111In-pentetreotide versus bone scintigraphy in the detection of bony metastases of neuroblastoma

Abstract

Bone scintigraphy (BS) is widely utilized for the assessment of bone metastases (BMs) of neuroblastoma (NB). Since 111In-pentetreotide scintigraphy (PS) has been used to image NB with high sensitivity, we compared the sensitivity and specificity of PS with that of BS for the detection of BMs of NB. Nine patients with NB underwent both PS and BS for staging and/or restaging of their disease. The sensitivity and specificity of both imaging approaches were compared based on the findings of histopathology, other conventional imaging methods and subsequent clinical follow-up. In five of the nine patients, both PS and BS were negative for BMs. Radiographic bone surveys (RBSs) were also negative in these patients, except in one who showed a suspicious tibial lesion, but a computed tomography-guided biopsy failed to show evidence of disease. These patients remained without clinical evidence of BMs after a median duration of more than 15 months (range, 6-19 months). In three of four remaining patients, both PS and BS were positive for BMs, whilst only PS was positive in one patient. Overall, PS showed a greater number of BMs (30 vs. 7) with greater conspicuity compared with BS. The initial experience comparing BS with PS suggests that PS may provide a better assessment of the extent of BMs of NB, and that it may be useful as an adjunct to BS at institutions in which 131I- or 123I-metaiodobenzylguanidine is not available, particularly if BS is negative. In patients with similarly positive BS, PS might still provide unique prognostic information beyond that provided by BS. Further studies are therefore warranted.

A Systematic Literature Review of Imaging Definitions for Detection of Bone and Bone Marrow Metastases in Neuroblastoma Patients

“…Of the 31 studies, 8 studies formulated a definition of bone metastases [8,[18][19][20][21][22][23][24], 13 of bone marrow metastases [25][26][27][28][29][30][31][32][33][34][35][36][37] and 10 defined both types of metastases [38][39][40][41][42][43][44][45][46][47] (Table 2). The included studies used different imaging methods to detect bone or bone marrow metastases (per study often more than one imaging method was used).…”

“…The included studies used different imaging methods to detect bone or bone marrow metastases (per study often more than one imaging method was used). The most frequent reported imaging technique was MIBG scintigraphy ( [28], Indium ( 111 In) pentetreotide scintigraphy [42]; and Thallium ( 201 Tl) scintigraphy [44]. Table 3A, all the definitions of bone metastases per imaging technique for the 18 included studies, are listed.…”

“…All studies reporting on bone scintigraphy (n=10) gave definitions of bone metastases. 5 studies gave clear definitions: "focal uptake" (n=3) [21,24,42] and "hotspots" (n=2) [40,45]. 5 other studies gave less clear definitions: "any uptake" (n=2) [23,47], "abnormal uptake" (n=2) [38,44], or "uptake throughout the skeleton with focal lesions that coalesce to produce a relatively diffuse image" (n=1) [39].…”

“…Of 12 studies reporting on MRI, 11 (92%) defined bone marrow metastases. Definitions were clear in 5: "focal areas" (n=1) [42], "diffuse and nodular type of lesions" (n=2) [28,35], or "diffuse abnormal uptake" (n=2) [26,31]. Furthermore, four studies (36%) reported "low intensity on T1 and high intensity on T2" [22,34,35,41].…”

“…The sensitivities and specificities for the detection of bone metastases are given in Table 4A for all studies. The sensitivity and specificity on all reported imaging techniques and with different definitions, ranged widely, from 0.17 to 1.00 in 6 studies [38,40,[43][44][45][46] and from 0.00 to 1.00 in 7 studies [38,40,[42][43][44][45][46] respectively (Table 4A). For most imaging techniques, pooling was not possible, because of the small number of studies with the same techniques and definitions.…”