Clinical impact of SPECT-CT on bone scintigraphy in oncology: Pattern approach

The recent addition of single photon emission computed tomography (SPECT)-CT into bone scintigraphy (BS), increased the accuracy of the test. The objective of this study was to define the main problematic scintigraphic patterns that were solved with the contribution of SPECT-CT and serve as a guide to the medical oncologist who will refer their patients to BS.

Two hundred and ten patients (median age 62 years, range 12-80, F/M:122/ 88) with diagnosis of cancer (breast 109;52%, prostate 63;30%, lung 15;7% and others 20;11%) were referred for BS. Subsequent SPECT-CT images (231 images from 210 patients) were obtained from the related body regions where suspicious skeletal radioactivity uptake had been observed. BS and SPECT-CT images were classified into groups according to the BS, clinical history and other imaging results in consideration with the role of SPECT-CT for more accurate diagnosis.

SPECT-CT studies resulted in the emergence of 6 main patterns that helped improve the interpretation of the whole-body BS for more accurate diagnosis. Pattern 1: Extraskeletal uptake and/or incidental findings (14/231;6%); Pattern 2: Identification of skeletal trauma and degenerative osteoarthritic diseases (147/231;64%); Pattern 3: Benign bone tumors and reactions (12/231;5%); Pattern 4: Sclerotic-mixed type metastases (32;14%); Pattern 5: Lytic/ bone marrow metastases (12/231;5%); Pattern 6: Metabolically inactive metastases (14/231;6%).

SPECT-CT is a revolutionary technique that improved the interpretation of BS. Recognition of patterns of disease that may be resolved with SPECT-CT will help significantly to better understanding the patient's bone disease.