Californium-252 is a neutron-emitting radioisotope used as a brachytherapy source for radioresistant tumors. Presented here are microdosimetric spectra measured as a function of simulated site diameter and distance from applicator tube 252Cf sources. These spectra were measured using miniature tissue-equivalent proportional counters (TEPCs). An investigation of the clinical potential of boron neutron capture (BNC) enhancement of 252Cf brachytherapy is also provided. The absorbed dose from the BNC reaction was measured using a boron-loaded miniature TEPC. Measured neutron, photon and BNC absorbed dose components are provided as a function of distance from the source. In general, the absorbed dose results show good agreement with results from other measurement techniques. A concomitant boost to 252Cf brachytherapy may be provided through the use of the BNC reaction. The potential magnitude of this BNC enhancement increases with increasing distance from the source and is capable of providing a therapeutic gain greater than 30% at a distance of 5 cm from the source, assuming currently achievable boron concentrations.
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http://dx.doi.org/10.1667/rr3409.1 | DOI Listing |
Phys Med Biol
November 2023
Radiological Physics and Advisory Division, Health, Safety and Environment Group, Bhabha Atomic Research Centre, Mumbai 400085, India.
To investigate biological effectiveness ofCf brachytherapy source using Monte Carlo-calculated microdosimetric distributions.Cf source capsule was placed at the center of the spherical water phantom and phase-space data were scored as a function of radial distance in water (= 1-5 cm) using TOPAS Monte Carlo code. The phase-space data were used to calculate microdosimetric distributions at 1m site size.
View Article and Find Full Text PDFCancer Radiother
April 2023
Department of Radiation Oncology, Institut Curie, Paris, France.
Hadrontherapy is a form of radiation therapy (RT) that relies on heavy particles, such as proton, heavy ions, or neutrons, to enhance anti-tumoral efficacy based on their specific dosimetric and radio-biological properties. Neutrons are characterized by specific radiobiological properties that might deserve greater consideration, including the high linear energy transfer and the low oxygen enhancement ratio. Neutron brachytherapy, relying on interstitial or intracavitary neutron sources, has been developed since the 1950s using Californium-252 (252Cf) as a mixed emitter of fission fast neutrons and γ-photos.
View Article and Find Full Text PDFFront Oncol
November 2021
Cancer Center, Daping Hospital, Army Medical University, Chongqing, China.
Purpose: To retrospectively and comparatively evaluate the improvement of the efficacy and safety on the addition of Cf neutron intracavitary brachytherapy (ICBT), individualized or individualized with intrarectal peritumoral injection of amifostine (IPIA) to external-beam radiotherapy (EBRT) or concurrent chemo-EBRT in 314 patients with T2N0-1 or T3N0-1 low-lying rectal adenocarcinoma.
Methods: Phase I: from 2009 to 2011, 157 patients were treated with additional Cf neutron ICBT for four fixed fractions with a total dose of 40-45 Gy-eq during the EBRT. Phase II: from 2011 to 2013, 75 patients were treated with individualized neutron ICBT delivered for two to five fractions with a total dose of 26-45 Gy-eq according to the response of tumor after concurrent chemo-EBRT.
Appl Radiat Isot
May 2021
Biomedical Engineering and Medical Physics Department, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address:
The purpose of this study is to evaluate the effect of tissue heterogeneities on dose distribution in Californium-252(Cf) neutron brachytherapy. The effect of location and size of heterogeneity on dose distribution was also evaluated. Neutron and photon dose rate distributions were determined in a water phantom in presence of air, lung, soft tissue and bone heterogeneities using MCNPX code.
View Article and Find Full Text PDFEJNMMI Phys
December 2020
Department of Physics, K.N. Toosi University of Technology, P.O. Box 15875-4416, Tehran, Iran.
Due to the sensitivity of this tissue, and the potential for metastasis of its cancer as well, finding accurate methods to be employed for the treatment of esophagus tumors is of especial interest for the researchers. The present study deals with a Monte Carlo simulation of Cf neutron brachytherapy for treating these tumors using MCNPX (Version 2.6.
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