THORACIC NEUROBLASTOMA - WHAT IS THE BEST IMAGING MODALITY FOR EVALUATING EXTENT OF DISEASE

Background. Thoracic neuroblastoma accounts for 15 % of all cases of n euroblastoma, A minority of children with thoracic neuroblastoma will have dumbbell tumors, i.e., intraspinal extension, but only half these patients will have neurologic signs or symptoms. Hypothesis. MR imagi ng is the single best test to evaluate the extent of thoracic and spin al disease in thoracic neuroblastoma after the diagnosis of a mass is established on plain film. Materials and Methods. A retrospective mult i-institutional investigation over 7 years of all cases of thoracic ne uroblastoma (n = 26) imaged with CT and/or MR were reviewed for detect ion of the extent of disease. The chest film, nuclear bone scan, and o ther imaging modalities were also reviewed. The surgical and histologi c correlation in each case, as well as the patients' staging and outco me, were tabulated. Results. The chest radiograph was 100 % sensitive in suggesting the diagnosis. MR imaging was 100 % sensitive in predict ing enlarged lymph nodes, intraspinal extension, and chest wall involv ement, CT was 88 % sensitive for intraspinal extension but only 20 % s ensitive for lymph node enlargement. CT was 100 % sensitive in detecti ng chest wall involvement. Direct comparison of CT and MR imaging in s ix cases revealed no difference in detection of enlarged lymph nodes o r chest wall involvement. Neither test was able to detect remote disea se, as noted by bone scan. Conclusion. The chest film is 100 % sensiti ve in suggesting the diagnosis of thoracic neuroblastoma; MR imaging a ppears to be the single best test for detecting nodal involvement, int raspinal extension, and chest wall involvement.