イリョウ ヒバク ノ ゲンジョウ

Interventional radiology （fluoroscopically-guided） techniques are being used by an increasing number of clinicians not adequately trained in radiation safety or radiobiology. In 1994, Food and Drug Administration of the United States first gave warning to the risk of serious X-ray-induced skin injuries including intractable ulcers among patients who received fluoroscopically-guided procedures. The Japan Radiological Society reacted promptly, and gave a warning in 1995, and the first report on radiation skin injury during prolonged fluoroscopy in Japan appeared in 1998 on a dermatological journal. Since then many cases have been reported on dermatological journals. Radiation skin injuries occurred mainly during cardiac studies, but cases of abdominal studies also have been reported. Recently there was a case report of skin malignancy in a long standing radiation induced ulcer. The international commission on radiation protection published“Publication 85 Avoidance of Radiation Injuries from Medical Interventional Procedures”in 2000. This document can be summarized in the following three major points : 1）The risk of radiation injury should be explained to the patient prior to IVR （informed consent. 2） Protocols should be prepared to define the number of images to be taken and the fluoroscopy time for each procedure of IVR so that standard radiation doses can be calculated. 3） If the cumulative absorbed dose to the patient’s skin exceeds 3 Gy （1 Gy for procedures likely to be repeated）, the site and dose of radiation given should be recorded in the patient’s record. If the dose is more than 3 Gy, the patient should be followed up 10 to 14 days after the procedure. It is very important to measure the cumulative absorbed dose of the skin, but very difficult. We developed a very reliable system for the measurement using a self-developing reflecting-type sheet film and reported their usefulness. CT examinations also have been increasing dramatically in Japan. There was a report of estimation of possible risk of cancer after CT examination based on a hypothesis. Although there has been no evidence of real risk of low dose radiation exposure such as CT reported, we should try to use CT appropriately. Especially we must try to reduce CT dose to children or young adults, because they are more sensitive to radiation and live longer than adults

カンワ ケア ニオケル ホウシャセン チリョウ ノ ヤクワリ

Radiation therapy is a valuable treatment for palliation of local symptoms with consistently high response rates in the relief and control of bone pain, neurological symptom, obstructive symptoms, and tumor hemorrhage. Over than ８０％ of patients who developed bone metastasis and superior vena cava syndrome obtained symptom relief by radiation therapy. Radiation therapy is also well established as an effective treatment for brain metastasis, improving symptoms and preventing progressive neurological deficits, and recently stereotactic irradiation had became a alternative treatment of surgery for small metastatic brain tumors. Both radiation therapy and surgery are effective in the initial treatment of malignant spinal cord compression syndrome, and no advantages of surgery over radiation therapy has been demonstrated in published series when patients have a previously conformed diagnosis of malignant disease and no evidence of vertebral collapse. The outcome of treatment depends primarily upon the speed of diagnosis and neurological status at initiation of treatment. It is very important to start radiation therapy before patient become non-ambulant. Low irradiation dose and short treatment period of palliative radiation therapy can minimize disruption and acute morbidity for the patients with advanced cancer with enabling control of symptoms and palliative radiation therapy is applicable to the patient even in poor general condition

クカンブ カクサン キョウチョウ MRI ガゾウ ノ リンショウ オウヨウ ト ユウヨウセイ

Recently the usefulness of diffusion-weighted MR imaging（DWI）in the body regions was reported in several studies. Various malignant tumors may show high signal intensity on DWI reflecting their high cellularity. Quantitative measurement of apparent diffusion coefficient（ADC）may be of value in distinguishing between benign and malignant tumors. We reviewed clinical application of body DWI in various diseases in this article

