Abstract
Increased accessibility and recent developments in positron emission tomography (PET) detector technology have enhanced PET's role in radiotherapy treatment planning. This study investigates the efficacy of silicon photomultiplier (SiPM) PET systems for improving volume delineation. The study used a modified NEMA IEC Body Phantom filled with fluorodeoxyglucose (F-18-FDG) imaged using both a digital SiPM-based PET scanner and a non-digital, photomultiplier tube PET scanner. Results show distinct differences in target volumes determined using the two systems, with the digital system consistently demonstrating larger delineated target volumes between 1.91 - 3.56 times larger than that of the non-digital system. Target volumes delineated by the digital system were more reflective of the true geometric volume of the spheres with a range between 440 mm(3) and 984 mm(3) versus 209 mm(3) and 419 mm(3) for the non-digital system compared to the geometric volume of the spheres which was 2156 mm(3). This was most pronounced for higher sphere-to-background activity concentration ratios and smaller structures. This study suggests that digital PET allows for better selection of appropriate cancer treatment and could offer benefits for targeted radiation therapy.