Association between magnetic resonance imaging patterns and baseline disease features in multiple myeloma: analyzing surrogates of tumour mass and biology.

OBJECTIVE: To assess associations between bone marrow infiltration patterns and localization in magnetic resonance imaging (MRI) and baseline clinical/prognostic parameters in multiple myeloma (MM).

METHODS: We compared baseline MM parameters, MRI patterns and localization of focal lesions to the mineralized bone in 206 newly diagnosed MM patients.

RESULTS: A high tumour mass (represented by International Staging System stage III) was significantly associated with severe diffuse infiltration (p = 0.015) and a higher number of focal lesions (p = 0.006). Elevated creatinine (p = 0.003), anaemia (p < 0.001) and high LDH (p = 0.001) correlated with severe diffuse infiltration. A salt and pepper diffuse pattern had a favourable prognosis. A higher degree of destruction of mineralized bone (assessed by X-ray or computed tomography) was associated with an increasing number of focal lesions on MRI (p < 0.001). Adverse cytogenetics (del17p/gain1q21/t(4;14)) were associated with diffuse infiltration (p = 0.008). The presence of intraosseous focal lesions exceeding the mineralized bone had a borderline significant impact on prognosis.

CONCLUSIONS: Diffuse bone marrow infiltration on MRI correlates with adverse cytogenetics, lowered haemoglobin values and high tumour burden in newly diagnosed MM whereas an increasing number of focal lesions correlates with a higher degree of bone destruction. Focal lesions exceeding the cortical bone did not adversely affect the prognosis.

KEY POINTS: • Diffuse MRI correlates with adverse cytogenetics, lowered haemoglobin and high tumour burden. • Higher numbers of MRI focal lesions correlate with increasing degree of bone destruction. • Focal lesions exceeding the cortical bone borderline significantly influence survival. • Moderate/severe diffuse infiltration and more than 23 focal lesions adversely affect survival.