WE-G-BRE-03: Dose Painting by Numbers Using Targeted Gold Nanoparticles

Journal Article · Sun Jun 15 04:00:00 EDT 2014 · Medical Physics

DOI:https://doi.org/10.1118/1.4889478· OSTI ID:22409744

Altundal, Y; Sajo, E ^[1]; Korideck, H ^[2]; Ngwa, W ^[1]

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1. University Massachusetts Lowell, Lowell, MA (United States)
2. Dana-Farber Cancer Institute, Boston, MA, (United States)

Purpose: Homogeneous dose enhancement in tumor cells of lung cancer patients treated with conventional dose of 60–66 Gy in five fractions is limited due to increased risk of toxicity to normal structures. Dose painting by numbers (DPBN) is the prescription of a non-uniform radiation dose distribution in the tumor for each voxel based on the intensity level of that voxel obtained from the tumor image. The purpose of this study is to show that DPBN using targeted gold nanoparticles (GNPs) could enhance conventional doses in the more resistant tumor areas. Methods: Cone beam computed tomography (CBCT) images of GNPs after intratumoral injection into human tumor were taken at 0, 48, 144 and 160 hours. The dose enhancement in the tumor voxels by secondary electrons from the GNPs was calculated based on analytical microdosimetry methods. The dose enhancement factor (DEF) is the ratio of the doses to the tumor with and without the presence of GNPs. The DEF was calculated for each voxel of the images based on the GNP concentration in the tumor sub-volumes using 6-MV photon spectra obtained using Monte Carlo simulations at 5 cm depth (10×10 cm2 field). Results: The results revealed DEF values of 1.05–2.38 for GNPs concentrations of 1–30 mg/g which corresponds to 12.60 – 28.56 Gy per fraction for delivering 12 Gy per fraction homogenously to lung tumor region. Conclusion: Our preliminary results verify that DPBN could be achieved using GNPs to enhance conventional doses to high risk tumor sub-volumes. In practice, DPBN using GNPs could be achieved due to diffusion of targeted GNPs sustainably released in-situ from radiotherapy biomaterials (e.g. fiducials) coated with polymer film containing the GNPs.

• OSTI ID: 22409744
• Journal Information: Medical Physics, Journal Name: Medical Physics Journal Issue: 6 Vol. 41; ISSN 0094-2405; ISSN MPHYA6
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
BIOLOGICAL MATERIALS
COMPUTERIZED SIMULATION
COMPUTERIZED TOMOGRAPHY
GOLD
LUNGS
MICRODOSIMETRY
MONTE CARLO METHOD
NANOPARTICLES
NEOPLASMS
RADIATION DOSE DISTRIBUTIONS
RADIATION DOSES
RADIOTHERAPY
TUMOR CELLS