Preoperative imaging in primary hyperparathyroidism: Are 11 C-Choline PET/CT and 99m Tc-MIBI/123 Iodide subtraction SPECT/CT interchangeable or do they supplement each other?

OBJECTIVE: Preoperative location of hyperfunctioning parathyroid glands (HPGs) is vital when planning minimally invasive surgery in patients with primary hyperparathyroidism (PHPT). Dual-isotope subtraction scintigraphy with 99m Tc-MIBI/123 Iodide using SPECT/CT and planar pinhole imaging (Di-SPECT) has shown high sensitivity, but is challenged by high radiation dose, time consumption and cost. 11 C-Choline PET/CT (faster with a lower radiation dose) is non-inferior to Di-SPECT. We aim to clarify to what extent the two are interchangeable and how often there are discrepancies. DESIGN: This is a prospective, GCP-controlled cohort study. PATIENTS AND MEASUREMENTS: One hundred patients diagnosed with PHPT were included and underwent both imaging modalities before parathyroidectomy. Clinical implications of differences between imaging findings and negative imaging results were assessed. Surgical findings confirmed by biochemistry and pathology served as reference standard. RESULTS: Among the 90 patients cured by parathyroidectomy, sensitivity was 82% (95% confidence interval [CI]: 74%-88%) and 87% (95% CI: 79%-92%) for Choline PET and Di-SPECT, respectively, p = .88. In seven cases at least one imaging modality found no HPG. Of these, neither modality found any true HPGs and only two were cured by surgery. When a positive finding in one modality was incorrect, the alternative modality was correct in approximately half of the cases. CONCLUSION: Choline PET and Di-SPECT performed equally well and are both appropriate as first-line imaging modalities for preoperative imaging of PHPT. When the first-line modality fails to locate an HPG, additional preoperative imaging with the alternate modality offers no benefit. However, if parathyroidectomy is unsuccessful, additional imaging with the alternate modality has merit before repeat surgery.

Assessment of myometrial invasion in endometrial cancer using three-dimensional ultrasound and magnetic resonance imaging.

INTRODUCTION: Preoperative knowledge of myometrial invasion in endometrial cancer is important for surgical planning. This study aimed to assess the diagnostic efficiency of two-dimensional (2D) and three-dimensional (3D) transvaginal ultrasonography (TVS) with and without saline infusion (SIS) and magnetic resonance imaging (MRI) for assessment of myometrial invasion in endometrial cancer. MATERIAL AND METHODS: 110 women with atypical endometrial hyperplasia or endometrial adenocarcinoma underwent preoperative 2D- and 3D-TVS with and without SIS and MRI. Offline 3D-TVS measurement was performed of the minimal tumor-free margin in relation to myometrial thickness expressed as deep (≥ 50%) myometrial invasion and subjective impression of cervix involvement. The quality of images was also evaluated. Diagnostic efficiencies were calculated for myometrial and cervical involvement for each method. The pathologist's final diagnosis served as the reference standard. RESULTS: For myometrial involvement, MRI showed greater accuracy than 3D-TVS or 2D-TVS (83, 71 and 75%, respectively). The efficiency of 3D-TVS was not superior to 2D-TVS and did not improve with SIS. The sensitivities of 2D-TVS and 3D-TVS were similar to that of MRI, and the efficiency of 3D-TVS improved when volumes of inadequate quality (39%) were excluded. For evaluating cervical involvement, the accuracy of 3D-TVS was 85%, comparable to the results of 2D-TVS (80%) and MRI (85%). The results did not improve when saline was added. CONCLUSION: 3D-TVS or 3D-SIS was not more efficient than 2D-TVS or MRI for assessment of myometrial invasion in endometrial cancer. 3D-TVS assessment without 2D-TVS was impeded by difficulties in obtaining 3D-TVS volumes of sufficient quality.