Sandro Rossi

The national center for oncological hadron therapy: status of the project and future clinical use of the facility

Aims and background Hadron therapy is an advanced radiotherapy technique that employs charged particle beams. Several particles (pions, oxygen, neon and helium ions) have been investigated in the past, but at present only protons and carbon ions are used in clinical practice. Hadron therapy has been used for more than 50 years, more than 50,000 patients have been treated worldwide, and many new facilities are being built. Indications are still a matter of debate. The Italian National Center for Oncological Hadron Therapy (CNAO) is under construction in Pavia and will begin to treat patients in the near future. Methods The CNAO will be a center capable of using both protons and carbon ions. In the first phase, three rooms with vertical and horizontal fixed beams will be available, subsequently the center will be upgraded with two more rooms equipped with a rotating gantry. The facility will use active scanning delivery systems and state-of-the-art immobilization and setup verification devices. One additional room will be devoted to physical and radiobiological research. The CNAO will be a high-patient-throughput facility capable of treating more than 3,000 patients per year. Seven areas of interest have been identified: lung cancer, liver cancer, head and neck malignancies, pediatric solid cancers, eye tumors, sarcoma and central nervous system cancers. A disease-specific working group has been created for each area and has defined selection criteria and protocols to be used at the CNAO. Two more working groups are being set up on gynecological and digestive (pancreas, biliary tract and rectum) tumors. All the patients will participate in clinical trials to establish with sound evidence the real indications for hadron therapy. National and international cooperation networks are being set up to facilitate patient referral and follow-up. A medical service is already operative to assist patients and in selected case to refer them abroad. Conclusions The CNAO will be the only carbon ion facility in Italy and will have an international basin. Close cooperation with existing oncological centers is of paramount importance to fully exploit its potential.

The power supply for the beam chopper magnets of a medical synchrotron

The ongoing design of the power supply for the beam chopper magnets of a medical synchrotron is presented. The four, series connected beam chopper magnets, which are placed on the extraction line, are used for blanking the beam both during routine operation and for emergency. To let the beam pass the magnets need to be energized with a current, proportional to the beam energy, whose maximum value was calculated to be about 650A. The required current should be reached from zero in less than 260μs and then can be maintained for an arbitrary long time. Finally is should fall back to zero in less than 260μs. The power supply is composed of an high voltage part (2.9kV), which is in charge of the rising and falling current ramp and of a low voltage part (60V) which is in turn responsible for the current flat top.

Online proton therapy monitoring: clinical test of a Silicon-photodetector-based in-beam PET

Particle therapy exploits the energy deposition pattern of hadron beams. The narrow Bragg Peak at the end of range is a major advantage but range uncertainties can cause severe damage and require online verification to maximise the effectiveness in clinics. In-beam Positron Emission Tomography (PET) is a non-invasive, promising in-vivo technique, which consists in the measurement of the β+ activity induced by beam-tissue interactions during treatment, and presents the highest correlation of the measured activity distribution with the deposited dose, since it is not much influenced by biological washout. Here we report the first clinical results obtained with a state-of-the-art in-beam PET scanner, with on-the-fly reconstruction of the activity distribution during irradiation. An automated time-resolved quantitative analysis was tested on a lacrimal gland carcinoma case, monitored during two consecutive treatment sessions. The 3D activity map was reconstructed every 10 s, with an average delay between beam delivery and image availability of about 6 s. The correlation coefficient of 3D activity maps for the two sessions (above 0.9 after 120 s) and the range agreement (within 1 mm) prove the suitability of in-beam PET for online range verification during treatment, a crucial step towards adaptive strategies in particle therapy.

Proton beam radiotherapy: report of the first patient treated at the Centro Nazionale di Adroterapia Oncologica (CNAO) [National Center of Oncologic Hadron Therapy].

