Investing in new technology: the PET experience

As funding available to health services is limited, demonstrating the cost effectiveness of new technologies is an important step in their introduction. This is especially challenging for diagnostic technologies, for which the usual paradigm of reliance on well-designed, randomised controlled trials may not be appropriate. A recently completed Health Technology Assessment of fluorine-18 deoxyglucose (FDG)-positron emission tomography (PET) imaging in cancer management, focused on addressing whether the introduction of PET imaging would be beneficial to patients in the NHS in Scotland, exemplifies some of the challenges. Although a substantial body of published literature exists for this technology, most of the studies report diagnostic accuracy rather than improved patient outcomes. Direct evidence that such improvement occurs, and is sufficient to meet the NHS' criteria for cost effectiveness, from well-designed trials would constitute the most immediately persuasive case for the introduction of PET imaging. In the absence of such evidence, collaboration is required between a variety of disciplines to synthesise evidence from a variety of sources to create informative decision models that estimate long-term patient outcomes. The use of such decision models enabled the Health Technology Board for Scotland (now a part of NHS Quality Improvement Scotland) to determine that FDG-PET imaging is likely to be cost effective in selected applications and identified long-term patient benefits that it would not be possible to study in a randomised controlled trial.