悪性食道狭窄に対する金属ステント療法

Self-expandable metallic stents were used for palliative treatment of malignant esophagogastric strictures. Twelve patients, nine men and three women, with a mean age of 73.1 years old (range, 48-87 years old) had dysphagia due to esophagogastric strictures with advanced malignant tumors. A total of 13 expandable metallic stents were placed, four non-covered Ultraflex stents (nitinol stents), two non-covered Wallstents and seven covered Wallstents. The strictures were caused by esophageal carcinoma (n=7), gastric carcinoma with lymphnode metastasis (n=2), lung carcinoma with mediastinal lymphnode metastasis (n=2), and cardioesophageal carcinoma (n=1). All stents were placed with fluoroscopic and endoscopic guidance. No technical failure or procedural critical complications occurred and the dysphagia was relieved in all patients. The mean dysphagia score was 0.58±0.52 (standard deviation) before treatment and 3.25±0.97 after insertion. Complications included chest and epigastric pain in four, gastroesophageal reflux in two, tumor ingrowth in one, and food impaction in one. Six complications easily managed with medical, endoscopic, or radiologic intervention. At the end of this study, eight patients were dead with a mean survival of 28.3 weeks (range, 4-96 weeks), and four patients were alive with a mean follow up of 35.5 weeks (range, 8-98 weeks). In our experience, self-expandable metallic stents provide relatively safe and long-term palliation in patients with malignant esophagogastric obstruction

Anonymization server system for DICOM images

We have developed an anonymization system for DICOM images. It requires consent from the patient to use the DICOM images for research or education. However, providing the DICOM image to the other facilities is not safe because it contains a lot of personal data. Our system is a server that provides anonymization service of DICOM images for users in the facility. The distinctive features of the system are, input interface, flexible anonymization policy, and automatic body part identification. In the first feature, we can use the anonymization service on the existing DICOM workstations. In the second feature, we can select a best policy fitting for the Protection of personal data that is ruled by each medical facility. In the third feature, we can identify the body parts that are included in the input image set, even if the set lacks the body part tag in DICOM header. We installed the system for the first time to a hospital in December 2005. Currently, the system is working in other four facilities. In this paper we describe the system and how it works

FDG-PET/CT for cancer management

FDG-PET/CT is increasingly being used for staging, restaging, and treatment monitoring for cancer patients. The introduction of a PET/CT system enables both morphological and metabolic imaging to be performed in a single session. Knowledge of the normal physiologic distribution of FDG and an understanding of the clinical indications and limitations of PET/CT enable accurate diagnosis and thus a better level of care for patients

Clinical utility of FDG PET

The aim of this article is to introduce the clinical utility of FDG PET as oncologic imaging. PET (positron emission tomography) is a newly developed imaging tool, and it has increased the accuracy of metabolic mapping of numerous malignancies, with significant impact on the management of cancer patients for initial staging, restaging and therapy monitoring. PET can provide functional information in addition tomorphology from conventional imaging modalities. 18F-labeled 2-fluoro-2-deoxyglucose (FDG) is the most commonly used PET tracer and FDG PET can demonstrate the activity of glucose metabolism throughout the entire body in a single session. We describe the clinical utility of FDG in PET and display images of normal distribution and of patients with head and neck and lung cancer

Evaluation of cerebral blood flow reserve in patients with cerebrovascular disease by SPECT using technetium-99m-L, L-ethyl cysteinate dimer

A technique for measuring the resting and acetazolamide (Acz)-activated cerebral blood flow without blood sampling by consecutive single-photon emission computed tomography (SPECT) using technetium-99m-L, L-ethyl cysteinate dimer (99mTc-ECD), called the 99mTc-ECD-RVR method, was recently developed by Matsuda et al . and Takeuchi et al . We evaluated the cerebral blood flow reserve in 77 patients with cerebrovascular diseases and 24 controls using this method. Baseline mean CBF (mCBF)was calculated from the application of Patlak plot graphical analysis with radionuclide angiography, and quantitative regional CBF (rCBF) images were obtained from qualitative axial SPECT images by the mCBF and Lassen’s linearization correction. The activated SPECT images were obtained by subtraction of the first image from the second image. The mean increment ratio (IR) by calculating the mean CBF for the pre- and post-Acz in the controls was 1.26±0.12 (mean±SD). In patients with cerebrovascular disease, the reduction of the mean IR and regional IR was parallel with the degree of stenosis. This noninvasive method was also considered to be useful in evaluating the change in the hemodynamic reserve in cerebrovascular disease