Improvement in the neutron beam collimation for application in boron neutron capture therapy of the head and neck region.

In June 2020, the Japanese government approved boron neutron capture therapy for the treatment of head and neck cancer. The treatment is usually performed in a single fraction, with the neutron irradiation time being approximately 30-60 min. As neutrons scatter in air and loses its intensity, it is preferable to bring the patient as close to the beam port as possible to shorten the irradiation time.

Effect of a lead block on alveolar bone protection in image-guided high-dose-rate interstitial brachytherapy for tongue cancer: using model-based dose calculation algorithms to correct for inhomogeneity.

Purpose: The purpose of this study was to evaluate the effect of a lead block for alveolar bone protection in image-guided high-dose-rate interstitial brachytherapy for tongue cancer.

Material And Methods: We treated 6 patients and delivered 5,400 cGy in 9 fractions using a lead block. Effects of lead block (median thickness, 4 mm) on dose attenuation by distance were visually examined using TG-43 formalism-based dose distribution curves to determine whether or not the area with the highest dose is located in the alveolar bone, where there is a high-risk of infection.

Evaluation of a treatment planning system developed for clinical boron neutron capture therapy and validation against an independent Monte Carlo dose calculation system.

Boron neutron capture therapy (BNCT) for the treatment of unresectable, locally advanced, and recurrent carcinoma of the head and neck cancer has been approved by the Japanese government for reimbursement under the national health insurance as of June 2020. A new treatment planning system for clinical BNCT has been developed by Sumitomo Heavy Industries, Ltd. (Sumitomo), NeuCure® Dose Engine To safely implement this system for clinical use, the simulated neutron flux and gamma ray dose rate inside a water phantom was compared against experimental measurements.

[Effect of contrast material pushed with saline solution using dual injection on enhancement of aorta, portal vein, and liver parenchyma in multislice CT of the liver].

We evaluated the effect of the enhancement value of the abdominal aorta, portal vein, and liver parenchyma by the saline flush technique. One hundred eight patients who underwent multislice CT of the liver were randomly divided into four groups: 100 ml of contrast material (Iomeprol 300 mgI/ml or 350 mgI/ml) only and 100 ml of contrast material (300 mgI/ml or 350 mgI/ml) flushed with 50 ml of saline solution at a rate of 5 ml/sec. The saline flush technique demonstrated statistically significantly greater portal enhancement.