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 \beta+ radioactivity produced from nuclear reactions of the protons with native nuclei. Since the dose and PET distributions are difficult to compare directly, 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, simulated PET (simPET) 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 simPET were examined along the direction of the beam and covering the cross section of the beam. The chosen endpoints of the simPET (x-intercept of the linear fit to the distal falloff) and planned 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 were compared and the spread of range differences was assessed. Among the six patients, the mean difference between MC-PET and dose depth was found to be -1.6 mm to +0.5 mm between patients, with a standard deviation of 1.1 to 4.0 mm across the individual beams. In clinical practice, regions with deviations beyond the safety margin need to be examined more closely and can potentially lead to adjustments to the treatment plan.
| Original language | English |
|---|---|
| Article number | 6596511 |
| Pages (from-to) | 3290-3297 |
| Number of pages | 8 |
| Journal | IEEE Transactions on Nuclear Science |
| Volume | 60 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 2013 Sep 19 |
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All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Nuclear Energy and Engineering
- Electrical and Electronic Engineering
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Feasibility of using distal endpoints for in-room pet range verification of proton therapy. / Grogg, Kira; Zhu, Xuping; Min, Chulhee; Winey, Brian; Bortfeld, Thomas; Paganetti, Harald; Shih, Helen A.; El Fakhri, Georges.
In: IEEE Transactions on Nuclear Science, Vol. 60, No. 5, 6596511, 19.09.2013, p. 3290-3297.Research output: Contribution to journal › Article
TY - JOUR
T1 - Feasibility of using distal endpoints for in-room pet range verification of proton therapy
AU - Grogg, Kira
AU - Zhu, Xuping
AU - Min, Chulhee
AU - Winey, Brian
AU - Bortfeld, Thomas
AU - Paganetti, Harald
AU - Shih, Helen A.
AU - El Fakhri, Georges
PY - 2013/9/19
Y1 - 2013/9/19
N2 - In an effort to verify the dose delivery in proton therapy, positron emission tomography (PET) scans have been employed to measure the distribution of \beta+ radioactivity produced from nuclear reactions of the protons with native nuclei. Since the dose and PET distributions are difficult to compare directly, 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, simulated PET (simPET) 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 simPET were examined along the direction of the beam and covering the cross section of the beam. The chosen endpoints of the simPET (x-intercept of the linear fit to the distal falloff) and planned 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 were compared and the spread of range differences was assessed. Among the six patients, the mean difference between MC-PET and dose depth was found to be -1.6 mm to +0.5 mm between patients, with a standard deviation of 1.1 to 4.0 mm across the individual beams. In clinical practice, regions with deviations beyond the safety margin need to be examined more closely and can potentially lead to adjustments to the treatment plan.
AB - In an effort to verify the dose delivery in proton therapy, positron emission tomography (PET) scans have been employed to measure the distribution of \beta+ radioactivity produced from nuclear reactions of the protons with native nuclei. Since the dose and PET distributions are difficult to compare directly, 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, simulated PET (simPET) 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 simPET were examined along the direction of the beam and covering the cross section of the beam. The chosen endpoints of the simPET (x-intercept of the linear fit to the distal falloff) and planned 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 were compared and the spread of range differences was assessed. Among the six patients, the mean difference between MC-PET and dose depth was found to be -1.6 mm to +0.5 mm between patients, with a standard deviation of 1.1 to 4.0 mm across the individual beams. In clinical practice, regions with deviations beyond the safety margin need to be examined more closely and can potentially lead to adjustments to the treatment plan.
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U2 - 10.1109/TNS.2013.2278140
DO - 10.1109/TNS.2013.2278140
M3 - Article
AN - SCOPUS:84885951962
VL - 60
SP - 3290
EP - 3297
JO - IEEE Transactions on Nuclear Science
JF - IEEE Transactions on Nuclear Science
SN - 0018-9499
IS - 5
M1 - 6596511
ER -