Imaging Practices in Patients with Plasma Cell Dyscrasias across the Asian Myeloma Network - Survey Results and Recommendations

Objective:

Though consensus imaging guidelines from International Myeloma Working Group (IMWG) for the detection of bone and marrow lesions in plasma cell disorders are available, significant challenges remain in adoption of such guidelines in Asia. The objectives of this study were: (1) To survey, document and evaluate the imaging practices in plasma cell disorders across Asian Myeloma Network (AMN) member countries and (2) To identify factors influencing decision making in choosing the imaging modalities with a view to explore barriers and solutions.

Methods:

AMN Members from China, Japan, Republic of Korea, Malaysia, Taiwan, Thailand and Singapore participated in the bone imaging work group organized during the 6 ^th AMN summit in Sep 2022 at Singapore. Members discussed the prevailing bone imaging practices and how they relate to IMWG recommendations. A bone imaging survey questionnaire was then designed from these inputs and circulated to the wider AMN members. The results were collated and analyzed.

Results & Discussion:

Forty-Eight responses were received from 37 public tertiary or academic hospitals, 9 from peripheral hospitals and 2 from private hospitals.

With regards to precursor plasma cell disorders (MGUS / SMM Vs MM), the preferred imaging modalities for screening bone disease in patients suspected to have myeloma were skeletal survey (SS) (n=13, 27%), whole body low dose CT (WBLDCT) (n=13, 27%) and PET CT (n=14, 29%). The preferred mode for 1 ^st line imaging in patients with confirmed newly diagnosed myeloma was PET CT (n=25, 52%) however half of the participants opted for SS (n=7, 15%), WBLDCT (n=10, 21%) and whole-body MRI (WBMRI) (n=6, 13%). Using SS prior to myeloma treatment or to differentiate SMM from MM can lead to significant under-recognition of bone disease and its consequences on disease classification and impact on treatment. Centers which are performing SS but have compatible CT scanners could consider adopting a WBLDCT protocol which is relatively easy and cost-effective.

Preferred first-line imaging options for Plasmacytoma and EMD were largely appropriate with 70-80% opting for PET CT or WBMRI. However, for response assessment in MM, the majority chose PET CT or MRI, some members or institutions are still using SS or WBLDCT. While CT scan might be able to show some sclerotic healing or a worsening lytic component, SS is unlikely to provide any useful information in this situation and should be avoided to reduce unnecessary radiation exposure. At least 5 participants indicated that they do not perform routine imaging in newly diagnosed multiple myeloma for disease response assessment.

Barriers identified in establishing cross-sectional imaging service include lack of financial reimbursement or subsidies, equipment, or personnel availability like the presence of nuclear medicine or specialized radiologists. While 81% of participants reported financial reimbursements for SS, only about 50% reported subsidies for WBMRI (56%) or PET CT (54%).

One shortfall of this study is that our survey was conducted within the framework of an academic myeloma community and while it may not be representative of the practices in the whole region, the use of sub-optimal imaging like SS underlines the need for standardisation and adoption of cross-sectional imaging.

Conclusion:

There is considerable variation in imaging practices for precursor plasma cell disorders and myeloma in centres across Asia. Resource limitation, specifically lack of financial subsidies for imaging, infrastructure or lack of experienced personnel all remain as major challenges in the implementation of standardized imaging practice for myeloma in Asia. However increased adoption of cross-sectional imaging in large tertiary centres are to be welcomed and suggest that in these centres, practices do closely mirror those in the IMWG recommendations. Increasing awareness of the potentially catastrophic nature of myeloma bone disease and the preventive role that cross sectional imaging could provide, representations and dialogues with healthcare funders to this aspect of myeloma care, incorporation of low dose CT protocols to help move away from skeletal survey in centres which already have CT scanners as well as myeloma patient and Physician education could all be useful tools to enhance bone imaging standards in Asia.