Dosimetric comparison of the BNCT treatment planning performances when using a nnU-NET to automatically segment Glioblastoma Multiforme

This work presents a preliminary evaluation of the use of the convolutional neural network nnU-NET to automatically contour the volume of Glioblastoma Multiforme in medical images of patients. The goal is to assist the preparation of the Treatment Planning of patients who undergo Boron Neutron Capture Therapy (BNCT). BNCT is a binary form of radiotherapy based on the selective loading of a suitable 10-boron concentration into the tumour and on subsequent low-energy neutron irradiation. The selectivity of the therapeutic effect is based on the capacity of the boron drug to target preferentially cancer cells, thus triggering the neutron capture only in the tumour and depositing there a lethal dose. Even if the tailoring of the beam to the tumour volume is less crucial for BNCT than for other radiation therapies, a proper delimitation of the tumour volume is needed to assess a safe and effective dosimetry. In clinical application the contour must be manually decided by the physician, however, a tool to automatically define important structures such as the Gross Tumour Volume (GTV) and the Organs At Risk (OAR) would be beneficial to enable medical physicists assessing preliminary positioning and simulated dosimetry before the approval or possible changes introduced by the radiotherapist. Moreover, an initial contouring may speed up the work of the physician. The nnU-NET was trained and tested and its performance was evaluated through different parameters such as the Dice Coefficient. To assess a more meaningful evaluation for BNCT, for the first time, this work analyzed the difference of the clinical dosimetry in 16 patients using the manual and the automatic contoured images

Understanding the potentiality of accelerator based-boron neutron capture therapy for osteosarcoma: Dosimetry assessment based on the reported clinical experience

Background: Osteosarcoma is the most frequent primary malignant bone tumour, and its incidence is higher in children and adolescents, for whom it represents more than 10% of solid cancers. Despite the introduction of adjuvant and neo-adjuvant chemotherapy that markedly increased the success rate in the treatment, aggressive surgery is still needed and a considerable percentage of patients do not survive due to recurrences or early metastases. Boron Neutron Capture Therapy (BNCT), an experimental radiotherapy, was investigated as a treatment that could allow a less aggressive surgery by killing infiltrated tumour cells in the surrounding healthy tissues. BNCT requires an intense neutron beam to ensure irradiation times of the order of 1h. In Italy, a Radio Frequency Quadrupole (RFQ) proton accelerator has been designed and constructed for BNCT, and a suitable neutron spectrum was tailored by means of Monte Carlo calculations. This paper explores the feasibility of BNCT to treat osteosarcoma using this neutron source based on accelerator. Methods: The therapeutic efficacy of BNCT was analysed evaluating the dose distribution obtained in a clinical case of femur osteosarcoma. Mixed field dosimetry was assessed with two different formalisms whose parameters were specifically derived from radiobiological experiments involving in vitro UMR-106 osteosarcoma cell survival assays and boron concentration assessments in an animal model of osteosarcoma. A clinical case of skull osteosarcoma treated with BNCT in Japan was re-evaluated from the point of view of dose calculation and used as a reference for comparison. Results: The results in the case of femur osteosarcoma show that the RFQ beam would ensure a suitable tumour dose painting in a total irradiation time of less than an hour. Comparing the dosimetry between the analysed case and the treated patient in Japan it turns out that doses obtained in the femur tumour are at least as good as the ones delivered in the skull osteosarcoma. The same is concluded when the comparison is carried out taking into account osteosarcoma irradiations with photon radiation therapy. Conclusions: The possibility to apply BNCT to osteosarcoma would allow a multimodal treatment consisting in neo-adjuvant chemotherapy, high-LET selective radiation treatment and a more conservative surgery.Fil: Bortolussi, Silva. University of Pavia; ItaliaFil: Postuma, Ian. University of Pavia; ItaliaFil: Protti, Nicoletta. University of Pavia; ItaliaFil: Provenzano, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Ferrari, Cinzia. University of Pavia; ItaliaFil: Cansolino, Laura. University of Pavia; ItaliaFil: Dionigi, Paolo. University of Pavia; ItaliaFil: Galasso, Olimpio. University of Catanzaro; ItaliaFil: Gasparini, Giorgio. University of Catanzaro; ItaliaFil: Altieri, Saverio. University of Pavia; ItaliaFil: Miyatake, Shin Ichi. Osaka Medical College; JapónFil: González, Sara Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentin

Extending neutron autoradiography technique for boron concentration measurements in hard tissues

