Proton range monitoring with in-beam PET: Monte Carlo activity predictions and comparison with cyclotron data

Abstract

We found a good agreement in Δw50% and in the ratio between beam-on and beam-off activity between the PET data and the FLUKA MC predictions in all irradiation conditions.

Proton therapy treatment monitoring with in-beam PET: Investigating space and time activity distributions

“…Each pair defines a line-of-response (LOR), and it is stored in a file containing the number of hit detected for each LOR. To obtain the 3-D activity image these data first undergo to a normalization procedure, based on an flatfield acquisition of a homogeneous planar phantom filled with 18 FDG [22], and subsequently are processed using a Maximum-Likelihood-Expectation-Maximization algorithm [23] which makes use of an analytical model of the system matrix. The reconstructed field of view (FOV) has a volume of 10×16×16 cm 3 , segmented into 1 mm 3 voxels.…”

“…Images are reconstructed using data collected within 120 s after the end of the irradiation: 1-D activity profiles are obtained projecting all the events included in an elliptical ROI in the transverse plane on the z axis, that represents the beam axis (see also [18]). This procedure is suggested by the geometrical configuration of DoPET which, as discussed in Sec.…”

“…In this study a large area dual head PET prototype developed and built in Pisa is used. The system is an upgraded version of DoPET prototype [18] with an active area of about 15×15 cm 2 which allows to cope with volumes encountered in the clinical practice. Irradiations were performed at the cyclotron of Trento Proton Therapy Center using plastic phantoms.…”

First tests for an online treatment monitoring system with in-beam PET for proton therapy

“…A standard correction for random coincidences was also included. No attenuation correction was performed, which is not expected to influence the fall-off position of the measured activity profile, as shown in [17]. The total reconstructed field-of-view (FOV) was 10 x 10 x 10 cm 3 and each voxel was 1 x 1 x 1 mm 3 .…”

Nuclear physics and particle therapy

“…Measured activity results were compared with predictions from the FLUKA MC generator [19,20]. For PMMA phantoms the difference between the MC prediction and the data, considering the distance between the 50% rise and 50% fall-off position of the activity distribution is less than 1 mm [21]. The system showed to be able to detect the presence of inhomogeneities in the phantom.…”