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102. Dose-guided patient positioning in proton radiotherapy using multicriteria-optimization

Author

Kurz, C., Süss, P., Arnsmeyer, C., Haehnle, J., Teichert, K., Landry, G., Hofmaier, J., Exner, F., Hille, L., Kamp, F., Thieke, C., Ganswindt, U., Valentini, C., Hölscher, T., Troost, E., Krause, M., Belka, C., Küfer, K., Parodi, K., Richter, C., Kurz, C., Süss, P., Arnsmeyer, C., Haehnle, J., Teichert, K., Landry, G., Hofmaier, J., Exner, F., Hille, L., Kamp, F., Thieke, C., Ganswindt, U., Valentini, C., Hölscher, T., Troost, E., Krause, M., Belka, C., Küfer, K., Parodi, K., and Richter, C.

Abstract

Proton radiotherapy (PT) requires accurate target alignment before each treatment fraction, ideally utilizing 3D in-room X-ray computed tomography imaging (CT). Typically, the optimal patient position is determined on the basis of anatomical landmarks or implanted markers. In the presence of non-rigid anatomical changes, however, the planning scenario cannot be exactly reproduced and positioning should rather aim at finding the optimal position in terms of the actually applied dose. In this work, dose-guided patient alignment, implemented as multicriterial optimization (MCO) problem, has been investigated in the scope of intensity modulated and double scattered proton therapy (IMPT and DSPT) for the first time. A method for automatically determining the optimal patient position with respect to pre-defined clinical goals was implemented. Linear dose interpolation was used to access a continuous space of potential patient shifts. Fourteen head and neck (H&N) and eight prostate cancer patients with repeated CT data (up to 5 control CTs) were included in this study. Dose interpolation accuracy was evaluated and the potential dosimetric advantages of dose-guided over anatomy-based patient alignment investigated by comparison of clinically relevant target and organ-at-risk (OAR) dose-volume histogram (DVH) parameters. Dose interpolation was found sufficiently accurate with average pass-rates of 90% and 99% for an exemplary H&N and prostate patient, respectively, using a 2% dose-difference criterion. Compared to anatomy-based alignment, the main impact of automated MCO-based dose-guided positioning was a reduced dose to the serial OARs (spinal cord and brain stem) for the H&N cohort. For the prostate cohort, under-dosage of the target structures could also be efficiently diminished. Limitations of dose-guided positioning were mainly found in reducing target over-dosage due to weight loss for H&N patients, which might require adaptation of the treatment plan. Since labor-in

Published
2019

103. Comparative study of alternative Geant4 hadronic ion inelastic physics models for prediction of positron-emitting radionuclide production in carbon and oxygen ion therapy

Author

Chacon, A, Guatelli, S, Rutherford, H, Bolst, D, Mohammadi, A, Ahmed, A, Nitta, M, Nishikido, F, Iwao, Y, Tashima, H, Yoshida, E, Akamatsu, G, Takyu, S, Kitagawa, A, Hofmann, T, Pinto, M, Franklin, DR, Parodi, K, Yamaya, T, Rosenfeld, A, Safavi-Naeini, M, Chacon, A, Guatelli, S, Rutherford, H, Bolst, D, Mohammadi, A, Ahmed, A, Nitta, M, Nishikido, F, Iwao, Y, Tashima, H, Yoshida, E, Akamatsu, G, Takyu, S, Kitagawa, A, Hofmann, T, Pinto, M, Franklin, DR, Parodi, K, Yamaya, T, Rosenfeld, A, and Safavi-Naeini, M

