Aim: To use 3D ultrasonography (3DUS) for the diagnosis of retinoblastoma. Methods: Five eyes of three children with retinoblastoma were evaluated using a commercially available computerised 3DUS system. Interactive sectioning of the stored and reconstructed 3D volumes were performed. 3DUS and histopathological findings were correlated after enucleation. Results: 3DUS examination revealed characteristics consistent with retinoblastoma: endophytic mass, retinal detachment, intratumoural calcifications, and secondary orbital shadowing. Unlike 2D imaging, 3DUS allowed for analysis of the acquired and stored volumes. Rotation and sectioning of this volume allowed the discovery of new oblique and coronal views. For example, calcium related orbital shadows were seen as 3D volumes and (coronal) cross sections of the optic nerve were evaluated for evidence of intraneural invasion by retinoblastoma. Conclusion: This is the first reported series of patients examined with 3DUS imaging for retinoblastoma. This technique allowed for new oblique and coronal views of the tumour and optic nerve. The ability to retrospectively analyse the (scanned and stored) ocular volume facilitated patient care, teaching, tumour-volume analysis, and telemedicine. R etinoblastoma is the most common primary intraocular malignancy in children. Imaging techniques are essential for the diagnosis and follow up of retinoblastomas. Ultrasonography has been used to reveal calcifications within the tumour and to evaluate extrascleral and optic nerve invasion.1-6 After treatment, ultrasonography and ophthalmoscopy are the main tools used to evaluate intraocular tumour regression.
7-10Computer assisted three dimensional ultrasonography (3DUS) has become available to ophthalmological oncology.
11There is an emerging literature on the use of 3DUS for tumour diagnosis, radiation plaque placement, and follow up of treated choroidal melanomas. [12][13][14][15] This study presents the first reported use and our initial experience with 3DUS in evaluation of retinoblastoma. We have found new and exciting capabilities which have allowed us to produce unique and interesting views. Further experience and comparative studies will determine the role of 3DUS in the care of patients with retinoblastoma.
MATERIALS AND METHODSOur methods of three dimensional ultrasonography (3DUS) have been described. [11][12][13][14] In sum, we utilised a commercially available computerised 3D ultrasound system (Ophthalmic Technologies Incorporated (OTI) Downsview, Ontario, Canada) to examine three patients (five eyes) with retinoblastoma. This system typically acquires data from 90 consecutive two dimensional (2D) images from which a 3D volume is rendered. The 3D volume is presented as a block, which was sliced, rotated, and examined from transverse, longitudinal, oblique, and coronal orientations.
RESULTSOur first patient had a unilateral retinoblastoma. Before enucleation, 3DUS revealed multiple highly reflective nodules consistent with calcification ( Fig 1A). Histopathology reveale...