International Commission on Radiological Protection (ICRP), an independent international organization established in 1925, develops, maintains, and elaborates radiological protection standards, legislation, and guidelines. United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) provides scientific evidence. World Health Organization (WHO) and International Atomic Energy Agency (IAEA) utilise the ICRP recommendations to implement radiation protection in practice. Finally, radiation protection agencies in each country adopt the policies, and adapt them to each situation. In Korea, Nuclear Safety and Security Commission is the governmental body for nuclear safety regulation and Korea Institute of Nuclear Safety is a public organization for technical support and R&D in nuclear safety and radiation protection.
History, 20th Century ; Humans ; International Agencies/*organization & administration ; Radiation Injuries/etiology/prevention & control ; Radiation Protection/history/*legislation & jurisprudence ; Radiation, Ionizing

After the rapid development of medical equipment including CT or PET-CT, radiation doses from medical exposure are now the largest source of man-made radiation exposure. General principles of radiation protection from the hazard of ionizing radiation are summarized as three key words; justification, optimization, and dose limit. Because medical exposure of radiation has unique considerations, diagnostic reference level is generally used as a reference value, instead of dose limits. In Korea, medical radiation exposure has increased rapidly. For medical radiation exposure control, Korea has two separate control systems. Regulation is essential to control medical radiation exposure. Physicians and radiologists must be aware of the radiation risks and benefits associated with medical exposure, and understand and implement the principles of radiation protection for patients. The education of the referring physicians and radiologists is also important.
Guidelines as Topic ; Humans ; International Agencies ; *Occupational Exposure ; Positron-Emission Tomography ; Radiation Injuries/etiology/prevention & control ; *Radiation Protection ; Radiation, Ionizing ; Radiotherapy Dosage/standards ; Reference Values ; Tomography, X-Ray Computed

In recent years, more head and neck cancer patients have been treated with radiotherapy. Radiation-induced mucositis is a common and dose limiting toxicity of radiotherapy among patients with head and neck cancers. Patients undergoing radiation therapy for head and neck cancer are also at increased risk of developing oral candidiasis. A number of new agents applied locally or systemically to prevent or treat radiation-induced mucositis have been investigated, but there is no widely accepted prophylactic or effective treatment for mucositis. Topical Aloe vera is widely used for mild sunburn, frostbites, and scalding burns. Studies have reported the beneficial effects of Aloe gel for wound healing, mucous membrane protection, and treatment of oral ulcers, in addition to antiinflammatory, immunomudulation, antifungal, scavenging free radicals, increasing collagen formation and inhibiting collagenase. Herein the author postulates that oral Aloe vera mouthwash may not only prevent radiation-induced mucositis by its wound healing and antiinflammatory mechanism, but also may reduce oral candidiasis of patients undergoing head and neck radiotherapy due to its antifungal and immunomodulatory properties. Hence, Aloe vera mouthwash may provide an alternative agent for treating radiation-induced oral mucositis and candidiasis in patients with head and neck cancers.
Aloe ; chemistry ; Clinical Trials as Topic ; Head and Neck Neoplasms ; radiotherapy ; Humans ; Mouthwashes ; therapeutic use ; Radiation Injuries ; drug therapy ; etiology ; prevention & control ; Stomatitis ; drug therapy ; etiology ; prevention & control

OBJECTIVETo observe the effect of Shaogen Decoction (SGD) for the prevention and treatment of acute radiation esophagitis (ARE).

METHODSSixty patients with breast tumor receiving chemo/radiotherapy were assigned to two groups, the SGD group and the control group. The patients in the SGD group were administered with SGD, a Chinese preparation consisted of Radix Sophorae tonkinensis 10 g, Radix Paeoniae Alba 30 g, Radix Scrophulariae 15 g, Rhizoma Bletillae 15 g, Radix Notoginseng 3 g, etc., starting from the initial day of radiotherapy, 10 mL, thrice a day, while in case of 2nd or over 2nd grade ARE occurred, it was changed to 10 mL, every 2 h, medicated by keeping in mouth and slowly swallowed followed with 5-min forbiddance of food and water. The patients in the control group were treated, in case of 2nd or over 2nd grade ARE occurred, with antibiotic drugs (such as cefuroxime 4.5 g) and hormone (dexamethasone 5 mg) by intravenous infusion for 7 days. The incidence, happening time, and retaining time of ARE, therapeutic effect on it, as well as the proportion of patients for whom antibiotics and hormone were used in the two groups were observed.

RESULTSThe incidence of 2nd or over 2nd grade ARE in the SGD group and the control group was 33.33% and 63.33%, respectively, that in the former was significantly lower (chi2 = 5.406, P<0.05). Different degrees of acute esophageal toxic response occurred in both groups, initially presenting at 19.8 +/- 7.4 days in the SGD group and at 20.2 +/- 9.6 days in the control group after radiotherapy, that was delayed in the former (t=2.130, P<0.05). Clinical symptom of ARE retained for 56.4 +/- 19.5 days and 58.2 +/- 15.0 days in the two groups, respectively, it was shorter in the SGD groups (t=2.441, P<0.05). Moreover, the proportion of patients for whom antibiotics and hormone were used in the SGD group was less.

