Dose estimation for internal organs during boron neutron capture therapy for body-trunk tumors

Our plain-English summary of Dose estimation for internal organs during boron neutron capture therapy for body-trunk tumors, by Y. Sakurai, H. Tanaka, M. Suzuki, et al (Applied Radiation and Isotopes, 2014).

The study

• Authors: Y. Sakurai, H. Tanaka, M. Suzuki, S. Masunaga, Y. Kinashi, N. Kondo, K. Ono, A. Maruhashi
• Journal: Applied Radiation and Isotopes
• Published: 2014;88:43-5
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Radiation doses during boron neutron capture therapy for body-trunk tumors were estimated for various internal organs, using data from patients treated at Kyoto University Research Reactor Institute. Dose-volume histograms were constructed for tissues of the lung, liver, kidney, pancreas, and bowel. For pleural mesothelioma, the target total dose to the normal lung tissues on the diseased side is 5Gy-Eq in average for the whole lung. It was confirmed that the dose to the liver should be carefully considered in cases of right lung disease.

Copyright © 2014 Elsevier Ltd. All rights reserved.

In plain English

This short technical report from Kyoto University Research Reactor Institute in Japan looked at boron neutron capture therapy (BNCT), a radiation treatment, for tumors in the chest and abdomen, including pleural mesothelioma. It did not study asbestos exposure. By December 2012 the facility had performed 46 such irradiations: 9 for liver tumors, 34 for lung tumors and 3 for other abdominal tumors. The authors used a computer dose-planning system and patients' CT scans to estimate radiation doses to nearby organs. For liver-tumor treatment, assuming a typical irradiation geometry and a boron-10 concentration of 10 ppm, the estimated kidney dose ranged from 1 to 6 Gy-Eq, averaging 3 Gy-Eq. In one patient with lung cancer recurring in the lower left lung, the colon had the highest average dose, 9.1 Gy-Eq. In one patient with right-sided pleural mesothelioma, average doses were 4.9 Gy-Eq to the diseased lung, 1.4 to the healthy lung and 2.9 to the liver. The authors concluded that bowel dose needs careful consideration when treating the lower lung, and liver dose when the right lung is diseased. They noted the kidney doses may be overestimated.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Radiation dose-estimation (treatment-planning) analysis using data from patients treated with BNCT, with example cases. It is not an epidemiological study of asbestos.
• Who was studied: Patients with body-trunk tumors treated at the Heavy Water Neutron Irradiation Facility of the Kyoto University Reactor, Japan. There were 46 irradiations as of December 2012 (9 liver, 34 lung, 3 other abdominal). Detailed dose results are shown for one patient with recurrent lower-left lung cancer and one patient with pleural mesothelioma.
• Exposure: Therapeutic radiation from boron neutron capture therapy using the boron compounds boronophenylalanine (BPA) and/or borocaptate sodium (BSH). Only BPA was used for lung tumors. For pleural mesothelioma, the whole diseased lung was irradiated from four fields. Asbestos exposure was not studied.
• Main results:
  • In BNCT for liver tumors, the estimated kidney dose ranged from 1 to 6 Gy-Eq, with an average of 3 Gy-Eq. These estimates assume the typical irradiation geometry and a boron-10 concentration of 10 ppm.
  • In liver-tumor BNCT, the estimated right kidney dose was 10 to 50% higher than the liver dose. The left kidney dose was about one-tenth of the right kidney dose.
  • In one patient with cancer of the lower left lung, the colon received the highest dose (average 9.1 Gy-Eq, maximum 17.6 Gy-Eq). Other average doses were lung 2.5, kidney 4.8, pancreas 1.8, stomach 3.6 and spinal cord 1.9 Gy-Eq.
  • In one patient with pleural mesothelioma of the right lung, average and maximum doses were: diseased lung 4.9 and 9.1 Gy-Eq; healthy lung 1.4 and 4.1 Gy-Eq; liver 2.9 and 9.4 Gy-Eq.
  • In the mesothelioma patient, the liver's maximum dose was almost the same as the diseased lung's dose. The healthy lung's average dose was less than one-third of the diseased lung's.
• The authors' conclusion: The authors concluded that bowel dose should be carefully considered when irradiating the lower lung. In mesothelioma of the right lung, the liver dose is higher and is also important.
• Limitations the authors state:
  • The kidney doses in liver-tumor BNCT may be overestimated because of high estimates for the biological effectiveness factor and the boron-10 concentration.
  • The biological effectiveness factor for the kidney was a tentative assumption and is not precisely known.
  • For liver tumors, the embolized regions could not be measured exactly, so the whole liver was used as the target volume.

Topics

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma.

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