Roberto Sacchi

The CNAO system to monitor and control hadron beams for therapy

Hadrotherapy might be the last chance option for patients with cancers growing deep in the body or surrounded by very sensitive organs. The Italian National Center of Oncological Hadrotherapy (CNAO) in Pavia is a synchrotron based center for the treatment of tumors with protons and carbon ion beams. The result of this sophisticated technique is strongly affected by the beam delivery performances. A powerful on-line system to monitor and deliver particles inside the target will be available at CNAO.

A large dynamic range charge measurement ASIC family for beam monitoring in radiotherapy applications

A family of Application Specific Integrated Circuits ( ASICs ) called TERA have been developed for the readout of pixel and strip gas detectors used in radiotherapy applications. The TERA ASICs are based on the charge balancing integration technique in order to obtain a good linearity over a dynamic range of five order of magnitude.

Commissioning operations and performances of the Dose Delivery system for CNAO

The first Italian hospital-based facility for hadron therapy, the Centro Nazionale di Adroterapia Oncologica (CNAO), is treating patients since a few weeks. The optimization and commissioning of the Dose Delivery system have been performed in the course of the current year and were concluded in August 2011. After a short introduction on the CNAO and the Dose Delivery features, the paper describes the main operations from the Treatment Planning System output to the end of the particle delivery operation. A second section focuses on the tests and measurements performed for the commissioning reporting also on the measured performances. The Dose Delivery short-term perspectives are then added to the conclusions.

Control of the Dose Distribution in Charged Particle Therapy

The use of ions in radiation therapy aims at improving the selectivity of the irradiation thanks to a favourable depth-dose profile and, in case of heavy ions, to their enhanced radiobiological effect. The treatment modality employing actively scanned pencil beams provides highly conformal dose distributions but is sensitive to uncertainties in the dose calculation, delivery and measurement. During the treatment, the delivery of the beam has to be controlled in real time and monitored with high accuracy, including any effect due to patient positioning and motion. Based on the experience gained in the collaboration with the CNAO (Centro Nazionale di Adroterapia Oncologica, Pavia, Italy), this paper is intended to give an overview of recent techniques and trends for the delivery, measurement and verification of the dose distribution in charged particle therapy with scanned ion beams, focusing in particular on real time and online techniques.

WE‐C‐AUD B‐09: Evaluation of Radiobiological Effects of Carbon Ion Beams: Mixed Particle Fields and Fragmentation

Purpose: The purpose of this report is to investigate the effects on the Relative Biological Effectiveness (RBE) due to nuclear fragmentation during irradiation with therapeuticcarbonion beams, by using biological model calculations. Method and Materials: In order to disentangle the biological effects of the mixed particle fields, we evaluated the RBE originated by primary carbon ions and by fragments together and separately. The radiobiological efficiency of charged particles is mainly characterized by their high local ionization density which can be directly correlated to the local density of DNA damage. We developed a code based on the Local Effect Model (LEM) for the calculation of the cell survival after irradiation with carbon ions. As input we use particle distributions sampled at different depths in a water volume, for different energies of the primary ions (between 150 and 400 MeV/u), generated by Monte Carlo simulations using the package GEANT4. The computational effort was performed using the distributed INFN (Istituto Nazionale di Fisica Nucleare) Grid computing resources. Results: For carbon ions, high RBE values were found in the high‐LET region (Bragg peak), as well as in the low‐dose region, the distal region after the Bragg peak, where the contribution to the RBE is mainly due to fragments. We show that the global biological effect can be well reconstructed by a weighted combination of the alpha and beta parameters of the Linear‐Quadratic Model (LQM) evaluated separately for primary ions and fragments. The analysis provided also an estimate of the RBE sensitivity to the uncertainties present in the experimental data of fragment yield. Conclusion: Our work estimated the impact of the fragments in hadrontherapy using carbonion beams. Due to the high RBE values found, the resulting biological dose can be important in regions outside the irradiated target, in presence of organs at risk.

Searches for physics beyond the standard model at HERA

This article summarizes the results of searches for new physics beyond the standard model at HERA performed by the ZEUS and H1 experiments. Recent results are presented on direct searches for electron–quark resonant states such as leptoquarks or squarks in R-parity violating SUSY, on indirect searches for new physics leading to eeqq contact interactions and on searches for single top-quark production through anomalous flavour-changing coupling in neutral-current processes. Most of the results shown are based on the full statistics collected before the luminosity upgrade of HERA and some of them were also updated with newer results made available after the workshop.