Abstract

© 2019 Commonwealth of Australia, Australian Nuclear Science and Technology Organisation, ANSTO.. The distribution of fragmentation products predicted by Monte Carlo simulations of heavy ion therapy depend on the hadronic physics model chosen in the simulation. This work aims to evaluate three alternative hadronic inelastic fragmentation physics options available in the Geant4 Monte Carlo radiation physics simulation framework to determine which model most accurately predicts the production of positron-emitting fragmentation products observable using in-beam PET imaging. Fragment distributions obtained with the BIC, QMD, and INCL + + physics models in Geant4 version 10.2.p03 are compared to experimental data obtained at the HIMAC heavy-ion treatment facility at NIRS in Chiba, Japan. For both simulations and experiments, monoenergetic beams are applied to three different block phantoms composed of gelatin, poly(methyl methacrylate) and polyethylene. The yields of the positron-emitting nuclei 11C, 10C and 15O obtained from simulations conducted with each model are compared to the experimental yields estimated by fitting a multi-exponential radioactive decay model to dynamic PET images using the normalised mean square error metric in the entrance, build up/Bragg peak and tail regions. Significant differences in positron-emitting fragment yield are observed among the three physics models with the best overall fit to experimental 12C and 16O beam measurements obtained with the BIC physics model.

Published
2019

104. Clinical investigations of a 4D ML reconstruction strategy for PET-based treatment verification in ion beam therapy

Author

Gianoli, C, Ricotti, R, DE BERNARDI, E, Riboldi, M, Bauer, J, Debus, J, Baroni, G, Parodi, K, DE BERNARDI, ELISABETTA, Parodi, K., Gianoli, C, Ricotti, R, DE BERNARDI, E, Riboldi, M, Bauer, J, Debus, J, Baroni, G, Parodi, K, DE BERNARDI, ELISABETTA, and Parodi, K.

Abstract

In ion beam therapy, Positron Emission Tomography (PET) imaging can be applied to provide a consistency check of the delivered treatment with respect to the treatment plan. Treatment verification relies on the comparison between a PET distribution measured during or after treatment delivery (measured PET) and a PET simulation calculated on the basis of the treatment plan (expected PET). The method is challenged by the poor image quality of the measured PET, which may result in a low sensitivity to detectable mismatches between planned and applied treatment. In this work we propose the application of a motion-aware 4D Maximum Likelihood (ML) reconstruction strategy for PET-based treatment verification in ion beam therapy. This approach is specifically tested on simulated clinical-like scenarios, as well as on a real clinical dataset. The measured PET and the expected PET are interpreted as two different motion states of a 4D PET dataset. The idea is to estimate the deformation field mapping the expected PET onto the measured PET as a measure of mismatches. An enhanced measured PET is therefore obtained by warping the expected PET according to the estimated motion field. Clinical-like scenarios were reproduced by means of Monte Carlo simulations corresponding to a hypo-fractionated carbon ion treatment of liver tumour. The measured PET was attributed to different simulations introducing positioning mismatches by means of rigid translations, to be compared to the reference expected PET simulation without mismatch. Real clinical dataset include PET data acquired shortly after treatment at a dedicated PET-CT scanner installed at HIT (Heidelberg Ion beam Therapy Center, Germany), in comparison to the corresponding expected PET coming from Monte Carlo simulations. The accuracy of mismatch estimation and the robustness to noise are shown.

Published
2016

126. Integration of spatial distortion effects in a 4D computational phantom for simulation studies in extra‐cranial MRI‐guided radiation therapy: Initial results.

Author

Kroll, C., Dietrich, O., Bortfeldt, J., Kamp, F., Neppl, S., Belka, C., Parodi, K., Baroni, G., Paganelli, C., and Riboldi, M.

Subjects
MAGNETIC resonance imaging, IMAGE-guided radiation therapy, FOUR-dimensional imaging, RADIOTHERAPY, MAGNETIC declination, MAGNETIC susceptibility, ENDORECTAL ultrasonography
Abstract

