服部 秀計

Background: Radiation pneumonitis (RP) and organizing pneumonia (OP) are the two main types of lung damage that can occur after lung irradiation. The goal of this study was to evaluate the relationship between RP and OP after irradiation for breast cancer. Methods: Four hundred and twenty-eight patients who underwent radiotherapy for breast cancer were identified. The whole breast was irradiated with two tangential photon beams. Chest computed tomography (CT) scan were performed when patients showed any symptoms that were suspicious for pneumonitis. Results: Five patients (1.2%) were diagnosed with OP. All five patients showed ground glass opacities and consolidation of the border of the lesion of RP in the radiation fields. Infiltration of OP spread from the site of RP to the hilum of the ipsilateral lung. Between RP and OP, a free region space (FRS) could be detected. Conclusions: OP is closely related to RP. All OP lesions developed near the site of RP.

Purpose: The incident at the Fukushima Daiichi nuclear power station in 2011 has again raised concerns with the public regarding radiation exposure, especially so in medical workers and patients undergoing treatment involving the use of radiation. Radioisotopes are currently used during sentinel node navigation surgery (SNNS) in operating rooms without radiation monitoring. To re-evaluate the safety issues, the potential effective dose (E poten) from 99mTc-tin (-Sn) colloid in breast cancer surgery was estimated and personal dose equivalents, H p(10) and H p(0.07), were measured during SNNS. Materials and methods: Seventeen breast cancer patients were enrolled. One day before SNNS, 99mTc-Sn colloid was injected around the tumor and radiation exposure rates were measured using survey meters. Personal dose equivalents for the surgical workers were measured. H p(10) and H p(0.07) for the body and H p(0.07) for the hands were recorded using semiconductor detectors and ring-type glass dosimeters. Results: The maximum E poten was 29 μSv per 74 MBq injection. The maximum H p(10) for the primary and assisting surgeons, nurse, and anesthetist was 3.7, 1.4, 0.3 and 0.6 μSv per SNNS, respectively. The maximum H p(0.07) for the hands was 100 μSv. Maximum radiocontamination 20 times higher than background (0.05 μSv/h) was detected in bloody gauze. Conclusion: The workers' radiation dose exposure from SNNS was not high, although radiation management such as a temporary cooling off period may be required. © Ejiri et al.

【目的】早期前立腺がんに対するI-125を用いた永久挿入治療においては脱落線源の紛失による環境汚染が問題となっている．本研究では，挿入後から一時管理区域病室退院までの間の脱落線源を確実に捕捉しうる方策を検討する．【方法】2006年 7 月から2007年12月までの期間で，密封小線源挿入療法を施行した121例(7718個)を対象とした．挿入直後から退院までの脱落線源の発見事例における発見場所ならびに発見時期を検討し，脱落の場所，時期を推定した．【結果】退院までに総計43個発見され，頻度は43/7718(0.56%)であった．挿入後手術室にて 4 個，一時管理区域病室では膀胱内留置カテーテル抜去前が 2 個，そして，膀胱内留置カテーテル抜去後，一時管理区域病室退院時のサーベイで32個発見された．膀胱鏡にて，膀胱内より取り除いたのは 5 個であった．別に，退院後自宅で脱落したとして持参したのが 5 個であった．【結語】脱落線源を紛失しないためには，管理病室への入退室者の注意深いモニターと慎重なサーベイが必要と考えられた．