Volumetric analysis of mandibular lesions with SPECT/CT: a pilot clinical study of maximum standardized uptake value

Introduction
This study was designed to investigate mandibular lesions using volumetric analysis with bone single-photon emission computed tomography/computed tomography (SPECT/CT).

Material and methods
Eight patients with mandibular lesions underwent SPECT/CT scan acquisition 4 hours after injection of Tc-99m hydroxymethylene diphosphonate (HMDP). Regarding volumetric analysis, maximum standar­dized uptake value (SUV) was obtained using software and a workstation (Q.Volumetrix MI and GEniE-Xeleris 4 DR, respectively). The localization and size of the volume of interest (VOI) can be drawn over the lesion, mesial, distal, and opposite side as normal using the CT, SPECT, and SPECT/CT transaxials, coronals, and sagittals as the anatomical reference. Q.Volumetrix MI can analyse SUV of lesions by organ segmentation using optional pan and zoom imaging. Then, the dosimetry software provided multiple quantitative data for a given VOI. Statistical analyses for the maximum SUV were performed by Mann-Whitney U test. A p-value lower than 0.05 was considered as statistically significant.

Results
Maximum SUVs for medication-related osteonecrosis of the jaw (n = 4, 25.4 ± 4.9), chronic osteomyelitis (n = 3, 14.6 ± 3.1), and squamous cell carcinoma (n = 1, 31.7) were significantly higher than those of the opposite side as normal mandible (3.8 ± 0.7, 4.6 ± 1.8, and 7.4, respectively; p = 0.000).

Conclusions
Volumetric analysis with SPECT/CT could be useful for the evaluation of mandibular lesions, such as detecting and surgical planning.