Purpose: Spatial distortions in magnetic resonance imaging (MRI) are mainly caused by inhomogeneities of the static magnetic field, nonlinearities in the applied gradients, and tissue‐specific magnetic susceptibility variations. These factors may significantly alter the geometrical accuracy of the reconstructed MR image, thus questioning the reliability of MRI for guidance in image‐guided radiation therapy. In this work, we quantified MRI spatial distortions and created a quantitative model where different sources of distortions can be separated. The generated model was then integrated into a four‐dimensional (4D) computational phantom for simulation studies in MRI‐guided radiation therapy at extra‐cranial sites. Methods: A geometrical spatial distortion phantom was designed in four modules embedding laser‐cut PMMA grids, providing 3520 landmarks in a field of view of (345 × 260 × 480) mm3. The construction accuracy of the phantom was verified experimentally. Two fast MRI sequences for extra‐cranial imaging at 1.5 T were investigated, considering axial slices acquired with online distortion correction, in order to mimic practical use in MRI‐guided radiotherapy. Distortions were separated into their sources by acquisition of images with gradient polarity reversal and dedicated susceptibility calculations. Such a separation yielded a quantitative spatial distortion model to be used for MR imaging simulations. Finally, the obtained spatial distortion model was embedded into an anthropomorphic 4D computational phantom, providing registered virtual CT/MR images where spatial distortions in MRI acquisition can be simulated. Results: The manufacturing accuracy of the geometrical distortion phantom was quantified to be within 0.2 mm in the grid planes and 0.5 mm in depth, including thickness variations and bending effects of individual grids. Residual spatial distortions after MRI distortion correction were strongly influenced by the applied correction mode, with larger effects in the trans‐axial direction. In the axial plane, gradient nonlinearities caused the main distortions, with values up to 3 mm in a 1.5 T magnet, whereas static field and susceptibility effects were below 1 mm. The integration in the 4D anthropomorphic computational phantom highlighted that deformations can be severe in the region of the thoracic diaphragm, especially when using axial imaging with 2D distortion correction. Adaptation of the phantom based on patient‐specific measurements was also verified, aiming at increased realism in the simulation. Conclusions: The implemented framework provides an integrated approach for MRI spatial distortion modeling, where different sources of distortion can be quantified in time‐dependent geometries. The computational phantom represents a valuable platform to study motion management strategies in extra‐cranial MRI‐guided radiotherapy, where the effects of spatial distortions can be modeled on synthetic images in a virtual environment. [ABSTRACT FROM AUTHOR]

Published
2021
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127. 4D ML reconstruction as a tool for volumetric PET-based treatment verification in ion beam radiotherapy

Author

De Bernardi, E, Ricotti, R., Riboldi, Marco, Baroni, Guido, Parodi, K., Gianoli, Chiara, DE BERNARDI, E, Ricotti, R, Riboldi, M, Baroni, G, Parodi, K, and Gianoli, C

Subjects
Radiology, Nuclear Medicine and Imaging, Likelihood Functions, PET-based treatment verification, Biophysics, 4D ML reconstruction, ion beam therapy, positron emission tomography (PET), Biophysic, Nuclear Medicine and Imaging, Positron-Emission Tomography, Image Processing, Computer-Assisted, Radiology, Monte Carlo Method, Algorithms, Radiotherapy, Image-Guided
Abstract

Purpose: An innovative strategy to improve the sensitivity of positron emission tomography (PET)- based treatment verification in ion beam radiotherapy is proposed. Methods: Low counting statistics PET images acquired during or shortly after the treatment (Measured PET) and a Monte Carlo estimate of the same PET images derived from the treatment plan (Expected PET) are considered as two frames of a 4D dataset. A 4D maximum likelihood reconstruction strategy was adapted to iteratively estimate the annihilation events distribution in a reference frame and the deformation motion fields that map it in the Expected PET and Measured PET frames. The outputs generated by the proposed strategy are as follows: (1) an estimate of the Measured PET with an image quality comparable to the Expected PET and (2) an estimate of the motion field mapping Expected PET to Measured PET. The details of the algorithm are presented and the strategy is preliminarily tested on analytically simulated datasets. Results: The algorithm demonstrates (1) robustness against noise, even in the worst conditions where 1.5-104 true coincidences and a random fraction of 73% are simulated; (2) a proper sensitivity to different kind and grade of mismatches ranging between 1 and 10 mm; (3) robustness against bias due to incorrect washout modeling in the Monte Carlo simulation up to 1/3 of the original signal amplitude; and (4) an ability to describe the mismatch even in presence of complex annihilation distributions such as those induced by two perpendicular superimposed ion fields. Conclusions: The promising results obtained in this work suggest the applicability of the method as a quantification tool for PET-based treatment verification in ion beam radiotherapy. An extensive assessment of the proposed strategy on real treatment verification data is planned.