CONCLUSIONSGD acted, in coordinating with chemo-radiotherapy, to reduce the incidence, retard the happening and shorten the retaining time of 2nd or over 2nd grade ARE, and reduce the proportion of patients needing antibiotics and hormone treatment as well, showing equivalent efficacy in treating ARE as Western drugs.

Drugs, Chinese Herbal ; therapeutic use ; Esophageal Neoplasms ; radiotherapy ; Esophagitis ; drug therapy ; etiology ; prevention & control ; Female ; Humans ; Male ; Middle Aged ; Paeonia ; chemistry ; Phytotherapy ; Radiation Injuries ; drug therapy ; prevention & control

Objective: To investigate the nursing care of prostate cancer (PCa) patients againstradioactive proctitisinduced byCyberKnifetreatment. METHODS: Sixty-eightPCapatients undergoingCyberKnife treatment in the observation group receivedspecialnursing care againstradioactive proctitis. The nursing measures includedthoserelevant toCyberKnife treatment, prevention ofradioactive proctitis, skin care, and discharge guidance. Meanwhile, another 54 prostate cancer patients received traditional nursing care as controls. We compared the incidence rate and severity of radioactive proctitis between the two groups of patients. RESULTS: The incidence rate of radioactive proctitiswas markedly lower in the observation group than in the control (2.9% vs 13.0%, P<0.05), but no statistically significant difference was observed in the severity of radioactive proctitis between the two groups of patients. CONCLUSIONS The special nursing care againstCyberKnife-induced radioactiveproctitiscan significantlyreduce the incidence of radioactive proctitis andimprove the effect of CyberKnife treatment of prostate cancer, which therefore deserves wide clinical application.
Case-Control Studies ; Humans ; Male ; Proctitis ; etiology ; nursing ; prevention & control ; Prostatic Neoplasms ; radiotherapy ; Radiation Injuries ; nursing ; prevention & control ; Radiosurgery ; adverse effects

Amifostine ; therapeutic use ; Animals ; Head and Neck Neoplasms ; radiotherapy ; Humans ; Oral Health ; Radiation Injuries ; etiology ; prevention & control ; therapy ; Radiation-Protective Agents ; therapeutic use ; Radiotherapy ; adverse effects ; Radiotherapy, Conformal ; Salivary Glands ; radiation effects ; Salivation ; radiation effects ; Submandibular Gland ; surgery ; transplantation ; Xerostomia ; etiology ; prevention & control ; therapy

This study evaluated the incidence of hepatic toxicity after stereotactic ablative radiotherapy (SABR) using 3 fractions to the liver, and identified the predictors for hepatic toxicity. We retrospectively reviewed 78 patients with primary and metastatic liver cancers, who underwent SABR using 3 fractions between 2003 and 2011. To examine the incidence of hepatic toxicity, we defined newly developed hepatic toxicity> or =grade 2 according to the National Cancer Institute Common Terminology Criteria for Adverse Events v4.0 within 3 months after the end of SABR as a significant adverse event. To identify the predictors for hepatic toxicity, we analyzed several clinical and dosimetric parameters (rV(5Gy)-rV(35Gy): normal liver volume receiving or =grade 2 occurred in 10 patients (13%): grade 2 in 9 patients and grade 3 in 1 patient. On univariate analysis, baseline Child-Pugh (CP) score (5 vs. 6-8), normal liver volume, and planning target volume were the significant clinical predictors. All dosimetric parameters were significant: rV(20Gy) was the most significant predictor. On multivariate analysis, baseline CP score (hazard ratio, 0.026; P=0.001) was the only significant predictor. In conclusion, SABR using 3 fractions in primary and metastatic liver cancers produces low hepatic toxicity, especially in patients with a baseline CP score of 5. However, further studies are needed to minimize hepatic toxicity in patients with baseline CP scores> or =6.
Aged ; *Dose Fractionation ; Female ; Hepatitis/*etiology/pathology/prevention & control ; Humans ; Liver Neoplasms/complications/pathology/*surgery ; Male ; Middle Aged ; Neoplasm Metastasis ; Radiation Injuries/*etiology/pathology/prevention & control ; Radiosurgery/*adverse effects/*methods ; Radiotherapy Dosage ; Treatment Outcome

BACKGROUNDRetinal light injury can lead to degeneration of the photoreceptor cell layer. It has been hypothesized that the mechanism for this process is the photochemical damage. Ginkgo balboa extract (Ginkgo biloba extract EGB761) EGB761 is a free radical scavenger. The purpose of this study was to investigate the possible effect of orally administered EGB761 on retinal light damage of mouse photoreceptor cells.