Proton beam radiotherapy, an innovative treatment modality, allows delivery of high radiation doses to the target while sparing surrounding healthy structures. The Centro Nazionale di Adroterapia Oncologica (CNAO), equipped with a synchrotron and capable of using both protons and ions, initiated its clinical activity in September 2011. The first treatment of a skull base tumor with protons is reported here. The case of a 26-year-old man with an intracranial low-grade chondrosarcoma of the right petroclival junction is discussed with emphasis on technical and clinical details. Two previous surgical interventions had achieved partial removal of the tumor and the patient was treated with protons for residual disease. The prescribed dose was 70 GyE in 35 fractions of 2 GyE. Treatment was completed with minimal acute toxicity consisting of grade 1 alopecia and nausea. Nine months after treatment the disease is locally controlled. Use of high-energy protons at CNAO is a safe and effective means of treating a tumor located near critical normal structures.

Monte Carlo simulation tool for online treatment monitoring in hadrontherapy with in-beam PET: A patient study

Hadrontherapy is a method for treating cancer with very targeted dose distributions and enhanced radiobiological effects. To fully exploit these advantages, in vivo range monitoring systems are required. These devices measure, preferably during the treatment, the secondary radiation generated by the beam-tissue interactions. However, since correlation of the secondary radiation distribution with the dose is not straightforward, Monte Carlo (MC) simulations are very important for treatment quality assessment. The INSIDE project constructed an in-beam PET scanner to detect signals generated by the positron-emitting isotopes resulting from projectile-target fragmentation. In addition, a FLUKA-based simulation tool was developed to predict the corresponding reference PET images using a detailed scanner model. The INSIDE in-beam PET was used to monitor two consecutive proton treatment sessions on a patient at the Italian Center for Oncological Hadrontherapy (CNAO). The reconstructed PET images were updated every 10 s providing a near real-time quality assessment. By half-way through the treatment, the statistics of the measured PET images were already significant enough to be compared with the simulations with average differences in the activity range less than 2.5 mm along the beam direction. Without taking into account any preferential direction, differences within 1 mm were found. In this paper, the INSIDE MC simulation tool is described and the results of the first in vivo agreement evaluation are reported. These results have justified a clinical trial, in which the MC simulation tool will be used on a daily basis to study the compliance tolerances between the measured and simulated PET images.

Clinical activity after fingolimod cessation: disease reactivation or rebound?

There is debate as to whether the apparent rebound after fingolimod discontinuation is related to the discontinuation itself or whether it is due to the natural course of highly active multiple sclerosis (MS). Our aim was to survey the prevalence of severe reactivation and rebound after discontinuation of fingolimod in a cohort of Italian patients with MS.

Indications of Carbon Ion Therapy at CNAO

CNAO will be a dual center capable of providing therapeutic beams of protons and carbon ions with maximum energy of 400 MeV/u. At the beginning, it will be equipped with three treatment rooms with fixed horizontal and vertical beam lines. In a subsequent phase, two more rooms with a rotating gantry are foreseen. An active spot scanning dose delivery system will be employed. Initially, 80% of the treatments will be carried out with carbon ions. All patients will be treated within clinical trials to assess carbon ion indications with an evidence‐based methodology. Seven disease‐specific working groups have been developed: lung tumors, liver tumors, sarcomas, head and neck tumors, central nervous system lesions, eye tumors and pediatric tumors. The last two groups will be treated mainly with protons. In the first phase, CNAO will focus on head and neck cancers, treating inoperable, residual or recurrent malignant salivary gland tumors, mucosal melanoma, adenocarcinoma and unfavorably located SCC (nasal and p...

Ion cooling and accumulation

For the preparation of dense bunches of ions for the LHC it has been proposed to accumulate in a small storage ring the beam from a linac with an ECR source. The scheme involves combined transverse and longitudinal multiturn injection and strong electron cooling to free phase space for the next injection. Successful experiments to determine the optimum parameters of a low-energy ion accumulator were performed at the Low Energy Antiproton Ring (LEAR) with Pb-ions of charge state 52+ to 55+ at an energy of 4.2 MeV/u. The reported measurements include: lifetime for different charge states as a function of the electron cooler current, cooling rates with different optical settings, efficiencies of the combined multiturn injection and results of accumulation. The transformation of LEAR into an accumulator ring for a wide range of ion species will be based on these results.