Radioimmunotherapy with radioactive nanoparticles: Biological doses and treatment efficiency for vascularized tumors with or without a central hypoxic area

Journal Article · Thu Apr 15 00:00:00 EDT 2010 · Medical Physics

DOI:https://doi.org/10.1118/1.3368599· OSTI ID:22096674

Bouchat, V.; Nuttens, V. E.; Michiels, C. ^[1]; others, and

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1. Research Center in Physics of Matter and Radiation (PMR), Laboratoire d'Analyses par Reactions Nucleaires (LARN), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000 Namur (Belgium)

Purpose: Radioactive atoms attached to monoclonal antibodies are used in radioimmunotherapy to treat cancer while limiting radiation to healthy tissues. One limitation of this method is that only one radioactive atom is linked to each antibody and the deposited dose is often insufficient to eradicate solid and radioresistant tumors. In a previous study, simulations with the Monte Carlo N-Particle eXtended code showed that physical doses up to 50 Gy can be delivered inside tumors by replacing the single radionuclide by a radioactive nanoparticle of 5 nm diameter containing hundreds of radioactive atoms. However, tumoral and normal tissues are not equally sensitive to radiation, and previous works did not take account the biological effects such as cellular repair processes or the presence of less radiosensitive cells such as hypoxic cells. Methods: The idea is to adapt the linear-quadratic expression to the tumor model and to determine biological effective doses (BEDs) delivered through and around a tumor. This BED is then incorporated into a Poisson formula to determine the shell control probability (SCP) which predicts the cell cluster-killing efficiency at different distances ''r'' from the center of the tumor. BED and SCP models are used to analyze the advantages of injecting radioactive nanoparticles instead of a single radionuclide per vector in radioimmunotherapy. Results: Calculations of BED and SCP for different distances r from the center of a solid tumor, using the non-small-cell lung cancer as an example, were investigated for {sup 90}Y{sub 2} O{sub 3} nanoparticles. With a total activity of about 3.5 and 20 MBq for tumor radii of 0.5 and 1.0 cm, respectively, results show that a very high BED is deposited in the well oxygenated part of the spherical carcinoma. Conclusions: For either small or large solid tumors, BED and SCP calculations highlight the important benefit in replacing the single {beta}-emitter {sup 90}Y attached to each antibody by a {sup 90}Y{sub 2} O{sub 3} nanoparticle.

• OSTI ID: 22096674
• Journal Information: Medical Physics, Vol. 37, Issue 4; Other Information: (c) 2010 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-2405
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
61 RADIATION PROTECTION AND DOSIMETRY
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL REPAIR
CARCINOMAS
DOSIMETRY
EFFICIENCY
LUNGS
MONOCLONAL ANTIBODIES
MONTE CARLO METHOD
NANOSTRUCTURES
POISSON EQUATION
RADIATION DOSES
RADIOIMMUNOTHERAPY
SIMULATION
YTTRIUM 90
YTTRIUM COMPOUNDS