Fig. 3

Depiction of a representative case (Patient 15). Patient 15 was a 61-year-old man who had been treated for bone metastasis of prostate cancer at our hospital. After being administered denosumab 15 times, the patient complained of mandibular pain while wearing a mandibular denture. No gingival swelling or bone exposure is observed in tooth number 32 (black arrow) (a). However, the tooth was tender on percussion. A panoramic radiograph shows a widening of the PDL space, suggestive of periodontitis, in tooth number 32 (black arrow) (b). The 2-h image for the first SPECT shows an SUVmax of 16.45 and strong accumulation in the midline of the mandible (c). In the 3-h image for the first SPECT, both the SUVmax of the parietal bones and SUVmax of the jawbone lesions are highly equivalent to the SUVmax of the corresponding 2-h images (d). In the second SPECT (2-h image), which was obtained 3 months later, improvement is observed in the lesion (SUVmax, 12.72). However, the SUVmax of the parietal bones has not changed (e). In the second SPECT, as in the first SPECT, the SUVmax of the parietal bones and the jawbone lesions show high equivalence in the comparative imaging evaluations of the 2-h and 3-h images (f). PDL, Periodontal ligament; SPECT, single-photon emission computed tomography; SUVmax, maximum standardized uptake value