Performed at one institution, Observational, Retrospective, Metastases, Education, MR-Diffusion/Perfusion, Paediatric, Oncology, Nuclear medicine, Oncologic Imaging
M. C. Colombo1, E. J. Inarejos Clemente2, J. Munuera1, A. Castañeda1, J. Mora1, I. Barber3; 1Barcelona/ES, 2Esplugues de Llobregat, Barcelona/ES, 3Esplugues de Llobregat (Barcelona)/ES
This is, to our knowledge, the first study comparing MIBG and MR DWI in the evaluation of bone metastatic disease in NBL in children. On the one hand, several papers have demonstrated the value of MR and DWI in the evaluation of skeletal metastasis in other malignancies and population groups. On the other hand, evaluation of bone involvement in paediatric neuroblastoma has been considered a drawback of MR with limitation in the differentiation between viable tumour and non-viable residual lesion.
Our results suggest that active metastatic bone lesions that are depicted on MIBG imaging are also evident on MR imaging and show restricted diffusion compared to “residual” bone lesions that are not evident on MIBG.
Nevertheless, our results showed 9 bone lesions that were not evident on MR. We considered this to be real MR “false negative” although we have no histological confirmation of any of the lesions.
Our results also showed a few bone lesions with low ADC values (-3 mm2/sec) but negative result on MIBG. A possible explanation could be the small size of these lesions on MRI (<12mm). Further studies should be conducted to evaluate this finding.
MIBG positive bone lesions showed statistically significant lower ADC values on DWI.
Compared to MIBG as the gold standard, MR DWI with ADC values is useful for the evaluation of bone involvement in stage IV neuroblastoma. Complementary use of WBMRI DWI and MIBG scintigraphy probably increases diagnostic accuracy in the evaluation of bone involvement.