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[P194] Breast cancer radiosurgery with a synchrotron radiation beam
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Abstracts / Physica Medica 52 (2018) 99–187
Film samples were digitized using a flatbed scanner Epson 10000XL. Several opaque and transparent templates for digitization were developed and tested. The uncertainties related to the films and digitization process were quantified in a previous work, and helped to determine which variations needed to be minimized (e.g. film-to-light source distance), and which could be treated more flexibly. Results. The use of samples smaller than 1 1.5 cm2 was discarded as impractical. Film samples of 1.5 1.0 cm2; 1 cm apart, proved the best option for adequate coverage of the irradiated length, using strips of 3–8 samples according to applicator size. The selected template allows simultaneous digitization of a nonirradiated film piece (reference) and up to eight irradiated samples, reducing inter-scan fluctuations and total digitization time. For films irradiated with 10 to 15 Gy (dose interval of interest), this template minimizes the lateral discontinuity effect previously observed on the measured response at the films’ edges. A glass plate is used for compression, to ensure uniform film-to-light source distance. Conclusions. The methodology for in vivo measurements was optimized by using smaller samples and an opaque template to read up to eight films in a single scan. These changes allow a better characterization of the irradiated area with a simpler and faster digitization method. https://doi.org/10.1016/j.ejmp.2018.06.490
[P194] Breast cancer radiosurgery with a synchrotron radiation beam Giovanni Mettivier a, Anton io Sarno b, Francesca Di Lillo a, Marica Masi a, Riccardo Calandrino c, Claudio Fiorini c, Mauro Cattaneo c, Antonio Brunetti d, Viviana Fanti e, Bruno Golosio e, Gabriela Hoff e, Cecilia Ceresa f, Guido Cavaletti f, Gabriella Nicolini f, Paolo Russo a,* a Università DI Napoli ‘‘Federico II”, Istituto Nazionale DI Fisica Nucleare, Sez. Napoli, Dipartimento DI Fisica ‘‘E. Pancini”, Napoli, Italy b Dipartimento DI Fisica ‘‘E. Pancini”, Università DI Napoli ‘‘Federico II”, Istituto Nazionale DI Fisica Nucleare, Sez. Napoli, Istituto Nazionale DI Fisica Nucleare, Sez. Napoli, Napoli, Italy c Istituto Scientifico San Raffaele, Medical Physics Department, Milan, Italy d Università DI Sassari, Istituto Nazionale DI Fisica Nucleare, Sez, Cagliari, Dipartimento DI Fisica, Sassari, Italy e Università DI Cagliari, Istituto Nazionale DI Fisica Nucleare, Sez. Cagliari, Dipartimento DI Fisica, Cagliari, Italy f University of Milano Bicocca, Scuola DI Medicina e Chirurgia, Milan, Italy ⇑ Corresponding author.
Purpose. Recently, we proposed the use of the synchrotron radiation (SR) beam for a new rotational radiotherapy technique for breast cancer treatment (SR3T) [1];. In this work, we show, via Monte Carlo (MC) simulations, the potential of SR3T also for application in breast radiosurgery with the patient in prone position. Methods. We simulated the irradiation condition of the breast rotational radiosurgery with a MC code based on GEANT 4 toolkit. The pendant breast was modeled as a polyethylene cylinder with a diameter of 14 cm and height of 9 cm with a 1-cm tumor simulated in the centre or at 4 cm from the cylinder axis. A monoenergetic laminar SR beam of size 1.5 cm 1.0 cm with energy ranging between 60 and 120 keV irradiated the phantom during a complete rotation with the center of rotation along the tumor mass. Results. A collimated SR beam irradiating a pendant breast produces a dose distribution peaked at the center of rotation. MC simulations showed that is possible to perform partial-breast irradiation with a skin sparing comparable with that from a conventional MV breast radiotherapy.
Conclusions. We proposed a kV SR beam for partial-breast irradiation, for breast radiosurgery in the treatment of small lesions. We foresee the use of dose-enhancement agents in order to improve the dose to the target volume with proper sparing of healthy tissues. References 1. Di Lillo F et al. Towards breast cancer rotational radiotherapy with synchrotron radiation. Phys Med 2017;41:20–5. https://doi.org/10.1016/j.ejmp.2018.06.491
[P197] Measurement of neutron-induced radioactivity in animal tissue Przemysław Se˛kowski *, Izabela Skwira-Chalot, Tomasz Matulewicz University of Warsaw, Faculty of Physics, Warsaw, Poland Corresponding author.
