Next-generation stationary full-ring SPECT/CT: enhancing theranostic quantification and 4D dynamic volumetric imaging

While novel full-ring SPECT systems are increasingly being applied in clinical settings, there is a critical lack of intra-individual, head-to-head comparative studies between these advanced platforms and conventional dual-head SPECT. Consequently, their definitive impact on clinical diagnostic and therapeutic decision-making remains unclear. To address this gap, we conducted an intra-patient head-to-head comparison to evaluate the image quality, diagnostic yield, and quantitative performance of a stationary full-ring SPECT/CT platform across several clinical applications. A prospective, randomized, intra-patient crossover study was conducted in 30 patients undergoing SPECT/CT. Patients were imaged sequentially using a novel stationary full-ring SPECT/CT system (AIMS Epoch 310) and a conventional dual-head camera (GE-D870). The clinical cohort encompassed bone scintigraphy, thyroid imaging, myocardial perfusion imaging, dynamic renal scintigraphy, and post-radioligand therapy (RLT) imaging ( 131 I and 177 Lu-PSMA). Diagnostic yield, signal-to-noise ratio (SNR), and lesion detection rates were evaluated comparatively. The stationary full-ring system showed higher image quality and diagnostic metrics compared to the conventional system. In bone scintigraphy, the full-ring platform detected 20.0% additional metastatic lesions that were occult on the dual-head system, corresponding to a 1.7-fold increase in SNR ( P = 0.010). In theranostic applications, the platform significantly enhanced the delineation of metastatic foci, demonstrating 3.2-fold and 4.8-fold higher SNRs for 131 I and 177 Lu imaging, respectively ( P < 0.05). Furthermore, synchronous four-dimensional volumetric dynamic acquisition yielded glomerular filtration rate (GFR) estimates that were 26.2% higher than those obtained using the traditional two-dimensional planar Gates method ( P < 0.05). The stationary full-ring SPECT/CT architecture may reduce some limitations associated with conventional dual-head systems, showed potential value for clinical advantages in oncologic staging and theranostic dosimetry. By ensuring broad-spectrum quantitative accuracy and enabling synchronous 4D volumetric imaging, this platform may provide additional technical options for quantitative SPECT/CT and functional imaging, although further validation in larger cohorts is required.