Hadron-therapy exploits light ions to treat tumors by maximizing the dose released to the target and sparing healthy tissues. With hadrons, the dose distribution rises sharply at the end of the range, providing the Bragg peak, and drops quickly to a negligible value. During hadron-therapy, positron-emitters are produced along the beam path before the Bragg peak. Following positron annihilation, two γ-photons are produced, which can be detected with a PET scanner. However, low yield of β-emitters and the wash out of the positron activity from the target region make the use of PET in hadron-therapy a significant challenge. In-beam PET represents a potential candidate to measure high fluence of β-emitters, at the cost of degraded contrast due to the partial rings. TOF information can potentially be used to enhance image contrast, and counteract for the loss of information. Alternatively, including total variation (TV) as prior information in the MAP reconstruction produces images with low noise without degrading spatial resolution. In this work we compare hadron-beams simulated using a complete and a partial ring Gemini TF PET scanner as model, reconstructed with ML-EM with and without TOF, and MAP-TV. MAP-TV demonstrates to produce lower noise images compared to ML-EM without and with TOF. Additionally, distal fall-off has been measured and no resolution loss has been observed.
Cabello, Jorge, Irene Torres-Espallardo, John Gillam, Faruk Diblen, and Magdalena Refercas. 2012. “Reconstruction from Truncated Projections Using Constrained Total-variation Minimization Applied to PET for Hadron-therapy Monitoring.” In IEEE Nuclear Science Symposium Conference Record, ed. B Yu, 3874–3879. New York, NY, USA: IEEE.
Cabello, J., Torres-Espallardo, I., Gillam, J., Diblen, F., & Refercas, M. (2012). Reconstruction from truncated projections using constrained total-variation minimization applied to PET for hadron-therapy monitoring. In B Yu (Ed.), IEEE Nuclear Science Symposium Conference Record (pp. 3874–3879). Presented at the 2012 IEEE Nuclear Science symposium and Medical Imaging Conference record (NSS/MIC 2012) ; Workshop on Room-Temperature Semiconductor X-Ray and Gamma-Ray Detectors, New York, NY, USA: IEEE.
Cabello J, Torres-Espallardo I, Gillam J, Diblen F, Refercas M. Reconstruction from truncated projections using constrained total-variation minimization applied to PET for hadron-therapy monitoring. In: Yu B, editor. IEEE Nuclear Science Symposium Conference Record. New York, NY, USA: IEEE; 2012. p. 3874–9.
Cabello, Jorge, Irene Torres-Espallardo, John Gillam, et al. “Reconstruction from Truncated Projections Using Constrained Total-variation Minimization Applied to PET for Hadron-therapy Monitoring.” IEEE Nuclear Science Symposium Conference Record. Ed. B Yu. New York, NY, USA: IEEE, 2012. 3874–3879. Print.