Aim. The aim of this study was to evaluate the clinical feasibility of three-dimensional gated blood pool scintigraphy (3D GBPS) on a 3D-ring cadmium zinc telluride (CZT) single photon emission computed tomography(SPECT)/computed tomography (CT) system for the assessment of left ventricular function. Clinical feasibility was evaluated in a patient study comparing 3D GBPS on a 3D-ring CZT SPECT/CT system to two-dimensional (2D) planar multigated acquisition (MUGA) on a conventional dual-head sodium iodide (NaI) gamma camera. Acquisition and reconstruction protocols were optimized for 3D GBPSon a3D-ring CZT SPECT/CT system for clinical application.

Methods. Patients referred for 2D planar MUGA to assess left ventricular function as part of their clinical work-up were prospectively enrolled. Patients received 550 MBq technetium-99m-labeled human serum albumin and underwent both 2D planar MUGA on a conventional dual-head NaI gamma camera and 3D GBPS on a 3D-ring CZT SPECT/CT system in direct succession. Left ventricular ejection fraction (LVEF), end-diastolic volume (LVEDV), and end-systolic volume (LVESV) were assessed on both systems. Correlations and systematic differences in LVEF, LVEDV, LVESV between the systems were evaluated. Acquisition optimization was performed by retrospectively reducing acquisition time using list-mode data, and assessing its impact on LVEF accuracy. Reconstruction parameters were optimized based on image quality and agreement of LVEF accuracy.

Results. Ten patients were included. An acquisition and optimized reconstruction protocol was established: 15-minute acquisition time, 16 RR bins, focus mode and ordered subset expectation maximization (OSEM) with 6 iterations, 10 subsets, voxel size 4.92 mm, no scatter correction, and no post-reconstruction filtering. 3D GBPS yielded significantly higher median LVEF values compared to 2D planar MUGA (73.5% vs. 61.5%, p < 0.05) and significantly lower LVESV values (22.0 mL vs. 46.0 mL, p < 0.05), while LVEDV values were comparable between modalities (91.5 mL vs. 93.5 mL, p > 0.05). Correlation between the two systems was poor for LVEF (ρ = 0.20), moderate for LVEDV (ρ = 0.46), and absent for LVESV (ρ = 0.10). No significant difference in LVEF was observed between 75% and 100% acquisition times, with the strongest correlation at 75% (ρ = 0.96). Significant differences and lower correlations were found at 50% (ρ = 0.92) and 25% (ρ = 0.82) compared to 100%.

Conclusion. 3D GBPS on a 3D-ring CZT SPECT/CT system yielded systematically higher LVEF and lower LVESV values compared to 2D planar MUGA on a conventional dual-head NaI gamma camera, indicating that the two methods are not interchangeable. Acquisition time could potentially be reduced by 25%, from 15 to 11 minutes, without affecting LVEF accuracy. Our findings suggest that 3D GBPS is clinically feasible, but further validation is required.

Thermal ablation is an effective treatment for hepatocellular carcinoma (HCC), the most common type of primary liver cancer. However, early recurrence (ER) after treatment for HCC remains a significant challenge. This study aimed to (1) establish a robust and reproducible pipeline for prognostic model development, and (2) apply this pipeline to develop a preliminary model predicting ER in a Western HCC-cohort. Clinical data and contrast-enhanced pre- and post-ablation CT-scans from the Dutch multicentre PROMETHEUS cohort were used. Predictors included clinical characteristics, radiomics predictors, deep learning (DL) based predictors from two pre-trained models (ResNet18 and VGG16), and the minimal ablation margin (MAM). Cox regression models were constructed using principal component analysis (PCA) and regularised predictor selection (LASSO). Model performance was internally validated using bootstrapping and evaluated with the concordance index (C-index), calibration plots, and decision curve analysis. Using the developed pipeline, several individual and combination models were developed. The highest C-index in the validation sets was achieved by the model incorporating radiomics predictors and the MAM, which was trained on data from 68 patients (C-index = 0.63, 95% CI: 0.44 – 0.79). Despite promising performance in training sets, all models showed signs of overfitting and limited calibration in unseen data. The pipeline adheres to current guidelines and supports further refinement and validation. An externally validated prognostic model could help personalise treatment and follow-up strategies after thermal ablation in western HCC patients.