Refining the role of presurgical PET/4D‐CT in a large series of patients with primary hyperparathyroidism undergoing [18F]Fluorocholine PET/CT.

Background Methods Results Conclusions 4D‐CT has garnered attention as complementary imaging for patients with primary hyperparathyroidism (pHPT). Herein we evaluated a diagnostic strategy using [18F]Fluorocholine Positron Emission Tomography/Computed Tomography (PET/CT), followed by 4D‐CT integrated into PET/4D‐CT after negative/inconclusive PET/CT results in a single‐center retrospective cohort of 166 pHPT patients who underwent parathyroidectomy after [18F]Fluorocholine PET/4D‐CT.PET/CT and 4D‐CT images were interpreted by three nuclear medicine physicians and one expert radiologist. Pathological findings were documented, and concordance rates were assessed. PET/CT results were categorized as positive/negative, with positive cases rated on a 3‐level certitude scale: low, moderate, high. Inconclusive cases included low/moderate positivity. The added value of PET/4D‐CT was assessed for negative/inconclusive cases through joint reading.PET/CT lesion‐based analysis showed almost perfect interobserver concordance (Cohen's kappa >.8). Across the cohort, PET/CT had a sensitivity of 83%, specificity of 97%, PPV of 90% and NPV of 94%. For 4D‐CT, these values were sensitivity: 53%, specificity: 84%, PPV: 56% and NPV: 82%. PET/CT was significantly more accurate than 4D‐CT. Among 44 patients with negative/inconclusive results, PET/CT had sensitivity: 60%, specificity: 91%, PPV: 71% and NPV: 86%. In the same patients, sensitivity and specificity of the sequential diagnostic algorithm increased to 80% and 97%, showing significantly better global accuracy (92% vs. 83%) than standard PET/CT.We support a personalized imaging algorithm for pHPT, placing [18F]Fluorocholine PET/CT at the forefront, followed by 4D‐CT integrated into PET/4D‐CT in the same imaging session for negative/inconclusive results. When PET/CT results are clearly positive, the additional sensitivity benefit of 4D‐CT is minimal. [ABSTRACT FROM AUTHOR]