Improving the efficiency of small animal 3D printed compensator IMRT with total variation regularization
Year: 2021
Type: preprint
Abstract: Purpose: There is growing interest in the use of modern 3D printingtechnology to implement intensity-modulated radiation therapy (IMRT) on the
preclinical scale which is analogous to clinical IMRT. However, current
3D-printed IMRT methods suffer from long delivery times, excess filament usage,
and complex modulation patterns. In this work, we have developed a total
variation regularization (TVR) approach to address these issues. Methods: TVR-IMRT, a technique designed to minimize the intensity difference
between neighboring beamlets, was used to optimize the beamlet intensity map,
which was then converted to corresponding compensator thicknesses in
copper-doped PLA filament. IMRT and TVR-IMRT plans using five beams were
generated to treat a mouse heart while sparing lung tissue. The individual
field doses and composite dose were delivered to film and compared to the
corresponding planned doses using gamma analysis. Results: TVR-IMRT reduced the total variation of both the beamlet intensities
and compensator thicknesses around 50 when compared to standard 3D printed
compensator IMRT. The total mass of compensator material consumed and radiation
beam-on time were reduced by 20-30%, while DVHs remained comparable. Gamma
analysis passing rate with 3%/0.3mm criterion was 89.07% for IMRT and 95.37%
for TVR-IMRT. Conclusion: TVR can be applied to small animal IMRT in order to produce
fluence maps and subsequent 3D-printed compensator patterns with less total
variation, facilitating 3D printing and reducing the amount of filament
required. The TVR-IMRT plan required less beam-on time while maintaining the
dose conformity when compared to a traditional IMRT plan.
Source: arXiv (Cornell University)
Language: English
Subfield: Radiation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3179072389