Use of FDG PET-CT to monitor response to chemotherapy by neuroblastoma in children

Objectives The objective of this study is to determine utility of FDG PET-CT for monitoring response to treatment by neuroblastoma (NB) and its impact on clinical management of the children diagnosed with NB.

Methods Pre-treatment PET-CT was performed on the children diagnosed with NB as a baseline study prior to initiation of chemotherapy. Subsequently, post-treatment PET-CT was performed at end of chemotherapy which varies at number of cycles depending on different protocols. Post-treatment PET-CT studies were compared with pre-treatment PET-CT studies by visual examination and semiquantitive analysis of maximum standardized uptake values (SUV). Response to treatment was graded as complete resolution, partial response, or non-responsive. The results from PET-CT were correlated with prior CT and MRI when they were available.

Results Eight children diagnosed with NB, including one twin, received both pre-treatment and post-treatment PET-CT. Complete resolution of abnormal FDG uptake was found on the post-treatment PET-CT images from 6 out of 8 of the children included in this study, despite presence of residual tumor mass lesions on the CT or MRI images. Two children with residual abnormal FDG uptake were found to have early relapse and refractory to chemotherapy.

Conclusions The results of this study suggest that FDG PET-CT is usful for monitoring response to treatment by NB in children and persistent abnormal FDG uptake on the post-treatment PET-CT is predictive of early relapse of NB refractory to chemotherapy.