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Purpose. The basis of neutron radiotherapy is to induce the decay of 10B to 7Li, an alpha particle and gamma ray. Emitted particles deposit dose in surrounding cancer cells what lead to their death. Though neutron beam can also lead to production other radioactive isotopes with lives longer than 11B⁄. The main goal of out project is to measure the induced radioactivity in human tissues after the irradiation and identify the produced radioisotopes and estimate the dose from those nuclides. The secondary aim of this work is the validation of simulation calculations in comparison with experimental results. Methods. In order to estimate which radioisotopes are produced during the irradiation the GATE/Geant4 Monte Carlo code was used. For tissue materials, the pig liver and beef bone were chosen. The irradiation will be performed using PuBe neutron source and neutron beam which is available in BNCT treatment room at National Center for Nuclear Research, Otwock. The samples will be irradiated with high dose in order to create a large number of short-lived isotopes or with fractionated dose in order to express the radiation of long-lived isotopes. For gamma spectroscopy measurements the HPGe or LaBr3 detectors will be used. Results. The Monte Carlo calculations show the most intense, for gamma spectroscopy, radioisotopes produced within the liver sample by neutron irradiation are 24Na, 28Al and 31Si. In case of bone sample neutron irradiation mostly produced gamma radioisotopes are 28Al, 31Si and 42K. As a result of high occupancy of neutron sources the experimental data will be obtained in April. Conclusions. Based on theoretical calculations, one can conclude that a lot of radioisotopes are created in human tissues. For example, the 24Na can wash out from the irradiated volume and circulate through patients body with blood. That is why the dose from induced radioactivity cannot be omitted in calculations of received total dose. In addition, some of the mentioned above nuclides (high cross-section for production) can be useful for off-line measurements of fast neutron fluence. https://doi.org/10.1016/j.ejmp.2018.06.492
[P198] Cone beam CT as a clinical QA tool for prostate MRI-only workflows Emilia Palmér a, Emilia Persson b, Petra Ambolt a, Christian Gustafsson b, Adalsteinn Gunnlaugsson a, Lars E. Olsson c,* a Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden b Hematology, Oncology and Radiation Physics, Translational Medicine, Medical Radiation Physics, Skåne University Hospital, Lund, Sweden
Abstracts / Physica Medica 52 (2018) 99–187
Film samples were digitized using a flatbed scanner Epson 10000XL. Several opaque and transparent templates for digitization were developed and tested. The uncertainties related to the films and digitization process were quantified in a previous work, and helped to determine which variations needed to be minimized (e.g. film-to-light source distance), and which could be treated more flexibly. Results. The use of samples smaller than 1 1.5 cm2 was discarded as impractical. Film samples of 1.5 1.0 cm2; 1 cm apart, proved the best option for adequate coverage of the irradiated length, using strips of 3–8 samples according to applicator size. The selected template allows simultaneous digitization of a nonirradiated film piece (reference) and up to eight irradiated samples, reducing inter-scan fluctuations and total digitization time. For films irradiated with 10 to 15 Gy (dose interval of interest), this template minimizes the lateral discontinuity effect previously observed on the measured response at the films’ edges. A glass plate is used for compression, to ensure uniform film-to-light source distance. Conclusions. The methodology for in vivo measurements was optimized by using smaller samples and an opaque template to read up to eight films in a single scan. These changes allow a better characterization of the irradiated area with a simpler and faster digitization method. https://doi.org/10.1016/j.ejmp.2018.06.490
[P194] Breast cancer radiosurgery with a synchrotron radiation beam Giovanni Mettivier a, Anton io Sarno b, Francesca Di Lillo a, Marica Masi a, Riccardo Calandrino c, Claudio Fiorini c, Mauro Cattaneo c, Antonio Brunetti d, Viviana Fanti e, Bruno Golosio e, Gabriela Hoff e, Cecilia Ceresa f, Guido Cavaletti f, Gabriella Nicolini f, Paolo Russo a,* a Università DI Napoli ‘‘Federico II”, Istituto Nazionale DI Fisica Nucleare, Sez. Napoli, Dipartimento DI Fisica ‘‘E. Pancini”, Napoli, Italy b Dipartimento DI Fisica ‘‘E. Pancini”, Università DI Napoli ‘‘Federico II”, Istituto Nazionale DI Fisica Nucleare, Sez. Napoli, Istituto Nazionale DI Fisica Nucleare, Sez. Napoli, Napoli, Italy c Istituto Scientifico San Raffaele, Medical Physics Department, Milan, Italy d Università DI Sassari, Istituto Nazionale DI Fisica Nucleare, Sez, Cagliari, Dipartimento DI Fisica, Sassari, Italy e Università DI Cagliari, Istituto Nazionale DI Fisica Nucleare, Sez. Cagliari, Dipartimento DI Fisica, Cagliari, Italy f University of Milano Bicocca, Scuola DI Medicina e Chirurgia, Milan, Italy ⇑ Corresponding author.
