Rajender Kumar1, Kousik Vankadari1, Bhagwant Rai Mittal2, Deepak Bansal3, Amita Trehan3, Jitendra K Sahu4, Naveen Sankhyan4. 1. Department of Nuclear Medicine and PET/CT, Post Graduate Institute of Medical Education and Research, Chandigarh, 160012, India. 2. Department of Nuclear Medicine and PET/CT, Post Graduate Institute of Medical Education and Research, Chandigarh, 160012, India. brmittal@yahoo.com. 3. Department of Pediatric Oncology, Post Graduate Institute of Medical Education and Research, Chandigarh, India. 4. Department of Pediatric Neurology, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
Abstract
OBJECTIVES: Opsoclonus myoclonus ataxia (OMA) syndrome, also known as "Kinsbourne syndrome" or "dancing eye syndrome," is a rare, paraneoplastic entity which may be associated with pediatric neuroblastic tumors and carry a grave prognosis. We aimed to evaluate the role of 68Ga DOTANOC PET/CT for detecting neuroblastic tumors in patients with OMA syndrome. METHODS: We retrospectively evaluated the 68Ga-DOTANOC PET/CT data of pediatric patients presenting with OMA syndrome from March 2012 to November 2018. A somatostatin receptor (SSTR)-expressing lesion with corresponding morphological change on CT image was considered PET-positive, while no abnormal SSTR expression or lesion was noticed in PET-negative patients. Histopathology and/or clinical/imaging follow-up (minimum one year) was considered a reference standard for comparing the PET/CT findings. The results of 68Ga-DOTANOC PET/CT were also compared with 131I MIBG whole-body scintigraphy, which was available in five patients. RESULTS: Of 38 patients (13 males, 25 females, aged 3-96 months), 18 (47.3%) had SSTR-expressing lesions (PET-positive), and histopathology revealed neuroblastic tumors in 17/18 lesions (neuroblastoma 14, ganglioneuroblastoma 2, and ganglioneuroma 1) and reactive hyperplasia in 1/18. The remaining 20/38 (52.6%) patients did not demonstrate SSTR-expressing lesions (PET-negative) and had an uneventful follow-up. The average SUVmax of the PET-positive lesions was 10.3 (range 2.8-34.5). The PET/CT results revealed 17 true-positive, one false-positive, 20 true-negative, and zero false-negative. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 100%, 95.2%, 94.4%, 100%, and 97.3% respectively. CONCLUSIONS: 68Ga-DOTANOC PET/CT identified neuroblastic tumors with a high diagnostic accuracy in our cohort compared to histology and follow-up. KEY POINTS: • Opsoclonus myoclonus ataxia (OMA) syndrome or "dancing eye syndrome" is a rare paraneoplastic entity which may be associated with pediatric neuroblastic tumors with a grave prognosis. • 123I/131I MIBG imaging has a proven role for functional imaging in neuroblastoma or patients with OMA, but the role of 68Ga-DOTANOC PET/CT is not yet studied. • 68Ga-labelled DOTANOC PET/CT (SSTR) imaging, in our cohort, was able to positively identify neuroblastic tumors with high diagnostic accuracy when compared with histology.
OBJECTIVES:Opsoclonus myoclonus ataxia (OMA) syndrome, also known as "Kinsbourne syndrome" or "dancing eye syndrome," is a rare, paraneoplastic entity which may be associated with pediatric neuroblastic tumors and carry a grave prognosis. We aimed to evaluate the role of 68Ga DOTANOC PET/CT for detecting neuroblastic tumors in patients with OMA syndrome. METHODS: We retrospectively evaluated the 68Ga-DOTANOC PET/CT data of pediatric patients presenting with OMA syndrome from March 2012 to November 2018. A somatostatin receptor (SSTR)-expressing lesion with corresponding morphological change on CT image was considered PET-positive, while no abnormal SSTR expression or lesion was noticed in PET-negative patients. Histopathology and/or clinical/imaging follow-up (minimum one year) was considered a reference standard for comparing the PET/CT findings. The results of 68Ga-DOTANOC PET/CT were also compared with 131I MIBG whole-body scintigraphy, which was available in five patients. RESULTS: Of 38 patients (13 males, 25 females, aged 3-96 months), 18 (47.3%) had SSTR-expressing lesions (PET-positive), and histopathology revealed neuroblastic tumors in 17/18 lesions (neuroblastoma 14, ganglioneuroblastoma 2, and ganglioneuroma 1) and reactive hyperplasia in 1/18. The remaining 20/38 (52.6%) patients did not demonstrate SSTR-expressing lesions (PET-negative) and had an uneventful follow-up. The average SUVmax of the PET-positive lesions was 10.3 (range 2.8-34.5). The PET/CT results revealed 17 true-positive, one false-positive, 20 true-negative, and zero false-negative. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 100%, 95.2%, 94.4%, 100%, and 97.3% respectively. CONCLUSIONS:68Ga-DOTANOC PET/CT identified neuroblastic tumors with a high diagnostic accuracy in our cohort compared to histology and follow-up. KEY POINTS: • Opsoclonus myoclonus ataxia (OMA) syndrome or "dancing eye syndrome" is a rare paraneoplastic entity which may be associated with pediatric neuroblastic tumors with a grave prognosis. • 123I/131I MIBG imaging has a proven role for functional imaging in neuroblastoma or patients with OMA, but the role of 68Ga-DOTANOC PET/CT is not yet studied. • 68Ga-labelled DOTANOC PET/CT (SSTR) imaging, in our cohort, was able to positively identify neuroblastic tumors with high diagnostic accuracy when compared with histology.