Published
2016

132. OC-0417: Random breathing states sampling in a 4D MC dose calculation framework to quantify interplay effects

Author

Von Münchow, A., primary, Straub, K., additional, Losert, C., additional, Shpani, R., additional, Hofmaier, J., additional, Freislederer, P., additional, Heinz, C., additional, Thieke, C., additional, Söhn, M., additional, Alber, M., additional, Floca, R., additional, Belka, C., additional, Parodi, K., additional, Reiner, M., additional, and Kamp, F., additional

Published
2018
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136. A novel approach to electron data background treatment in an online wide-angle spectrometer for laser-accelerated ion and electron bunches

Author

Lindner, F. H., primary, Bin, J. H., additional, Englbrecht, F., additional, Haffa, D., additional, Bolton, P. R., additional, Gao, Y., additional, Hartmann, J., additional, Hilz, P., additional, Kreuzer, C., additional, Ostermayr, T. M., additional, Rösch, T. F., additional, Speicher, M., additional, Parodi, K., additional, Thirolf, P. G., additional, and Schreiber, J., additional

Published
2018
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138. Commissioning of a Compton Camera for particle beam range monitoring

Author

Thirolf, P. G., Aldawood, S., Böhmer, M., Bortfeldt, J., Castelhano, I., Dedes, G., Enghardt, W., Fiedler, F., Gernhäuser, R., Golnik, C., Helmbrecht, S., Hueso-González, F., Kolff, H. V. D., Kormoll, T., Lang, C., Liprandi, S., Maier, L., Marinšek, T., Miani, A., Pausch, G., Petzoldt, J., Pocevicius, M., Römer, K., Schaart, D. R., Valencia-Lozano, I., and Parodi, K.

Subjects
Physics::Instrumentation and Detectors, compton camera, radiooncology, proton therapy, cancer, imaging, ion beam therapy, prompt gamma, in-vivo dosimetry
Abstract

A Compton camera prototype for the position-sensitive detection of prompt γ rays from nuclear reactions between proton (or ion) beams and organic targets is being commissioned in Garching. The detector system is designed to allow for reconstructing the γ-source position from the Compton scattering kinematics of the primary photon as well as from tracking the Compton-scattered electron trajectory. The camera consists of a monolithic LaBr3(Ce) scintillation absorber crystal, read out by a 256-fold segmented multi-anode PMT and preceded by a stacked array of 6 double-sided silicon strip detectors acting as scatterers. The detector system has been calibrated and characterized in the laboratory as well as at different accelerator facilities, including clinical proton beams. Results from online commissioning runs will be presented, demonstrating excellent agreement between experimental prompt-γ spectra and Monte-Carlo simulations. Particular effort was dedicated to characterize the spatial resolution achievable with the monolithic LaBr 3 (Ce) scintillator when targeting the primary photon interaction position. Intense, tightly collimated 137Cs and 60Co sources were used for 2D irradiation scans as prerequisite for studying the performance of the “k-Nearest Neighbour”-algorithm developed in Delft and extending its applicability into the energy range beyond 511 keV. Systematic results of the monolithic scintillator’s spatial resolution will be presented as a function of the k-NN parameters (e.g. events per irradiation position) and the PMT segmentation, resulting in the realization of the presently optimum spatial resolution (3.8(2) mm @1.3 MeV) already for a reduced PMT segmentation (8x8). An outline of ongoing and planned further experimental activities and upgrade plans will be presented. This work is supported by the DFG Cluster of Excellence MAP (Munich-Centre for Advanced Photonics).

