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Dr. Tsubokura's Radiation Lecture Vol.52

Author: Masaharu Tsubokura

Editors: Akihiko Ozaki M.D., Yuki Senoo

103. Medical radiation does not increase lung cancer risk

The impact of radiation on health is determined by the extent of the exposure dose, not by whether one has experienced any exposure in the past. In that case, what level of radiation exposure is deemed dangerous? Numerous investigations have been conducted to find answers to this question, including those for medical radiation,1 natural background radiation,2 and occupational radiation exposure.3

Well-known previous research papers on the topic of medical radiation are ones that investigated the risks of breast and lung cancer due to radiation exposure during chest examinations for pulmonary tuberculosis. In the first half of the 20th century, it was common practice to artificially induce a pneumothorax (collapse a part of the lungs) as a surgical treatment for pulmonary tuberculosis. During this operation, it was necessary to apply radiation to the patient’s chest to guide the procedure by constantly monitoring (seeing through) the lung.

Because it was necessary to repeat this procedure several times a month for several years, the patients received a high level of radiation exposure, which was equivalent to more than 100 times the dose received during a chest CT and more than 1000 times the dose received during a chest X-ray. Although this procedure was necessary for medical purp