Poster Presentation Advances in Neuroblastoma Research Congress 2016

A comparison of 123I-mIBG planar imaging and SPECT/CT with 68Ga-DOTATATE PET/CT for staging and response assessment of high-risk neuroblastoma (#160)

Jennifer E Gains 1 , Maria Vittoria Mattoli 1 , Matthew D Aldridge 1 , Jamshed B Bomanji 1 , Lorenzo Biassoni 2 , Caroline Walker 1 , Ananth Shankar 1 , Mark N Gaze 1
  1. University College London Hospitals NHS Foundation Trust, London, United Kingdom
  2. Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom

Aims

Standard neuroblastoma staging involves 123I-mIBG planar scintigraphy. Neuroblastoma can also be imaged with radiolabelled somatostatin analogues. The aims were (1) to compare planar 123I-mIBG imaging (mIBG) with maximum intensity projection 68Ga-DOTATE PET (GaDO), and (2) to assess the additional information that may be acquired through the use of mIBG SPECT/CT data and the CT component of GaDO imaging.

Methods

Paired mIBG and GaDO scans were analysed. Uptake patterns on GaDO PET/CT maximum-intensity projection and mIBG planar scintigraphy were compared and evaluated by semi-quantitative scoring. Additional mIBG SPECT/CT data were compared with the cross sectional CT component of GaDO imaging.

Results

42 patients, 22 male, 20 female, median age 8 years (range 2 - 51 years) were imaged: 3 at diagnosis, 13 had refractory disease and 26 had relapsed disease. The mean time between scans was 24 days.

GaDO was positive in all 42 patients; mIBG was positive in 40 patients. Bone lesions were identified 36 patients. GaDO identified bone lesions in 35, and mIBG in only 29 patients. GaDO identified soft tissue lesions 33 patients, whereas 123I-mIBG identified these in only 29 patients. Overall, GaDO revealed more lesions than mIBG, and semi-quantitative scores were significantly higher with GaDO. In 61% of patients GaDO revealed more extensive disease, in 5% mIBG revealed more. In 28%, both modalities gave the same results, and in 6% images were discordant as different lesions demonstrated different tracer uptake patterns.

The use of SPECT/CT in addition to planar scans increased the accuracy of mIBG imaging.

Conclusions

Planar scintigraphy alone with mIBG is insufficient to map disease extent accurately. SPECT/CT increases diagnostic accuracy. GaDO imaging often shows more extensive disease, and discordant uptake in some patients has implications for molecular radiotherapy. Both modalities should be used for optimal imaging.