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This study aimed to obtain details regarding treatment planning techniques for lung stereotactic body radiation therapy (SBRT) employed at each institution in Japan by using a questionnaire survey. An Internet questionnaire survey on SBRT procedures performed in 2016 was conducted by the QA/QC committee of the Japan Society of Medical Physics from April to June 2017. The questionnaire assessed two aspects: the environment for SBRT at each institution and the treatment planning techniques with and without respiratory motion management techniques (RMMT). Of the 309 evaluated responses, 218 institutions had performed SBRT. A total of 186 institutions performed SBRT without RMMT and 139 institutions performed SBRT with RMMT. When respiratory motion was ≥10 mm, 69 institutions applied RMMT. The leading RMMT were breath holding (77 institutions), respiratory gating (49 institutions) and real-time tumor tracking (11 institutions). The most frequently used irradiation technique was 3D conformal radiotherapy, which was used in 145 institutions without RMMT and 119 institutions with RMMT. Computed tomography (CT) images acquired under free breathing were mostly used for dose calculation for patients treated without RMMT. The usage ratio of IMRT/VMAT to SBRT is low in Japan, compared to elsewhere in the world (<20% vs ≥70%). Among the available dose calculation algorithms, superposition convolution was the most frequently used regardless of RMMT; however, 2% of institutions have not yet made heterogeneity corrections. In the prescription setting, about half of the institutions applied point prescriptions. The survey results revealed the most frequently used conditions, which may facilitate standardization of treatment techniques in lung SBRT. [ABSTRACT FROM AUTHOR]

In 2016, the American Association of Physicists in Medicine (AAPM) has published a report of task group (TG) 100 with a completely new concept, entitled "application of risk analysis methods to radiation therapy quality management." TG-100 proposed implementation of risk analysis in radiotherapy to prevent harmful radiotherapy accidents. In addition, it enables us to conduct efficient and effective quality management in not only advanced radiotherapy such as intensity-modulated radiotherapy and image-guided radiotherapy but also new technology in radiotherapy. It should be noted that treatment process in modern radiotherapy is absolutely more complex and it needs skillful staff and adequate resources. TG-100 methodology could identify weakness in radiotherapy procedure through assessment of failure modes that could occur in overall treatment processes. All staff in radiotherapy have to explore quality management in radiotherapy safety.

The work of radiological technologists is changing and more complicated because of the development of medical technology and implementation of information technology (IT). Although the cases of incident and accident have been reported, they have not been comprehensively analyzed in the workflow for radiotherapy. In this study, we visualized the workflow of radiological technologists in radiotherapy and revealed the causes of incidents and accidents. The work process was visualized by drawing workflow map. The structuring of problem was performed with interpretive structural modeling (ISM) method based on graph theory by analyzing of work categorized by safety management. Our results may be able to clarify the work of radiological technologists leads to the reduction of incidents and accidents in radiation therapy.

In past decade, several reports for patient safety in radiotherapy were published. Process of radiotheray has been recognized complex because its sub-processes are performed with interaction by multidisciplinaly team. Thus, there are many opportunities to occur human failure such as communication error and equipment operation error in the sub-process. This tutorial paper was focused non-technical issues towards patient safety in external radiotherapy.

Dose audit is an important topic in radiology and variations in dose attributable to sex have not been fully investigated. The primary purpose of our study was to determine the entrance surface dose (ESD) for men and women, from which we established an easy estimation equation for ESD, using the body mass index (BMI) as a variable. From April 2000 to March 2002, 15424 patients (8586 men, 6838 women; mean age, 58 years old; age range, 20 to 90 years old) were recruited in this study. Estimated equation of ESD was obtained from the dispersion data of BMI and ESD. Welch's t-test was used as the test of significance. P values evaluated levels of significance at 5%. Analysis for correlation coefficients was used for Peason's correlation coefficient test. And, we also performed a simple regression analysis. The results of the simple regression equation with BMI as variable (y: ESD [mGy], x: BMI [kg/m(2)), and the median values of ESD were as follows: for chest PA, men, 0.22, y = 0.0145 x - 0.0876, women, 0.20, y = 0.0126 x - 0.0704; for abdomen AP, men, 2.12, y = 0.2707 x - 3.7206, women, 1.65, y = 0.2561 x - 3.7989; for pelvis AP, men, 1.87, y = 0.0517 x + 0.8753, women, 1.77, y = 0.0674 x + 0.4775; for lumbar spine AP, men, 3.08, y = 0.3462 x - 4.1416, women, 2.66, y = 0.2525 x - 2.8131; and for lumbar spine lateral, men, 9.31, y = 0.6012 x - 3.7216, women, 7.42, y = 0.3147 x + 0.3384. The results of ESD had a significant difference between sexes (P < 0.05). Chest PA, abdomen AP, lumbar spine AP, and lumbar spine lateral each had a good correlation between ESD and BMI (r: 0.4 to 0.8). We successfully obtained the estimation equation using BMI as variable.