Imaging plays an important role in the diagnosis,
staging,
treatment planning,
and response evaluation and in follow-up of a case of Neuroblastoma.
• CT/MRI is the initial mode of investigation in detecting neuroblastoma.
• Most common appearances are large,
lobulated,
heterogeneous mass with stippled calcifications.• PET CT is superior in depicting local staging.
• MIBG is superior in evaluation of metastatic disease.
IMAGING
Mandatory
-CT/MRI (evaluation of loco‑regional disease extent)
123‑I MIBG scan (to look for avidity in the primary and screen for metastatic disease‑ ideally done prior to excision of primary)
Problem solving
- Bone scan (MIBG non‑avid tumor or primary has been excised)
Radiographs/MRI (equivocal focus of metastatic disease on MIBG or bone scan)
FDG‑PET/CT (MIBG non‑avid tumors,
equivocal lesions especially in soft tissues)
CT chest: For suspected pleural or pulmonary metastases
Needs further evaluation
- Somatostatin receptor studies.
Whole body MRI (radiation free tool for marrow metastases)
Other radionuclides
Terminology:
(1) Separation Visible fat plane between the tumor and adjacent vital structure – L1
(2) Contact Loss of fat plane between the tumor and adjacent vital structure; for an artery the angle of contact < 180 degree and for a vein,
flattening of shape but lumen visible -L1 status (except for renal arteries).
(3) Encasement - Tumor encases vital structure; for an artery >180 degree of contact and for a vein no visible lumen seen - L2 status
(4) Compression (used only for airways) - Reduction in short axis of the lumen - L2 status
(5) Infiltration - For vital structures other than vessels - L2 status
(6) Invasion - spinal canal extension -L2 status
(7) Spinal canal involvement - more than one‑third of the spinal canal in the axial plane is invaded or the leptomeningeal fluid space is not visible,
or the spinal cord shows abnormal signal intensity on MRI - L2 status
Fig.1(a)
Ga68-Dotanoc PET CT:
Enhancing SSR (somatostatin receptors) expressing mass with adjacent osteolysis in the olfactory groove,
roof of the nasal cavity and right ethmoid air cells with intracranial extension – Esthesioneuroblastoma.
Fig.1(b) – Post radiotherapy
Ga68-Dotanoc PET CT:
Moderate interval regression in the size of enhancing SSR (somatostatin receptors) expressing mass and Interval resolution of intracranial extension
Fig 2(a) Protocol: 300 micro curies of MIBG administered IV.
Whole body scan was done after 24 and 48 hours.
FINDINGS:
Evidence of abnormal accumulation of MIBG is seen in the left suprarenal and left orbital region.
IMPRESSION :
Consider MIBG avid left adrenal Neuroblastoma with left spheno-orbital metastases.
Fig 2(b) Purpose:
Left adrenal neuroblastoma with left spheno-orbital metastases – post left adrenalectomy,
post chemotherapy.
Response evaluation.
Protocol:
300 micro curies of MIBG administered IV.
Whole body scan was done after 24hrs later.
FINDINGS:
•Evidence of abnormal accumulation of MIBG in the left spheno-orbital mass.•Faint uptake is seen in the left suprarenal region.
IMPRESSION:
•MIBG avid residual disease in the left spheno – orbital mass.
•Faint MIBG uptake in the left suprarenal region is of concern for residual disease.
Fig.
3: 11 years,
Male.
Ga68-Dotanoc PET CT
Large well defined metabolically active left suprarenal mixed solid cystic mass shows heterogeneous enhancement with amorphous calcifications.
– Left Adrenal Neuroblastoma with metastasis.
Fig.
4: 10months,
Male.
FDG PET CT :Large partly calcified metabolically active mass in the pelvic cavity – Pelvic Neuroblastoma.
Fig.
5(a): 8 years,
Female.
• FDG PET CT :Large metabolically active heterogeneously enhancing mass with calcifications in the right posterior thoracic cavity with subtle erosion and periosteal reaction of the posterior end of 7th rib–Thoracic Neuroblastoma.
Fig.
5(b) : FDG PET CT : Thoracic neuroblastoma – post-op and post chemotherapy.
Evaluation of disease status.
Marked interval regression of heterogeneous mass with multiple calcific foci in the right posterior thoracic cavity with residual soft tissue abutting the parietal pleura with adjacent periosteal reaction of the posterior end of right 7th rib.
Fig.
6: 3 years,
Male.
• FDG PET CT :
• Large metabolically active heterogeneously enhancing mass with calcifications in retroperitoneum and multiple enlarged retroperitoneal and retrocrural lymphnodes – Retroperitoneal Neuroblastoma.
Fig.
7: 3 years,
Male.
• FDG PET CT :
• Metabolically active left paravertebral soft tissue at T7 – T8 level – Paravertebral Neuroblastoma.
Fig.
8: 10 years,
Male.
Ga68 – Dotanoc PET CT: Confluent lobulated metabolically active heterogeneously enhancing soft tissue lesion in the left lower jugular and supraclavicular region extending along the left upper mediastinum – Cervical Neuroblastoma.
Fig.
9: 1 years,
Male.
FDG PET CT:
• Large lobulated heterogeneously enhancing metabolically active mass in the right suprarenal region,
abutting the inferior surface of the right lobe of liver and porta hepatis with displacement of the pancreatic head and other bowel loops.
Mass effect over the gallbladder,
infrahepatic IVC and anterior surface of the right kidney– Right adrenal Neuroblastoma.