Whole body (WB) ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) images cellular glucose avidity and has shown clinical utility in breast cancer staging, restaging, and therapy response assessment. Quantitative and semiquantitative metrics, most notably the standardized uptake value (SUV), are integral to such applications. For accurate quantification in PET, images must have voxel intensities proportional to a corresponding activity concentration in the subject and are generated by the correction of emission data for count losses, noise, and the system response.

The combination of WB PET with x-ray computed tomography (CT) in a single platform (PET/CT) has been shown to have increased utility over either PET or CT alone for the management of breast cancer. The CT component allows for the creation of fused images, showing the location of ¹⁸F-FDG uptake on an anatomical background. With both WB PET and PET/CT, however, detection and quantification of tracer uptake is significantly reduced when lesions are small (< 1 cm diameter).</p>

In an effort to improve the performance of PET/CT for primary breast cancer imaging our group has constructed a hybrid dedicated breast PET/CT scanner, DbPET/CT. The goal of this research is to characterize and correct for the factors influencing image quantification in the PET portion of the system, and explore methods to improve quantification with alternative dedicated breast PET system designs.

As a proof-of-principle study and to measure the magnitude of factors influencing quantification in DbPET/CT imaging we performed a clinical trial with women highly likely to have breast cancer. Using the system performance results measured from this clinical trial as a guide, we developed hardware and software emission data correction schemes and validated these methods with custom performance measurements. Additionally, we used Monte Carlo simulations with anthropomorphic models to determine quantification trade-offs between alternative dedicated breast PET geometries.