1996 Annual Report
Human Health

Nuclear medicine

Applied radiation biology and radiotherapy

Dosimetry

Nutritional and health related environmental studies

Agency activities in the area of human health concentrated on applications of nuclear and radiation techniques, especially those suitable for the diagnosis and treatment of diseases prevalent in developing Member States. Increasing emphasis was also given to aspects of preventive medicine such as early detection of neonatal hypothyroidism, hepatitis and other communicable diseases, accurate evaluation of nutritional deficiencies in children and pregnant women, as well as opportune diagnosis of common genetic (hereditary) diseases. in dosimetry, the main emphasis was on the continuation and expansion of services to Member States (i.e. the SSDL network and dose quality audits) and educational programmes for hospital physicists. All activities in the programme are aimed at increasing the availability and quality of the applications through education at all levels, cost reduction in reagents and technology, and increased interaction between physicians, medical physicists and technologists.

Nuclear Medicine

Activities aimed at reducing the cost of nuclear medicine practices in developing countries continued. Field trials were carried out on more than 50 gamma camera- personal computer interface electronic cards developed by Cuba, India and Slovenia with Agency support. These were designed to upgrade the performance and capability of gamma cameras, with feedback from the field laboratories. As a result of past CRPs, the quality control, care and maintenance of gamma cameras improved: the practice of acceptance testing has risen from 20 to 50% and routine quality control checks have increased from 40 to 70% during the past three years. A low cost single photon emission computed tomography system has been commercialized as a result of contacts between the Agency and the manufacturer.

Agency work on the use of in vitro radionuclide methods to diagnose diseases has yielded significant results: over 1.5 million newborn babies were screened for neonatal hypothyroidism in 14 Latin American countries; 650 babies were found to be suffering from the disease, enabling prompt and effective treatment to be provided. About 150 000 people in ten Asian countries, most belonging to high risk groups such as pregnant women and blood donors, were screened for hepatitis B infection and the incidence was found to be 5.75%. A universal antigen (consisting of four recombinant antigens) which reacts with all sera from patients with Chagas disease in Brazil has been developed. Field validation will now be initiated.

One hundred and eight patients were included in the first Agency sponsored multi-centre clinical trial to compare the efficacy and toxicity of phosphorus-32 and strontium-89 for the palliative treatment of bone pain from cancer metastases, given that phosphorus is five times less expensive than strontium. The results of this unique trial, which was carried out in India, Indonesia, Peru and Slovenia, will be known in early 1997.

There are more than 3000 technicians working without formal training in nuclear medicine laboratories in developing countries. To address this situation, the Agency's first training course for nuclear medicine technologists was conducted in Cape Town, South Africa. The pilot phase of a distance education project for nuclear medicine technologists was completed in India, Indonesia, Malaysia and Sri Lanka. After final evaluation, the teaching material will be translated from English into other languages for the training of technologists in different countries. These activities are part of a concerted effort to improve the competence of nuclear medicine technologists in developing countries.

After conducting its second certifying examination in 1996, the Ibero-American Board of Nuclear Physicians, founded in 1992 under Agency sponsorship, certified 75 specialists in nuclear medicine from 14 countries.

Applied Radiation Biology and Radiotherapy

Co-ordinated Research Programmes and new regional projects focused on improving the cure rates of cancer of the cervix - the most common female cancer in Africa, South America and Asia and one that is curable even when diagnosed at a fairly advanced stage - while optimizing the limited equipment and personnel resources of these regions.

One of the main problems in cancer care in developing countries is the treatment of advanced and incurable tumours. To address this, efforts were focused on palliative treatment using radiotherapy. A new CRP was initiated utilizing hemibody irradiation for widespread metastasis and treatment of incurable oesophageal cancer with limited intraluminal irradiation.

Sound management principles enhance the efficacy of radiotherapy. The entire process from the selection of patients through optimized therapy to eventual assessment of treatment success was studied in a new CRP on quality assurance (QA). Initial tasks will be focused on Latin America. As this is an especially important problem in developing countries, clinical QA work will shortly be extended to other parts of the world.

Dosimetry

A comprehensive QA programme for the Agency's Dosimetry Laboratory at Seibersdorf began implementation. When completed, it will serve as a model for Secondary Standard Dosimetry Laboratories (SSDLs) to develop their own QA programmes. It is based on the recommendations of the ISO and specifically on 'Guide 25' (General Requirements for the Competence of Calibration and Testing Laboratories). The QA programme will result in a manual describing the operation of the Dosimetry Laboratory, supported by nine standard operating procedures.

The activities of the SSDLs in the IAEA/WHO network have been closely monitored, with only active participants remaining. The active members include 69 laboratories and 6 SSDL national organizations in 57 Member States; the network also has 19 affiliated members, mainly Primary Standard Dosimetry Laboratories (PSDLs), the International Commission for Radiation Units and Measurements, the Bureau Inter-national des Poids et Mesures, and other international organizations.

To establish a link to the International Measurement System, the Agency's Laboratories at Seibersdorf calibrated 18 reference ionization chambers and dosimeters for 12 laboratories. A total of 27 ionization chambers have been calibrated (96 calibration points at different radiation qualities). The quality audit system based on mailed thermoluminescence dosimeters (TLDs) has been applied to 65 SSDLs in order to verify their calibrations of cobalt-60 therapy units and medical accelerator radiation beams.

The IAEA/WHO TLD postal service distributed 294 dosimeters to radiotherapy centres in developing countries for dose quality audits of clinical beams from cobalt-60 treatment units and medical accelerators. New actions have been implemented to follow up on TLD results outside the limits.

