Feasibility of using distal endpoints for In-room PET Range Verification of Proton Therapy

K. Grogg, X. Zhu, C. H. Min, B. Winey, T. Bortfeld, H. Paganetti, H. Shih, G. El Fakhri

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

In an effort to verify the dose delivery in proton therapy, Positron Emission Tomography (PET) scans have been employed to measure the distribution of β+ radioactivity produced from nuclear reactions of the protons with native nuclei. Because the dose and PET distributions are not directly comparable, the range verification is currently carried out by comparing measured and Monte Carlo (MC) simulation predicted PET distributions. In order to reduce the reliance on MC, MC-PET and dose distal endpoints were compared to explore the feasibility of using distal endpoints for in-room PET range verification. MC simulations were generated for six head and neck patients with corrections for radiological decay, biological washout, and PET resolution. One-dimensional profiles of the dose and MC-PET were examined along the direction of the beam and covering the cross section of the beam. The chosen endpoints of the MC-PET (y-intercept of the linear fit to the distal falloff) and MC dose (20-50% of maximum dose) correspond to where most of the protons are below the threshold energy for the nuclear reactions. The difference in endpoint range between the distal surfaces of the dose and MC-PET are compared and the spread of range differences are assessed. Among the six patients, the mean difference between MC-PET and dose depth was found to be -1.5 mm to +3.7 mm between patients, with a standard deviation of 1.3 to 6 mm across the individual beams.

Original languageEnglish
Title of host publication2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record, NSS/MIC 2012
Pages3890-3894
Number of pages5
DOIs
Publication statusPublished - 2012 Dec 1
Event2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record, NSS/MIC 2012 - Anaheim, CA, United States
Duration: 2012 Oct 292012 Nov 3

Publication series

NameIEEE Nuclear Science Symposium Conference Record
ISSN (Print)1095-7863

Other

Other2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record, NSS/MIC 2012
CountryUnited States
CityAnaheim, CA
Period12/10/2912/11/3

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All Science Journal Classification (ASJC) codes

  • Radiation
  • Nuclear and High Energy Physics
  • Radiology Nuclear Medicine and imaging

Cite this

Grogg, K., Zhu, X., Min, C. H., Winey, B., Bortfeld, T., Paganetti, H., Shih, H., & El Fakhri, G. (2012). Feasibility of using distal endpoints for In-room PET Range Verification of Proton Therapy. In 2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record, NSS/MIC 2012 (pp. 3890-3894). [6551892] (IEEE Nuclear Science Symposium Conference Record). https://doi.org/10.1109/NSSMIC.2012.6551892