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Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): The E-MIOT project receives “no-profit support” from industrial sponsorships (Chiesi Farmaceutici S.p.A. and Bayer). Background The T2* magnetic resonance imaging (MRI) technique for the noninvasive quantification of iron overload has significantly improved the survival of patients with hemoglobinopathies by tailoring the chelation therapy. In Italy, the E-MIOT (Extension-Myocardial Iron Overload in Thalassemia) Network, a collaborative project among MRI and hematological centers, has assured high-quality quantification of iron in vital organs such as heart, liver, and pancreas. The COVID-19 pandemic has disrupted healthcare services around the world, also leading to postpone or delete deferable diagnostic evaluations. Aim We evaluated the impact of the COVID-19 pandemic on MRI services for iron overload quantification in Italy. Methods The activity of the MRI centers of the E-MIOT Network in the year 2020 was compared to the activity in the same months of 2019. A specific survey was filled out by the MRI operators to evaluate if the availability of MRI slots for patients with hemoglobinothies was reduced and the reasons. Results In comparison with the year 2019, in 2020 there was a significant reduction in the number of T2* MRIs performed (350 vs 656; P Figure 2 shows the percentage of decline (year 2020 vs 2019) in the number of T2*MRI scans for each MRI center. If no decline or an increase were present, the vertical axis was set at 0. All centers experienced a significant drop in the number of the T2* MRIs in the four-month period March-June (from 75 to 100%). In the three-month period July-September only the centers of Pisa and Taranto dropped the number of T2* MRIs due to the rescheduling of the other MRI appointments deleted during the lockdown. In the three-month period October-December a reduction of the T2* MRI scans was experienced by all centers, except for Campobasso. In the centers of Ferrara and Lamezia Terme the reduction was the consequence of the general reduction in the number of the total MRIs scheduled per day for the sanitation procedures. In the other centers, the availability for T2* MRI scans was unchanged in comparison to 2019, but the patients refused the MRI follow up for fear of getting sick of COVID. Conclusion The COVID-19 pandemic is having a strong negative impact on the quantification of iron overload by MRI, which may seriously worsen the prognosis of patients with hemoglobinopathies. Strategies to ensure proved lifesaving MRI exam and to reassure patients about the health safety of the hospitals are recommended. Abstract Figure 1

A general ray-tracing method is proposed to determine the radiative properties of porous media. The particular case of random packing of equal sized spheres is studied. The method is used to calculate the forward and backward fluxes inside the medium. The two-flux model is then used to derive the absorption and scattering coefficients of the medium, from which the radiant conductivity can be calculated. Quantitative agreement is obtained in comparison with previous experimental and numerical works.

Purpose: Fast neutron therapy is offered at the University of Washington Medical Center for treatment of selected cancers. The hardware and control systems of the UW Clinical Neutron Therapy System are undergoing upgrades to enable delivery of IMNT. To clinically implement IMNT, dose verification tools need to be developed. We propose a portal imaging system that relies on the creation of positron emitting isotopes (11C and 15O) through (n, 2n) reactions with a PMMA plate placed below the patient. After field delivery, the plate is retrieved from the vault and imaged using a reader that detects the annihilation photons. The pattern of activity produced in the plate provides information to reconstruct the neutron fluence map that can be compared to fluence maps from Monte Carlo (MCNP) simulations to verify treatment delivery. We have previously performed Monte Carlo simulations of the portal imaging system (GATE simulations) and the beam line (MCNP simulations). In this work, initial measurements using a prototype system are presented. Methods: Custom electronics were developed for BGO detectors read out with photomultiplier tubes (previous generation PET detectors from a CTI ECAT 953 scanner). Two detectors were placed in coincidence, with a detector separation of 2 cm. Custom software was developed to create the crystal look up tables and perform a limited angle planar reconstruction with a stochastic normalization. To test the initial capabilities of the system, PMMA squares were irradiated with neutrons at a depth of 1.5 cm and read out using the prototype system. Doses ranging from 10–200 cGy were delivered. Results: Using the prototype system, dose differences in the therapeutic range could be determined. Conclusion: The prototype portal imaging system is capable of detecting neutron doses as low as 10–50 cGy and shows great promise as a patient QA tool for IMNT.

Purpose: The University of Washington Medical Center offers neutron therapy for the palliative and definitive treatment of selected cancers. In vivo field verification has the potential to improve the safe and effective delivery of neutron therapy. We propose a portal imaging method that relies on the creation of positron emitting isotopes (11C and 15O) through (n, 2n) reactions with a PMMA plate placed below the patient. After field delivery, the plate is retrieved from the vault and imaged using a reader that detects annihilation photons. The spatial pattern of activity produced in the PMMA plate provides information to reconstruct the neutron fluence map needed to confirm treatment delivery. Methods: We used MCNP to simulate the accumulation of 11C activity in a slab of PMMA 2 mm thick, and GATE was used to simulate the sensitivity and spatial resolution of a prototype imaging system. BGO crystal thicknesses of 1 cm, 2 cm and 3 cm were simulated with detector separations of 2 cm. Crystal pitches of 2 mm and 4 mm were evaluated. Back-projection of the events was used to create a planar image. The spatial resolution was taken to be the FWHM of the reconstructed point source image. Results: Themore » system sensitivity for a point source in the center of the field of view was found to range from 58% for 1 cm thick BGO with 2 mm crystal pitch to 74% for the 3 cm thick BGO crystals with 4 mm crystal pitch. The spatial resolution at the center of the field of view was found to be 1.5 mm for the system with 2 mm crystal pitch and 2.8 mm for the system with the 4 mm crystal pitch. Conclusion: BGO crystals with 4 mm crystal pitch and 3 cm length would offer the best sensitivity reader.« less

Poster: "ECR 2014 / C-1269 / Movement abnormalities in the left ventricle of Thalassemia Major patients" by: "C. Tudisca1, A. Meloni2, E. Grassedonio1, C. Argento3, G. Restaino4, G. Giannotti5, M. Lombardi2, M. Midiri1, A. Pepe2; 1Palermo/IT, 2Pisa/IT, 3Agrigento/IT, 4Campobasso/IT, 5Paterno (CT)/IT"