Dose Profiler

The space selectivity of the hadrontherapy asks for a new approach to the delivered dose monitoring. The uncertainty on the position of the dose released in hadrontherapy is of the order of few millimeters that can be larger than the dimension of the peak of the dose release (Bragg Peak). A precise monitoring of the dose is then essential for a good quality control of the treatment. Furthermore, the dose monitoring would be particularly useful if provided during the treatment (in-beam monitoring) in order to provide a fast feedback to the beam.

It has been demonstrated that the longitudinal distribution of the emission point of charged secondaries can be correlated with the Bragg Peak position. Within the INSIDE (INnovative Solutions for In-beam DosimEtry in hadron therapy) project a new device has been designed and built to measure with high efficiency the charge particle (proton dominated) emission profile in carbon treatments.

The detector (schematized in the figure) is composed of 8 planes (in orange) of two orthogonally placed scintillating fibers layer (384 fibers each) to provide bi-dimentional view. The fibers readout is performed by means of Silicon Photomultipliers (SiPM) coupled to the the fibers on both the sides.

Useful documents:

Thesis from M. De Simoni (pdf)
Thesis from F. Galante (pdf-Presentation)
Thesis from B. Di Lullo (pdf-Presentation)
Review article from Physica Medica

Who:

G. Battistoni, M. De Simoni, M. Fischetti, M. Marafini, I. Mattei, S. Muraro, V. Patera, A. Sarti, A. Schiavi, A. Sciubba, G. Traini.

Collaborations:

• Fluka group in Milano and CERN

• GSI

• HIT

• Politecnico di Milano

• Univ. di Pisa

INSIDE: INnovative Solutions for In-beam DosimEtry in hadrontherapy

The INSIDE (Innovative Solutions for In-Beam Dosimetry in hadrontherapy) MIUR project is born from the collaboration of a number of Italian Universities and INFN to build a multimodal in-beam dose monitoring system able to detect at the same time, back-to-back gammas from β + annihilation and charged secondary particles with kinetic energy higher than 30 MeV. The monitor is made up of 2 planar of 10 × 20 cm² PET heads for back-to-back gammas detection and of a 20×20 cm² dose profiler for protons detection.

INSIDE started the first clinical trial in July 2019 to study the sensitivity of the two detectors for an inter-fractional monitoring. It is currently taking data from patients during real treatments as it is possible to see in the picture.