Page 167 - HA Convention 2015

Parallel Sessions

PS3.4 Allied Health II – Technology Advancement and Innovation 13:15 Theatre 2

Transition to Digital Operation in Radiation Therapy Tuesday, 19 May
Pang CWY
Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong

The urgency to change is ever present in the healthcare sector because there is a constant demand for better and more
cost effective clinical care. Yet the implementation of change is often met with challenges as healthcare provision involves a
diversity of individuals from different disciplines.

Applying the advanced technology, the Department of Clinical Oncology of Queen Elizabeth Hospital has recently
established a filmless working environment to relieve the disturbing problem of squeezing for extra storage space. Evolving
into a new system from an existing one, the department has undergone a transition from manual to digital operation by
replacing localisation x-ray films and verification x-ray films by digital imaging at the simulator units.

Simulation is a pre-treatment process by which the radiation treatment fields are defined, filmed and marked on the patient.
Before this change, localisation x-ray films were printed for oncologists to delineate the treatment area. Treatment fields
were digitised and imported to the planning system for dose calculation. Acuity of Varian, the newly installed simulator at our
department, is able to take and save localisation images in digital format. Oncologists may delineate treatment area directly
with the planning system. Verification images to confirm the accuracy of the patient’s treatment position can also be taken
and saved in digital format. Verification images are compared with computed tomography digitally reconstructed radiograph
through anatomy image matching.

Digital operation in radiation therapy lowers the demand for medical film storage and manpower in sorting films. The
Department of Clinical Oncology has made the transition from film-based to filmless operation a success. Through engaging
and communicating with different stakeholders, the department has overcome many technical and operational challenges
which are inevitable when implementing a change.

PS3.5 Allied Health II – Technology Advancement and Innovation 13:15 Theatre 2

3D Processing of Computed Tomography Images HOSPITAL AUTHORITY CONVENTION 2015
Lee MC
Department of Radiology, Queen Mary Hospital, Hong Kong

Thanks to the speedy image acquisition and excellent spatial resolution of cutting-edge multi-detector Computed
Tomography (CT) scanner, the presentation of CT image data is not only restricted to conventional axial or other orthogonal
planes, but also in various 3D models to facilitate clinical diagnosis. The 3D image processing is a labour intensive process
requiring holistic knowledge of the related radiological appearance and technical parameter of imaging examination. It
is rather common that the time used for processing the data is much longer than the scanning time of CT examination.
However, the processed images can optimise the identification and localisation of imaging abnormalities as well as accurate
demonstration of the extent of lesions. Nevertheless, 3D image processing may also lead to pitfalls in radiological diagnosis
through introduction of reconstruction artifacts. Only the appropriately trained healthcare professionals shall apply the image
processing techniques for the related image data.

The basic 3D image processing techniques shall include multi-planar reformation (MPR), volume rendering (VR), maximum
intensity projection (MIP) and 2D measurement. These techniques can apply to different clinical scenarios and different
imaging parameters can significantly affect the quality of the processed images. The advanced imaging processing
techniques shall include volume measurement in liver donor workup, functional imaging in different body parts and the
application of virtual endoscopy in computed tomography.

165