Jinn-Jer Peir

BNCT for locally recurrent head and neck cancer: preliminary clinical experience from a phase I/II trial at Tsing Hua Open-Pool Reactor.

To introduce our preliminary experience of treating locally and regionally recurrent Head and Neck cancer patients at Tsing Hua Open-Pool Reactor in Taiwan, four patients (M/F=3/1, median age 68 Y/O) were enrolled. BNCT with BPA (400 mg/kg) injected in 2 phases and prescription dose of 12-35 Gy (Eq.)/fraction for 2 fractions at 30 day interval can be given with sustained blood boron concentration and tolerable early toxicities for recurrent H & N cancer.

The use of radioactive zinc oxide nanoparticles in determination of their tissue concentrations following intravenous administration in mice

The increasing uses of zinc oxide nanoparticles (ZnONPs) in coatings, paints, personal care products and many other products increase the possibility of the bodys exposure to ZnONPs. Accurate and quantitative profiling on the tissue distribution and body clearance of ZnONPs, which is an important factor to clarify the acute and chronic safety concerns of ZnONPs, is interfered by the abundance of the bodys endogenous zinc moiety. In this report, radioactive zinc oxide nanoparticles (R-ZnONPs) generated from neutron activation were employed for the in vivo bio-distribution studies using mice as the animal model. Gamma-ray emitting radioactive R-ZnONPs were produced from neutron activation. Zeta potentials of the ZnONPs before and after the neutron irradiation remained about the same, and R-ZnONPs largely remained its original nano-particulate form after neutron irradiation. After intravenous administration into ICR mice, R-ZnONPs exhibited a primary retention in lung (43.6% injected dose (ID)/g tissue wet weight) for the first hour and began to be translocated to intestinal tract for feces excretion at a later stage. This type of labeling free and radioactive nanoparticles retains the surface property and can be a convenient protocol for studying bio-distribution of nanoparticles in pristine chemical form.

Fractionated BNCT for locally recurrent head and neck cancer: experience from a phase I/II clinical trial at Tsing Hua Open-Pool Reactor.

To introduce our experience of treating locally and regionally recurrent head and neck cancer patients with BNCT at Tsing Hua Open-Pool Reactor in Taiwan, 12 patients (M/F=10/2, median age 55.5 Y/O) were enrolled and 11 received two fractions of treatment. Fractionated BNCT at 30-day interval with adaptive planning according to changed T/N ratios was feasible, effective and safe for selected recurrent head and neck cancer in this trial.

Fractionated Boron Neutron Capture Therapy in Locally Recurrent Head and Neck Cancer: A Prospective Phase I/II Trial

PURPOSE To investigate the efficacy and safety of fractionated boron neutron capture therapy (BNCT) for recurrent head and neck (H&N) cancer after photon radiation therapy. METHODS AND MATERIALS In this prospective phase 1/2 trial, 2-fraction BNCT with intravenous L-boronophenylalanine (L-BPA, 400 mg/kg) was administered at a 28-day interval. Before each fraction, fluorine-18-labeled-BPA-positron emission tomography was conducted to determine the tumor/normal tissue ratio of an individual tumor. The prescription dose (D80) of 20 Gy-Eq per fraction was selected to cover 80% of the gross tumor volume by using a dose volume histogram, while minimizing the volume of oral mucosa receiving >10 Gy-Eq. Tumor responses and adverse effects were assessed using the Response Evaluation Criteria in Solid Tumors v1.1 and the Common Terminology Criteria for Adverse Events v3.0, respectively. RESULTS Seventeen patients with a previous cumulative radiation dose of 63-165 Gy were enrolled. All but 2 participants received 2 fractions of BNCT. The median tumor/normal tissue ratio was 3.4 for the first fraction and 2.5 for the second, whereas the median D80 for the first and second fraction was 19.8 and 14.6 Gy-Eq, respectively. After a median follow-up period of 19.7 months (range, 5.2-52 mo), 6 participants exhibited a complete response and 6 exhibited a partial response. Regarding acute toxicity, 5 participants showed grade 3 mucositis and 1 participant showed grade 4 laryngeal edema and carotid hemorrhage. Regarding late toxicity, 2 participants exhibited grade 3 cranial neuropathy. Four of six participants (67%) receiving total D80 > 40 Gy-Eq had a complete response. Two-year overall survival was 47%. Two-year locoregional control was 28%. CONCLUSIONS Our results suggested that 2-fraction BNCT with adaptive dose prescription was effective and safe in locally recurrent H&N cancer. Modifications to our protocol may yield more satisfactory results in the future.

