ALTIERI, SAVERIO

BORTOLUSSI, SILVA

Daniele Panetta

Debora Petroni

Domenico Bufalino

Giuseppe G. Daquino

Guglielmo Lomonaco

Luca Menichetti

Nicola Cerullo

Piero A. Salvadori

English

Archivio Istituzionale della Ricerca - Università degli Studi di Pavia

UNIVERSITA’ DEGLI STUDI DI PISA UNIVERSITA’ DEGLI STUDI DI PAVIA   Methods for the assessment of the treatment dose using micro-PET/CT suitable for NCT Treatment Planning Systems in experimental animal models.  Luca Menichetti1*, Daniele Panetta1, Giuseppe G. Daquino2, Nicola Cerullo3,4, Guglielmo Lomonaco3, Domenico Bufalino4, Debora Petroni1, Silva Bortolussi5, Saverio Altieri5, Piero A. Salvadori1  1.CNR IFC, Pisa, Italy, 2. DIMNP, University of Pisa, Italy, 3. DIME/TEC, University of Genova, Italy, 4. SORIT s.r.l., Pisa, Italy, 5. Department of Physics, University of Pavia and INFN Pavia, Italy  (*) Corresponding author: luca.menichetti@ifc.cnr.it 15th International Congress on Neutron Capture Therapy – September 10-14, 2012 – Tsukuba, Japan  BDTPS MCNP Treatment plan/Isodose curves mCT stack mPET stack MCNP cards MCNP tallies Output Purpose To evaluate and optimize strategies for BNCT dose calculation in an animal model, by using a Monte Carlo-based treatment planning system working on co-registered mPET/CT images.  Animal model of F98 glioma 18F-FET extraction was determined after the second week (18th day) after tumor implantation in rat [2]. All the animals have been anaesthetized during the intervention following an authorized protocol in compliance with the Italian regulatory statements on animal experiments. References [1] Daquino GG. et al., Appl Radiat Isot. 2004 Nov;61(5):893-7 [2] Menichetti L. et al., Appl Radiat Isot. 2009;67:S351-4 [3] AL Grosu et al., Radiother Oncol 2010; 96:325–7 [4] Weber DC et al.,  Radiat.Oncol 2008;3:44 [5] Wittig A et al, Crit Rev Oncol Hematol. 2008 Oct;68(1):66-90 [6] Panetta et al, Physica Medica 2012;28:166-173 [7] Del Guerra et al, IEEE Trans. Nucl. Sci. 2006;53 (2):1078–1083 YAP-(S)PET II XaltHR + 1. Micro-PET/CT Imaging 18F-FET extraction was determined after the second week (18th day) after tumor implantation. Each animal (n=3) has been injected with 18F-FET (150kBq/g of body weight) and 10B-BPA (300 mg/Kg BPA-fructose complex b.w.). The images were acquired with the Xalt micro-CT scanner [6] and the YAP-(S)PET scanner (ISE srl, Italy) [7].  The focal uptake of 18FET by the tumor is clearly visible, thus allowing a reliable definition of the Region of Interests (ROI) [2].  The PET and CT images have been  co-registered and resampled to have the same voxel size (0.23x0.23x1.0 mm3), and then they have been sent to BDTPS, where the ROIs were drawn. Why 18F-FET-PET? The pharmacokinetics of 18F-BPA is assumed to be similar to that of BPA, but this has been only verified ex-vivo. In this work, an alternative to 18F-BPA-PET has been studied to predict the BPA extraction with O-(2-18F-fluoroethyl)-D,L-tyrosine (18F-FET, more commonly FET), probably the more promising candidate among the aromatic aminoacids [2].  18F-FET demonstrated high in vivo stability in patients [3] , fast brain and tumour uptake kinetics, low accumulation in non-tumour tissue and ease of synthesis. FET–PET was already proposed to be appropriate for accurate RT-planning [4]  Spatial correlation between FET and BPA has been confirmed by ex vivo neutron radiography analysis at the Pavia Research Reactor: high-resolution quantitative Neutron Capture Radiography (NCR) was used as reference methodology to compare the mPET data for 10B mapping in the corresponding slice. Even though NCR and mPET have different spatial resolution, they can be spatially correlated within few mm2 [5]. 2. Definition of the ROIs BDTPS implements a specific tool for manual outlining the ROIs on PET and CT slices. More specifically, the following regions have been defined in this study:  1. Skin (external surface) 2. Soft tissues 3. Bones 4. Tumor  ROIs from 1 to 3 have been defined on CT slices, whereas the tumor has been delineated from the PET slices. Introduction The present study explores the possibility to include the small animal PET data into a specific Boron Distribution Treatment Planning System (BDTPS), integrating CT-based and PET-based Regions of Interest (ROIs) functionality in the same framework.  In a previous work, we validated the BDTPS with PET data using a heterogeneous phantom (HEBOM: Heterogeneous Boron Model), already used in previous BNCT researches [1]. In this second step, the animal model with implanted F98 glioma has been developed in order to simulate the tissue dose distribution.  TPS workflow 3. Results BDTPS is a pre- and post-processing system. It prepares the MCNP input through an integrated environment where CT and PET (but also MRI, if needed) are combined in a single 3D model  for the dose and fluence calculations. PET data have been normalised, being the maximum FET concentration value equal to ~30 ppm (as acquired by neutron radiography). Quantification of boron uptake by PET with [18F]FET in future studies will requires the introduction of parameters, that could corrects the different affinity between BPA and FET to aromatic amimoacid transporters. In post-processing, BPTPS shows the isodose and isofluence surfaces, reading through the MCNP output. The data evaluation is in progress, but the preliminary results show  that FET-BNCT could be a reliable methodology for a successful treatment. Conclusions • Due to its high specificity to brain tumour cells and its affinity to BPA, FET has a high potential as a PET tracer for the delineation of target volume in BNCT treatment planning.   • Our approach could lead to the use of dose evaluation in tumour and healthy tissues in an experimental animal models before the animal irradiation. 

Methods for the assessment of the treatment dose using micro-ET/CT suitable for NCT Treatment Planning Systems in experimental animal models

https://iris.unipv.it/bitstream/11571/581759/1/poster-pisa-pv-icnct-15.pdf

Methods for the assessment of the treatment dose using micro-ET/CT suitable for NCT Treatment Planning Systems in experimental animal models

Abstract

Similar works

Full text

Available Versions

Archivio Istituzionale della Ricerca - Università degli Studi di Pavia