Diagnosis and localization of parathyroid adenomas using 16-slice SPECT/CT: A clinicopathological correlation

INTRODUCTION

This study aimed to evaluate a new 16-slice SPECT/CT scanner at Auckland City Hospital for its use in the detection and localization of parathyroid adenomas in patients with primary, secondary and tertiary hyperparathyroidism. The secondary outcome was to compare findings from SPECT/CT with ultrasound and operative findings.

METHODS

One hundred patients who underwent a SPECT/CT scan for primary/secondary/tertiary hyperparathyroidism were included in this study. Of these patients, 45 received surgery. SPECT/CT and ultrasound findings were collated for each patient, and of those who received surgery, operative and pathological findings were compared with those on SPECT/CT.

RESULTS

The sensitivity of diagnosis and localization was 86.5% (95% CI: 71.2-95.5%). Specificity was 25.0% (95% CI: 3.2-65.1%). Comparison between SPECT/CT and ultrasound findings demonstrated a kappa coefficient of 0.203 (95% CI: -0.036 to 0.442), correlating with fair agreement. These figures are in line with other published series.

CONCLUSION

The SPECT/CT scanner (and associated reporters) at Auckland City Hospital demonstrates high sensitivity in the detection and localization of parathyroid adenomas and is an effective first-line investigation in patients with primary/secondary/tertiary hyperparathyroidism.

99mTc-sestamibi SPECT/CT and 18F-FDG-PET/CT have similar performance but different imaging patterns in newly diagnosed multiple myeloma

PURPOSE

F-fluorodeoxiglucose (F-FDG)-PET/CT has been widely used to evaluate multiple myeloma. Tc-sestamibi (MIBI) scintigraphy has also been proposed for assessing multiple myeloma, but its use with state-of-the-art single-photon emission computed tomography/computed tomography (SPECT/CT) technology has not been fully evaluated.This study aimed to compare these two imaging modalities in multiple myeloma staging.

MATERIALS AND METHODS

Sixty-two patients with recently diagnosed multiple myeloma were submitted to whole-body F-FDG-PET/CT and whole-body MIBI scans plus SPECT/CT of the chest and abdomen/pelvis. Number of focal lesions, contiguous soft tissue involvement (CSTI), extramedullary lesions (EMLs) and diffuse bone marrow (BM) involvement were recorded.

RESULTS

PET/CT was positive in 59 patients (95%) and MIBI SPECT/CT in 58 (93%) (P = 0.69). MIBI detected more diffuse bone marrow involvement than PET/CT (respectively 78 vs. 58% of the patients), while PET/CT demonstrated more focal lesions than MIBI SPECT/CT (81 vs. 54% of the patients) (P = 0.002). PET/CT detected EMLs in four subjects and MIBI in one subject. CSTI was found in 28 (45%) and 23 (37%) patients on PET/CT and MIBI images, respectively (P = 0.36). Three patients with lytic lesions and no FDG uptake were MIBI positive, and two subjects with lytic lesions without MIBI uptake were FDG positive.

CONCLUSION

MIBI SPECT/CT performs similarly to F-FDG-PET/CT in identifying sites of active disease in multiple myeloma staging. MIBI is more efficient than FDG for detecting the diffuse involvement of bone marrow but less efficient for detecting focal lesions. Some patients presented a 'mismatch' pattern of FDG/MIBI uptake.