We developed a software for effective operation of a radiation oncology greater area database (ROGAD), which is currently under construction. The software employs a computer version of International Classification of Disease for Oncology (ICD-O) code, and will be connected to ROGAD. The system can perform code searching and indexing ICD-O code to anatomical name or anatomical illustration. The system can be used by many users, because it has keyboard entry, mouse clicking entry and dual language selection. Our system and a conventional hand written version of the ICD-O code were compared. When the system was used, the searching time was proven to be decreased to 30%∼50% of hand written time. This system is stand alone, but in future it can integrate the ROGAD by internet. We could take advantage of collecting many items of information.
To develop a long-lived performance test source that radiates medium-energy gamma rays in nuclear medicine, the author tried to work up a radiation source assembly having an energy peak around 200 keV by combination of a 137Cs sealed source with a scatterer. First, the scatterer material was determined to iron by Monte Carlo simulation because of a high photon backscattering rate. Then several iron scatterers of different shapes and sizes were compared, and the scatterer which has a cylindrical cavity of 8 cm inside diameter was observed to have the most excellent photon backscattering characteristics, an energy peak around 200 keV and spectral distribution ranging from 100 to 300 keV. Furthermore, uniformity of sensitivity and spatial resolution of gamma camera were determined using a developed radiation source assembly, which showed satisfying characteristics as a performance test source.
Radiographic diagnosis using heavy ion beam could be much more useful compared with proton radiography, especially in the deep seated lesion. Efficacy study on heavy ion radiography was performed in comparison with conventional X-ray radiography. Horizontal beam of carbon ion accelerated up to 400MeV/nucleon by HIMAC (Heavy Ion Accelerator in Chiba) of MRS (National Institute of Radiological Sciences) has been used throughout this work at a therapy room. The slight differences in soft tissue and the structure of low Z material such as Burger phantom in acrylate blocks were visualized by carbon ion radiography on the usual X-ray film placed at the falling edge of Bragg peak, while those could not be detected by X-ray. However, MTF curve obtained with high Z test chart plate for carbon ion fell bellow that for X-ray, since X-ray was better in detecting Z variation and in scattering problem.
The 21st Medical Standard Dose Study Meeting was held on August 30 and 31,1996, at Koriyama-city. Activities of medical radiation standard dose regional centers were started in 1970, but they have been limited to the calibrations of reference chambers of medical institutions and a some number of high dose rate brachytherapy sources. Necessities of feedback loop in quality assurance was discussed at the last board meeting. The study meeting was organized to call more discussions for taking a new step toward the comprehensive quality assurance. In the morning session of the first day of the meeting, the 14 regional centers reported their activities as usual. For the afternoon session, we set 2 topics. One was, “Concepts of Quality Assurance and Potentialities of Outreach Physics”, and the other was, “Future View of Radiation Treatment”. Focusing on these topics, lectures were made by 6 speakers. The followings are the transcriptions presented by the speakers on their subjects. We hope these articles will be good references for the improvement of our QA program. On the second day of the meeting, mutua l comparisons of regional standard dosimeters were made according to the established practice.
This is the transcription of a lecture at “The 21st Medical Standard Dose Study Meeting”. At first, the concepts of “Comprehensive QA for Radiation Oncology: Report of AAPM Radiation Therapy Committee Task Group 40” was analyzed. Secondary, the lecture was focused on the activities of Radiological Physics Center of M. D. Anderson Cancer Center. The author had a chance to visit the Department of Radiation Physics and RPC, MDACC, after “World Congress on Medical Physics and Biomedical Engineering”, held in San Antonio. He observed the activities of Outreach Physics, and learned the importance of External Audit Program. Dr. William F. Hanson was invited to the previous meeting to make the special lecture, titled “Calibration System in Radiotherapy and Dosimetry Quality Assurance in the USA” (Medical Standard Dose, Vol.1, No.1,1-19,1996). His lecture and my visit to MDACC made good references to this part. Thirdly, the activities of Department of Medical Physics in Memorial Sloan Kettering Cancer Center was introduced. The author had another chance of visiting MSKCC, after “Health Physics Society and AAPM Joint Meeting”, held in July 1995 in Boston. He reported his observations during his visit, including the facilities of the department, QA tests of high dose rate brachytherapy source and their activities as a Accredited Dosimetry Calibration Laboratory. Due to the limited space, only a portion of the third part is included in this transcription. As the final conclusion, the importance of followings were emphasized to take a new step toward the comprehensive QA program, which are; establishing QA committee in medical institutions, which should represent many specialties, setting their QA program, which should be comprehensive, feedback loop should be included in QA program, quality assurance should be confirmed by external audit and QA program should be support by medical physicists.
Ionization chamber is one of the most common device to measure absorbed dose with sufficient accuracy for radiotherapy. The International Electrotechnical Commission (IEC) prepared international standard for requirements and tests of functional performance characteristics of radiotherapy dosemeters. To make accurate and consistent absorbed dose determination at all radiation quantities in use for radiotherapy, a number of national and international protocols have been produced which provide absorbed dose calibration procedures for high energy X-ray and electron beams.
Quality assurance (QA) of radiation therapy can be divided into 3, namely, QA of physics, techniques and of clinical aspects. Owing to the members who participate in the standard dization of the dose calibration, QA of the dose has been fairly accomplished in Japan. On the other hand, Clinical QA is complicated and is difficult to ascertain at present. At Department of Radiation Oncology, National Cancer Center Hospital, we hold as part of the clinical QA, Morning Daily Conference, for presentation of the new patients and the alteration of the planning, and Wednesday Meeting for checking the record of the whole patients under irradiation. QA and quality control of the fractionated stereotactic radiotherapy in our facility was mentioned. Proposed QA guidelines by the Committee of QA, JASTRO was presented and the necessity of quality audit was stated.
The role of the nuclear medicine for cancer diagnosis and treatment was discussed in this paper. Nuclear medicine technique has much usefulness for cancer diagnostic situations, such as; (1) cancer screening (cancer detection), (2) differential diagnosis, (3) staging, (4) selection of treatment, (5) treatment planning for radiotherapy, (6) monitor of the treatment, (7) follow up after treatment. Nuclear medicine also play an important role in the treatment of the pain of bone metastasis employing unsealed sources. In the near future, Sr-89 may be commercially available in Japan. It is convinced that nuclear medicine make much contribution to cancer patients for their diagnosis and treatment, especially radiotherapy.