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Title: Alpha and recoil track detection in poly(methyl methacrylate) (PMMA)—Towards a method for in vitro assessment of radiopharmaceuticals internalized in cancer cells

A method for detection and characterization of single MeV α-particle and recoil tracks in PMMA photoresist by atomic force microscopy (AFM) analysis has been demonstrated. The energy deposition along the track is shown to lead to a latent pattern in the resist due to contrast reversal. It has been shown that the pattern, consisting of conical spikes, can be developed by conventional processing as a result of the dissolution rate of poly(methyl methacrylate) (PMMA) being greater than that for the modified material in the cylindrical volume of the track core. The spikes can be imaged and counted by routine AFM analysis. Investigations by angular-resolved near-grazing incidence reveal additional tracks that correspond to recoil tracks. The observations have been correlated with modelling, and shown to be in qualitative agreement with prevailing descriptions of collision cascades. The results may be relevant to technologies that are based on detection and characterization of single energetic ions. In particular, the direct visualization of the collision cascade may allow more accurate estimates of the actual interaction volume, which in turn will permit more precise assessment of dose distribution of α-emitting radionuclides used for targeted radiotherapy. The results could also be relevant to other diagnostic or processmore » technologies based on interaction of energetic ions with matter.« less
Authors:
;  [1] ;  [2]
  1. Oxford University Begbroke Science Park, University of Oxford, Oxford (United Kingdom)
  2. MRC/CRUK Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Oxford, United Kingdom and Department of Biomedical Science, Tshwane University of Technology, Pretoria (South Africa)
Publication Date:
OSTI Identifier:
22255290
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 85; Journal Issue: 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; ATOMIC FORCE MICROSCOPY; ENERGY ABSORPTION; METHACRYLIC ACID ESTERS; NEOPLASMS; PARTICLE TRACKS; PMMA; RADIATION DOSE DISTRIBUTIONS; RADIOPHARMACEUTICALS; RADIOTHERAPY; RECOILS; TAIL IONS