A High-Resolution Portable Gamma-Camera for Estimation of Absorbed Dose in Molecular Radiotherapy

• Published in: IEEE transactions on radiation and plasma medical sciences 2024-05, Vol.8 (5), p.556-570
• Main Authors: Bossis, T., Verdier, M.-A., Trigila, C., Pinot, L., Bouvet, F., Blot, A., Ramarijaona, H., Beaumont, T., Broggio, D., Caselles, O., Zerdoud, S., Menard, L.
• Format: Article
• Language: English
• Subjects: Artificial neural networks; Bulk density; Cameras; Collimators; Design optimization; Dosimetry; Dosimetry-guided radionuclide therapy; Energy resolution; Health services; high performance; Image reconstruction; Imaging; mobile gamma-camera; Monte Carlo simulation; Neural networks; Physics; Production methods; quantitative image; Radiation dosage; Radiation therapy; Scintillation counters; Scintillators; Signal to noise ratio; Spatial discrimination; Spatial resolution; Three dimensional printing; Thyroid; Thyroid diseases; Toxicity; Tungsten
• ISSN: 2469-7311; 2469-7303
• DOI: 10.1109/TRPMS.2024.3376826

Molecular radiotherapy is a treatment modality that requires personalized dosimetry for efficient treatment and reduced toxicity. Current clinical imaging systems and miniaturized gamma-cameras lack the necessary features for this task. In this article, we present the design and optimization of a mobile gamma-camera with a 10\times 10 cm2 field of view tailored for quantitative imaging during ^{131}\text{I} therapy of thyroid diseases. The camera uses a monolithic 10\times 10\times 1 cm3 CeBr3 scintillator coupled to a 16\times 16 SiPMs array and commercial electronics. It exhibits high imaging performance with an intrinsic spatial resolution (SR) of 1.15-mm FWHM, an energy resolution of 8% FWHM at 356 keV and negligible deadtime up to 150 kcps. Images are reconstructed in real time using a convolutional neural network. The manufacturing method of tungsten collimators and shielding was optimized using laser 3-D printing to achieve an effective density of 97% that of bulk tungsten. Their geometry was adjusted with Monte-Carlo simulations in order to reduce septal penetration and scattering and optimize the signal-to-noise ratio at short times after treatment administration. Two high-energy parallel-hole collimators with high sensitivity or very high SR were designed for treatment planning and post-treatment control. The fully operational gamma-camera will soon be clinically assessed.