Potential of using boric acid as a boron drug for boron neutron capture therapy for osteosarcoma.

Osteosarcoma is a malignant tumor commonly found in human and animals. The ability of boric acid (BA) to accumulate in osteosarcoma due to the mechanism of the bone formation of cancer cells would make boron neutron capture therapy (BNCT) an alternative therapy for osteosarcoma. This study evaluated the feasibility of using BA as the boron drug for BNCT of bone cancer. The cytotoxicity of BA to L929 cells exceeded that of UMR-106 cells. With 25 μg (10)B/mL medium of BA treatment, the boron concentration in UMR-106 cells was higher than that in L929 cells. The biodistribution and pharmacokinetics of BA in Sprague-Dawley (SD) rats were studied by administrating 25 mg (10)B/kg body weight to SD rats. Blood boron level decreased rapidly within one hour after BA injection. Boron concentration in the long bone was 4-6 time higher than that of blood. Results of this study suggest that BA may be a potential drug for BNCT for osteosarcoma.

An iterative approach for TRIGA fuel burn-up determination using nondestructive gamma-ray spectrometry.

The purpose of this work is to establish a method for evaluating the burn-up values of the rod-type TRIGA spent fuel by using gamma-ray spectrometry of the short-lived fission products 97Zr/97Nb, 132I, and 140La. Fuel irradiation history is not needed in this method. Short-lived fission-product activities were established by reirradiating the spent fuels in a nuclear reactor. Based on the measured activities, 235U burn-up values can be deduced by iterative calculations. The complication caused by 239Pu production and fission is also discussed in detail. The burn-up values obtained by this method are in good agreement with those deduced from the conventional method based on long-lived fission products 137Cs, 134Cs/137Cs ratio and 106Ru/137Cs ratio.

TRIGA fuel enrichment verification based on the measurement of short-lived fission products

Abstract A method is developed to verify the 235 U content of TRIGA fresh fuel using gamma-ray spectrometry of the short-lived fission products 97 Zr/ 97 Nb, 132 I and 140 La. The short-lived fission-product activities can be established by irradiating the fuel in a nuclear reactor. Based on the measured activities, the 235 U content can be deduced by iterative calculations. The aim of this work is to establish a calibration method for estimating the burnup values of the rod-type spent fuels without the need for detailed data on fuel irradiation history.

Comparisons between calculated and measured gamma-ray energy-deposition rates in a one-dimensional mixed fast-neutron/gamma-ray field

Abstract This paper provides calculated-to-experiment (C/E) comparisons of the γ-ray energy-deposition rates in one-dimensional, mixed fast-neutron/γ-ray fields. The experiments were made with three types of thermoluminescent dosimeters (TLDs). Calculations were performed with the AMPX-ANISN computer code package. Similar C/E variation with distance from source was found for all the 12 sets of experiments; this variation was believed to come primarily from inaccuracies in the calculations.

A Parametric Study of Fuel Lattice Design for HTR-10

In this study, the multiplication factor and neutron spectrum behaviors were investigated against the moderator-to-fuel ratio, the fuel loading height, and the detector location in high-temperature gas-cooled reactor (HTR)-10. The MCNP5 computer code (version 1.51) was employed to perform all the simulation computations. The results revealed that the multiplication factor varies significantly depending on the moderator-to-fuel ratio and the fuel loading height due to the competition among the neutron moderation and absorption abilities of the moderator as well as the neutron production ability of the fuel. Due to its inherent stability, HTR-10 is deliberately designed such that the multiplication factor decreases and the neutron spectrum softens as the moderator-to-fuel ratio increases. The average neutron energy level in the HTR-10 fuel balls is approximately 240 keV and ranges from smallest to largest at the middle, bottom, and top of the reactor core, respectively.

Autoradiographic and histopathological studies of boric acid-mediated BNCT in hepatic VX2 tumor-bearing rabbits: Specific boron retention and damage in tumor and tumor vessels.

Hepatoma is a malignant tumor that responds poorly to conventional therapies. Boron neutron capture therapy (BNCT) may provide a better way for hepatoma therapy. In this research, (10)B-enriched boric acid (BA, 99% (10)B) was used as the boron drug. A multifocal hepatic VX2 tumor-bearing rabbit model was used to study the mechanisms of BA-mediated BNCT. Autoradiography demonstrated that BA was selectively targeted to tumors and tumor vessels. Histopathological examination revealed the radiation damage to tumor-bearing liver was concentrated in the tumor regions during BNCT treatment. The selective killing of tumor cells and the destruction of the blood vessels in tumor masses may be responsible for the success of BA-mediated BNCT for liver tumors.