Poster Presentation Advances in Neuroblastoma Research Congress 2016

Post surgical 123I-MIBG SPECT/CT in neuroblastoma (#270)

Myriam Wartski 1 , Mathieu Gauthé 2 , Nina Jehanno 1 , Cécile Cellier 1 , Sabine Sarnacki 3 , Pascale Philippe Chomette 4 , Paul Fréneaux 5 , Michel Peuchmaur 6 , Gudrun Schleiermacher 7 , Jean Michon 8
  1. Medical Imaging Department, Institut Curie, Paris, France
  2. Biophysique et Médecine Nucléaire, H Tenon, Paris, France
  3. Department of Surgery, Hôpital Necker-Enfants Malades, Paris, France
  4. Department of Surgery, Hôpital Robert Debré, Paris, France
  5. Department of Pathology, Institut Curie, Paris, France
  6. Department of Pathology, Hôpital Robert Debré, Paris, France
  7. Laboratoire RTOP "Recherche Translationelle en Oncologie Pédiatrique", INSERM U830 and Department of Pediatric Oncology, Institut Curie, Paris, France
  8. Department of Pediatric Oncology, Institut Curie, Paris, France

Objectives: Post-surgical scintigraphy is of importance to assess residual tissue at surgical site in neuroblastoma. The objectives were (i) to to assess post-surgical residual tissue with 123I-MIBG scintigraphy and morphological imaging (ii) to compare 123I-MIBG SPECT/CT acquisition to planar scintigraphy (iii) to assess the impact of MIBG uptake in residual tissue on survival.

 

Methods: 30 patients consecutively operated for MIBG-positive neuroblastoma were included (INRG stage L1 n=4, L2 n=10, M n=12, Ms n=4). On operative report, surgery was considered as complete in 23 and incomplete in 7 patients, respectively.

Postoperative imaging included 123I-MIBG scintigraphy with 123I-MIBG SPECT/CT and planar acquisitions and morphological exams (MRI or CT or US).

Quantification of 123I-MIBG SPECT/CT was performed with tumor to mediastinum count rate ratio (TMCRR).

 

Results: Mean delay between surgery and post-operative MIBG or morphological imaging was 39 and 49 days, respectively. Mean additional radiation exposure induced by 123I-MIBG SPECT/CT was 149mGy.cm.

At surgical site, postoperative morphological exam was positive in 14 patients, negative in 16; 123I MIBG SPECT/CT positive in 6 patients (3 for MIBG planar imaging), negative in 24.

In case of reported complete surgery, morphological imaging was positive in 7/23 and MIBG SPECT in 2/23 patients.

With a median follow-up of 25 months (range 6-83), 10 pts had relapse or progression (local in 5 pts including 2 pts with slow local progression; metastatic in 4 pts, local and metastatic in 1 pt).

Median progression-free survival (Kaplan-Meier) was 57 weeks (42-72.5 CI95).

Using a TMCRR cutoff at 2.6 on 123I-MIBG SPECT/CT, we found a significant difference in progression-free survival (p=0.004), patients with a higher ratio having worst prognosis.

No significant difference was found in progression free survival in case of residual tissue presence on morphological exam (p=0.22).

 

Conclusion: Post-surgical 123I-MIBG SPECT/CT appears a key tool to assess residual tissue in neuroblastoma. Further studies are needed to assess impact for patient’s management.