Reconstructive dosimetry for cutaneous radiation syndrome.

According to the International Atomic Energy Agency (IAEA), a relatively significant number of radiological accidents have occurred in recent years mainly because of the practices referred to as potentially high-risk activities, such as radiotherapy, large irradiators and industrial radiography, especially in gammagraphy assays. In some instances, severe injuries have occurred in exposed persons due to high radiation doses. In industrial radiography, 80 cases involving a total of 120 radiation workers, 110 members of the public including 12 deaths have been recorded up to 2014. Radiological accidents in industrial practices in Brazil have mainly resulted in development of cutaneous radiation syndrome (CRS) in hands and fingers. Brazilian data include 5 serious cases related to industrial gammagraphy, affecting 7 radiation workers and 19 members of the public; however, none of them were fatal. Some methods of reconstructive dosimetry have been used to estimate the radiation dose to assist in prescribing medical treatment. The type and development of cutaneous manifestations in the exposed areas of a person is the first achievable gross dose estimation. This review article presents the state-of-the-art reconstructive dosimetry methods enabling estimation of local radiation doses and provides guidelines for medical handling of the exposed individuals. The review also presents the Chilean and Brazilian radiological accident cases to highlight the importance of reconstructive dosimetry.

Reconstructive dosimetry for cutaneous radiation syndrome

According to the International Atomic Energy Agency (IAEA), a relatively significant number of radiological accidents have occurred in recent years mainly because of the practices referred to as potentially high-risk activities, such as radiotherapy, large irradiators and industrial radiography, especially in gammagraphy assays. In some instances, severe injuries have occurred in exposed persons due to high radiation doses. In industrial radiography, 80 cases involving a total of 120 radiation workers, 110 members of the public including 12 deaths have been recorded up to 2014. Radiological accidents in industrial practices in Brazil have mainly resulted in development of cutaneous radiation syndrome (CRS) in hands and fingers. Brazilian data include 5 serious cases related to industrial gammagraphy, affecting 7 radiation workers and 19 members of the public; however, none of them were fatal. Some methods of reconstructive dosimetry have been used to estimate the radiation dose to assist in prescribing medical treatment. The type and development of cutaneous manifestations in the exposed areas of a person is the first achievable gross dose estimation. This review article presents the state-of-the-art reconstructive dosimetry methods enabling estimation of local radiation doses and provides guidelines for medical handling of the exposed individuals. The review also presents the Chilean and Brazilian radiological accident cases to highlight the importance of reconstructive dosimetry.

[Accidental exposure to X-ray from a diffractometer]. / Uma exposição acidental aos raios X de um difratômetro.

The patients's clinical pictures, characterized by an erythema preceding the skin manifestations, their aspect and the occupational histories, made the diagnosis of a radiation accident possible before its dosimetric identification. Doses evaluations using thermoluminescence dosimeters and ionizing chambers correlated well with the clinical estimations. The immediate cause of the accident was poor maintenance of the device that caused its back window to be permanently open, but lack of adequate information on the biological effects of ionizing radiation and on the correct operational procedures were contributory facts. The description of this accident is relevant in virtue of the misconception that such equipment have "virtually no occupational risk". The patients's medical evolutions have had a favorable course, specially because the low energy of the X-ray and its low penetrating capacity. This accident highlights the need for the adequate training of workers on the handling of radiation devices.

Uma exposição acidental aos raios X de um difratômetro / Accidental exposure to the X-ray of a diffractometer

As mãos de três trabalhadores foram irradiadas acidentalmente numa indústria em Camaçari, Estado da Bahia, Brasil. O diagnóstico clínico de radiodermite aguda foi possível, antes mesmo da confirmação dosimétrica da ocorrência, em virtude das manifestações cutâneas exibidas, precedidas por um eritema, e também pelas histórias ocupacionais. As avaliações das doses recebidas pelos acidentados, usando-se restituições com dosímetros termoluminescentes, tiveram boa correlação com as doses estimadas em função das manifestações clínicas. A causa imediata do acidente foi a má manutenção do equipamento que levou a sua janela posterior a ficar permanentemente aberta, porém foram fatores contributórios importantes a falta de informação dos empregados sobre os possíveis efeitos biológicos das radiações ionizantes e o não seguimento dos procedimentos operacionais corretos. A descrição deste acidente é importante, face ao grande número de difratômetros existentes em laboratórios, universidades, centros de pesquisa e indústrias. Tais aparelhos são considerados "virtualmente isentos de risco ocupacional", o que não é verdadeiro, como comprova a ocorrência que descrevemos. A evolução médica dos pacientes tem sido satisfatória, especialmente em virtude da baixa energia do feixe de raios X do difratômetro e, em conseqüência, da sua pequena penetração tissular.

Medical and related aspects of the Goiânia accident: an overview.

On 13 September 1987, a radiation accident occurred in the city of Goiânia in Central Brazil. Approximately 250 people were exposed to a 137Cs source from an abandoned radiotherapy unit. At least 14 patients showed some degree of bone marrow depression, and eight developed the classical signs and symptoms of acute radiation syndrome (ARS). Twenty-eight people presented local radiation injuries ranging from first to third degree, and 104 individuals showed evidence of internal contamination. This paper describes the circumstances of the event, the first-aid measures taken, the criteria adopted for triage of the exposed population, and the radiation protection procedures used during the clinical management of the irradiated individuals.

Localized lesions induced by 137Cs during the Goiânia accident.

A description is given of initial symptoms and clinical observations regarding acute localized radiation lesions in 28 persons exposed to 137Cs during the Goiânia radiological accident. Specialized procedures to estimate the extent and gravity of the lesions and establish a therapeutic strategy, as well as to anticipate the prognosis in each case, are briefly discussed. Measures taken for reduction of pain and inflammation are noted, and an explanation is given for difficulties encountered due to adverse working conditions and the serious clinical manifestations presented by various patients concomitantly with their lesions. Also noted is the difficulty in obtaining credible information regarding exposure, such as source-to-object distance, duration of exposure, and source activity, which precluded dosimetry studies in most cases.

Clinical and hematological aspects of 137Cs: the Goiânia radiation accident.

Fifty persons involved in the 137Cs accident in Goiânia showed symptoms of whole-body and local acute irradiation and also external or internal contamination mainly due to ingestion or absorption of 137Cs. Fourteen of the 50 developed severe bone marrow depression characterized by neutropenia and thrombocytopenia. Eight of these 14 received GM-CSF intravenously. None were submitted to bone marrow transplantation. Four of the 14 died due to hemorrhage and infection. For those with significant internal contamination evaluated by in-vitro and in-vivo assays, Prussian Blue was administered with doses ranging from 1.5 to 10 g d-1. Besides Prussian Blue, other measures were taken to increase decorporation of 137Cs, including administration of diuretics, water overload, and ergometric exercises. From 50 to 100 persons are being followed in a medical protocol.