SSDL newsletter. No. 43

The main article of this issue of the SSDL Newsletter deals with the calibration of low energy photon sources and beta-ray brachytherapy sources. It contains guidelines to SSDLs and hospital physicists for the calibration of these sources. The report has been prepared in close collaboration with the ICRU Report Committee on this subject, who is also planning to publish a report on the calibration of these types of sources. During the sixties and seventies, the IAEA published documents on computerized radiotherapy dose calculations, such as TRS-8 on Single-Field Isodose Charts for High-Energy Radiation (1962) and the 4 Volumes of the ''Atlas of Radiation Dose Distributions'' (1965-1972). During the eighties and nineties, no document was published by the IAEA in this field, even if major developments had occurred in that period. Specifically, fast computers and powerful Monte Carlo systems and application codes, addressed to radiotherapy treatment planning, were developed with the aim to provide sufficiently accurate dose calculations and great increases in speed. A consultants' meeting was held at the IAEA with a group of experts in the field to discuss current needs and trends, and to make recommendations to the IAEA. The consultants emphasized the need for the IAEA to play an active role in this field. Their full report is the second article of this Newsletter. Four new SSDLs have recently joined our Network: these are from Germany, Greece, Ethiopia and Vietnam. They have been added to the database of the IAEA/WHO Network of SSDLs and are listed on pages 44-45 of Member Laboratories