Uses of Radiological Imaging in Retinoblastoma

Abstract

Retinoblastoma is the most common primary ocular malignancy in children. Diagnosing retinoblastoma relies mainly on the clinical appearance of the lesion and not on histological description. Although histology still remains the gold standard in evaluation of tumor extension and progression risk factor, a tumor biopsy carries high risk of dissemination and is difficult to obtain. Retinoblastoma has characteristic clinical features of creamy-white mass associated with subretinal fluids and may be accompanied by retinal detachment and vitreous seeding. There are many factors contributing to metastatic risk factors like postlaminar optic nerve infiltration, scleral and choroidal invasion, and peribulbar fat invasion. Ancillary testing is necessary for any patient with a suspected retinoblastoma to assess the dimensions of the tumor as well as the tumor extension. An ultrasonography (B scan) will show the mass dimensions as well as the hyperechoic calcifications, which are commonly present with retinoblastoma. CT scan is not the modality of choice for diagnosis of retinoblastoma in children because of the radiation exposure. Magnetic resonance imaging is considered the examination of choice to assess the tumor extension as it has high soft tissue contrast. The use of MRI changed the accuracy of assessing metastatic risk factors as the results yielded before and after the use of MRI differed. This chapter will address the use of radiological imaging in retinoblastoma defining diagnostic characteristics and identifying parameters of metastatic risk factor assessment. This chapter will also include evidence-based review on the efficacy of radiological imaging of retinoblastoma and its impact on the choice of treatment and disease prognosis.

Histopathological assessment of optic nerve invasion guided by radiological findings in enucleated globes with retinoblastoma

“…MRI works without the use of ionizing radiation, preventing the occurrence of the potential risk of secondary tumors and has a high soft tissue contrast [2]. Using special surface coils with small diameter and a short penetration depth improved the ability to correlate the MRI findings with the actual ocular histopathological findings [2,18]. Results from many studies showed that preoperative MRI was more relevant in detecting ON invasion [17].…”

The Role of Intraarterial Chemotherapy in the Management of Retinoblastoma

“…e diagnosis of retinoblastoma is clinical as the biopsy is contraindicated due to the risk of tumour seeding [1]. However, various imaging modalities help to assess the extent of the disease [15]. Table 3 presents common investigations and possible findings.…”

“…Different imaging modalities used to visualise retinoblastoma[15]. (a) B scan of an eye with diffuse pattern retinoblastoma showing areas of calcification (see left) reproduced from Fahad Albader and Dalal Fatani 2019, (under the Creative Commons Attribution 3.0 License).…”

Histopathological assessment of optic nerve invasion guided by radiological findings in enucleated globes with retinoblastoma.

“…[2] Using special surface coils with small diameter and a short penetration depth improved the ability to correlate the MRI findings with the actual ocular histopathological findings. [2,18] Results from many studies showed that preoperative MRI was more relevant in detecting ON invasion. [17] Others have shown different sensitivity and specificity of MRI in detecting the level of ON invasion.…”