Objective: The use of technetium-99m methylene diphosphonate single-photon emission tomography/computed tomography (99mTc-MDP SPECT/CT) of the spine and sacrum has increased over the past years; however, there is little information about the optimal clinical role and true clinical impact of this modality.
Methods: All 99mTc-MDP SPECT/CT examinations of the spine and sacrum performed at our large multispecialty institution between 1 January 2008 and 12 April 2012 were identified. The indications, findings, clinical context, and impact on patient management were identified through a retrospective chart review.
Results: Of the 212 99mTc-MDP SPECT/CT examinations of the spine and sacrum identified, 191 (90%) were for pain evaluation, 14 (7%) were to assess infection, and seven (3%) were to evaluate a potential malignancy. The most common specific indication was evaluation of facet joint pain in 70/191 (37%) patients, and the most common finding was facet joint activity in 106/212 (50%) patients. Several findings were reported, although facet joint activity was the most frequent. The other findings included costovertebral joint activity, pars interarticularis defects, an osteoid osteoma, a lumbosacral pseudoarticulation, and a postoperative pseudoarthrosis. A resultant change in clinical management was documented in 168/212 (79%) patients. Ninety-two of the 212 (44%) patients had undergone an MRI of the same region for any indication within ±6 months.
Conclusion: 99mTc-MDP SPECT/CT of the spine and sacrum is most frequently used for the diagnosis and management of pain. It helps identify several potential pain generators, is often used in patients who have a near-contemporaneous MRI, and has an impact on the procedural and/or conservative management in most patients. In addition, several areas in need of future research to establish the optimal clinical role of this modality were identified.