On Wednesday November 2, 2016, Kalam (Minty) James Ciantar one of our Masters students presented his final research outcomes to the school of physics at UWA.
Minty’s thesis title was: “Voxel-based Analysis of Kidney Response to Radiation using SPECT/CT Imaging“, under supervision of Adj/Prof. Martin Ebert.
The abstract of his thesis is as follows:
Background: Kidneys are the-dose limiting organ in upper-abdominal radiotherapy and due to their central location require crucial consideration when treating tumours in this region. Current understanding radiation induced dose-volume effects of kidneys is limited and fails to account for the complex spatial and temporal nature of renal damage thus hindering the ability to apply modern radiation treatment techniques to their full potential.
Aim: To investigate methodologies that can be used to improve the understanding of the temporal and spatial relationship between dose, volume and healthy tissue damage in kidneys using RAPRASI (Radiotherapy of Abdomen with Precise Renal Assessment with SPECT/CT Imaging) study data.
Method: RAPRASI study participants undergoing upper-abdominal radiotherapy were recruited for analysis with SPECT images (Single Photon Emission Computed Tomography/Computed Tomography) and GFR (Glomerular Filtration Rate) measurements taken before treatment and at successive follow up visits 4, 12, 26, 52 and 78 weeks following radiotherapy. Images were co-registered before decomposition into individual voxels of SPECT intensity which were weighted by the measured GFR to quantify regional renal function. Various voxel-based analyses were generated to correlate global and regional changes in renal function over time to the planned 3D dose distribution using 4/40 participants as a pilot study.
Results: No conclusive temporal trends were observed as functional response appeared transient. Scatter plots provided an adequate display of the overall change in function across a near-continuous dose spectrum. Grouping voxels based on the dose received allowed for simultaneous viewing of a large quantity of data for easier dose-function correlation and suggested that voxels receiving lower doses suffer greater transient effects. Images of spatial function change between scans superimposed with contours of the dose distribution allowed regional dose-function correlation. Regional correlation was not-present in the other plots and suggested functional changes occur independently between anatomical structures within the kidney. All analyses displayed global and regional transient effects. Sub-acute radiation effects showed a consistent decrease in function throughout kidney regions and across all doses with no significant sign of renal compensation observed in any of the analyses within 4 weeks of treatment.
Conclusion: Sufficient understanding of functional renal response to dose was attained using the methodologies developed in this project which can be applied to future studies regarding renal radiation-response.
And here is a video recorded from his presentation.