The main hindrance to the diffusion of proton therapy facilities is the high cost for gantry installations. An alternative technical option is provided by fixed-beam treatment rooms, where the patient is rotated and translated in space with a robotic arm solution to enable beam incidence from various angles. The technological efforts based on robotic applications made up to now for patient positioning in proton beam facilities are described here, highlighting their limitations and perspectives.

Ovarian cancer is the second most prevalent gynecologic malignancy, and ovarian serous cystadenocarcinoma (OSCA) is the most common and lethal subtype of ovarian cancer. Current screening methods have strong limits on early detection, and the majority of OSCA patients relapse. In this work, we developed and cross-validated a method for detecting gene expression biomarkers able to discriminate OSCA tissues from healthy ovarian tissues and other cancer types with high accuracy. A preliminary ranking-based approach was applied, resulting in a panel of 41 over-expressed genes in OSCA. The RNA quantity gene expression of the 41 selected genes was then cross-validated by using NanoString nCounter technology. Moreover, we showed that the RNA quantity of eight genes (ADGRG1, EPCAM, ESRP1, MAL2, MYH14, PRSS8, ST14 and WFDC2) discriminates each OSCA sample from each healthy sample in our data set with sensitivity of 100% and specificity of 100%. For the other three genes (MUC16, PAX8 and SOX17) in combination, their RNA quantity may distinguish OSCA from other 29 tumor types.

A homemade computer code for designing the cou-pled microwave cavities of a linear accelerator (linac) has been developed. A hybrid approach, based on both analytical investi-gation and numerical calculation, is exploited. A Finite Element Method (FEM) based on 2D/3D electromagnetic simulation soft-ware is used to find the eigenmodes and eigenfrequencies of the accelerator cavities as well as the design typical figures of merit. The FEM investigation is integrated with a Multi-Objective Par-ticle Swarm Optimization (MOPSO) approach in order to auto-matically optimize the geometry of the accelerating tanks. This approach seems very promising and general, allowing the optimi-zation of a wide class of side-coupled resonant structures. The computer code is validated via measurements on a 27-MeV 3-GHz standing-wave Side-Coupled Linac (SCL) tank of five cavi-ties closed with suitable end cells. The agreement between simula-tion and experiment is excellent, the displacement between the maxima of the simulated and measured longitudinal electric field modulus is close to 0.2 %.

The aim of this study is to characterise the neutron flux generated directly behind targets used in medical cyclotrons. The characterisation process aims at determining the feasibility of using the generated neutrons for research purposes in neutron activation analysis. The study was performed by activating gold foils placed directly behind the cyclotron targets. The thermal and epithermal neutron flux were found to be 4.5E+05 ± 8.78E+04 neutrons cm⁻² s⁻¹ and 2.13E+06 ± 8.59E+04 neutrons cm⁻² s⁻¹, respectively. The flux value is the same order of magnitude listed in the manual produced by the cyclotron manufacturer. The results are encouraging and show high potential for using the cyclotron facility as a thermal neutron source for research purposes. However, it is important radiation protection procedures be followed to ensure the safety of researchers due to the high gamma dose rate measured directly behind the target at 2.46 Sv/h using an OSL chip during the beam on time.

In this study, the potential of a digital autoradiography system equipped with a super resolution screen has been evaluated to investigate the biodistribution of a 18F-PSMA inhibitor in a prostate cancer mouse model. Twelve double xenograft NOD/SCID mice (LNCAP and PC3 tumours) were divided into three groups according to post-injection time points of an 18F-PSMA inhibitor. Groups of 4 mice were used to evaluate the biodistribution of the radiopharmaceutical after 30-, 60- and 120-min post-injection. Data here reported demonstrated that the digital autoradiography system is suitable to analyse the biodistribution of an 18F-PSMA inhibitor in both whole small-animal bodies and in single organs. The exposure of both whole mouse bodies and organs on the super resolution screen surface allowed the radioactivity of the PSMA inhibitor distributed in the tissues to be detected and quantified. Data obtained by using a digital autoradiography system were in line with the values detected by the activity calibrator. In addition, the image obtained from the super resolution screen allowed a perfect overlap with the tumour images achieved under the optical microscope. In conclusion, biodistribution studies performed by the autoradiography system allow the microscopical modifications induced by therapeutic radiopharmaceuticals to be studied by comparing the molecular imaging and histopathological data at the sub-cellular level.

The design of suitable electromagnetic band-gap (EBG) cavities has been performed by means of a hybrid numerical/analytical approach implemented via a homemade code with the aim of optimizing a novel accelerating structure for proton linear accelerators (linacs). In particular, a 3-GHz proton linac tank with on-axis coupled EBG cavities closed with full end cells has been optimized. The proton beam input energy is 27 MeV. The performances of the proton linac EBG accelerating cavities has been compared with the performances of a 27-MeV 3-GHz side-coupled proton linac accelerating cavities in terms of typical linac figures of merit. The use of EBG cavities allows to increase the transit-time factor (by about 8%). Moreover, the peak surface electric field is strongly reduced (by about 65%), paving the way to the design of very high accelerating gradient microwave proton linacs. Furthermore, the wakefields of the EBG structure have been compared to the wakefields of the SCL structure, showing that the EBG structure provides effective damping of the transverse wakefields.