Published
2016

139. FLUKA Monte Carlo calculations for hadrontherapy application

Author

Battistoni, G, Boccone, V, Boehlen, Broggi, F, Brugger, M, Brunetti, G, Campanella, M, Cappucci, F, Cerutti, F, Chin, M, Colleoni, P, Empl, A, Fassò, A, Ferrari, A, Gadioli, E, Garcia Ortega, P, Garzelli, M, Lari, L, Lantz, M, Lechner, A, Lee, K, Lukasik, G, Mairani, A, Margiotta, A, Mereghetti, A, Morone, M, Murano, S, Nicolini, R, Parodi, K, Patera, V, Pelliccioni, M, Pinsky, L, Ranft, J, Rinaldi, I, Roesler, S, Rollet, S, Sala, P, Santana, M, Sarchiapone, L, Sioli, M, Smirnov, G, Theis, C, Trovati, S, Versaci, R, Vincke, H, Vlachoudis, V, Vollaire, J, Battistoni, G., Boccone, V., Broggi, F., Brugger, M., BRUNETTI G, Campanella, M., Cappucci, F., Cerutti, F., Chin, M., Colleoni, P., Empl, A., Fassò, A., Ferrari, A., Gadioli, E., Garcia Ortega, P., Garzelli, M. V., Lari, L., Lantz, M., Lechner, A., Lee, K. T., Lukasik, G., Mairani, A., Margiotta, A., Mereghetti, A., Morone, M. C., Murano, S., Nicolini, R., Parodi, K., Patera, V., Pelliccioni, M., Pinsky, L., Ranft, J., Rinaldi, I., Roesler, S., Rollet, S., Sala, P. R., Santana, M., Sarchiapone, L., Sioli, M., Smirnov, G., Theis, C., Trovati, S., Versaci, R., Vincke, H., Vlachoudis, V., Vollaire, J., Battistoni, G, Boccone, V, Boehlen, Broggi, F, Brugger, M, Brunetti, G, Campanella, M, Cappucci, F, Cerutti, F, Chin, M, Colleoni, P, Empl, A, Fassò, A, Ferrari, A, Gadioli, E, Garcia Ortega, P, Garzelli, M, Lari, L, Lantz, M, Lechner, A, Lee, K, Lukasik, G, Mairani, A, Margiotta, A, Mereghetti, A, Morone, M, Murano, S, Nicolini, R, Parodi, K, Patera, V, Pelliccioni, M, Pinsky, L, Ranft, J, Rinaldi, I, Roesler, S, Rollet, S, Sala, P, Santana, M, Sarchiapone, L, Sioli, M, Smirnov, G, Theis, C, Trovati, S, Versaci, R, Vincke, H, Vlachoudis, V, Vollaire, J, Battistoni, G., Boccone, V., Broggi, F., Brugger, M., BRUNETTI G, Campanella, M., Cappucci, F., Cerutti, F., Chin, M., Colleoni, P., Empl, A., Fassò, A., Ferrari, A., Gadioli, E., Garcia Ortega, P., Garzelli, M. V., Lari, L., Lantz, M., Lechner, A., Lee, K. T., Lukasik, G., Mairani, A., Margiotta, A., Mereghetti, A., Morone, M. C., Murano, S., Nicolini, R., Parodi, K., Patera, V., Pelliccioni, M., Pinsky, L., Ranft, J., Rinaldi, I., Roesler, S., Rollet, S., Sala, P. R., Santana, M., Sarchiapone, L., Sioli, M., Smirnov, G., Theis, C., Trovati, S., Versaci, R., Vincke, H., Vlachoudis, V., and Vollaire, J.

Abstract

Monte Carlo (MC) codes are increasingly spreading in the hadrontherapy community due to their detailed description of radiation transport and interaction with matter. The suitability of a MC code for application to hadrontherapy demands accurate and reliable physical models for the description of the transport and the interaction of all components of the expected radiation field (ions, hadrons, electrons, positrons and photons). This contribution will address the specific case of the general-purpose particle and interaction code FLUKA. In this work, an application of FLUKA will be presented, i.e. establishing CT (computed tomography)-based calculations of physical and RBE (relative biological effectiveness)-weighted dose distributions in scanned carbon ion beam therapy.