Purpose. Recently, we proposed the use of the synchrotron radiation (SR) beam for a new rotational radiotherapy technique for breast cancer treatment (SR3T) [1];. In this work, we show, via Monte Carlo (MC) simulations, the potential of SR3T also for application in breast radiosurgery with the patient in prone position. Methods. We simulated the irradiation condition of the breast rotational radiosurgery with a MC code based on GEANT 4 toolkit. The pendant breast was modeled as a polyethylene cylinder with a diameter of 14 cm and height of 9 cm with a 1-cm tumor simulated in the centre or at 4 cm from the cylinder axis. A monoenergetic laminar SR beam of size 1.5 cm 1.0 cm with energy ranging between 60 and 120 keV irradiated the phantom during a complete rotation with the center of rotation along the tumor mass. Results. A collimated SR beam irradiating a pendant breast produces a dose distribution peaked at the center of rotation. MC simulations showed that is possible to perform partial-breast irradiation with a skin sparing comparable with that from a conventional MV breast radiotherapy.
Conclusions. We proposed a kV SR beam for partial-breast irradiation, for breast radiosurgery in the treatment of small lesions. We foresee the use of dose-enhancement agents in order to improve the dose to the target volume with proper sparing of healthy tissues. References 1. Di Lillo F et al. Towards breast cancer rotational radiotherapy with synchrotron radiation. Phys Med 2017;41:20–5. https://doi.org/10.1016/j.ejmp.2018.06.491
[P197] Measurement of neutron-induced radioactivity in animal tissue Przemysław Se˛kowski *, Izabela Skwira-Chalot, Tomasz Matulewicz University of Warsaw, Faculty of Physics, Warsaw, Poland Corresponding author.
⇑
Purpose. The basis of neutron radiotherapy is to induce the decay of 10B to 7Li, an alpha particle and gamma ray. Emitted particles deposit dose in surrounding cancer cells what lead to their death. Though neutron beam can also lead to production other radioactive isotopes with lives longer than 11B⁄. The main goal of out project is to measure the induced radioactivity in human tissues after the irradiation and identify the produced radioisotopes and estimate the dose from those nuclides. The secondary aim of this work is the validation of simulation calculations in comparison with experimental results. Methods. In order to estimate which radioisotopes are produced during the irradiation the GATE/Geant4 Monte Carlo code was used. For tissue materials, the pig liver and beef bone were chosen. The irradiation will be performed using PuBe neutron source and neutron beam which is available in BNCT treatment room at National Center for Nuclear Research, Otwock. The samples will be irradiated with high dose in order to create a large number of short-lived isotopes or with fractionated dose in order to express the radiation of long-lived isotopes. For gamma spectroscopy measurements the HPGe or LaBr3 detectors will be used. Results. The Monte Carlo calculations show the most intense, for gamma spectroscopy, radioisotopes produced within the liver sample by neutron irradiation are 24Na, 28Al and 31Si. In case of bone sample neutron irradiation mostly produced gamma radioisotopes are 28Al, 31Si and 42K. As a result of high occupancy of neutron sources the experimental data will be obtained in April. Conclusions. Based on theoretical calculations, one can conclude that a lot of radioisotopes are created in human tissues. For example, the 24Na can wash out from the irradiated volume and circulate through patients body with blood. That is why the dose from induced radioactivity cannot be omitted in calculations of received total dose. In addition, some of the mentioned above nuclides (high cross-section for production) can be useful for off-line measurements of fast neutron fluence. https://doi.org/10.1016/j.ejmp.2018.06.492
[P198] Cone beam CT as a clinical QA tool for prostate MRI-only workflows Emilia Palmér a, Emilia Persson b, Petra Ambolt a, Christian Gustafsson b, Adalsteinn Gunnlaugsson a, Lars E. Olsson c,* a Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden b Hematology, Oncology and Radiation Physics, Translational Medicine, Medical Radiation Physics, Skåne University Hospital, Lund, Sweden