Thats a unique idea.You should consider the following idea to enhance your idea so that it would impact uniquely: The transit in vivo dosimetry performed by an electronic portal imaging device (EPID) is a very practical method to check error sources in radiotherapy. Recently, the present authors have developed an in vivo dosimetry method based on correlation functions, F (w, L), defined as the ratio beten the transit signal, St (w, L), by the EPID and the mid-plane dose, Dm (w, L), in a solid water phantom as a function of the phantom thickness, w, and of the field dimensions, L. In particular, generalized correlation functions F (w, L) for 6, 10 and 15 MV X-ray beams supplied by a pilot Varian linac, are here used by other three linacs operating in two centers. This way the workload, due to measurements in solid water phantom, needed to implement the in vivo dosimetry method was avoided. This article reports a feasibility study on the potentiality of this procedure for the adaptive radiotherapy of lung tumors treated by 3D conformal radiotherapy techniques. In particular, the dose reconstruction at the isocenter point Diso in the lung tumor has been used as dose-guided radiotherapy (DGRT), to detect the inter-fraction tumor anatomy variations that can require new CT scans and an adaptive plan. When a difference greater than 6% beten the predicted dose by the treatment planning system (TPS), Diso,TPS and the Diso was observed, the clinical action started to detect possible anatomical lung tumor changes. Tlve over tnty patients examined presented in vivo dose discrepancies due to the tumor morphological changes during treatments, and these results re successively confirmed by new CT scans. In this work, for a patient that shod for all beams, Diso values over the tolerance level, the new CT scan was used for an adaptive plan. The lung dose volume histogram for Diso,TPS = 2 Gy per fraction suggested the adaptive plan. In particular, the lung volume included in 2 Gy increased from 350 cm3 of the original plan to 550 cm3 of the hybrid plan, while for the adaptive plan the lung volume included in 2 Gy decreased to 15 cm3. Moreover, the mean doses to the organs at risk re reduced to 70%. The results of this research show that the DGRT procedure by the Diso reconstruction, integrated with radiological imaging, was feasible for periodic investigation on morphological lung tumor changes. This feasibility study takes into account the accuracy of two algorithms based on the pencil beam and collapsed cone convolution models for dose calculations where large density inhomogeneities are present.
['Angelo Piermattei', 'Andrea Fidanzio', 'Savino Cilla', 'Francesca Greco', 'Luigi Azario', 'Domenico Sabatino', 'Mattia Grusio', 'M. Cozzolino', 'V. Fusco']
I am writing a research paper on a idea Dose-guided radiotherapy for lung tumors.
[{"from": "human", "value": "I am writing a research paper on a idea Dose-guided radiotherapy for lung tumors."}, {"from": "gpt", "value": "Thats a unique idea.You should consider the following idea to enhance your idea so that it would impact uniquely: The transit in vivo dosimetry performed by an electronic portal imaging device (EPID) is a very practical method to check error sources in radiotherapy. Recently, the present authors have developed an in vivo dosimetry method based on correlation functions, F (w, L), defined as the ratio beten the transit signal, St (w, L), by the EPID and the mid-plane dose, Dm (w, L), in a solid water phantom as a function of the phantom thickness, w, and of the field dimensions, L. In particular, generalized correlation functions F (w, L) for 6, 10 and 15 MV X-ray beams supplied by a pilot Varian linac, are here used by other three linacs operating in two centers. This way the workload, due to measurements in solid water phantom, needed to implement the in vivo dosimetry method was avoided. This article reports a feasibility study on the potentiality of this procedure for the adaptive radiotherapy of lung tumors treated by 3D conformal radiotherapy techniques. In particular, the dose reconstruction at the isocenter point Diso in the lung tumor has been used as dose-guided radiotherapy (DGRT), to detect the inter-fraction tumor anatomy variations that can require new CT scans and an adaptive plan. When a difference greater than 6% beten the predicted dose by the treatment planning system (TPS), Diso,TPS and the Diso was observed, the clinical action started to detect possible anatomical lung tumor changes. Tlve over tnty patients examined presented in vivo dose discrepancies due to the tumor morphological changes during treatments, and these results re successively confirmed by new CT scans. In this work, for a patient that shod for all beams, Diso values over the tolerance level, the new CT scan was used for an adaptive plan. The lung dose volume histogram for Diso,TPS = 2 Gy per fraction suggested the adaptive plan. In particular, the lung volume included in 2 Gy increased from 350 cm3 of the original plan to 550 cm3 of the hybrid plan, while for the adaptive plan the lung volume included in 2 Gy decreased to 15 cm3. Moreover, the mean doses to the organs at risk re reduced to 70%. The results of this research show that the DGRT procedure by the Diso reconstruction, integrated with radiological imaging, was feasible for periodic investigation on morphological lung tumor changes. This feasibility study takes into account the accuracy of two algorithms based on the pencil beam and collapsed cone convolution models for dose calculations where large density inhomogeneities are present."}]