Published
2013

140. Development of a Compton camera for prompt-gamma medical imaging

Author

Aldawood, S., primary, Thirolf, P.G., additional, Miani, A., additional, Böhmer, M., additional, Dedes, G., additional, Gernhäuser, R., additional, Lang, C., additional, Liprandi, S., additional, Maier, L., additional, Marinšek, T., additional, Mayerhofer, M., additional, Schaart, D.R., additional, Lozano, I. Valencia, additional, and Parodi, K., additional

Published
2017
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141. Dose Reconstruction from PET Images in Carbon Ion Therapy: A Deconvolution Approach Using an Evolutionary Algorithm

Author

Hofmann, T, primary, Fochi, A, additional, Pinto, M, additional, Mohammadi, A, additional, Nitta, M, additional, Nishikido, F, additional, Iwao, Y, additional, Tashima, H, additional, Yoshida, E, additional, Safavi-Naeini, M, additional, Chacon, A, additional, Rosenfeld, A, additional, Yamaya, T, additional, and Parodi, K, additional

Published
2017
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144. Laser-driven ION (LION) acceleration at the centre for advanced laser applications (CALA)

Author

Rosch, T. F., primary, Haffa, D., additional, Bin, J. H., additional, Englbrecht, F., additional, Gao, Y., additional, Gisbert, V., additional, Gebhard, J., additional, Hahner, D., additional, Hartmann, J., additional, Haug, M., additional, Herr, S., additional, Hilz, P., additional, Kreuzer, C., additional, Lehrack, S., additional, Lindner, F. H., additional, Ostermayr, T. M., additional, Ridente, E., additional, Seuferling, S., additional, Speicher, M., additional, Wurl, M., additional, Yang, R., additional, Parodi, K., additional, and Schreiber, J., additional

Published
2017
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145. Laser interactions with micro-targets for imaging applications

Author

Ostermayr, T. M., primary, Kreuzer, C., additional, Englbrecht, F., additional, Hartmann, J., additional, Gebhard, J., additional, Speicher, M., additional, Haffa, D., additional, Hilz, P., additional, Bin, J., additional, McCary, E., additional, Stork, S., additional, Dyer, G., additional, Donovan, M. E., additional, Ditmire, T., additional, Hegelich, B. M., additional, Martinez, M., additional, Gaul, E., additional, Wenz, J., additional, Parodi, K., additional, Gordon, J., additional, Spinks, M., additional, Bolton, P. R., additional, and Schreiber, J., additional

Published
2017
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146. Development of TOF-spectrometry of laser-accelerated proton pulses using silicon microdosimeters

Author

Wurt, M., primary, Englbrecht, F., additional, Lehrack, S., additional, Haffa, D., additional, Kreuzer, C., additional, Lindner, F. H., additional, Rosch, T. F., additional, Reinhardt, S., additional, Karsch, S., additional, Assmann, W., additional, Tran, L. T., additional, Petasecca, M., additional, Lerch, M., additional, Schreiber, J., additional, Rosenfeld, A., additional, and Parodi, K., additional

Published
2017
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148. OC-0486: Multi-criterial patient positioning based on dose recalculation on scatter-corrected CBCT images

Author

Hofmaier, J., primary, Haehnle, J., additional, Kurz, C., additional, Landry, G., additional, Maihöfer, C., additional, Süss, P., additional, Teichert, K., additional, Traulsen, N., additional, Brachmann, C., additional, Weiler, F., additional, Thieke, C., additional, Küfer, K.H., additional, Belka, C., additional, Parodi, K., additional, and Kamp, F., additional

Published
2017
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150. PO-0809: A 3D polymer gel dosimeter coupled to a patient-specific anthropomorphic phantom for proton therapy

Author

Hillbrand, M., primary, Landry, G., additional, Dedes, G., additional, Pappas, E.P., additional, Kalaitzakis, G., additional, Kurz, C., additional, Dörringer, F., additional, Kaiser, K., additional, Würl, M., additional, Englbrecht, F., additional, Dietrich, O., additional, Makris, D., additional, Pappas, E., additional, and Parodi, K., additional

Published
2017
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