The neutron autoradiography technique using polycarbonate nuclear track detectors (NTD) has been extended to quantify the boron concentration in hard tissues, an application of special interest in Boron Neutron Capture Therapy (BNCT). Chemical and mechanical processing methods to prepare thin tissue sections as required by this technique have been explored. Four different decalcification methods governed by slow and fast kinetics were tested in boron-loaded bones. Due to the significant loss of the boron content, this technique was discarded. On the contrary, mechanical manipulation to obtain bone powder and tissue sections of tens of microns thick proved reproducible and suitable, ensuring a proper conservation of the boron content in the samples. A calibration curve that relates the 10B concentration of a bone sample and the track density in a Lexan NTD is presented. Bone powder embedded in boric acid solution with known boron concentrations between 0 and 100 ppm was used as a standard material. The samples, contained in slim Lexan cases, were exposed to a neutron fluence of 1012 cm−2 at the thermal column central facility of the RA-3 reactor (Argentina). The revealed tracks in the NTD were counted with an image processing software. The effect of track overlapping was studied and corresponding corrections were implemented in the presented calibration curve. Stochastic simulations of the track densities produced by the products of the 10B thermal neutron capture reaction for different boron concentrations in bone were performed and compared with the experimental results. The remarkable agreement between the two curves suggested the suitability of the obtained experimental calibration curve. This neutron autoradiography technique was finally applied to determine the boron concentration in pulverized and compact bone samples coming from a sheep experimental model. The obtained results for both type of samples agreed with boron measurements carried out by ICP-OES within experimental uncertainties. The fact that the histological structure of bone sections remains preserved allows for future boron microdistribution analysis.Fil: Provenzano, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Olivera, María Silvina. Comisión Nacional de Energía Atómica; ArgentinaFil: Saint Martin, María Laura Gisela. Comisión Nacional de Energía Atómica; ArgentinaFil: Rodriguez, Luis Miguel. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Fregenal, Daniel Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Thorp, Silvia Inés. Comisión Nacional de Energía Atómica; ArgentinaFil: Pozzi, Emiliano César Cayetano. Comisión Nacional de Energía Atómica; ArgentinaFil: Curotto, Paula. Comisión Nacional de Energía Atómica; ArgentinaFil: Postuma, Ian. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Altieri, Saverio. Istituto Nazionale di Fisica Nucleare; Italia. Universita Degli Studi Di Pavia; ItaliaFil: González, Sara Josefina. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bortolussi, Silva. Istituto Nazionale di Fisica Nucleare; Italia. Universita Degli Studi Di Pavia; ItaliaFil: Portu, Agustina Mariana. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Lithium halide filled carbon nanocapsules: Paving the way towards lithium neutron capture therapy (LiNCT)

Neutron capture therapy (NCT) is a form of radiotherapy that exploits the potential of some specific isotopes to capture thermal neutrons and subsequently yield high linear energy transfer (LET) particles, suitable for cancer treatment. Recently, relevant technological improvements have been made in terms of accelerators as suitable neutron sources for NCT at hospitals. However, low selective delivery of current drugs to cancer cells remains as the main challenge for successful clinical application of NCT. This work presents an innovative and previously unexplored approach for the design of nanotherapeutic NCT agents. Herein, a new concept based on carbon nanomaterials that seal 6Li active NCT nuclides is investigated. The 6Li active species are located in the inner cavity of the nanocarrier (carbon nanohorns or carbon nanotubes) and therefore, completely protected from the biological environment, avoiding toxicity and degradation. After encapsulation of the active cargo, the external surface of the nanocarrier is modified for improved biocompatibility. The developed 6Li-filled carbon nanohorns offered the possibility to explore 6Li compounds as active NCT agents by delivering therapeutic doses to cancer cells. We envisage that nanoencapsulation of 6Li can trigger the successful development and implementation of Lithium Neutron Cancer Therapy (LiNCT).G. T. acknowledges funding from ERC Consolidator Grant NEST (725743). G.G. gratefully acknowledges the funding by the Portuguese Science Foundation (FCT) for Programme Stimulus of Scientific Employment – Individual Support (CEECIND/01913/2017), financial support of project CARBONCT (2022.03596.PTDC), TEMA UIDB/00481/2020 and UIDP/00481/2020; and CENTRO-01-0145-FEDER-022083 - Centro Portugal Regional Operational Programme (Centro2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund. In addition, support through the project IF/00894/2015 and within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC) is gratefully acknowledged. We acknowledge funding by INFN (CSN5)-project ENTER_BNCT. ICMAB and ICN2 acknowledge financial support from the Spanish Ministry of Economy and Competitiveness (Spain), through the “Severo Ochoa” Programme for Centres of Excellence in R&D (CEX2019-000917-S and CEX2021-001214-S respectively). ICN2 is supported by CERCA programme. We acknowledge funding from Generalitat de Catalunya (2021-SGR-00439, 2017 SGR 327). M.Ll. has carried out this work in the framework of the Doctoral Degree Program in Materials Science of the Universitat Autònoma de Barcelona. We acknowledge fruitful discussions with Manuel Altabas and support with the XPS analysis by Guillaume Sauthier.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe

ipostuma/pyMCSRT: First Release of pyMCSRT

First release of the code. Full Changelog: https://github.com/ipostuma/pyMCSRT/commits/v1.0.

Python Monte Carlo Simulation Read Tool

pyMCSRT contains reading modules: one for reading the MCNP mesh tally out format, the other one for reading the PHITS output tally format