Usefulness of three-phase bone scintigraphy and SPECT/CT for the diagnosis of bone lesions of systemic sarcoidosis

We report a three-phase bone scintigraphy for the diagnosis of a peripheral bone lesion caused by systemic sarcoidosis. A 32-year-old man with suspected osteomyelitis of the right forefinger underwent three-phase bone scintigraphy with Tc-99m hydroxymethylene diphosphonate [HMDP] and single-photon emission computed tomography/computed tomography [SPECT/CT]. The lesion was rich in blood flow according to flow study and blood pool study on bone scintigraphy, and was associated with an osteolytic change on SPECT/CT imaging performed 3 hours after injection of a radioisotope [RI]. Whole-body bone scintigraphy indicated multiple high levels of abnormal RI accumulation. The findings of the three-phase bone scintigraphy and SPECT/CT suggested the presence of systemic sarcoidosis; however, a subsequent 18Ffluorodeoxyglucose positron emission tomography/CT [FDG-PET/CT] could not exclude the possibility of multiple metastases from testicular tumors. Therefore, testicular enucleation was performed, and the pathological examination confirmed the presence of sarcoidosis

Subcutaneous extravasation of Sr-89: usefulness of bremsstrahlung imaging in confirming Sr-89 extravasation and in the decision making for the choice of treatment strategies for local radiation injuries caused by Sr-89 extravasation

A male patient in his 20s presented at our clinic with pain caused by bone metastases of the primitive neuroectodermal tumor, and Sr-89 was administrated to palliate the pain. After receiving the injection, the patient complained of a slight burning pain at the catheterized area. Slight reddening and small circular swelling [diameter, 0.5 cm] were observed at the catheterized area. Sr-89 extravasation was suspected. To estimate the amount of subcutaneous Sr-89 leakage, bremsstrahlung imaging was immediately performed. We speculated that the skin-absorbed dose from the subcutaneous Sr-89 leakage was 1.78 Gy. The mildest clinical sign of local radiation injury was erythema. The received dose was higher than 3 Gy, and the time of onset was from 2 to 3 weeks. In our patient, local radiation injuries [LRIs] did not occur. Though requiring further verification, subsequent bremsstrahlung imaging and estimation of the skin-absorbed dose from the subcutaneous Sr-89 leakage are useful in confirming Sr-89 extravasation and in the decision making for the choice of treatment strategies for LRIs caused by Sr-89 extravasation