2004). Accessibility to rebates likely to improve in 2007-2008. Involvement of Oncologists and community in funding and promotion.

Conclusion : 

Conclusion A PET service will greatly enhance the delivery of oncology services in the region. And strengthen the practice’s reputation as a comprehensive provider. Clinical and cost effectiveness in major indications have been proven (eventually) and Government coming on board slowly.

References : 

References Gambier SS, Hoh CK, Phelps ME, et al. (1996), ‘Decision tree sensitivity analysis for cost-effectiveness of FDG-PET in the staging and management of non-small-cell lung carcinoma.’ Journal of Nuclear Medicine, vol. 37, pp. 1428-1436. Hicks RJ, Bins DS, Fawcett ME, Ware RE, Kalff V, McKenzie AF, Zalcberg JP, Peters LJ (1999), ‘Positron emission tomography (PET): experience with a large-field-of-view three-dimensional PET scanner.’ Medical Journal of Australia, vol. 171, pp. 529-532. Morris JG (1999), ‘The stage is set for the diffusion of positron emission tomography (PET) in oncology’. Medical Journal of Australia, vol. 171, pp. 527-528. Verboom P, Tinteren H, Hoekstra OF, Smit EF, Bergh JH, Schreurs AM, Stallaert RA, Velthoven PC, Comans EF, Diepenhorst FW, Mourik JC, Postmus PE, Boers M, Grijseels EW, Teule GJ, Uyl-de Groot CA (2003), ‘Cost-effectiveness of FDG-PET in staging non-small cell lung cancer: the PLUS study’, European Journal of Nuclear Medicine and Molecular Imaging, vol. 30, no. 11, pp. 1444-1449. Ware RE, Francis HW, Read KE (2004), ‘The Australian Government’s Review of Positron Emission Tomography: evidence-based policy-making in action.’ Medical Journal of Australia, vol. 180, no. 12, pp. 627-632.