Whole-body low-dose computed tomography (WBLDCT) in assessment of patients with multiple myeloma : pilot study and standard imaging protocol suggestion

BACKGROUND: For decades, the main imaging tool in multiple myeloma (MM) patients was plain radiography. However, computed tomography (CT) has been included in the updated criteria of MM. The main disadvantage of CT is a considerably high radiation dose. Therefore, low-dose CT protocols could be a solution. The aim of the study was to (1) preliminarily analyse the usefulness of Whole-Body Low-Dose CT (WBLDCT) in the evaluation of patients with MM and (2) to make adjustments in the standard CT imaging protocol. MATERIAL AND METHODS: In 41 patients with MM, WBLDCT was performed. The following parameters were used: detector configuration - 80×0.5 mm, scanning range in a single spiral acquisition from the skull to the proximal femoral bones, tube voltage - 120 kVp, current tube time product - 86 mAs, slice thickness 1 mm. Two sets of axial images were reconstructed for bone and soft tissue assessment, respectively. Secondary coronal and sagittal reconstructions were generated. Typical MM features were analysed and qualitatively compared with radiography results. RESULTS: A potentially increased sensitivity of CT, as compared to radiography, in detecting lytic foci obscured by other structures or with a small degree of destruction was seen. A potentially increased specificity of CT was found in detecting cases of small foci suspicious of lytic lesions on skull radiographs, seen as arachnoid granulations fovea in CT. The following radiation parameters were recorded: max. CTDIvol - 7.4 mGy and DLP - 660-810 mGy×cm. WBLDCT was much shorter and more convenient to patients. CONCLUSIONS: WBLDCT may become a valuable part of the assessment of MM features at a much lower radiation dose compared to standard CT protocols. It has a potential ability to increase diagnostic accuracy compared to radiography.