METHODSKunming mice were randomly chosen for the following groups containing 20 animals in each: control group, light damage group, saline control group, and drug treatment group. The drug treatment group and saline control group were given daily gavage of EGB761 (150 mg×kg(-1)×d(-1)) one week before light exposure. At 7, 14, and 30 days after light exposure, animals were sacrificed and eyes were examined by light microscopy, electron microscopy, and retinal histopathology using in situ detection of apoptotic cells.

RESULTSIn the light damage group after 7 days there was visible edema, and the outer nuclear layer appeared withered with deeply stained dead cells, leaving only a thin nuclear layer of 7 - 8 cells. After 14 days, the photoreceptor cell layer disappeared, leaving only the outer nuclear layer of 1 - 3 cells with an average thickness of (37.988 ± 1.207) µm. The average thickness of the retina was (126.32 ± 2.31) µm. In the drug treatment group, the photoreceptor cell layer and outer nuclear layer damage were significantly lower than the saline group (t = 21.993, P < 0.001), demonstrating that EGB761, especially at 14 days after light exposure, can reduce retinal light damage in mice.

CONCLUSIONOral administration of EGB761 can partially inhibit apoptosis of photoreceptor cells, resulting in increased photoreceptor cell survival.

Animals ; Eye Injuries ; etiology ; prevention & control ; Light ; adverse effects ; Male ; Mice ; Microscopy, Electron ; Photoreceptor Cells ; drug effects ; radiation effects ; ultrastructure ; Plant Extracts ; therapeutic use ; Rats ; Retina ; drug effects ; radiation effects ; ultrastructure

The long-period CT perfusion imaging leads to an excess amount of radiation dose to the patient. However, the radiation dose could be significantly reduced if a previous normal-dose image is acquired before a set of low-dose scans of perfusion, and a filtering processing is performed on the differences between the current low-dose images and the previous normal-dose image, then the results are added to the previous image. But the selection of plenty of parameters makes the algorithm complicated. This paper proposes an innovative approach performed in sinogram domain instead of in image domain. First a normal-dose image and a set of low-dose projection data are acquired before the perfusion. Second the perfusion information is commendably reconstructed with sparsity constraints of the differences between current low-dose perfusion sinograms and previous low-dose sinogram. Finally, the reconstructed perfusion information is added to the previous normal-dose image. The proposed method was validated by simulated experiments with a set of brain CT perfusion images, which showed that the new method provided more accurate perfusion information; the time-attenuation curve was more close to that for normal-dose scan and the mean transit time more repeatable.
Algorithms ; Brain ; diagnostic imaging ; Humans ; Perfusion Imaging ; methods ; Radiation Dosage ; Radiation Injuries ; etiology ; prevention & control ; Radiographic Image Interpretation, Computer-Assisted ; Subtraction Technique ; Tomography, X-Ray Computed ; adverse effects ; methods

OBJECTIVE: To evaluate the feasibility of sinogram-affirmed iterative reconstruction (SAFIRE) and automated kV modulation (CARE kV) in reducing radiation dose without increasing image noise for abdominal CT examination. MATERIALS AND METHODS: This retrospective study included 77 patients who received CT imaging with an application of CARE kV with or without SAFIRE and who had comparable previous CT images obtained without CARE kV or SAFIRE, using the standard dose (i.e., reference mAs of 240) on an identical CT scanner and reconstructed with filtered back projection (FBP) within 1 year. Patients were divided into two groups: group A (33 patients, CT scanned with CARE kV); and group B (44 patients, scanned after reducing the reference mAs from 240 to 170 and applying both CARE kV and SAFIRE). CT number, image noise for four organs and radiation dose were compared among the two groups. RESULTS: Image noise increased after CARE kV application (p < 0.001) and significantly decreased as SAFIRE strength increased (p < 0.001). Image noise with reduced-mAs scan (170 mAs) in group B became similar to that of standard-dose FBP images after applying CARE kV and SAFIRE strengths of 3 or 4 when measured in the aorta, liver or muscle (p > or = 0.108). Effective doses decreased by 19.4% and 41.3% for groups A and B, respectively (all, p < 0.001) after application of CARE kV with or without SAFIRE. CONCLUSION: Combining CARE kV, reduction of mAs from 240 to 170 mAs and noise reduction by applying SAFIRE strength 3 or 4 reduced the radiation dose by 41.3% without increasing image noise compared with the standard-dose FBP images.
Adult ; Aged ; Aged, 80 and over ; *Algorithms ; Equipment Design ; Female ; Humans ; Male ; Middle Aged ; Multidetector Computed Tomography/adverse effects/*instrumentation ; Radiation Dosage ; Radiation Injuries/etiology/*prevention & control ; Radiographic Image Interpretation, Computer-Assisted/*methods ; Radiography, Abdominal/adverse effects/*methods ; Retrospective Studies