Table 3. International guidelines for diagnosis and imaging follow-up [9].

Tumour site	Recommended tests
Primary tumour	CT and/or MRI scan with 3D measurements; MIBG scan if available
Metastatic sites
Bone marrow	Bilateral posterior iliac crest marrow aspirates and trephine (core) bone marrow biopsies required to exclude marrow involvement. A single positive site documents marrow involvement. Core biopsies must contain at least 1 cm of marrow (excluding cartilage) to be considered adequate
Bone	MIBG scan; 99Tc scan required if MIBG scan negative or unavailable, and plain radiographs of positive lesions are recommended
Lymph nodes	Clinical examination (palpable nodes), confirmed histologically. CT scan for non-palpable nodes (3D measurements)
Abdomen/liver/chest	CT and/or MRI scan with three dimensional measurements. Anteroposterior and lateral chest radiographs. CT/MRI necessary if chest radiograph positive, or if abdominal mass/nodes extend into chest

3D, three-dimensional; MIBG,¹⁸I-metaiodobenzylguanidine.