Abstract: Eleven studies met the inclusion criteria. Ten studies reported data on patient level: the scan was positive or negative. One study reported on all single lesions (lesion level). The sensitivity of ¹²³I-MIBG (SPECT-CT) scintigraphy (objective 1.1), determined in 608 of 621 eligible patients included in the 11 studies, varied from 67% to 100%. One study, that reported on a lesion level, provided data to calculate the specificity: 68% in 115 lesions in 22 patients. The sensitivity of ¹²³I-MIBG scintigraphy for detecting metastases separately from the primary tumour in patients with all neuroblastoma stages ranged from 79% to 100% in three studies and the specificity ranged from 33% to 89% for two of these studies. One study reported on the diagnostic accuracy of 18F-FDG-PET(-CT) imaging (add-on test) in patients with negative ¹²³I-MIBG scintigraphy (objective 1.2). Two of the 24 eligible patients with proven neuroblastoma had a negative ¹²³I-MIBG scan and a positive 18F-FDG-PET(-CT) scan. The sensitivity of 18F-FDG-PET(-CT) imaging as a single diagnostic test (objective 2.1) and compared to ¹²³I-MIBG (SPECT-CT) (objective 2.2) was only reported in one study. The sensitivity of 18F-FDG-PET(-CT) imaging was 100% versus 92% of ¹²³I-MIBG (SPECT-CT) scintigraphy. We could not calculate the specificity for both modalities. The reported sensitivities of ¹²³-I MIBG scintigraphy for the detection of neuroblastoma and its metastases ranged from 67 to 100% in patients with histologically proven neuroblastoma. Only one study in this review reported on false positive findings. It is important to keep in mind that false positive findings can occur. For example, physiological uptake should be ruled out, by using SPECT-CT scans, although more research is needed before definitive conclusions can be made. As described both in the literature and in this review, in about 10% of the patients with histologically proven neuroblastoma the tumour does not accumulate ¹²³I-MIBG (false negative results). For these patients, it is advisable to perform an additional test for staging and assess response to therapy. Additional tests might for example be 18F-FDG-PET(-CT), but to be certain of its clinical value, more evidence is needed. The diagnostic accuracy of 18F-FDG-PET(-CT) imaging in case of a negative ¹²³I-MIBG scintigraphy could not be calculated, because only very limited data were available. Also the detection of the diagnostic accuracy of index test 18F-FDG-PET(-CT) imaging for detecting a neuroblastoma tumour and its metastases, and to compare this to comparator test ¹²³I-MIBG (SPECT-CT) scintigraphy, could not be calculated because of the limited available data at time of this search. At the start of this project, we did not expect to find only very limited data on specificity. We now consider it would have been more appropriate to use the term "the sensitivity to assess the presence of neuroblastoma" instead of "diagnostic accuracy" for the objectives.

Plain-language summary: We searched scientific databases for clinical studies comparing ¹²³I-MIBG or 18F-FDG-PET imaging, or both, with microscopic examination of tissue suspected of neuroblastoma (histopathology). The evidence is current up to 11 September 2012. We identified 11 eligible studies including 621 children that fulfilled our inclusion criteria: children < 18 years old with a neuroblastoma and ¹²³I-MIBG or 18F-FDG-PET imaging or both. All studies included proven neuroblastoma. All 11 included studies had methodological limitations. Only one included study provided data on specificity (the ability of a test to correctly classify an individual as 'disease-free') and therefore we could not perform all of the planned analyses. When compared to histopathological results the sensitivity (the ability of a test to correctly classify an individual person as 'diseased') of ¹²³I-MIBG imaging varied from 67% to 100% in patients with histologically proven neuroblastoma. This means that in 100 children with proven neuroblastoma ¹²³I-MIBG imaging will correctly identify 67 to 100 of the neuroblastoma cases. Only one study, that reported on a lesion level, provided data to calculate the specificity (the ability of a test to correctly classify an individual as 'disease-free'): 68% in 115 lesions. This means that of 100 disease-free lesions in patients with proven neuroblastoma ¹²³I-MIBG imaging will correctly identify 68 lesions. So, in about 10% of the cases the neuroblastoma is not visible on ¹²³I-MIBG imaging (false negative results). For these cases, it is advisable to perform an additional test like 18F-FDG-PET imaging, but to be certain of its clinical value, more evidence is needed. Only one included study reported on false positive findings. This means that ¹²³I-MIBG imaging and 18F-FDG-PET imaging incorrectly identified neuroblastoma lesions in patients which might result in wrongly classifying a patient with metastatic disease. It is important to keep in mind that false positive findings can occur, although more research is needed before definitive conclusions can be made. We could not determine the diagnostic accuracy of 18F-FDG-PET imaging, in case the neuroblastoma was incorrectly not identified with ¹²³I-MIBG, due to limited data. Also, we could not calculate the diagnostic accuracy of 18F-FDG-PET imaging for detecting a neuroblastoma and compare this to ¹²³I-MIBG imaging because of the limited available data.