Whole-body low-dose computed tomography in multiple myeloma staging: Superior diagnostic performance in the detection of bone lesions, vertebral compression fractures, rib fractures and extraskeletal findings compared to radiography with similar radiation exposure

Abstract

Abstract. The primary objective of the present prospective study was to compare the diagnostic performance of conventional radiography (CR) and whole-body low-dose computed tomography (WBLDCT) with a comparable radiation dose reconstructed using hybrid iterative reconstruction technique, in terms of the detection of bone lesions, skeletal fractures, vertebral compressions and extraskeletal findings. The secondary objective was to evaluate lesion attenuation in relation to its size. A total of 74 patients underwent same-day skeletal survey by CR and WBLDCT. In CR and WBLDCT, two readers assessed the number of osteolytic lesions at each region and stage according to the International Myeloma Working Group (IMWG) criteria. A single reader additionally assessed extraskeletal findings and their significance, the number of vertebral compressions and bone fractures. The radiation exposure was 2.7±0.9 mSv for WBLDCT and 2.5±0.9 mSv for CR (P= 0.054). CR detected bone involvement in 127 out of 486 regions (26%; P<0.0001), confirmed by WBLDCT. CR underestimated the disease stage in 16% and overestimated it in 8% of the patients (P=0.0077). WBLDCT detected more rib fractures compared with CR (188 vs. 47; P<0.0001), vertebral compressions (93 vs. 67; P= 0.010) and extraskeletal findings (194 vs. 52; P<0.0001). There was no correlation observed between lesion size (≥5 mm) and its attenuation (r=-0.006; P=0.93). The inter-observer agreement for the presence of osteolytic lesions was κ= 0.76 for WBLDCT, and κ= 0.55 for CR. The present study concluded that WBLDCT with hybrid iterative reconstruction technique demonstrates superiority to CR with an identical radiation dose in the detection of bone lesions, skeletal fractures, vertebral compressions and extraskeletal findings, which results in up-or downstaging in 24% patients according to the IMWG criteria. The attenuation of osteolytic lesions can be measured with the avoidance of the partial volume effect.

Organ dose and total effective dose of whole-body CT in multiple myeloma patients

“…Moreover, WBLDCT has been shown to provide important information for disease monitoring and detection of incidental findings [16], thereby improving the management of MM patients. In recent literature, WBLDCT protocols with estimated effective doses comparable to or lower than radiographic skeletal surveys have been described, using for instance hybrid iterative reconstruction techniques [10] or spectral shaping [24]. Although these studies show the potential for further decreasing radiation exposure of WBLDCT in MM, the radiation doses in our study reflect those that result from current daily practice.…”

“…Therefore, more sensitive imaging techniques for the diagnosis and follow-up of MM have been described, such as WBLDCT, MRI and PET/CT. Wholebody MRI and 18F-fluorodeoxyglucose-PET/CT have been described to be more accurate in detecting bone lesions in MM as compared to skeletal surveys [8][9][10][11][12][13][14], and wholebody MRI have been found to detect significantly more MM bone involvement compared to PET/CT [12]. Whole-body MRI and PET/CT are, however, limited in their availability and are relatively costly.…”

“…However, the value of conventional radiographs in detecting osteolytic lesions is limited since at least 30% of trabecular bone must be destroyed to be visible by radiograph [7]. Cross-sectional imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI) and integrated positron emission tomography/CT (PET/CT), have proven to be more accurate in detecting osteolytic and marrow replacing lesions as compared to skeletal surveys using radiographs [8][9][10][11][12][13][14]. As a result, more accurate diagnosis, staging and follow-up of MM is possible [8,9].…”

Recommendations for acquisition, interpretation and reporting of whole body low dose CT in patients with multiple myeloma and other plasma cell disorders: a report of the IMWG Bone Working Group

“…The inclusion of osteolytic lesions found on CT alone, in the so-called myeloma-defining events according to the novel IMWG criteria for MM, was the result of multiple studies showing that CT has a greater sensitivity than the CSS for detection of multiple myeloma bone lesions. Most of these studies have focused on WBLDCT protocols, which offer the advantage of both whole-body coverage and lower effective radiation dose delivered to the patient 11 – 15 . Although low dosage comes at the cost of reduced image quality overall (mainly owing to image noise), the study of the skeleton is not significantly impaired due to the intrinsic contrast between high-density mineralized bone and soft-tissue density osteolytic lesions 4 .…”

Automated Whole-Body Bone Lesion Detection for Multiple Myeloma on 68Ga-Pentixafor PET/CT Imaging Using Deep Learning Methods

“…In [ 37 ] a semiautomatic software was developed to perform pixel thresholding based segmentation for the assessment of bone marrow metabolism while automatic quantification of bone marrow myeloma volume was conducted in [ 38 ]. A hybrid iterative reconstruction technique was used to compare the diagnostic performance of conventional radiography (CR) and whole-body low-dose computed tomography (WBLDCT) with a comparable radiation dose reconstructed for MM staging [ 39 ]. However, none of the above-mentioned approaches can be directly transferred to automatically detect systemic bone lesions on PET imaging.…”