The Agency carried out pilot studies at two SSDLs which had experience with postal TLDs. The objective was to allow the Agency to provide services elsewhere and to establish national services capable of rapidly providing results and local follow-up. Since the findings from these investigations were not satisfactory, additional studies have been added to an ongoing CRP on the development of a QA programme for radiation therapy dosimetry in developing countries.

The Agency continued to offer the International Dose Assurance Service (IDAS) at radiation processing dose levels using alanine dosimeters issued and measured at the Agency's Laboratories. An audited traceability chain was established to a PSDL. The fee for this service was waived for non-commercial laboratories, and direct contact between the Agency and users in Member States was established. This has resulted in a 65% increase in participation in the programme. The IDAS distributed dosimeter sets to 33 facilities in 30 Member States.

The impact of the new standards in PSDLs of absorbed dose to water on current procedures at the SSDLs and hospitals was analysed by a group of experts. Their findings were that the present air kerma based Agency Code of Practice uses theoretical methods for deriving absorbed dose that do not take into account individual variations within a particular type of chamber. Direct calibration in terms of absorbed dose to water will potentially remove much of the variation and it was recommended that a new Code of Practice be prepared.

Nutritional and Health Related Environmental Studies

Micronutrient malnutrition (sometimes referred to as 'hidden hunger') continues to affect hundreds of millions of people, particularly - but not only - in the developing world. Efforts to eliminate undernourishment focus on vitamin A, iron and iodine deficiencies because they are known to occur commonly in developing countries; moreover, because treatment methods exist progress can be measured unambiguously. The Agency has greatly expanded its work in this area, with attention directed to the use of isotopic techniques - mainly with stable isotopes - to identify populations at risk, and to monitor and improve the effectiveness of dietary intervention programmes. A new CRP in Latin America is using isotopes to measure the breast milk intake of infants, and to study the impact of breast milk volume and composition on growth. Isotope methods for measuring deuterium kinetics will be used in place of conventional measurements of breast milk intake, and other isotopic tracers will be used to evaluate nutritional reserves of vitamin A, iron and zinc.

Through the Agency's programmes and under the IAEA/UNEP/IOC Tripartite Memorandum of Understanding, one intercomparison exercise was completed (trace organic contaminants in IAEA-142, Mussel Homogenate) and two were ongoing (trace metals and trace organic contaminants in Sea Plant Homogenate IAEA-140/TM and IAEA-140/OC, respectively). The current list of participants includes over 450 laboratories worldwide.

In an interagency collaborative effort, emergency assistance was provided in the Seychelles, where there was a large fish kill accident. Careful screening of the problem revealed that this was due to the high concentration of endsosulfan, a pesticide used in local agriculture.

In collaboration with UNDP, a pilot monitoring assessment within the Black Sea region was performed. The results indicated that the levels of oil, sewage and DDT contamination are generally comparable with those reported for the Mediterranean Sea and other regions of the world. Some 'hot spots' were, however, identified and substantial sewage contamination was recorded in some areas. For some compounds, such as combustion derived PAHs and industrial PCBs, levels in the Black Sea appear to be very low. Contamination by heavy metals also does not appear to be a basin-wide problem.

Together with Warwick University in the United Kingdom, a contaminant screening project on sediments and surface microlayers of water samples was conducted off the Chagos area in the Indian Ocean. It has been shown that this area is not affected by heavy pollution, and the only source of contamination in this pristine oceanic region is the long range atmospheric deposition of PAHs, PCBs and organochlorine pesticides.

Another contaminant screening programme was co-ordinated with the Regional Organization for the Protection of the Marine Environment (ROPME) in the Persian Gulf with the aim of pinpointing contamination hot spots in the coastal region. A report, issued in early 1996, played a key role in reorienting the ROPME regional monitoring programme for the next three years.

A Research Co-ordination meeting was held in Costa Rica as part of a project supported by Sweden on the distribution, fate and effects of pesticides on biota in the tropical marine environment using radiolabelled tracers. New information was presented on the degradation rates and bioaccumulation of chlorpyrifos, DDT and lindane, which was derived from the Agency's model ecosystem. This system comprises laboratory studies using radiotracers of these compounds under carefully controlled, simulated tropical conditions.

Biogeochemical cycling of mercury was studied in contaminated areas of the northern Adriatic Sea, where the main source of inorganic mercury is through riverine inputs originating from a mercury mining area. It has been shown that the major source of methylmercury, the most toxic mercury compound, is from sediments due to sulphate reducing bacterial activity. These results represent a valuable contribution to the development of ecological modelling of mercury in contaminated sites.

In collaboration with an international team of scientists, the Agency's Laboratories at Seibersdorf played a leading role in a radiological study on marine and terrestrial samples collected at the atolls of Mururoa and Fangataufa in French Polynesia, where nuclear testing took place in 1995-1996. Measurements of samples were made both at the Agency's own laboratories and also by the Analytical Laboratories for Measuring Environmental Radioactivity (ALMERA), a network established by the Agency for this purpose.

A symposium was held in Hyderabad, India, in November on the harmonization of health related environmental measurements using nuclear and isotopic techniques. One strength of nuclear methods is in analytical quality assurance, including the validation of methods and the development of new reference materials. These methodologies are therefore helping to harmonize the data produced not only by nuclear techniques, but also by other non-nuclear methods of analysis. They are thus playing an important role in the application of newly emerging quality management and quality assurance standards (e.g. ISO-25 and ISO-9000). The meeting dealt with numerous applications of nuclear and related analytical techniques as used in the study of air particulates, solid waste products, sediments, food, water, human tissue and many other types of environmental samples. The Proceedings will be published in mid-1997.