Computational evaluation of dose distribution for BNCT treatment combined with X-ray therapy or proton beam therapy

Abstract Proton beam therapy can potentially offer improved treatment for cancers of the head and neck and in paediatric patients. There has been asharp uptake of proton beam therapy in recent years as improved delivery techniques and patient benefits are observed. However, treatments are currently planned using conventional x-ray CT images due to the absence of devices able to perform high quality proton computed tomography(pCT) under realistic clinical conditions. A new plastic-scintillator-based range telescope concept, named ASTRA, is proposed here to measure the proton’s energy loss in a pCT system. Simulations conducted using GEANT4 yield an expected energy resolution of 0.7%. If calorimetric information is used the energy resolution could be further improved to about 0.5%. In addition, the ability of ASTRA to track multiple protons simultaneously is presented. Due to its fast components, ASTRA is expected to reach unprecedented data collection rates, similar to 10^8 protons/s.The performance of ASTRA has also been tested by simulating the imaging of phantoms. The results show excellent image contrast and relative stopping power reconstruction.

Download Full-text

Comparison of Proton and Photon Beam Irradiation in Radiation-Induced Intestinal Injury Using a Mouse Model

International Journal of Molecular Sciences ◽

10.3390/ijms20081894 ◽

2019 ◽

Vol 20 (8) ◽

pp. 1894 ◽

Cited By ~ 4

Author(s):

Changhoon Choi ◽

Chansu Lee ◽

Sung-Won Shin ◽

Shin-Yeong Kim ◽

Sung Noh Hong ◽

...

Keyword(s):

Proton Beam ◽

Mouse Models ◽

Proton Irradiation ◽

Apoptotic Cell ◽

Proton Beam Therapy ◽

Tunel Assay ◽

Terminal Deoxynucleotidyl Transferase ◽

Limiting Factor ◽

X Rays ◽

X Ray

When radiotherapy is applied to the abdomen or pelvis, normal tissue toxicity in the gastrointestinal (GI) tract is considered a major dose-limiting factor. Proton beam therapy has a specific advantage in terms of reduced doses to normal tissues. This study investigated the fundamental differences between proton- and X-ray-induced intestinal injuries in mouse models. C57BL/6J mice were irradiated with 6-MV X-rays or 230-MeV protons and were sacrificed after 84 h. The number of surviving crypts per circumference of the jejunum was identified using Hematoxylin and Eosin staining. Diverse intestinal stem cell (ISC) populations and apoptotic cells were analyzed using immunohistochemistry (IHC) and a terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) assay, respectively. The crypt microcolony assay revealed a radiation-dose-dependent decrease in the number of regenerative crypts in the mouse jejunum; proton irradiation was more effective than X-ray irradiation with a relative biological effectiveness of 1.14. The jejunum is the most sensitive to radiations, followed by the ileum and the colon. Both types of radiation therapy decreased the number of radiosensitive, active cycling ISC populations. However, a higher number of radioresistant, reserve ISC populations and Paneth cells were eradicated by proton irradiation than X-ray irradiation, as shown in the IHC analyses. The TUNEL assay revealed that proton irradiation was more effective in enhancing apoptotic cell death than X-ray irradiation. This study conducted a detailed analysis on the effects of proton irradiation versus X-ray irradiation on intestinal crypt regeneration in mouse models. Our findings revealed that proton irradiation has a direct effect on ISC populations, which may result in an increase in the risk of GI toxicity during proton beam therapy.

Download Full-text

INVESTIGATION OF TUMOR CELL TOXICITY FROM PARTICLE INDUCED X-RAY EMISSION FROM A 45-MeV PROTON BEAM IRRADIATED FERRITE NANOPARTICLE

International Journal of PIXE ◽

10.1142/s0129083509001837 ◽

2009 ◽

Vol 19 (03n04) ◽

pp. 143-155 ◽

Cited By ~ 4

Author(s):

KI-HONG KIM ◽

HONG-TAE KIM ◽

JONG-HEE KIM ◽

SEUNG-JUN SEO ◽

DUCK-SOO CHUNG ◽

...

Keyword(s):

Proton Beam ◽

Proton Beam Therapy ◽

Ferrite Nanoparticles ◽

Cancer Center ◽

Control Group ◽

X Ray ◽

Nanoparticle Distribution ◽

Acridine Orange Staining ◽

Horizontal Beam ◽

Center Hospital

In order to investigate the potential cytotoxic effects of particle-induced x-ray emission (PIXE) on tumor cells, 45 MeV proton beam was irradiated on C6 glioma cell lines that had taken up alginate-coated ferrite nanoparticles (Alg-SNP). Cells were anchored in vertical 96-well dishes facing a horizontal beam where the Bragg peak was placed on the upper part of the 96-well dish. Experimental groups included cells without SNP as a control (No-SNP), and cells incubated with SNP for 6 hours (6hr-SNP) or overnight (ON-SNP). A 0 to 200 Gy proton beam from an MC50 cyclotron (Scanditronix, Sweden) at the Korea Cancer Center Hospital (Seoul, Korea) was used to irradiate each experimental group. Perinuclear Alg-SNP nanoparticle distribution was observed in glioma cells. The test groups (6hr-SNP or ON-SNP) showed an estimated 20-28% (ANOVA, P < 0.05) less cell survival compared to the control group based on MTT assay. Nuclear damage, indicating apoptosis, was present at a higher frequency in the 6hr-SNP and ON-SNP groups up to relatively low radiation dose of 100 Gy by fluorescence microscopy upon Hoechst 33342 and Acridine Orange staining. Ferrite nanoparticles alone were not cytotoxic at the experimental concentration of 0.15 mg/ml. Therefore ferrite nanoparticles may induce additional cytotoxicity from X-ray emission from potential PIXE effects. PIXE and metal nanoparticles may be developed as a therapeutic factor and prodrug for localized proton beam therapy without side effects of solid or disseminate tumors on the surrounding normal tissue.

Download Full-text